Ignition coil for internal combustion engines

Patent metadata

Field	Value
Publication number	US-10796847-B2
Application number	US-201715485612-A
Country	US
Kind code	B2
Filing date	Apr 12, 2017
Priority date	Apr 13, 2016
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

An ignition coil for an internal combustion engine, provided with a primary coil, a secondary coil, a bobbin, a center core and a mold resin member. The primary coil and secondary coil are magnetically connected to each other. The primary coil is directly wound on the bobbin. The center core is disposed in close contact with the bobbin at an inner space thereof. The mold resin member has the primary coil, the secondary coil, the bobbin, and the center core embedded at the inner side thereof. The bobbin includes thermoplastic resin and dispersed phase particles which are dispersed in the thermoplastic resin. The dispersed phase particles being lower in elasticity than the thermoplastic resin.

First claim

What is claimed is:

1. An ignition coil for an internal combustion engine, the ignition coil comprising:
a center core;
a bobbin having an axial direction, a circumferential direction, a radial direction and an inner space extending in the axial direction, the bobbin being made of thermoplastic resin and dispersed phase particles dispersed in the thermoplastic resin, the dispersed phase particles being lower in elasticity than the thermoplastic resin and having the center core disposed in the inner space in close contact with the bobbin;
a primary coil directly wound around the bobbin in the circumferential direction;
a secondary coil magnetically connected to the primary coil; and
a mold resin member in which the primary coil, the secondary coil, the bobbin, and the center core are embedded in the inner space, wherein
the bobbin includes an elastomer layer on an outer circumferential surface of the bobbin and a skin layer disposed on the outer circumferential surface of the elastomer layer, in the radial direction, the skin layer being in direct contact with the primary coil that is disposed on the outer circumferential surface of the skin layer.

2. The ignition coil for an internal combustion engine according to claim 1 , wherein the dispersed phase particles are elastomer.

3. The ignition coil for an internal combustion engine according to claim 1 , wherein the thermoplastic resin is polybutylene terephthalate resin.

4. The ignition coil for an internal combustion engine according to claim 1 , wherein the thermoplastic resin is either polyphenylene sulfide resin or polyphenylene ether resin.

5. The ignition coil for an internal combustion engine according to claim 1 , wherein the bobbin has an elastomer content ratio in a range of 3 to 10 percent mass.

6. The ignition coil according to claim 1 , wherein the bobbin has a cross section having corners, when viewed in the axial direction.

7. An ignition coil for an internal combustion engine, the ignition coil comprising:
a center core;
a bobbin having an axial direction, a circumferential direction, a radial direction and an inner space extending in the axial direction and the center core disposed on the inner space in close contact with the bobbin;
a primary coil directly wound around the bobbin in the circumferential direction;
a secondary coil magnetically connected to the primary coil; and
a mold resin member in which the primary coil, the secondary coil, the bobbin, and the center core are embedded in the inner space,
wherein the bobbin includes an elastomer layer disposed on an outer circumferential surface of the bobbin and a skin layer disposed around the outer circumferential surface of the elastomer layer, the skin layer is in direct contact with the primary coil that is disposed on the outer circumferential surface of the skin layer, the elastomer layer being formed of cohered elastomer particles, and the skin layer being formed of thermoplastic resin and dispersed phase particles of elastomer which are dispersed in the thermoplastic resin, the cohered elastomer particles having a lower elasticity than the thermoplastic resin.

8. The ignition coil for an internal combustion engine according to claim 7 , wherein the bobbin has an elastomer content ratio in a range of 3 to 10 percent mass.

9. The ignition coil for an internal combustion engine according to claim 8 , wherein the thermoplastic resin is polybutylene terephthalate resin.

10. The ignition coil for an internal combustion engine according to claim 8 , wherein the thermoplastic resin is either polyphenylene sulfide resin or polyphenylene ether resin.

11. The ignition coil for an internal combustion engine according to claim 7 , wherein the thermoplastic resin is polybutylene terephthalate resin.

12. The ignition coil for an internal combustion engine according to claim 7 , wherein the thermoplastic resin is either polyphenylene sulfide resin or polyphenylene ether resin.

13. The ignition coil according to claim 7 , wherein the bobbin has a cross section having corners, when viewed in the axial direction.

Assignees

• Denso Corp

Inventors

• Kato Akihiro

Classifications

• H01F38/12 Primary

  Ignition, e.g. for IC engines · CPC title

• H01F2005/025

  wound on coaxial arrangement of two or more formers · CPC title

• H01F27/325

  Coil bobbins (formers for coils in general H01F5/02) · CPC title

• F02P3/02

  having inductive energy storage, e.g. arrangements of induction coils {(ignition coils structurally combined with sparking plugs F02P13/00; constructional details of ignition coils H01F38/12)} · CPC title