Ignition coil for internal combustion engine

• US 9,548,156 B2
• Filed: 01/21/2016
• Issued: 01/17/2017
• Est. Priority Date: 01/21/2015
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Kawai, Kazuhide
• Primary Examiner(s): NGUYEN, TUYEN T
• Application Number:
  US15/002,805
• Publication Number:
  US 20160211072A1
• Time in Patent Office: 362 Days
• Field of Search: 336/65, 336/107, 336/192, 336/198, 336220-223, 123/634
• US Class Current: 1/1
• CPC Class Codes: F02P 13/00 Sparking plugs structurally combined with other parts of internal-combustion engines connection of ignition coil to spark plug connector F02P3/02; with fuel injectors F02M57/06 ; spark plug connector per se H01T13/04 – H01T13/06; predominant aspects of sparking plug, see H01T13/40 – H01T13/44
• CPC Class Codes: F02P 3/02 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 Class Codes: H01F 27/24 Magnetic cores
• CPC Class Codes: H01F 27/29 Terminals; Tapping arrangements for signal inductances
• 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
• CPC Class Codes: H01T 13/04 Means providing electrical connection to sparking plugs
• CPC Class Codes: H01T 15/00 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

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.

Claims

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.