Ignition coil and method of assembly

Patent metadata

Field	Value
Publication number	US-9796165-B2
Application number	US-201414531407-A
Country	US
Kind code	B2
Filing date	Nov 3, 2014
Priority date	Dec 18, 2013
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

An ignition coil for delivering a spark-generating current to a spark plug includes a magnetically-permeable core; a primary winding disposed outward of the core; and a secondary winding disposed outward of the primary winding and inductively coupled to the primary winding. The secondary winding terminates at one end thereof in a low-voltage end and terminates at another end thereof in a high-voltage end. At least one of the low-voltage end of the secondary winding and the high-voltage end of the secondary winding is electrically connected directly to a terminal through an electrically conductive polymer.

First claim

We claim:

1. An ignition coil for delivering a spark-generating current to a spark plug; said ignition coil comprising:
a magnetically-permeable core;
a primary winding disposed outward of said core; and
a secondary winding disposed outward of said primary winding and inductively coupled to said primary winding, said secondary winding terminating at one end thereof in a low-voltage end and terminating at another end thereof in a high-voltage end;
wherein at least one of said low-voltage end of said secondary winding and said high-voltage end of said secondary winding is electrically connected directly to a terminal through an electrically conductive polymer;
wherein said terminal is a high-voltage terminal and said high-voltage end of said secondary winding is electrically connected directly to said high-voltage terminal through said electrically conductive polymer;
wherein said ignition coil further comprises a case defining an interior having an interior surface such that said core, said primary winding, and said secondary winding are received within said interior of said case, said interior surface defining a high-voltage recess therein such that said high-voltage end of said secondary winding, said high-voltage terminal, and said electrically conductive polymer are disposed within said high-voltage recess; and
wherein said ignition coil further comprises a secondary winding spool upon which said secondary winding is wound, said secondary winding spool having a high-voltage post extending therefrom such that said high-voltage end of said secondary winding is wrapped around said high-voltage post.

2. An ignition coil as in claim 1 wherein said high-voltage post is disposed within said high-voltage recess of said case.

3. An ignition coil as in claim 1 wherein said high-voltage post is steel, whereby said high-voltage end of said secondary winding wrapped around said high-voltage post forms an inductor which reduces RFI in use.

4. An ignition coil as in claim 2 wherein said high-voltage post includes a retention feature for preventing said high-voltage end of said secondary winding from sliding on said high-voltage post when said high-voltage post and said high-voltage end of said secondary winding are inserted into said high-voltage recess containing said electrically conductive polymer.

5. An ignition coil as in claim 4 wherein said retention feature is a step.

6. An ignition coil for delivering a spark-generating current to a spark plug; said ignition coil comprising:
a magnetically-permeable core;
a primary winding disposed outward of said core; and
a secondary winding disposed outward of said primary winding and inductively coupled to said primary winding, said secondary winding terminating at one end thereof in a low-voltage end and terminating at another end thereof in a high-voltage end;
wherein at least one of said low-voltage end of said secondary winding and said high-voltage end of said secondary winding is electrically connected directly to a terminal through an electrically conductive polymer;
wherein said terminal is a high-voltage terminal and said high-voltage end of said secondary winding is electrically connected directly to said high-voltage terminal through said electrically conductive polymer; and
wherein said ignition coil further comprises a case defining an interior having an interior surface such that said core, said primary winding, and said secondary winding are received within said interior of said case, said interior surface defining a high-voltage recess therein such that said high-voltage end of said secondary winding, said high-voltage terminal, and said electrically conductive polymer are disposed within said high-voltage recess, wherein said high-voltage recess comprises:
a first high-voltage recess compartment with said high-voltage end of said secondary winding and said electrically conductive polymer disposed therein;
a second high-voltage recess compartment with said high-voltage terminal and said electrically conductive polymer disposed therein; and
a high-voltage recess channel connecting said first high-voltage recess compartment to said second high-voltage recess compartment with said electrically conductive polymer disposed therein.

7. An ignition coil as in claim 6 wherein said high-voltage recess channel has a width that is narrower than said first high-voltage recess compartment and said second high-voltage recess compartment.

8. An ignition coil as in claim 6 wherein said electrically conductive polymer within said high-voltage recess channel acts as a resistor for reducing RFI in use.

9. An ignition coil as in claim 8 wherein said electrically conductive polymer within said high-voltage recess channel has a resistance between about 500 ohms and about 2000 ohms.

10. An ignition coil as in claim 3 further comprising an inductor within said high-voltage recess between said high-voltage end of said secondary winding and said high-voltage terminal which reduces RFI in use.

11. A method of assembling an ignition coil for delivering a spark-generating current to a spark plug, the ignition coil comprising a magnetically-permeable core, a primary winding disposed outward of said core, a secondary winding disposed outward of said primary winding and inductively coupled to said primary winding, said secondary winding terminating at one end thereof in a low-voltage end and terminating at another end thereof in a high-voltage end, a case defining an interior having an interior surface defining a high-voltage recess therein, and a secondary winding spool upon which said secondary winding is wound, said secondary winding spool having a high-voltage post extending therefrom; said method comprising:
providing an electrically conductive polymer;
using said electrically conductive polymer to directly electrically connect at least one of said low-voltage end of said secondary winding and said high-voltage end of said secondary winding to a terminal through said electrically conductive polymer, wherein said terminal is a high-voltage terminal and said high-voltage end of said secondary winding is connected directly electrically to said high-voltage terminal through said electrically conductive polymer;
dispensing said electrically conductive polymer within said high-voltage recess;
positioning said high-voltage end of said secondary winding within said high-voltage recess, wherein said step of positioning said high-voltage end of said secondary winding within said high-voltage recess is after said step of dispensing said electrically conductive polymer and includes positioning said high-voltage end of said secondary winding within said electrically conductive polymer; and
wrapping said high-voltage end of said secondary winding around said high-voltage post before said step of positioning said high-voltage end of said secondary winding within said high-voltage recess.

12. A method as in claim 11 wherein said step of positioning said high-voltage end of said secondary winding within said electrically conductive polymer includes positioning said high-voltage post within said electrically conductive polymer.

13. A method as in claim 11 wherein said high-voltage post is steel, said method further comprising using said high-voltage end of said secondary winding and said high-voltage post as an inductor to reduce RFI in use.

14. A method of assembling an ignition coil for delivering a spark-generating current to a spark plug, the ignition coil comprising a magnetically-permeable core, a primary winding disposed outward of said core, a secondary winding disposed outward of said primary winding

Assignees

• Delphi Tech Inc

Inventors

• Skinner Albert A
• Levers Jr Harry O
• Skinner Mary A
• Meza Marco

Classifications

• H01F38/12 Primary

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

• H01F41/04

  for manufacturing coils {(coils for transformer or inductances H01F27/28)} · 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

• B32B37/142

  Laminating of sheets, panels or inserts, e.g. stiffeners, by wrapping in at least one outer layer, or inserting into a preformed pocket · CPC title

• B32B2457/00

  Electrical equipment · CPC title