Gas generator for multi-stage air bag and air bag device
First Claim
1. A multistage gas generator for an air bag, comprising:
- a housing including a diffuser shell having a plurality of gas discharge ports formed in a circumferential outer wall thereof, and a closure shell attached to the diffuser shell;
a first combustion chamber and a second combustion chamber provided inside the housing, each of the first combustion chamber and the second combustion chamber accommodating gas generating agents which generate combustion gas that inflates the air bag;
a first ignition unit attached to the housing for directly igniting only the gas generating agent accommodated in the first combustion chamber;
a second ignition unit attached to the housing for directly igniting only the gas generating agent accommodated in the second combustion chamber;
an inner cylinder for accommodating the first ignition unit therein and having at least an open end opposing the diffuser shell; and
a lid made of an element independent from said inner cylinder and provided between the open end and the diffuser shell such that a first surface of said lid opposes the diffuser shell and a second surface thereof covers the open end, said lid being substantially flat and having no opening at least in a portion thereof where the lid covers the open end, wherein, said inner cylinder is provided eccentrically with respect to a center axis of said housing, and the first ignition unit and the second ignition unit are disposed in said housing eccentrically with respect to the center axis of said housing.
1 Assignment
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Accused Products
Abstract
There is provided a multistage gas generator for an air bag in which the entire size of a container is suppressed, a volume ratio of each combustion chamber can arbitrarily be adjusted. Ignition means 311 are respectively disposed in the combustion chambers 305 and 306 provided in a housing 303. At least one of the combustion chambers is provided inside an inner shell 304 disposed eccentrically with respect to the center axis of the housing 3. The respective ignition means are disposed eccentrically with respect to the center axis of the housing 3. Further, a communication hole which allows mutual communication between the combustion chambers is provided. An automatic ignition material (AIM) which is to be ignited and burnt by a transmitted heat is provided in either one of the combustion chambers. One or both of axial end surfaces of a cylindrical filter means 350 are formed as inclining end surfaces 351 which get narrower in the axial extending direction. A supporting member 353 for supporting the inclining end surfaces 351 of the filter means 350 which is expanded radially by passage of an activation gas is provided in the housing.
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Citations
72 Claims
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1. A multistage gas generator for an air bag, comprising:
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a housing including a diffuser shell having a plurality of gas discharge ports formed in a circumferential outer wall thereof, and a closure shell attached to the diffuser shell;
a first combustion chamber and a second combustion chamber provided inside the housing, each of the first combustion chamber and the second combustion chamber accommodating gas generating agents which generate combustion gas that inflates the air bag;
a first ignition unit attached to the housing for directly igniting only the gas generating agent accommodated in the first combustion chamber;
a second ignition unit attached to the housing for directly igniting only the gas generating agent accommodated in the second combustion chamber;
an inner cylinder for accommodating the first ignition unit therein and having at least an open end opposing the diffuser shell; and
a lid made of an element independent from said inner cylinder and provided between the open end and the diffuser shell such that a first surface of said lid opposes the diffuser shell and a second surface thereof covers the open end, said lid being substantially flat and having no opening at least in a portion thereof where the lid covers the open end, wherein, said inner cylinder is provided eccentrically with respect to a center axis of said housing, and the first ignition unit and the second ignition unit are disposed in said housing eccentrically with respect to the center axis of said housing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
a cylindrical filter unit for at least one of purifying and cooling an activation gas and including an inclining end surface formed at an end portion thereof to be narrower in an axial extending direction such that an interior angle with respect to an inner peripheral surface is an acute angle, and said housing is provided with a supporting member that opposes and contacts the inclining end surface.
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38. A multistage gas generator for an air bag according to claim 37, wherein the supporting member is an inner peripheral surface of the housing opposed to the inclining end surface.
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39. A multistage gas generator for an air bag according to claim 37, wherein
said supporting member is a filter unit supporting member disposed in the housing and said inclining end surface engages said filter unit supporting member. -
40. A multistage gas generator for an air bag according to claim 37, wherein at least one end portion of the filter unit is formed with an inclining end surface, and the supporting member is provided in the axial direction of the filter unit and on a side where the inclining end surface is formed.
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41. A multistage gas generator for an air bag according to claim 40, wherein
said lid is part of a retainer having an annular portion and an outer peripheral wall disposed in the housing on an axially opposite side of the inclining end surface of the filter unit, and an inner surface of the outer peripheral wall of the retainer is opposed to an outer peripheral surface of the filter unit. -
42. A multistage gas generator for an air bag according to claim 37, wherein said cylindrical filter unit has a self-contracting structure that prevents the filter unit from expanding in a radial direction thereof when the filter unit is pushed against an inner surface of the housing by pressure generated by combustion of the gas generating agents to prevent the combustion gas from passing between the supporting member and the inclining end surface.
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43. A multistage gas generator for an air bag according to claim 37, wherein
said lid is a portion of a retainer provided inside said housing and in contact with said cylindrical filter unit. -
44. A multistage gas generator for an air bag according to claim 1, wherein the gas generating agent provided inside the first combustion chamber and said second combustion chamber are different from each other in at least one of burning rate, composition, composition ratio, shape, and amount.
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45. A multistage gas generator for an air bag according to claim 1, further comprising:
a single filter unit provided inside said housing for at least one of purifying and cooling combustion gas generated by combustion of the gas generating agent disposed in said first combustion chamber and said second combustion chamber, and combustion gases generated in said first combustion chamber and said second combustion chamber pass through the single filter unit.
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46. An air bag apparatus, comprising:
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a gas generator for an air bag, an impact sensor for sensing an impact to actuate the gas generator, an air bag which is expanded by introducing thereinto gas generated by the gas generator, and a module case for accommodating the air bag, wherein the gas generator for the air bag is the air bag gas generator for the multistage type air bag described in claim 1 or 23.
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47. A multistage air bag apparatus, comprising:
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an air bag gas generator, including, a housing including a diffuser shell having a plurality of gas discharge ports formed in a circumferential outer wall thereof, and a closure shell attached to the diffuser shell;
a first combustion chamber and a second combustion chamber provided inside said housing, each of the first combustion chamber and the second combustion chamber accommodating gas generating agents which generate combustion gas that inflates the air bag, a first ignition unit for directly igniting only the gas generating agent accommodated in the first combustion chamber;
a second ignition unit for directly igniting only the gas generating agent accommodated in the second combustion chamber;
an inner cylinder for accommodating the first ignition unit therein and having at least an open end opposing the diffuser shell;
a lid made of an element independent from said inner cylinder and provided between the open end and the diffuser shell such that a first surface of said lid opposes the diffuser shell and a second surface thereof covers the open end, said lid being substantially flat and having no opening at least in a portion thereof where the lid covers the open end; and
a control unit including a first outputting portion and a second outputting portion for outputting activation signals to said first ignition unit and said second ignition unit through a first lead wire and a second lead wire, respectively, the first lead wire and the second lead wire including, at one end thereof, a first connector and a second connector provided with a first defining unit for selectively and electrically communicating the first outputting portion with the first connector, and the second outputting portion with the second connector, wherein said inner cylinder is provided eccentrically with respect to a center axis of said housing, and said first ignition unit and said second ignition unit are disposed in said housing eccentrically with respect to the center axis of said housing. - View Dependent Claims (48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59)
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60. A multistage gas generator for an air bag, comprising:
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a housing including a diffuser shell having a plurality of gas discharge ports formed in a circumferential outer wall thereof, and a closure shell attached to the diffuser shell;
a first combustion chamber and a second combustion chamber provided inside the housing, each of the first combustion chamber and the second combustion chamber accommodating gas generating agents which generate combustion gas that inflates the air bag;
a first ignition unit attached to the housing for directly igniting only a gas generating agent accommodated in the first combustion chamber;
a second ignition unit attached to the housing for directly igniting only a gas generating agent accommodated in the second combustion chamber;
an inner cylinder for accommodating the first ignition unit therein and having at least an open end opposing the diffuser shell;
a single retainer provided with a bent portion bent in an axial direction of said housing, and disposed inside the first combustion chamber such that the bent portion is in engagement with an outer circumferential surface of said inner cylinder; and
a cylindrical filter unit for at least one of purifying and cooling an activation gas and including an inclining end surface formed at an end portion thereof to be narrower in an axial extending direction such that an interior angle with respect to an inner peripheral surface is an acute angle, and said housing is provided with a supporting member that opposes and contacts the inclining end surface, wherein said inner cylinder is provided eccentrically with respect to a center axis of said housing, and the first ignition unit and the second ignition unit are disposed in said housing eccentrically with respect to the center axis of said housing, and wherein said cylindrical filter unit is provided with an inclining end surface at both ends thereof. - View Dependent Claims (61)
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62. A method of manufacturing a multistage gas generator for an air bag, comprising:
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providing a cylindrical housing including a diffuser shell provided with a plurality of gas discharge ports formed in a circumferential outer wall thereof, and a closure shell;
providing, within the housing, a first combustion chamber and a second combustion chamber, each of the first combustion chamber and the second combustion chamber accommodating gas generating agents which generate combustion gas that inflates the air bag;
providing, within the housing, a coolant for at least one of cooling and filtering combustion gas generated upon combustion of the gas generating agents;
providing first ignition means for directly igniting and burning only the gas generating agent accommodated in the first combustion chamber;
providing second ignition means for directly igniting and burning only the gas generating agent accommodated in the second combustion chamber;
providing, within the housing, a cylindrical member for accommodating the first ignition means therein, and having at least an open end opposing the diffuser shell;
providing, within the housing, a single retainer having a bent portion bent in an axial direction of said housing, and disposed inside the first combustion chamber such that the bent portion is in engagement with an outer circumferential surface of said cylindrical member;
providing a lid, made of an element independent from said inner cylinder, between the open end and the diffuser shell such that a first surface of said lid opposes the diffuser shell and a second surface thereof covers the open end, said lid being substantially flat and having no opening at least in a portion thereof where the lid covers the open end; and
attaching the closure shell to the diffuser shell by friction welding. - View Dependent Claims (63, 64, 65, 66)
providing a coolant inside the first combustion chamber; and
providing, inside the housing, a retainer between the diffuser shell and the open end of the inner shell, the retainer being adapted to contact the coolant to retain the coolant at a predetermined position.
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64. A multistage gas generator for an air bag, according to claim 62, wherein the bent portion of the single retainer engages with an outer circumferential surface of said inner cylinder.
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65. The method of manufacturing a multistage gas generator for an air bag according to claim 62, further comprising:
welding the inner shell to the closure shell by friction welding while the inner shell is provided eccentrically with respect to a center axis of the housing.
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66. The method of manufacturing a multistage gas generator for an air bag according to claim 62, further comprising:
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providing the closure shell having a flange portion provided with a positioning portion for mounting the gas generator to a module case, wherein the step of welding the diffuser shell further includes the step of, welding the diffuser shell to the closure shell while the closure shell is fixed at a predetermined position by positioning the closure shell with the positioning portion.
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67. A multistage gas generator for an air bag, comprising:
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a cylindrical housing including a diffuser shell provided with a plurality of gas discharge ports and a closure shell, said cylindrical housing containing a first combustion chamber therein;
an inner shell defining a second combustion chamber therein, said inner shell being provided inside the housing such that a center axis of said inner shell is eccentric with respect to a center axis of said housing;
a first gas generating agent provided inside the first combustion chamber and in direct contact with said inner shell;
a second gas generating agent, provided inside the second combustion chamber, for generating combustion gas that inflates the air bag;
a single coolant that cools combustion gas generated by combustion of at least one of said first gas generating agent and said second gas generating agent, said single coolant being provided within said housing such that an inner circumferential surface defines a first combustion chamber;
a first ignition unit for directly igniting and burning only the first gas generating agent; and
a second ignition unit for directly igniting and burning only the second gas generating agent.
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68. A multistage gas generator for an air bag, comprising:
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a cylindrical housing including a diffuser shell, provided with a plurality of gas discharge ports, and a closure shell, said cylindrical housing defining a first combustion chamber therein;
an inner shell defining a second combustion chamber therein, said inner shell being provided inside said housing such that a center axis of said inner shell is eccentric with respect to a center axis of said housing;
a first gas generating agent provided inside the first combustion chamber;
a second gas generating agent, provided inside the second combustion chamber, for generating combustion gas that inflates the air bag;
a first igniter provided inside the first combustion chamber;
a second igniter provided inside the second combustion chamber;
a transfer charge provided inside the first combustion chamber to be ignited by said first igniter and for igniting said first gas generating agent, said transfer charge generating a combustion product;
an inner cylinder provided within the first combustion chamber for accommodating said transfer charge therein, a center axis of said inner cylinder being eccentric with respect to the center axis of said housing and having a plurality of flame transferring holes provided in equal intervals for evenly distributing the combustion product, generated in said inner cylinder, into the first combustion chamber except in directions along an imaginary line that intersects with a center axis of the inner cylinder and the center axis of said housing for evenly igniting the first gas generating agent. - View Dependent Claims (70, 71, 72)
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69. A multistage gas generator for an air bag, comprising:
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a housing including a diffuser shell having a plurality of gas discharge ports formed in a circumferential outer wall thereof, and a closure shell attached to the diffuser shell;
a first combustion chamber and a second combustion chamber provided inside the housing, each of the first combustion chamber and the second combustion chamber accommodating gas generating agents which generate combustion gas that inflates the air bag;
first ignition means attached to the housing for directly igniting only the gas generating agent accommodated in the first combustion chamber;
second ignition means attached to the housing for directly igniting only the gas generating agent accommodated in the second combustion chamber;
an inner cylinder including a circumferential wall and accommodating the second ignition means therein, the circumferential wall having an opening portion; and
a shielding plate disposed outside the inner cylinder and opposing and spaced apart from the opening portion, the shielding plate preventing a combustion flame, generated in the combustion chamber provided outside the inner cylinder, from coming into direct contact with the opening portion.
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Specification