Ignition coil for vehicle
View Patent ↗A spark plug coil assembly has a primary core bearing primary windings and a secondary winding spool around which secondary windings are wound and in which the primary core is received. A case receives the spool with core. The entire case can be made of composite Iron to function as a magnetic return path for the core, or a composite Iron shield can be overmolded to an otherwise plastic case.
1. Spark plug coil assembly comprising:
a primary core bearing primary windings;
a secondary winding spool around which secondary windings are wound, the primary core being received in the spool; and
a case defining an exterior portion of the spark plug coil assembly and receiving the spool and core, the case being made of a composite comprising both Iron and one of thermoplastic and fiberglass to function as a magnetic return path for the core.
2. The assembly of claim 1 , wherein the core is made of composite Iron or laminated Iron.
3. The assembly of claim 1 , wherein the assembly has no magnetic shield inside or outside of the case.
4. The assembly of claim 1 , wherein the core is integrally formed with a pole piece on an end of the core.
5. The assembly of claim 1 , wherein the core is press fit into a depression of the case.
6. The assembly of claim 1 , wherein the entire case is 40%-70% by volume Iron particles injection molded into the thermoplastic.
7. The assembly of claim 1 , wherein the case is formed with a bottom and a wall orthogonal to the bottom, and the bottom is thicker than the wall.
8. The assembly of claim 7 , wherein the bottom is formed with an opening through which a portion of a high voltage tower is pressed.
9. Spark plug coil assembly comprising:
a primary core bearing primary windings;
a secondary winding spool around which secondary windings are wound, the primary core being received in the spool;
a case receiving the spool and core, the case being made of electrically insulative material; and
a shield overmolded to the case, the shield being made of a composite comprising both Iron and one of thermoplastic and fiberglass to function as a magnetic return path for the core.
10. The assembly of claim 9 , wherein the core is made of composite Iron or laminated Iron.
11. The assembly of claim 9 , wherein the core is integrally formed with a pole piece on an end of the core.
12. The assembly of claim 9 , wherein the entire shield is 40%-70% by volume Iron particles injection molded into the thermoplastic.
13. The assembly of claim 9 , wherein the case is formed with a bottom and a wall orthogonal to the bottom, and the bottom is thicker than the wall.
14. The assembly of claim 11 , wherein the pole piece is not radially symmetric about the longitudinal axis of the primary core.
15. The assembly of claim 9 , wherein the shield does not completely surround the spool.
16. Method comprising:
providing a primary core bearing primary windings and a secondary winding spool around which secondary windings are wound, the primary core being received in the spool; and
at least partially surrounding the spool and core with one and only one member, the one and only one member being made of a composite comprising both iron and one of thermoplastic and fiberglass to provide a magnetic flux return path for the core.
17. The method of claim 16 , wherein the member is a case holding the spool and core.
18. The method of claim 16 , wherein the member is a shield overmolded to a case holding the spool and core.
19. The method of claim 16 , wherein the member is 40%-70% by volume Iron particles injection molded into the thermoplastic.
20. The method of claim 16 , wherein the core is made of compression molded composite Iron or laminated Iron.