Stick-type ignition coil having improved structure against crack or dielectric discharge

• US 20050212636A1
• Filed: 05/26/2005
• Published: 09/29/2005
• Est. Priority Date: 02/14/1997
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nakase, Yoshimi, Chiba, Tomonari, Kawai, Kazuhide, Adachi, Norihiro
• Granted Patent: US 6,995,644 B2
• Time in Patent Office: Days
• US Class Current: 336/90
• CPC Class Codes: H01F 2038/122 with rod-shaped core
• CPC Class Codes: H01F 2038/125 with oil insulation
• CPC Class Codes: H01F 27/022 Encapsulation
• CPC Class Codes: H01F 27/325 Coil bobbins formers for coils in general H01F5/02
• CPC Class Codes: H01F 27/327 Encapsulating or impregnating encapsulating coil and core H01F27/022
• CPC Class Codes: H01F 38/12 Ignition, e.g. for IC engines

Abstract

A stick-type ignition coil have a central core, a cylindrical member, primary spool, primary coil, secondary spool, secondary coil, outer core and a resin insulator. The two longitudinal end corners and faces of the core are covered by respective buffer members. The inner circumferential corners of the outer core is supported by ring members. Some of the members disposed radially inside and other members disposed radially outside of the inside members are held slidably to each other in the ignition coil. The spools are made of resin containing a rubber in excess of 5 weight percent and reinforcing materials. The resin insulator contains a flexible material.

Claims

1. -13. (canceled)

14. An ignition coil for an engine comprising:

a rod-shaped core;

a primary coil and a secondary coil wound on an outer circumference of the rod-shaped core;

a primary spool having the primary coil wound thereon, and a secondary spool having the secondary coil wound thereon;

an outer core arranged around the outer circumferences of the primary coil and the secondary coil; and

a resin insulator filled around the rod-shaped core,

wherein at least one of the primary spool and the secondary spool has a flange formed at a longitudinal end portion thereof and extending radially beyond an outer circumference of the outer core to cover the longitudinal end portion of the outer core.

15. The ignition coil of claim 14, wherein:

the primary spool is arranged around an outer circumference of the secondary spool, and

the flange is formed in the primary spool at a low voltage side of the secondary coil.

45. The ignition coil of claim 14, wherein:

the flange is in contact with the longitudinal end portion of the outer core.

46. The ignition coil of claim 15, wherein:

the flange is in contact with the longitudinal end portion of the outer core.

47. The ignition coil of claim 46, wherein:

the resin fills a space between the primary coil and the outer core.

48. The ignition coil of claim 14, wherein:

the flange is spaced away from the longitudinal end portion of the outer core in a longitudinal direction of the outer core to leave a space between the flange and the end portion of the outer core.

49. The ignition coil of claim 48, wherein:

the resin insulator fills said space.

50. The ignition coil of claim 48, wherein:

the flange is in contact with a longitudinal end portion of the primary coil; and

the resin insulator fills a space between the primary coil and the outer core.

51. The ignition coil of claim 15, wherein:

the flange is spaced away from the longitudinal end portion of the outer core in a longitudinal direction of the outer core to leave a space between the flange and the end portion of the outer core.

52. The ignition coil of claim 51, wherein:

the resin insulator fills said space.

53. The ignition coil of claim 51, wherein:

the flange is in contact with a longitudinal end portion of the primary coil; and

the resin insulator fills a space between the primary coil and the outer core.

58. The ignition coil of claim 51, wherein:

the flange is in contact with a longitudinal end portion of the outer core.

59. The ignition coil of claim 51, wherein:

the flange radially extends beyond an outer circumference of the outer core.

60. The ignition coil of claim 14, wherein:

each of said primary and secondary spools has a radially extending flange, the flange of the radially outer one of said spools extending to cover the outer core and the flange of the radially inner one of said spools radially extends to cover at least an inner circumferential corner portion of the radially outer one of said spools.

16. -44. (canceled)

54. An ignition coil for an engine comprising:

a rod-shaped core;

a primary coil and a secondary coil wound on an outer circumference of the rod-shaped core;

a primary spool having the primary coil wound thereon, and a secondary spool having the secondary coil wound thereon,

an outer core arranged around the outer circumferences of the primary coil and the secondary coil; and

a resin insulator filled around the rod-shaped core;

wherein the primary spool has a flange formed at a longitudinal end portion thereof and extending radially to cover at least an inner circumferential corner portion of the longitudinal end portion of the outer core.

55. The ignition coil of claim 54, wherein:

the flange is formed at a low voltage side of the secondary coil.

56. The ignition coil of claim 54, wherein:

the resin fills a space between the primary coil and the outer core.

57. The ignition coil of claim 54, wherein:

the flange is spaced away from the longitudinal end portion of the outer core in a longitudinal direction of the outer core to leave a space between the flange and the end portion of the outer core; and

the resin insulator fills said space.

61. The ignition coil of claim 54, wherein:

the secondary spool has a flange formed at a longitudinal end portion thereof and the flange of the secondary spool radially extends to cover at least an inner circumferential corner portion of the primary spool.

62. The ignition coil of claim 61, wherein:

the flange of the primary spool radially extends beyond an outer circumference of the outer core.