AIRBAG INFLATOR AND AN AIRBAG APPARATUS

• US 20030042718A1
• Filed: 12/31/1998
• Published: 03/06/2003
• Est. Priority Date: 04/08/1996
• Status: Active Grant

• Current Assignee: Katsuda N
• Original Assignee: Katsuda N
• Inventors: UEDA, MASAYUKI, ODA, SHINGO, KATSUDA, NOBUYUKI
• Granted Patent: US 6,695,345 B2
• Time in Patent Office: Days
• US Class Current: 280/736
• CPC Class Codes: B01D 2275/105 Wound layers
• CPC Class Codes: B01D 2279/10 for air bags, e.g. inflators therefor
• CPC Class Codes: B01D 46/2411 Filter cartridges
• CPC Class Codes: B01D 46/4263 Means for active heating or cooling
• CPC Class Codes: B60R 21/2035 using modules containing inflator, bag and cover attachable to the steering wheel as a complete sub-unit steering wheel covers with tear lines B60R21/21656; assembling of modules B60R21/217
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: B60R 21/33 Arrangements for non-electric triggering of inflation electrical circuits for triggering safety arrangements B60R21/01
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

An airbag inflator includes non-azide gas generating propellants, surrounding an ignition device, disposed inside a housing. The gas generating propellants are surrounded by a coolant/filter device having a pressure loss of 0.3×10⁻² to 1.5×10⁻² kg/cm² at a flow rate of 100 l/min/cm². A space is provided between an outer periphery of the coolant/filter device and the housing such that the combustion gas passes through the entire area of the coolant/filter device. The coolant/filter device is also surrounded by a swell suppressing layer which prevents the coolant/filter device from swelling due to a combustion of the gas generating propellants.

Claims

1. An airbag inflator comprising:

a housing having a diffuser shell and a closure shell, the diffuser shell being formed by pressing a metal plate and having gas discharge ports, the closure shell being formed by pressing a metal plate and having a center hole;

a non-azide gas generating material in said housing;

a central cylinder member installed in the housing, and disposed concentric with the center hole to form an ignition device accommodating chamber, said central cylinder member further having through-holes defined therein;

an ignition device in said central cylinder member; and

a coolant/filter device disposed surrounding the central cylinder member to define a combustion chamber for said non-azide gas generating material and having a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature, said coolant/filter device being adapted to cool combustion gas and arrest combustion particulates resulting from ignition of said gas generating material.

2. An airbag inflator according to claim 1, wherein said housing has a circumferential side wall formed by said diffuser shell and closure shell, said wall including said discharge ports;

and

wherein the diffuser shell and the closure shell are made of stainless steel plate 1.2-3.0 mm thick and have outer diameters of 45-75 mm and 45-75 mm, respectively, and a narrow space 1.0-4.0 mm wide is formed between said circumferential wall and said coolant/filter device.

3. An airbag inflator according to claim 1 or claim 2, wherein the gas discharge ports in the diffuser shell have a diameter of 2.0-5.0 mm and a total of 16 to 24 such gas discharge ports are arranged in a circumferential direction.

4. An airbag inflator according to claim 1 or claim 2, wherein said central cylinder member has a plurality of circumferentially disposed through-holes therein communicating from said ignition device accommodating chamber to said combustion chamber

5. An airbag inflator according to claim 4, wherein the central cylinder member has a total of six to nine through-holes 1.5-3.0 mm in diameter arranged in a circumferential direction;

and

wherein the gas discharge ports in the diffuser shell have a diameter of 2.0-5.0 mm and a total of 16 to 24 such gas discharge ports are arranged in a circumferential direction.

6. An airbag inflator according to claim 5, wherein said through-holes are arranged in two staggered rows, one of the rows having three through-holes 1.5 mm in diameter and the other row having three through-holes 2.5 mm in diameter.

7. An airbag inflator according to claim 1 or claim 2, wherein said coolant/filter device has a support member for preventing displacement of said coolant/filter device;

said support member includes a flame resisting plate portion disposed to face said through-holes in said central cylinder member and covering an inner circumferential surface of said coolant/filter device, said through-holes being adapted to pass flames from said igniter to said combustion chamber.

8. An airbag inflator according to claim 1 or claim 2, wherein said gas discharge ports in the diffuser shell are closed with a moisture barrier comprising an aluminum tape whose width is 2-3.5 times the diameter of the gas discharge ports.

9. An airbag inflator according to claim 1 or claim 2, wherein a cushion for said gas generating material is installed in the combustion chamber.

10. An airbag inflator according to claim 9, wherein said cushion is made of a stainless steel mesh and fixed to a support plate, and the support plate has bent portions at inner and outer circumferential portions thereof and is securely held between the central cylinder member and the coolant/filter device by an elastic force of said bent portions.

11. An airbag inflator according to claim 1 or claim 2, wherein said housing has an overall height of 24-40 mm;

and

wherein said coolant/filter device is formed in an annular configuration having an outer diameter of 40-65 mm, an inner diameter of 30-55 mm, a height of 19-37.6 mm, and further comprises a multi-layer metal mesh structure having a bulk density of 3.0-5.0 g/cm³.

222. An airbag inflator of claim 1, further comprising:

a perforated basket disposed between said non-azide gas generating material and an inner circumferential surface of said coolant/filter device.

223. An airbag inflator of claim 222, wherein said perforated basket is in contact with said non-azide gas generating material and said inner circumferential surface.

224. An airbag inflator of claim 222 or 223, wherein said perforated basket has a plurality of through-holes defined therein.

225. An airbag inflator of claim 224, wherein a size of each through-hole is determined such that said perforated basket prevents said non-azide gas generating material from directly contacting said inner circumferential surface.

226. An airbag inflator of claim 223, wherein a total area of said through-holes is determined such that a pressure outside said perforated basket is maintained at substantially the same as a pressure inside said perforated basket when said non-azide gas generating material is generating gas.

227. An airbag inflator of claim 222, wherein said perforated basket includes a flame resisting plate portion disposed to face said through-holes in said central cylinder member and covering said inner circumferential surface, said through-holes being adapted to pass flames from said igniter to said combustion chamber.

228. An airbag inflator of claim 227, wherein said flame resisting plate has a height of approximately 8-15 mm.

267. An airbag apparatus of claim 1 or 12, wherein said ignition device includes, a mechanical-type shock sensor which detects a shock for activating said inflator.

268. An airbag apparatus of claim 267, wherein said ignition device further includes,

a firing pin ejected by said mechanical-type sensor,

a detonator ignited by being pierced by said firing pin, and

a transfer charge which burns said non-azide gas generating material by a flame from said detonator.

269. An airbag apparatus of claim 268, wherein said ignition device further includes,

chambers for housing said detonator and said transfer charge, respectively,

a detonator piece for supporting said detonator between said firing pin and said transfer charge, said detonator piece including a penetration port which connects the chamber where said detonator is installed and the chamber where said transfer charge is installed.

270. An airbag apparatus of claim 269, wherein said detonator piece is provided with a sealing tape on at least one end of said penetration port for preventing said detonator from adsorbing moisture.

271. An airbag apparatus of claim 267, wherein said mechanical-type shock sensor detects the shock by a movement of a mass provided therein.

272. An airbag inflator according to any one of claims 1, 23, 45, 53, 69, 87, 92, and 106, wherein said airbag inflator is disposed on a steering wheel of a vehicle.

273. An airbag inflator according to any one of claims 1, 23, 45, 53, 69, 87, 92, and 106, wherein said airbag inflator is disposed inside a passenger-side dashboard of a vehicle.

276. An airbag inflator of claim 7, wherein said flame resisting plate has a height of approximately 8-15 mm.

277. An airbag inflator of claim 227, wherein said flame resisting plate extends at least 2 mm below said through-holes in said central cylinder member.

278. An airbag inflator according to claim 7, wherein said flame resisting plate extends at least 2 mm below said through-holes in said central cylinder member.

279. An airbag inflator according to claim 7, wherein said support member is made of a steel stainless steel plate or a steel plate having a thickness of 0.5-1.0 mm.

280. An airbag inflator according to claim 10, wherein said support plate is made of a steel stainless steel plate or a steel plate having a thickness of 0.5-1.0 mm.

12. An airbag apparatus comprising:

an airbag inflator including;

a housing having a diffuser shell and a closure shell, the diffuser shell being formed by pressing a metal plate and having gas discharge ports, the closure shell being formed by pressing a metal plate and having a center hole;

a non-azide gas generating material in said housing;

a central cylinder installed in the housing, and disposed concentric with the center hole to form an ignition device accommodating chamber;

an ignition device in said accommodating chamber; and

a coolant/filter device disposed surrounding the central cylinder member to define a combustion chamber for said non-azide gas generating material and having a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature, the coolant/filter device being adapted to cool combustion gas and arrest combustion particulates resulting from ignition of said gas generating material;

said airbag apparatus further including;

an impact sensor for detecting an impact and outputting an impact detection signal;

a control unit for receiving the impact detection signal and outputting a drive signal to the ignition device of said airbag inflator to activate said ignition device and ignite said gas generating material;

an airbag to be inflated by admitting gas generated by said airbag inflator; and

a module case for accommodating said airbag.

13. An airbag apparatus according to claim 12, wherein the diffuser shell and the closure shell are made of a stainless steel plate 1.2-3.0 mm thick and have outer diameters of 45-75 mm and 45-75 mm, respectively, and a narrow space 1.0-4.0 mm wide is formed between a circumferential wall formed by the diffuser shell and the closure shell and the coolant.

14. An airbag apparatus according to claim 12 or claim 13, wherein the gas discharge ports in the diffuser shell have a diameter of 2.0-5.0 mm and a total of 16 to 24 such gas discharge ports are arranged in a circumferential direction.

15. An airbag apparatus according to claim 12 or claim 13, wherein said central cylinder member has a plurality of circumferentially disposed through-holes therein communicating from said ignition device accommodating chamber to said combustion chamber.

16. An airbag apparatus according to claim 15, wherein said central cylinder member has a total of six to nine through-holes 1.5-3.0 mm in diameter arranged in a circumferential direction.

17. An airbag apparatus according to claim 16, wherein the through-holes are arranged in two staggered rows, one of the rows having three through-holes 1.5 mm in diameter and the other row having three through-holes 2.5 mm in diameter.

18. An airbag apparatus according to claim 12 or claim 13, wherein said coolant/filter device has a support member for preventing displacement of said coolant/filter device;

and

said support member includes a flame resisting plate portion disposed to face the said through-holes in said central cylinder member and covering an inner circumferential surface of said coolant/filter device, the through-holes being adapted to pass flames from said igniter to said combustion chamber.

19. An airbag apparatus according to claim 12 or claim 13, wherein said gas discharge ports in the diffuser shell are closed with a moisture barrier comprising an aluminum tape whose width is 2-3.5 times the diameter of the gas discharge ports.

20. An airbag apparatus according to claim 12 or claim 13, wherein a cushion for said gas generating material is installed in the combustion chamber.

21. An airbag apparatus according to claim 20, wherein the cushion is made of a stainless steel mesh and fixed to a support plate, and the support plate has bent portions at inner and outer circumferential portions thereof and is securely held between the central cylinder member and the coolant/filter device by an elastic force of said bent portions.

22. An airbag apparatus according to claim 12 or 13, wherein the housing has an overall height of 25-40 mm;

and

wherein said coolant/filter device is formed in an annular configuration having an outer diameter of 40-65 mm, an inner diameter of 30-55 mm, a height of 19-37.6 mm, and further comprises a multi-layer metal mesh structure having a bulk density of 3.0-5.0 g/cm³.

229. An airbag apparatus of claim 12, further comprising:

a perforated basket disposed between said non-azide gas generating material and an circumferential surface of said coolant/filter device.

230. An airbag apparatus of claim 229, wherein said perforated basket is in contact with said non-azide gas generating material and said inner circumferential surface.

231. An airbag apparatus of claim 229 or 230, wherein said perforated basket has a plurality of through-holes defined therein.

232. An airbag apparatus of claim 231, wherein a size of each through-hole is determined such that said perforated basket prevents said non-azide gas generating material from directly contacting said inner circumferential surface.

233. An airbag apparatus of claim 231, wherein a total area of said through-holes is determined such that a pressure outside said perforated basket is maintained at substantially the same as a pressure inside said perforated basket when said non-azide gas generating material is generating gas.

234. An airbag apparatus of claim 229, wherein said perforated basket includes a flame resisting plate portion disposed to face said through-holes in said central cylinder member and covering said inner circumferential surface, said through-holes being adapted to pass flames from said igniter to said combustion chamber.

235. An airbag apparatus of claim 234, wherein said flame resisting plate has a height of approximately 8-15 mm.

236. An airbag apparatus of claim 12, wherein said airbag inflator is disposed in a steering wheel of a vehicle.

274. An airbag apparatus according to claim 12 or 34, wherein said airbag is made of nylon.

275. An airbag apparatus according to claim 12 or 34, wherein said module case is made of polyurethene.

281. An airbag apparatus according to claim 18, wherein said support member is made of a steel stainless steel plate or a steel plate having a thickness of 0.5-1.0 mm.

282. An airbag apparatus according to claim 21, wherein said support plate is made of a steel stainless steel plate or a steel plate having a thickness of 0.5-1.0 mm.

23. An airbag inflator comprising:

a housing having a diffuser shell and a closure shell, the diffuser shell being formed by pressing a metal plate and having gas discharge ports, the closure shell being formed by pressing a metal plate and having a center hole;

a non-azide gas generating material in said housing;

a central cylinder member installed in the housing, and disposed concentric with the center hole to form an ignition device accommodating chamber, said central cylinder member further having through-holes defined therein;

an ignition device in said accommodating chamber; and

a coolant/filter device made of a metal mesh with a wire diameter of 0.3-0.6 mm, having a bulk density of 3.0-5.0 g/cm³, disposed surrounding said central cylinder member to define gas generating material accommodating and combustion chambers in said housing, and having the function of cooling combustion gas and arresting combustion particulates resulting from ignition of said non-azide gas generating material.

24. An airbag inflator according to claim 23, wherein the diffuser shell and the closure shell are made of a stainless steel plate 1.2-3.0 mm thick and have outer diameters of 45-75 mm and 45-75 mm, respectively, and a narrow space 1.0-4.0 mm wide is formed between a circumferential wall formed by the diffuser shell and the closure shell and the coolant/filter device.

25. An airbag inflator according to claim 23 or 24, wherein the gas discharge ports in the diffuser shell have a diameter of 2.0-5.0 mm and a total of 16 to 24 such gas discharge ports are arranged in a circumferential direction.

26. An airbag inflator according to claim 23 or claim 24, wherein said central cylinder member has a plurality of circumferentially disposed through-holes therein communicating from said ignition device accommodating chamber to said combustion chamber.

27. An airbag inflator according to claim 26, wherein the central cylinder member has a total of six to nine through-holes 1.5-3.0 mm in diameter arranged in a circumferential direction;

and

wherein the gas discharge ports in the diffuser shell have a diameter of 2.0-5.0 mm and a total of 16 to 24 such gas discharge ports are arranged in a circumferential direction.

28. An airbag inflator according to claim 27, wherein the through-holes are arranged in two staggered rows, one of the rows having three through-holes 1.5 mm in diameter and the other row having three through-holes 2.5 mm in diameter.

29. An airbag inflator according to claim 23 or claim 24, wherein said coolant/filter device has a support member for preventing displacement of said coolant/filter device;

said support member includes a flame resisting plate portion disposed to face said through-holes in said central cylinder member and covering an inner circumferential surface of said coolant/filter device, said through-holes being adapted to pass flames from said igniter to said combustion chamber.

30. An airbag inflator according to claim 23 or claim 24, wherein the gas discharge ports in the diffuser shell are closed with a moisture barrier comprising an aluminum tape whose width is 2-3.5 times the diameter of the gas discharge ports.

31. An airbag inflator according to claim 23 or claim 24, wherein a cushion for a gas generating means is installed in the combustion chamber.

32. An airbag inflator according to claim 31, wherein said cushion is made of a stainless steel mesh and fixed to a support plate, and the support plate has bent portions at inner and outer circumferential portions thereof and is securely held between the central cylinder member and the coolant/filter by an elastic force of said bent portions.

33. An airbag inflator according to claim 23 or claim 24, wherein the housing has an overall height of 25-40 mm;

and

wherein said coolant/filter device is formed in an annular configuration having an outer diameter of 40-65 mm, an inner diameter of 30-55 mm, and a height of 19-37.6 mm.

237. An airbag inflator of claim 23, further comprising:

a perforated basket disposed between said non-azide gas generating material and an circumferential surface of said coolant/filter device.

238. An airbag inflator of claim 237, wherein said perforated basket is in contact with said non-azide gas generating material and said inner circumferential surface.

239. An airbag inflator of claim 237 or 238, wherein said perforated basket has a plurality of through-holes defined therein.

240. An airbag inflator of claim 239, wherein a size of each through-hole is determined such that said perforated basket prevents said non-azide gas generating material from directly contacting said inner circumferential surface.

241. An airbag inflator of claim 238, wherein a total area of said through-holes is determined such that a pressure outside said perforated basket is maintained at substantially the same as a pressure inside said perforated basket when said non-azide gas generating material is generating gas.

242. An airbag inflator of claim 237, wherein said perforated basket includes a flame resisting plate portion disposed to face said through-holes in said central cylinder member and covering said inner circumferential surface, said through-holes being adapted to pass flames from said igniter to said combustion chamber.

243. An airbag inflator of claim 242, wherein said flame resisting plate has a height of approximately 8-15 mm.

283. An airbag inflator according to claim 29, wherein said support member is made of a steel stainless steel plate or a steel plate having a thickness of 0.5-1.0 mm.

284. An airbag inflator according to claim 32, wherein said support plate is made of a steel stainless steel plate or a steel plate having a thickness of 0.5-1.0 mm.

34. An airbag apparatus comprising:

an airbag inflator including;

a housing having a diffuser shell and a closure shell, the diffuser shell being formed by pressing a metal plate and having gas discharge ports, the closure shell being formed by pressing a metal plate and having a center hole;

a non-azide gas generating material in said housing;

a central cylinder member installed in the housing, and disposed concentric with the center hole to form an ignition device accommodating chamber, said central cylinder member further having through-holes defined therein;

a ignition device in said accommodating chamber; and

a coolant/filter device made of a metal mesh with a wire diameter of 0.3-0.6 mm, having a bulk density of 3.0-5.0 g/cm³, disposed surrounding the central cylinder member to define gas generating material accommodating and combustion chambers in said housing, and having the functions of cooling combustion gas and arresting combustion particulates resulting from ignition of said gas generating material;

an impact sensor for detecting an impact and outputting an impact detection signal;

a control unit for receiving said impact detection signal and outputting a drive signal to said ignition device of the airbag inflator to actuate said ignition device and ignite said gas generating material;

an airbag to be inflated by admitting gas generated by said airbag inflator; and

a module case for accommodating said airbag.

35. An airbag apparatus according to claim 34, wherein the diffuser shell and the closure shell are made of a stainless steel plate 1.2-3.0 mm thick and have outer diameters of 45-75 mm and 45-75 mm, respectively, and a narrow space 1.0-4.0 mm wide is formed between a circumferential wall formed by the diffuser shell and the closure shell and the coolant/filter device.

36. An airbag apparatus according to claim 34 or claim 35, wherein the gas discharge ports in the diffuser shell have a diameter of 2.0-5.0 mm and a total of 16 to 24 such gas discharge ports are arranged in a circumferential direction.

37. An airbag apparatus according to claim 34 or claim 35, wherein said central cylinder member has a plurality of circumferentially disposed through-holes therein communicating from said ignition device accommodating chamber to said combustion chamber.

38. An airbag apparatus according to claim 37, wherein said central cylinder member has a total of six to nine through-holes 1.5-3.0 mm in diameter arranged in a circumferential direction;

and

wherein the gas discharge ports in the diffuser shell have a diameter of 2.0-5.0 mm and a total of 16 to 24 such gas discharge ports are arranged in a circumferential direction.

39. An airbag apparatus according to claim 38, wherein said through-holes are arranged in two staggered rows, one of the rows having three through-holes 1.5 mm in diameter and the other row having three through-holes 2.5 mm in diameter.

40. An airbag apparatus according to claim 34 or claim 35, wherein said coolant/filter device has a support member for preventing displacement of said coolant/filter device;

said support member includes a flame resisting plate portion disposed to face said through-holes in said central cylinder member and covering an inner circumferential surface of said coolant/filter device, said through-holes being adapted to pass flames from said igniter to said combustion chamber.

41. An airbag apparatus according to claim 34 or claim 35, wherein the gas discharge ports in the diffuser shell are closed with a moisture barrier comprising an aluminum tape whose width is 2-3.5 times the diameter of the gas discharge ports.

42. An airbag apparatus according to claim 34 or claim 35, wherein a cushion for said gas generating material is installed in the combustion chamber.

43. An airbag apparatus according to claim 42, wherein said cushion is made of a stainless steel mesh and fixed to a support plate, and the support plate has bent portions at inner and outer circumferential portions thereof and is securely held between the central cylinder member and the coolant/filter device by an elastic force of said bent portions.

44. An airbag apparatus according to claim 34 or claim 35, wherein the housing has an overall height of 25-40 mm;

and

wherein said coolant/filter device is formed in an annular configuration having an outer diameter of 40-65 mm, an inner diameter of 30-55 mm, and a height of 19-37.6 mm.

245. An airbag apparatus of claim 34, further comprising:

a perforated basket disposed between said non-azide gas generating material and an circumferential surface of said coolant/filter device.

246. An airbag apparatus of claim 245, wherein said perforated basket is in contact with said non-azide gas generating material and said inner circumferential surface.

247. An airbag apparatus of claim 245 or 246, wherein said perforated basket has a plurality of through-holes defined therein.

248. An airbag apparatus of claim 247, wherein a size of each through-hole is determined such that said perforated basket prevents said non-azide gas generating material from directly contacting said inner circumferential surface.

249. An airbag apparatus of claim 247, wherein a total area of said through-holes is determined such that a pressure outside said perforated basket is maintained at substantially the same as a pressure inside said perforated basket when said non-azide gas generating material is generating gas.

250. An airbag apparatus of claim 245, wherein said perforated basket includes a flame resisting plate portion disposed to face said through-holes in said central cylinder member and covering said inner circumferential surface, said through-holes being adapted to pass flames from said igniter to said combustion chamber.

251. An airbag apparatus of claim 250, wherein said flame resisting plate has a height of approximately 8-15 mm.

252. An airbag apparatus of claim 34, wherein said airbag inflator is disposed in a steering wheel of a vehicle.

285. An airbag apparatus according to claim 40, wherein said support member is made of a steel stainless steel plate or a steel plate having a thickness of 0.5-1.0 mm.

286. An airbag apparatus according to claim 43, wherein said support plate is made of a steel stainless steel plate or a steel plate having a thickness of 0.5-1.0 mm.

45. An inflator for an airbag comprising:

a housing having a plurality of gas-discharge ports, an ignition device installed in the housing, a gas-generating material installed around the ignition device and a coolant/filter device installed around the gas-generating material;

said gas generating material being a solid non-azide material ignitable by said igniter to produce combustion gas having a linear burn rate no greater than 30 mm/sec under a pressure of 70 kg/cm²; and

said coolant/filter device having a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature and acting to convey said combustion gas to said discharge ports and to cool said combustion gas and arrest therein to minimize the particulate content of gas discharged by said inflator into a said airbag.

46. The inflator of claim 45, wherein said solid gas generating material has a decomposition initiation temperature of 330°

C. or lower and a combustion temperature of 2000°

K or higher.

47. The inflator of claim 45 or claim 46, wherein said coolant/filter device has a substantially annular configuration constructed flat-plaited metal meshes laminated in a radial direction and compressed in both radial and axial directions to provide the desired range of pressure loss.

48. The inflator of claim 45 or claim 46, wherein said coolant/filter device has a bulk density of 3.0-5.0 g/cm³.

49. The inflator of claim 45 or claim 46, wherein said coolant/filter device is constructed of metal mesh with a wire diameter of 0.3-0.6 mm.

50. The inflator of claim 47, wherein said coolant/filter device has a bulk density of 3.0-5.0 g/cm³.

51. The inflator of claim 47, wherein said coolant/filter device is constructed of metal mesh with a wire diameter of 0.3-0.6 mm.

52. The inflator of claim 48, wherein said coolant/filter device is constructed of metal mesh with a wire diameter of 0.3-0.6 mm.

53. An airbag inflator for inflating airbags in driver seat, front passenger seat, and side impact applications comprising:

a housing having a plurality of gas discharge ports having a total open area A_t;

an ignition device installed in the housing;

a solid gas generating material having a known surface area A installed in the housing and ignitable by the ignition device to produce a combustion gas; and

a coolant/filter device accommodating the solid gas generating material and adapted to cool the combustion gas and arrest combustion contaminant particulates from said gas;

wherein the ratio of the total surface area A of the solid gas generating material to the sum A_t of open areas of the gas discharge ports, A/At, of said inflator is (a) 100-300 for an airbag for a driver'"'"'s seat, (b) 80-240 for an airbag for a front passenger seat and (c) 250-3600 for an airbag for side collision protection.

54. An airbag inflator according to claim 53, wherein the solid gas generating material has a linear burning velocity of 5-30 mm/sec under a pressure of 70 kg/cm².

55. An airbag inflator according to claim 53, wherein the solid gas generating material has a linear burning velocity of 5-15 mm/sec under the pressure of 70 kg/cm².

56. An airbag inflator according to claim 53, wherein the housing has an inner volume of 60-130 cc.

57. An airbag inflator according to claim 53, wherein the amount of the solid gas generating material there in is 20-50 g.

58. An airbag inflator according to claim 54 or claim 55, wherein the housing has an inner volume of 60-130 cc.

59. An airbag inflator according to any one of claims 54 to 56, wherein the amount of the solid gas generating material therein is 20-50 g.

60. An airbag inflator according to any one of claims 53 to 57, wherein the housing comprises a diffuser shell and a closure shell, the diffuser shell includes a circular portion with no holes formed therein, a circumferential wall portion formed at an outer circumference of the circular portion and having said gas discharge ports formed therein, and a flange portion extending radially outwardly at a free end of the circumferential wall portion;

said closure shell, together with said diffuser shell, forms a space therein and has a circular portion, a center hole formed at a center of the circular portion, a circumferential wall portion formed at an outer circumference of the circular portion and a flange portion extending radially outwardly at a free end of the circumferential wall portion, and said ignition device is installed in the center hole of said closure shell.

61. An airbag inflator according to any one of claims 53 to 57, wherein a narrow space is formed between said coolant/filter device and the outer circumferential wall of the housing.

62. An airbag inflator according to claim 60, wherein the diffuser shell and the closure shell are formed from pressed metal plates.

63. An airbag apparatus comprising:

an airbag inflator of claim 53;

an impact sensor for detecting an impact and outputting an impact detection signal;

a control unit for receiving the impact detection signal and outputting a drive signal to the ignition device of said airbag inflator;

an airbag to be inflated by admitting a gas thereto generated by said airbag inflator; and

a module case for accommodating said airbag.

64. An airbag apparatus according to claim 63, wherein the solid gas generating material has a linear burning velocity of 5-30 mm/sec under a pressure of 70 kg/cm².

65. An airbag apparatus according to claim 63, wherein the solid gas generating material has a linear burning velocity of 5-15 mm/sec under a pressure of 70 kg/cm².

66. An airbag apparatus according to claim 63, wherein the housing has an inner volume of 60-130 cc.

67. An airbag apparatus according to claim 63, wherein an amount of the solid gas generating material therein is 20-50 g.

68. An airbag apparatus according to any one of claims 63 to 67, wherein a narrow space is formed between the coolant/filter device and the outer circumferential wall of the housing.

124. An airbag inflator of claim 254, wherein a total area of said through-holes is determined such that a pressure outside said perforated basket is maintained at substantially the same as a pressure inside said perforated basket when said solid gas generating material is generating gas.

219. An airbag apparatus according to any one of claims 63 to 67, wherein the housing comprises a diffuser shell and a closure shell, the diffuser shell includes a circular portion with no holes formed therein, a circumferential wall portion formed at an outer circumference of the circular portion and having said gas discharge ports formed therein, and a flange portion extending radially outwardly at a free end of the circumferential wall portion, the closure shell, together with the diffuser shell, forms a space therein and has a circular portion, a center hole formed at a center of the circular portion, a circumferential wall portion formed at an outer circumference of the circular portion and a flange portion extending radially outwardly at a free end of the circumferential wall portion, and said ignition device is installed in the center hole of said closure shell.

220. An airbag apparatus according to claim 67, wherein said diffuser shell and said closure shell are formed from pressed metal plates.

253. An airbag inflator of claim 54, further comprising:

a perforated basket disposed between said solid gas generating material and an inner circumferential surface of said coolant/filter device.

254. An airbag inflator of claim 253, wherein said perforated basket is in contact with said solid gas generating material and said inner circumferential surface.

255. An airbag inflator of claim 253 or 254, wherein said perforated basket has a plurality of through-holes defined therein.

256. An airbag inflator of claim 255, wherein a size of each through-hole is determined such that said perforated basket prevents said solid gas generating material from directly contacting said inner circumferential surface.

69. An airbag inflator for an airbag of the pyrotechnological type comprising:

a non-azide gas generating material;

a housing containing said gas generating material and having gas discharge ports;

an ignition device for igniting said gas generating material to produce combustion gas and combustion particulates; and

a coolant/filter device for entrapping combustion particulates of said gas generating material;

said coolant/filter device and said non-azide gas generating material cooperating to limit the combustion particulates discharged from said discharge ports to 2 g or less.

70. An airbag inflator for an airbag according to claim 69, wherein the quantity of combustion particulates contained in said gas discharged from said gas discharge ports is in an amount of not larger than 1 g.

71. An airbag inflator for an airbag according to claim 69, wherein the quantity of combustion particulates contained in said gas discharged from said gas discharge ports is in an amount of not larger than 0.7 g.

72. An airbag inflator for an airbag according to any one of claims 69 to 71, wherein the gas generating material comprises at least an organic nitrogen compound, an oxidizing agent and a slag-forming material.

73. An airbag inflator for an airbag according to claim 72, wherein the organic nitrogen compound is a nitroguanidine.

74. An airbag inflator for an airbag according to claim 72, wherein the slag-forming material is an acid clay.

75. The airbag inflator of claim 73, wherein the slag-forming material is an acid clay.

76. An airbag inflator for an airbag according to claim 75, wherein the gas generating material contains the nitroguanidine in an amount of from 25 to 60% by weight, the oxidizing agent in an amount of from 40 to 65% by weight, and the acid clay in an amount of from 1 to 20% by weight.

77. The airbag inflator of claim 74, wherein the gas generating material contains the nitroguanidine in an amount of from 25 to 60% by weight, the oxidizing agent in an amount of from 40 to 65% by weight, and the acid clay in an amount of from 1 to 20% by weight.

78. An airbag inflator for an airbag according to any one of claims 69 to 71, wherein the coolant/filter device for entrapping the combustion particulates from the gas generating material has a bulk density of from 3.0 to 5.0 g/cm³.

79. An airbag inflator of an airbag according to claim 78, wherein the coolant/filter device for filtrating the combustion particulates of the gas generating material exhibits a pressure loss of from 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at normal temperature at a flow rate of 100 l/min.

80. The airbag inflator of claim 79, wherein the gas generating material comprises at least an organic nitrogen compound, an oxidizing agent and a slag-forming material.

81. The airbag inflator of claim 80, wherein the organic nitrogen compound is a nitroguanidine.

82. The airbag inflator of claim 80, wherein the slag-forming material is an acid clay.

83. The airbag inflator of claim 81, wherein the slag-forming material is an acid clay.

84. The airbag inflator of claim 83, wherein the gas generating material contains the nitroguanidine in an amount of from 25 to 60% by weight, the oxidizing agent in an amount of from 40 to 65% by weight, and the acid clay in an amount of from 1 to 20% by weight.

85. The airbag inflator of claim 82, wherein the gas generating material contains the nitroguanidine in an amount of from 25 to 60% by weight, the oxidizing agent in an amount of from 40 to 65% by weight, and the acid clay in an amount of from 1 to 20% by weight.

86. An airbag apparatus comprising at least:

an impact sensor for detecting an impact;

an airbag inflator for an airbag that is activated when said impact sensor has detected an impact to generate a gas; and

an airbag that inflates upon the introduction of a gas generated by said airbag inflator;

wherein said airbag inflator is constructed according to any one of claims 69-71.

347. An airbag inflator of claim 69, further comprising:

a space defined by an outer periphery of said coolant/filter device and the interior of an outer peripheral wall of said housing,

said space enhancing uniformity of the flow of combustion gas throughout said coolant/filter device resulting from combustion of said gas generating material.

348. An airbag inflator of claim 70, further comprising:

a space defined by an outer periphery of said coolant/filter device and the interior of an outer peripheral wall of said housing,

said space enhancing uniformity of the flow of combustion gas throughout said coolant/filter device resulting from combustion of said gas generating material.

349. An airbag inflator of claim 71, further comprising:

a space defined by an outer periphery of said coolant/filter device and the interior of an outer peripheral wall of said housing,

said space enhancing uniformity of the flow of combustion gas throughout said coolant/filter device resulting from combustion of said gas generating material.

350. An airbag inflator of claim 78, further comprising:

a space defined by an outer periphery of said coolant/filter device and the interior of an outer peripheral wall of said housing,

said space enhancing uniformity of the flow of combustion gas throughout said coolant/filter device resulting from combustion of said gas generating material.

351. An airbag inflator of claim 79, further comprising:

a space defined by an outer periphery of said coolant/filter device and the interior of an outer peripheral wall of said housing,

said space enhancing uniformity of the flow of combustion gas throughout said coolant/filter device resulting from combustion of said gas generating material.

87. A coolant/filter device for confining a gas generating material in an airbag inflator housing and cooling and arresting particles contained in combustion gas generated by ignition of said gas generating material, comprising:

a plurality of metal mesh laminates, each comprising flat plaited metallic mesh;

said laminates being radially laminated in an annular configuration; and

said laminates being compressed in both radial and axial directions to provide desired pressure loss and filtration characteristics for said coolant/filter device.

88. The coolant/filter device of claim 87, wherein said coolant/filter device has a bulk density of 3.0-5.0 g/cm³.

89. The coolant/filter device of claim 87 or 88, wherein said coolant/filter device exhibits a pressure loss therethrough of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature.

90. The coolant/filter device of claim 89, wherein said metal mesh consists of metal wire having a diameter of 0.3-0.6 mm.

91. The coolant/filter device of claim 87 or claim 88, wherein said metal mesh consists of metal wire having a diameter of 0.3-0.6 mm.

92. An airbag inflator comprising:

a housing having a diffuser shell and a closure shell, the diffuser shell having a plurality of gas discharge ports formed therein, the closure shell forming a space in combination with the diffuser shell;

a coolant/filter device defining a combustion chamber in combination with the housing and adapted to cool a combustion gas and arrest combustion particulates from said combustion gas generated in said combustion chamber;

an igniter installed in the combustion chamber; and

a solid gas generating material disposed adjacent to the igniter, having a decomposition initiation temperature of 330°

C. or lower and a combustion temperature of 2000°

K or higher, said material being ignitable by said igniter to produce the combustion gas.

93. An airbag inflator according to claim 92, wherein the solid gas generating material has the decomposition initiation temperature of 310°

C. or lower and the combustion temperature of 2000°

K or higher.

94. An airbag inflator according to claim 92 or claim 93, wherein said housing has an inner volume of 60-130 cc.

95. An airbag inflator according to claim 94, wherein the amount of charge of the solid gas generating material is 20-50 g.

96. An airbag inflator according to claim 92 or claim 93, wherein a space is formed between the coolant/filter device and an outer circumferential wall of the housing, said space acting to enhance the uniformity of flow of combustion gas through said coolant/filter device.

97. The airbag inflator of claim 94, wherein a space is formed between the coolant/filter device and an outer circumferential wall of the housing, said space acting to enhance the uniformity of flow of combustion gas through said coolant/filter device.

98. The airbag inflator of claim 95, wherein a space is formed between the coolant/filter device and an outer circumferential wall of the housing, said space acting to enhance the uniformity of flow of combustion gas through said coolant/filter device.

99. An airbag inflator according to claim 92 or claim 93, wherein the diffuser shell has a circular portion, a circumferential wall portion formed at an outer circumference of the circular portion, and a flange portion formed at a free end of the circumferential wall portion and extending radially outwardly;

and

the closure shell has a circular portion, a center hole formed at the center of the circular portion, and a circumferential wall portion formed at an outer circumference of the circular portion, the diffuser shell and the closure shell being formed from pressed metal plates.

100. An airbag apparatus comprising:

an airbag inflator of claim 92 or claim 93;

an impact sensor for detecting an impact and outputting an impact detection signal;

a control unit for receiving the impact detection signal and outputting an activation signal to an ignition means of the airbag inflator;

an airbag to be inflated by introducing a gas generated by the airbag inflator into the airbag; and

a module case accommodating the airbag.

101. An airbag apparatus according to claim 100, wherein the housing has an inner volume of 60-130 cc.

102. An airbag apparatus according to claim 100, wherein the amount of charge of the solid gas generating material is 20-50 g.

103. An airbag apparatus according to claim 100, wherein a space is formed between the coolant/filter device and an outer circumferential wall of the housing.

104. An airbag apparatus according to claim 101, wherein a space is formed between the coolant/filter device and an outer circumferential wall of the housing.

105. An airbag apparatus according to claim 102, wherein a space is formed between the coolant/filter device and an outer circumferential wall of the housing.

106. An inflator for an airbag comprising:

a housing having a plurality of gas-discharge ports, an ignition device installed in the housing, a gas-generating material installed around the ignition device and a coolant/filter device installed around the gas-generating material;

said housing having an outer peripheral wall containing said gas discharge ports;

said coolant/filter device surrounding and confining said gas generating material;

said coolant/filter device having an outer periphery further defining a space between said outer periphery and the interior of said outer peripheral wall of said housing;

said space enhancing uniformity of the flow of combustion gas throughout said coolant/filter device resulting from combustion of said gas generating material; and

said coolant/filter device acting to cool said combustion gas and arrest particulates contained therein, prior to the discharge of said gas from said gas discharge ports of said housing.

107. The inflator of claim 106, wherein said coolant/filter device further includes an external peripheral swell suppressor layer for maintaining the dimensional integrity of said coolant/filter device and said space defined thereby.

108. The inflator of claim 106, wherein said inflator housing includes a top plate, a bottom plate, and a circumferential outer wall containing said gas discharge ports;

said coolant/filter device is a substantially annular structure extending between said top and bottom walls; and

said inflator further includes an annular shield extending over at least the junction between said coolant/filter device and said top plate within said combustion chamber to preclude a short pass of said combustion gas to said discharge ports between said coolant/filter device and said top plate.

109. The inflator of claim 106, wherein said gas generating material is a non-azide material;

and

wherein the total area of said discharge ports per volume of combustion gas generated within said inflator is in the range of 0.5 to 2.50 cm²/mol and the maximum internal pressure in said inflator is controlled thereby in a range of 100-300 kg/cm².

110. The inflator of any one of claims 106 to 109, wherein said gas generating material has a solid composition and is disposed adjacent to said igniter in said combustion chamber;

said gas generating material having a decomposition initiation temperature of 330°

C. or lower and a combustion temperature of 2000°

K or higher.

111. The inflator of any one of claims 106 to 109, wherein said space defined by said coolant/filter device and said outer peripheral wall of said housing is annular in cross-section having an area S_t;

wherein the total open area of said discharge ports is A_t; and

wherein the ratio S_t/A_t is no less than 1.

112. The inflator of claim 111, wherein said gas generating material has a solid composition and is disposed adjacent to said igniter in said combustion chamber;

said gas generating material having a decomposition initiation temperature of 330°

C. or lower and a combustion temperature of 2000°

K or higher.

113. An airbag apparatus comprising:

an airbag inflator of any one of claims 106 to 109;

an impact sensor for detecting an impact and outputting an impact detection signal;

a control unit for receiving the impact detection signal and outputting a drive signal to the ignition device in said airbag inflator;

an airbag to be inflated by admitting a gas thereto generated by said airbag inflator; and

a module case for accommodating said airbag.

114. The airbag apparatus of claim 113, wherein said gas generating material has a solid composition and is disposed adjacent to said igniter in said combustion chamber;

said gas generating material having a decomposition initiation temperature of 330°

C. or lower and a combustion temperature of 2000°

K or higher.

115. The airbag apparatus of claim 114, wherein said space defined by said coolant/filter device and said outer peripheral wall of said housing is annular in cross-section having an area S_t;

wherein the total open area of said discharge ports is A_t; and

wherein the ratio S_t/A_t is no less than 1.

116. The airbag apparatus of claim 113, wherein said space defined by said coolant/filter device and said outer peripheral wall of said housing is annular in cross-section having an area S_t;

wherein the total open area of said discharge ports is A_t; and

wherein the ratio S_t/A_t is no less than 1.

257. An airbag inflator of claim 106, further comprising:

a perforated basket disposed between said gas generating material and an inner circumferential surface of said coolant/filter device.

258. An airbag inflator of claim 257, wherein said perforated basket is in contact with said gas generating material and said inner circumferential surface.

259. An airbag inflator of claim 257 or 258, wherein said perforated basket has a plurality of through-holes defined therein.

260. An airbag inflator of claim 259, wherein a size of each through-hole is determined such that said perforated basket prevents said non-azide gas generating material from directly contacting said inner circumferential surface.

261. An airbag inflator of claim 258, wherein a total area of said through-holes is determined such that a pressure outside said perforated basket is maintained at substantially the same as a pressure inside said perforated basket when said non-azide gas generating material is generating gas.

302. The inflator for an airbag of claim 106, wherein an area S_t of the gas passage in a radial cross-section is equal to or greater than a sum A_t of open areas of the gas-discharge ports.

303. The inflator for an airbag of claim 302, wherein a ratio of the area S_t to the sum area A_t, S_t/A_t, is between 1 and 10.

304. The inflator for an airbag of claim 302, wherein a ratio of the area S_t to the sum area A_t, S_t/A_t, is between 2 and 5.

305. The inflator for an airbag of claim 106, wherein said coolant/filter device has a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min at normal temperatures.

306. The inflator for an airbag of claim 106, wherein said coolant/filter device has a bulk density of 3.0-5.0 g/cm³.

307. The inflator for an airbag of claim 306, wherein said coolant/filter device is made of a metal mesh with a wire diameter of 0.3-0.6 mm.

308. The inflator of claim 106, wherein said space has a radial width of 1.0-4.0 mm.

309. The inflator of claim 107, wherein said swell suppressor layer prevents expansion of said coolant/filter device.

310. The airbag inflator of claim 309, wherein said swell suppressor layer is a porous cylinder member that fits over an outer circumferential surface of said coolant/filter device.

311. The airbag inflator of claim 309, wherein said swell suppressor layer is a metal mesh layer formed on the outside of said coolant/filter device.

312. The airbag inflator of claim 106, further comprising:

an inner cylinder disposed in said housing, said inner cylinder defining an ignition device accommodating chamber for installing said ignition device therein, and a combustion chamber for storing said gas-generating material and said coolant/filter device.

313. The airbag inflator of claim 106, wherein said coolant/filter device maintains dimensional integrity thereof and said space even after combustion of said gas generating material.

314. The inflator of claim 107, wherein said inflator housing includes a top plate, a bottom plate, and a circumferential outer wall containing said gas discharge ports;

said coolant/filter device is a substantially annular structure extending between said top and bottom walls; and

said inflator further includes an annular shield extending over at least the junction between said coolant/filter device and said top plate within said combustion chamber to preclude a short pass of said combustion gas to said discharge ports between said coolant/filter device and said top plate.

315. The inflator of claim 107, wherein said gas generating material is a non-azide material;

and

wherein the total area of said discharge ports per volume of combustion gas generated within said inflator is in the range of 0.5 to 2.50 cm²/mol and the maximum internal pressure in said inflator is controlled thereby in a range of 100-300 kg/cm².

316. The inflator of claim 108, wherein said gas generating material is a non-azide material;

and

wherein the total area of said discharge ports per volume of combustion gas generated within said inflator is in the range of 0.5 to 2.50 cm²/mol and the maximum internal pressure in said inflator is controlled thereby in a range of 100-300 kg/cm².

117. The method of forming an annular coolant/filter device for cooling and filtering particulates from combustion gases generated in an airbag inflator, comprising:

providing a sheet of metal mesh;

forming said sheet into a cylinder;

repetitively folding one end of said cylinder outwardly of itself and toward the opposite end of said cylinder to form an annular multi-layer body; and

compressing said multi-layer body in a forming die to impart desired gross density, pressure loss, and dimensional characteristics thereto.

118. The method of claim 117, wherein the desired gross density imparted to said coolant/filter device is from 3.0 to 5.0 g/cm³.

119. The method of claim 117, wherein the desired pressure loss characteristic is 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at normal temperature at a flow rate of 10 l/min/cm².

120. The method of any one of claims 117 to 119, wherein said metal mesh is formed of metal wire having a wire diameter of 0.3 to 0.6 mm.

121. The method of any one of claims 117 to 119, wherein said metal is stainless steel.

122. The method of any one of claim 117 to 119, wherein said desired dimensions imparted to said annular coolant/filter device are an inside diameter of 30 to 55 mm, an outer diameter of 40 to 65 mm, and a height of 19 to 37.6 mm.

123. The method of any one of claims 117 to 119, including the further step of providing an external swell suppressing layer on the outer periphery of said coolant/filter device.

125. The method of claim 123, including the step of forming a porous cylinder as said swell suppressing layer and fitting said porous cylinder over said annular coolant/filter device.

126. The method of forming an annular coolant/filter device for cooling and filtering particulates from combustion gas generated in an airbag inflator comprising:

forming a metal mesh into a cylinder;

pressing said cylinder in the radial direction to form a plate member;

rolling said plate member into a multi-layer cylindrical body; and

compressing said multi-layer cylindrical body in a forming die to impart desired gross density, pressure loss and dimensional characteristics thereto.

127. The method of claim 126, including the steps of forming at least one metal mesh cylinder of metal wire having diameters of 0.3 to 0.6 mm;

forming at least one other metal mesh cylinder of metal wire having diameters of 0.5 to 0.6 mm; and

constraining said at least one other cylinder to define an inside layer of the finished annular coolant/filter device.

128. The method of claim 126, which further includes, prior to said compressing of said multi-layer cylindrical body, the steps of repetitively folding one end of said cylinder outwardly of itself and toward the other end of said cylinder to form said multi-layer cylindrical body.

129. The method of any one of claims 126 to 128, wherein the gross density characteristic imparted to said coolant/filter device is from 3.0 to 5.0 g/cm³.

130. The method of any one of claims 126 to 128, wherein the desired pressure loss characteristic is 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at normal temperature at a flow rate of 10 l/min/cm².

131. The method of any one of claims 126 to 128, wherein said metal mesh is formed of metal wire having a wire diameter of 0.3 to 0.6 mm.

132. The method of any one of claims 126 to 128, wherein said metal is stainless steel.

133. The method of any one of claims 126 to 128, wherein said desired dimensions imparted to said annular coolant/filter device are an inside diameter of 30 to 55 mm, an outer diameter of 40 to 65 mm, and a height of 19 to 37.6 mm.

134. The method of any one of claims 126 to 128, including the further step of providing an external swell suppressing layer on the outer periphery of said coolant/filter device.

136. The method of claim 134, including the step of forming a porous cylinder as said swell suppressing layer and fitting said porous cylinder over said annular coolant/filter device.

137. The method of controlling the flow of gas from a gas generator to an airbag associated therewith comprising:

providing an inflator housing;

placing a combustible gas generating material in said housing;

providing a plurality of diffusion openings in said inflator housing in communication with said gas generating material and said airbag; and

correlating the total area of said diffusion openings and the characteristics of said gas generating material such that said total area/volume of gas generated is in the range of 0.50 to 2.50 cm²/mol and the maximum internal pressure in said housing created by said gas is in the range of 100 to 300 kg/cm².

138. The method of claim 137, wherein said plurality of diffusion openings are sized in the range of circle equivalent diameters of 2 to 5 mm.

139. The method of either of claims 137 and 138, wherein the total area of said diffusion openings is 1.00 to 1.50 cm²/mol.

140. The method of claim 139, in which the gas generating material placed in said housing is a non-azide gas generating material.

141. The method of claim 139, in which the housing is dimensioned to provide an internal volume of 130 cc or less when said inflator is for use with a driver'"'"'s side airbag apparatus.

142. The method of claim 139, which includes the step of sealing the diffusion openings with a readily frangible moisture proof layer to preclude moisture deterioration of said gas generating material.

143. The method of claim 142, wherein said readily frangible moisture proof layer is a material having such characteristics as to rupture in response to combustion of said gas generating material without controlling the maximum internal pressure created in said housing by said generated gas.

144. The method of claim 139, wherein said diffusion opening are sized in groups with at least two respective circle equivalent diameters.

145. The method of claim 139, wherein said diffusion openings are provided in an array of between 12 and 20 such openings circumferentially of said housing.

146. The method of claim 139, which further includes selecting a non-azide gas generating material which has a linear combustion velocity of 30 mm/sec or less under a pressure of 70 kg/cm².

147. The method of either of claims 137 and 138, in which the gas generating material placed in said housing is a non-azide gas generating material.

148. The method of either of claims 137 and 138, in which the housing is dimensioned to provide an internal volume of 130 cc or less when said inflator is for use with a driver'"'"'s side airbag apparatus.

149. The method of either of claims 137 and 138, which includes the step of sealing the diffusion openings with a readily frangible moisture proof layer to preclude moisture deterioration of said gas generating material.

150. The method of either of claims 137 and 138, wherein said readily frangible moisture proof layer is a material having such characteristics as to rupture in response to combustion of said gas generating material without controlling the maximum internal pressure created in said housing by said generated gas.

151. The method of either of claims 137 and 138, wherein said diffusion openings are sized in groups with at least two respective circle equivalent diameters.

152. The method of either of claims 137 and 138, wherein said diffusion openings are provided in an array of between 12 and 20 such openings circumferentially of said housing.

153. The method of either of claims 137 and 138, which further includes selecting a non-azide gas generating material which has a linear combustion velocity of 30 mm/sec or less under a pressure of 70 kg/cm².

154. The method of controlling the internal pressures and quality of a predetermined amount of gas produced in a pyrotechnic airbag inflator housing comprising:

providing a housing having a combustion chamber and an igniter associated with that chamber;

providing a combustible gas generating material in said combustion chamber;

providing a coolant/filter structure surrounding said gas generating material in said combustion chamber;

providing a plurality of gas discharge ports in said housing to convey generated gas toward an airbag at the exterior of said housing;

correlating the total open area of said plurality of discharge ports and the characteristics of said gas generating material to control the maximum internal pressures generated in said housing by combustion of said gas generating material; and

further correlating the characteristics of said coolant/filter structure with the characteristics of said gas generating material for producing combustion contaminants, to effect entrapment of particulates of combustion in said coolant/filter structure to a predetermined degree.

155. The method of claim 154, wherein said gas generating material is selected as a solid material having a linear burning velocity of 30 mm/sec or less under a pressure of 70 kg/cm².

156. The method of claim 155, wherein the total open area of said discharge ports is selected in a range of 0.5 to 2.50 cm²/mol of gas generated material to control the maximum internal pressure generated in said housing is a range of 100 to 300 kg/cm².

157. The method of any one of claims 154 to 156, wherein each of said discharge ports has a circle equivalent diameter of 2 to 5 mm.

158. The method of any one of claims 154 to 156, wherein the volume of said housing internally of said discharge ports is correlated with the combustion characteristics of said gas generating material.

159. The method of claim 158, wherein said housing volume is 130 cc or less.

160. The method of claims 154 or 155, wherein the total area of said discharge ports is 1.00 to 1.50 cm²/mol of gas generated in said housing to control the maximum internal pressure generated in said housing in a range of 100 to 300 kg/cm².

161. The method of claim 160, wherein each of said discharge ports has an equivalent circle diameter of 2 to 5 mm.

162. The method of claim 160, wherein the volume of said housing internally of said discharge ports is correlated with the combustion characteristics of said gas generating material.

163. The method of claim 162, wherein each of said discharge ports has an equivalent circle diameter of 2 to 5 mm.

164. The method of claim 162, wherein said housing volume is 130 cc or less.

165. The method of claim 164, wherein each of said discharge ports has an equivalent circle diameter of 2 to 5 mm.

166. The method of any one of claims 154 to 156, wherein said discharge ports are sized to include ports of at least two different size openings.

167. The method of any one of claims 154 to 156, which further includes sealing said discharge ports with a frangible moisture blocking sealing tape having substantially no controlling effect on said maximum interval pressure range.

168. The method of claim 167, wherein said discharge ports are sized to include ports of at least two different size openings.

169. The method of claim 167, wherein said sealing tape is aluminum tape having a width of 2 to 3.5 times the diameter of said discharge ports and a thickness of 25 to 80 μ

m.

170. The method of claim 160, wherein said discharge ports are sized to include ports of at least two different size openings.

171. The method of claim 160, which further includes sealing said discharge port with a frangible moisture blocking sealing tape having substantially no controlling effect on said maximum interval pressure range.

172. The method of claim 171, wherein said discharge ports are sized to include ports of at least two different size openings.

173. The method of claim 171, wherein said sealing tape is aluminum tape having a width of 2 to 3.5 times the diameter of said discharge ports and a thickness of 25 to 80 μ

m.

174. The method of claims 154 to 156, wherein the number of discharge ports is selected in the range of 12 to 20 and positioned circumferentially in the housing between the gas generating material and an airbag mounted externally of the housing.

175. The method of claim 160, wherein the number of discharge ports is selected in the range of 12 to 20 and positioned circumferentially in the housing between the gas generating material and an airbag mounted externally of the housing.

176. The method of claim 174, wherein said discharge ports are sized to include ports of at least two different size openings.

177. The method of claim 174, which further includes sealing said discharge port with a frangible moisture blocking sealing tape having substantially no controlling effect on said maximum interval pressure range.

178. The method of claim 177, wherein said discharge ports are sized to include ports of at least two different size openings.

179. The method of claim 177, wherein said sealing tape is aluminum tape having a width of 2 to 3.5 times the diameter of said discharge ports and a thickness of 25 to 80 μ

m.

180. The method of claim 175, wherein said discharge ports are sized to include ports of at least two different size openings.

181. The method of claim 175, which further includes sealing said discharge port with a frangible moisture blocking sealing tape having substantially no controlling effect on said maximum interval pressure range.

182. The method of claim 181, wherein said discharge ports are sized to include ports of at least two different size openings.

183. The method of claim 181, wherein said sealing tape is aluminum tape having a width of 2 to 3.5 times the diameter of said discharge ports and a thickness of 25 to 80 μ

m.

184. The method of any one of claims 154 to 156, wherein said coolant/filter structure is provided with a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature.

185. The method of claim 184, wherein each of said discharge ports has a circle equivalent diameter of 2 to 5 mm.

186. The method of claim 184, wherein the volume of said housing internally of said discharge ports is correlated with the combustion characteristics of said gas generating material.

188. The method of claims 154 or 155, wherein the total area of said discharge ports is 1.00 to 1.50 cm²/mol of gas generated in said housing to control the maximum internal pressure generated in said housing in a range of 100 to 300 kg/cm²;

and

wherein said coolant/filter structure is provided with a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>″

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature.

189. The method of any one of claims 154 to 156, wherein the housing has an outer wall containing said discharge ports;

and

including the further step of providing a space between the coolant/filter structure and the said circumferential wall to enhance the uniformity of flow of gas from said gas generating material throughout the entire body of said coolant/filter device.

190. The method of claim 189, wherein said coolant/filter device is provided with a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature.

191. The method of claims 154 or 155, wherein the total area of said discharge ports is 1.00 to 1.50 cm²/mol of gas generated in said housing to control the maximum internal pressure generated in said housing in a range of 100 to 300 kg/cm²;

wherein the housing has an outer wall containing said discharge ports; and

including the further step of providing a space between the coolant/filter device and the said circumferential wall to enhance the uniformity of flow of gas from said gas generating material throughout the entire body of said coolant/filter device.

195. The method of anyone of claims 154 to 156, which further includes providing a peripheral space between the outer periphery of the said coolant/filter structure and the interior of a wall of said housing containing said plurality of discharge ports for enhancing the uniformity of flow through said coolant/filter device of combustion gas from said combustion chamber toward said discharge ports.

196. The method of claim 195, in which the radial cross-sectional area S_t of said peripheral space is related to the total open areas A_t of said discharge ports in the ratio of S_t/A_t is in the range of 1-10 for controlling the maximum internal pressures in said housing.

197. The method of claim 196, wherein the maximum internal pressure in said housing is maintained in the range of 130 to 180 kg/cm².

198. The method of claim 196, in which the ratio S_t/A_t is in the range of 2-5.

199. The method of claim 198, wherein the maximum internal pressure in said housing is maintained in the range of 130 to 180 kg/cm².

200. The method of claim 195, wherein both the coolant/filter device and the peripheral space provided are annular in shape and are substantially coextensive at the outer periphery of said coolant/filter device.

201. The method of claim 200, wherein the radial extent of said peripheral space is in the range of 1.0 to 4.0 mm.

202. The method of claim 201, wherein the radial cross-sectional area S_t of said peripheral space is equal to or greater than the total areas A_t of the gas discharge ports for controlling the maximum internal pressure in said housing.

203. The method of claim 202, wherein the ratio S_t/A_t is in the range of 1-10.

204. The method of claim 202, wherein the ratio S_t/A_t is in the range of 2-5.

205. The method of claim 200, wherein said maximum internal pressure in said housing is in the range of 130 to 180 kg/cm².

206. The method of claim 205, wherein the radial extent of said annular peripheral space is 1.0 to 4.0 mm.

207. The method of claim 205, wherein the radial cross-sectional area S_t of said peripheral space is equal to or greater than the total areas A_t of the gas discharge ports for controlling the maximum internal pressure in said housing.

208. The method of claim 207, wherein the radial extent of said annular peripheral space is 1.0 to 4.0 mm.

209. The method of claim 207, wherein the ratio S_t/A_t is in the range of 1-10.

210. The method of claim 209, wherein the radial extent of said annular peripheral space is 1.0 to 4.0 mm.

211. The method of claim 207, wherein the ratio S_t/A_t is in the range of 2-5.

212. The method of claim 211, wherein the radial extent of said annular peripheral space is 1.0 to 4.0 mm.

213. The method of claim 195, in which the radial cross-sectional area S_t of said peripheral space is equal to or greater than the total open areas A_t of said discharge ports for controlling the maximum pressure within said housing.

214. The method of claim 213, wherein the maximum pressure within the housing is 130 to 180 kg/cm².

215. The method of claim 213, wherein said coolant/filter structure is provided with a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/ cm² at a flow rate of 100 l/min/cm² at a normal temperature.

216. The method of claim 215, wherein the maximum pressure within the housing is 130 to 180 kg/cm².

217. The method of claim 189, wherein said space is annular in shape and has a radial cross-sectional area S_t which is equal to or greater than the sum of the open areas A_t of the discharge ports for controlling the maximum pressure within said housing.

218. The method of claim 217, wherein said coolant/filter structure is provided with a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature.

221. The method of claim 191, wherein said coolant/filter device is provided with a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature.

262. The method of claim 154, further comprising:

providing a perforated basket between said combustible gas generating material and an inner circumferential surface of said coolant/filter structure, said perforated basket having a plurality of through-holes defines therein.

263. The method of claim 262, further comprising:

determining a size of each through-hole such that said perforated basket prevents said combustible material from directly contacting said inner circumferential surface.

264. The method of claim 262, further comprising:

determining a total area of said through-holes such that a pressure outside said perforated basket is maintained at substantially the same as a pressure inside said perforated basket when said combustible material is generating gas.

358. The method of claim 154, wherein a total weight of combustion particles discharged from said discharge ports is 2 g or less.

187. The method of 186, wherein said housing volume is 120 cc or less.

192. The method of maximizing the gas output of an airbag inflator while minimizing the physical size thereof comprising:

forming an inflator housing having an internal volume of no greater than 130 cc; and

charging said housing with a solid gas generating material having a decomposition initiation temperature of 330°

C. or lower and a combustion temperature of 2000°

K or higher.

193. The method of claim 192, which further includes providing said solid gas generating material with a linear burning velocity of no greater than 30 mm/sec under a pressure of 70 kg/cm².

194. The method of claims 192 or 193, including selecting the inflator housing capacity in the range of 60 to 130 cc and the amount of solid gas generating material in the range of 20 to 50 g.

287. An inflator for an airbag comprising:

a housing having a plurality of gas-discharge ports, an ignition device installed in the housing, a gas-generating material installed around the ignition device and a coolant/filter device installed around the gas-generating material;

said gas generating material being a solid non-azide material ignitable by said igniter to produce combustion gas; and

said coolant/filter device having a pressure loss of 0.3×

10<sup>−

2</sup> to 1.5×

10<sup>−

2</sup> kg/cm² at a flow rate of 100 l/min/cm² at a normal temperature and acting to convey said combustion gas to said discharge ports and to cool said combustion gas and arrest therein to minimize the particulate content of gas discharged by said inflator into a said airbag.

288. An inflator of claim 287, further comprising:

an inner cylinder disposed in said housing, said inner cylinder defining an ignition device accommodating chamber for installing said ignition device therein, and a combustion chamber for storing said gas-generating material and said coolant/filter device.

289. An inflator of claim 287, wherein said coolant/filter device is obtained by forming a stainless steel mesh into a cylinder, repetitively folding one end portion of the cylinder outwardly to form an annular multi-layer body, and compressing the multi-layer body in a die.

290. An inflator of claim 287, wherein said coolant/filter device is obtained by forming a stainless steel mesh into a cylinder, pressing the cylinder in a radial direction to form a plate member, rolling the plate member into a multi-layer cylinder body, and compressing the multi-layer cylinder body in a die.

291. An inflator of claim 290, wherein said coolant/filter device includes metal meshes of a wire diameter of 0.3 to 0.6 mm, and has at the inside thereof a layer of a thickness of 1.5 to 2.0 mm comprising metal meshes of a wire diameter of 0.5 to 0.6 mm.

292. An inflator of claim 287, wherein said coolant/filter device has an outer diameter of 40 to 65 mm, an inner diameter of 30 to 55 mm, and a height of 19 to 37.5 mm.

293. An inflator of claim 287, wherein said coolant/filter device is obtained by laminating flat-plaited metal meshes of a wire diameter of 0.3 to 0.6 mm in a radial direction and compressing them in radial and axial directions, said coolant/filter device having a bulk density of 3.0 to 5.0 g/cm³.

294. An inflator of claim 293, wherein said coolant/filter device has a thickness of 5 to 10 mm.

295. An inflator of claim 293, wherein said coolant/filter device is obtained by forming a stainless steel mesh into a cylinder, repetitively folding one end portion of the cylinder outwardly to form an annular multi-layer body, and compressing the multi-layer body in a die.

296. An inflator of claim 293, wherein said coolant/filter device is obtained by forming a stainless steel mesh into a cylinder, pressing the cylinder in a radial direction to form a plate member, rolling the plate member into a multi-layer cylinder body, and compressing the multi-layer cylinder body in a die.

297. An inflator of claim 296, wherein said coolant/filter device includes metal meshes of a wire diameter of 0.3 to 0.6 mm, and has on the inside thereof a layer of a thickness of 1.5 to 2.0 mm having a metal meshes of a wire diameter of 0.5 to 0.6 mm.

298. An inflator of according to claim 293, wherein said coolant/filter device has an outer diameter of 40 to 65 mm, an inner diameter of 30 to 55 mm, and a height of 19 to 37.6 mm.

299. An inflator of claim 298, wherein the outer periphery of said coolant/filter device includes a swell suppressor layer.

300. An inflator of claim 299, wherein said swell suppressor layer is a metal mesh layer formed on the outer peripheral surface of the coolant/filter device and has a pressure loss being smaller than the coolant/filter device under the conditions of a normal temperature and a flow rate of 100 l/min.

301. An airbag inflator for an airbag of claim 299, wherein said swell suppressor layer includes a porous cylinder fitted over the outer peripheral surface of the coolant/filter device.

317. An airbag inflator for an airbag, comprising:

a housing which includes a diffuser shell and a closure shell, said diffuser shell having a circular portion with no holes formed therein, a circumferential wall portion formed at an outer circumference of the circular portion and having gas discharge ports formed therein, and a flange portion extending radially outwardly at a free end of said circumferential wall portion, said closure shell, together with said diffuser shell, forms a space therein and has a circular portion, a center hole formed at a center of said circular portion, a circumferential wall portion formed at an outer circumference of said circular portion and a flange portion extending radially outwardly at a free end of said circumferential wall portion, and said ignition device is installed in said center hole of said closure shell.

318. An airbag inflator of claim 317, wherein said diffuser shell and said closure shell are formed by pressing a plate.

319. An airbag inflator of claim 317, wherein said flange portion of said diffuser shell has mounting portions to be mounted to a fitting of a pad module.

320. An airbag inflator of claim 317, wherein said flange portion of said diffuser shell and said flange portion of said closure shell are joined by welding.

321. An airbag inflator of claim 317, wherein one or both of said circular portions of said diffuser shell and said closure shell are formed with reinforcement ribs or a reinforcement stepped portion, or both.

322. An airbag inflator of claim 317, wherein said center hole of said closure shell has an axial bent portion at an edge thereof in which to accommodate the ignition device.

323. An airbag inflator of claim 317, wherein said flange portion of said diffuser shell and said flange portion of said closure shell are stacked and joined in a transverse cross-sectional plane at or near an axially central position of said housing.

324. An airbag inflator of claim 317, wherein said diffuser shell and said closure shell are made of a metal plate 1.2-3.0 mm thick.

325. An airbag inflator of claim 324, wherein said metal plate is a stainless steel plate, a nickel-plated steel plate, or an aluminum alloy plate.

326. An airbag inflator of claim 317, wherein said diffuser shell and said closure shell have outer diameters of 45-75 mm.

327. An airbag inflator of claim 317, wherein a height from a top surface of said diffuser shell to a bottom surface of said closure shell is 25-40 mm.

328. An inflator for an airbag comprising:

a housing having a plurality of gas-discharge ports, an ignition device installed in the housing, a gas-generating material installed around the ignition device and a coolant/filter device installed around the gas-generating material; and

said gas generating material being a solid non-azide material ignitable by said igniter to produce combustion gas, wherein

said coolant/filter device has a flame-resisting plate disposed to face through-holes in a central cylinder member and covering an inner circumferential surface of said coolant/filter device, said through-holes being adapted to pass flames from said igniter to said combustion chamber.

329. An inflator of claim 328, wherein said coolant/filter device has a support member for preventing displacement of said coolant/filter device;

said support member includes said flame resisting plate.

330. An airbag inflator of claim 328, wherein said flame resisting plate has a height of approximately 8-15 mm.

331. An inflator of claim 328, further comprising:

a space defined by an outer periphery of said coolant/filter device and the interior of an outer peripheral wall of said housing,

said space enhancing uniformity of the flow of combustion gas throughout said coolant/filter device resulting from combustion of said gas generating material.

332. An inflator for an airbag comprising:

a housing having a top plate, a bottom plate, and a circumferential outer wall containing a plurality of gas discharge ports;

an ignition device installed in said housing;

a gas-generating material installed around said ignition device, said gas generating material being a solid non-azide material ignitable by said igniter to produce combustion gas;

a coolant/filter device installed around said gas-generating material;

an annular shield extending over at least a junction between said coolant/filter device and at least one of said top plate and said bottom plate within said combustion chamber to preclude a short pass of said combustion gas to said discharge ports between said coolant/filter device and at least on of said top plate and said bottom plate.

333. An inflator of claim 332, wherein said annular shield is a plate member which includes a circular portion closing an end opening of said coolant/filter device and a circumferential wall portion formed integral with said circular portion and engaging an inner circumferential surface of said coolant/filter device.

334. An inflator of claim 333, further comprising:

a wall defining an ignition device accommodating chamber for installing said ignition device, wherein said plate member has a center hole in said circular portion that fits over an outer circumferential portion of said wall.

335. An inflator of claim 332, wherein said housing includes a diffuser shell and a closure shell,

said diffuser shell has,

a first circular portion with no holes formed therein,

a first circumferential wall portion formed at an outer circumference of said first circular portion, said first circumferential wall portion having said gas discharge ports, and

a first flange portion extending radially outwardly at a free end of said first circumferential wall portion, and

said closure shell has,

a second circular portion,

a center hole formed at a center of said second circular portion,

a second circumferential wall portion formed at an outer circumference of said second circular portion, and

a second flange portion extending radially outwardly at a free end of said second circumferential wall portion,

said closure shell, together with said diffuser shell, forming a space therein, wherein said ignition device being installed in said center hole of said closure shell.

336. An inflator of claim 332, wherein said housing includes,

a cylindrical portion having said plurality of discharge ports, and

sidewall portions provided at both ends of said cylindrical portion, wherein said ignition device being installed in one of said sidewall portions.

337. An inflator of claim 332, wherein an inclined portion being inclined with respect to a center axis of the inflator is formed at an inner circumferential surface of said housing between an outer circumferential wall of said housing and said coolant/filter device.

338. An inflator of claim 332, wherein at least one of end faces of said coolant/filter device is secured to an inner surface of said housing by welding.

339. An inflator for an airbag comprising:

a housing having a plurality of gas-discharge ports;

an ignition device installed in said housing;

a gas-generating material installed around said ignition device, said gas generating material being a solid non-azide material ignitable by said igniter to produce combustion gas;

a coolant/filter device installed around said gas-generating material; and

a perforated basket disposed between said gas generating material and an inner circumferential surface of said coolant/filter device.

340. An inflator of claim 339, wherein said perforated basket is in contact with said gas generating material and said inner circumferential surface.

341. An inflator of claim 339, wherein said perforated basket has a plurality of through-holes defined therein.

342. An inflator of claim 341, wherein a size of each through-hole is determined such that said perforated basket prevents said non-azide gas generating material from directly contacting said inner circumferential surface.

343. An inflator of claim 340, wherein a total area of said through-holes is determined such that a pressure outside said perforated basket is maintained at substantially the same as a pressure inside said perforated basket when said non-azide gas generating material is generating gas.

344. An inflator of claim 339, further comprising:

a central cylinder member having flame through-holes defined therein installed in said housing, said central cylinder member forming an ignition device accommodating chamber, wherein said perforated basket includes a flame resisting plate portion disposed to face said flame through-holes in said central cylinder member and covering said inner circumferential surface, said flame through-holes being adapted to pass flames from said igniter to said combustion chamber.

345. An inflator of claim 344, wherein said flame resisting plate has a height of approximately 8-15 mm.

346. An inflator of claim 344, wherein said flame resisting plate extends at least 2 mm below said flame through-holes in said central cylinder member.

352. An inflator for an airbag comprising:

a housing having a plurality of gas-discharge ports;

an ignition device installed in said housing;

a gas-generating material installed around said ignition device, said gas generating material being a solid non-azide material ignitable by said igniter to produce combustion gas; and

a coolant/filter device installed around said gas-generating material, wherein the total area of said gas-discharge ports per volume of combustion gas generated within said inflator is in the range of 0.5 to 2.50 cm²/mol and the maximum internal pressure in said inflator is controlled thereby in a range of 100-300 kg/cm².

135. An inflator of claim 352, wherein said plurality of gas-discharge ports have one or two differing areas.

244. An inflator of claim 352, wherein a total of 12 to 20 such gas-discharge ports are arranged in said housing or in a separation wall, separating said ignition device and said gas-generating material, in a circumferential direction.

265. An inflator of claim 352, wherein said gas-discharge ports are sealed with a moisture prevention seal tape.

266. An inflator of claim 265, wherein said seal tape is an aluminum tape having a width 2 to 3.5 times the diameter of said gas-discharge ports and a thickness of 25-80 μ

m.

353. An inflator of claim 352, wherein each of said gas-discharge ports has an equivalent circle diameter of 2-5 mm.

354. An inflator of claim 352, wherein the total area of said gas-discharge ports per unit volume of generated gas is 1.00-1.50 cm²/mol and the maximum internal pressure during the operation is 130-180 kg/cm².

355. An inflator of claim 352, wherein an inner volume of the housing is 120 cc or less.

356. An inflator of claim 352, wherein the gas-generating material is a non-azide gas generating material whose linear combustion velocity is 30 mm/sec or less under a pressure of 70 kg/cm².

357. An inflator of claim 352, wherein said plurality of gas-discharge ports that control the combustion of said gas-generating material are provided in at least one of said housing and a separation wall, separating said ignition device and said gas-generating material, in the direction in which a gas produced by said gas-generating material stored in said housing flows into an airbag.