Ignition coil for internal combustion engine

Patent metadata

Field	Value
Publication number	US-9548156-B2
Application number	US-201615002805-A
Country	US
Kind code	B2
Filing date	Jan 21, 2016
Priority date	Jan 21, 2015
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

An ignition coil for an internal combustion engine includes a wire-wound resistor. The wire-wound resistor includes a core material, a conductor winding, a pair of metal caps disposed at both ends of the core material, the pair of metal caps in contact with the conductor winding, and a resin coating material disposed so as to be in close contact with the core material and the conductor winding. The resin coating material is filled between the conductive winding and the resin coating material is formed to cover the conductor winding from an outer peripheral side of the conductor winding The metal cap includes a bottom portion and a cylindrical side portion. An inner peripheral side of the side portion is provide with ridges projecting internally formed along a direction crossing a winding direction of the conductor winding.

First claim

What is claimed is:

1. An ignition coil for an internal combustion engine comprising:
a coil body formed by accommodating a primary coil and a secondary coil within a body case having an insulating property;
a high-voltage tower formed by disposing a high-voltage output terminal that is electrically connected to the secondary coil as well as projecting from the coil body towards a tip side of the coil body inside the high-voltage tower; and
a wire-wound resistor constituting at least a part of a conductive path from the high-voltage output terminal to a spark plug; wherein,
the wire-wound resistor includes an insulating core material, a conductor winding wound spirally on an outer periphery of the core material, a pair of metal caps disposed at both ends in an axial direction of the core material, the pair of metal caps contacting with the conductor winding, and a resin coating material disposed so as to be in close contact with the core material and the conductor winding;
the resin coating material is filled between the conductive winding in the axial direction and the resin coating material is formed to cover the conductor winding from an outer peripheral side of the conductor winding;
the metal cap includes a bottom portion that faces the core material in the axial direction, and a cylindrical side portion protruding from an outer peripheral edge of the bottom portion in the axial direction; and
an inner peripheral side of the side portion is provided with ridges projecting internally formed along a direction crossing a winding direction of the conductor winding.

2. The ignition coil for the internal combustion engine according to claim 1 , wherein,
the ridge has a shape such that a projecting height decreases as it goes farther from the bottom portion.

3. The ignition coil for the internal combustion engine according to claim 1 , wherein,
each of the metal caps is provided with three or more ridges disposed at equal intervals in a circumferential direction.

4. The ignition coil for the internal combustion engine according to claim 2 , wherein,
each of the metal caps is provided with three or more ridges disposed at equal intervals in a circumferential direction.

Assignees

• Denso Corp

Inventors

• Kawai Kazuhide

Classifications

• H01F27/24

  Magnetic cores · CPC title

• H01F38/12 Primary

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

• H01F27/327

  Encapsulating or impregnating (encapsulating coil and core H01F27/022) · CPC title

• H01F27/29

  Terminals; Tapping arrangements {for signal inductances} · CPC title

• H01T15/00

  Circuits specially adapted for spark gaps, e.g. ignition circuits (ignition circuits for internal-combustion engines F02P; electric spark ignition for combustion apparatus F23Q; protection circuits using spark gaps H02H9/06) · CPC title