Denso Corporation

Junichi Wada

Kanechiyo Terada

Kazutoyo Osuka

Takashi Nagata

Atsuyuki Konishi

Masamichi Shibata

Kazuhide Kawai

Shunichi Takeda

Masataka Deguchi

Makoto Toriyama

Kaori Doi

Satoru Nakayama

Hironori Osamura

Norihiro Adachi

Yasuomi Imanaka

Masafuyu Sano

Hisaharu Morita

Hidekazu Fujimoto

Yuuki Tsukamoto

Naohisa Nakamura

Takehiro Torii

Junji Shirai

An ignition coil has primary and secondary coils, a central core and a pair of split cores. One of the split cores has a first opposing face orthogonal to a coil axial direction X facing a core front end face of the central core in the coil axial direction X. The respective split cores have second opposing surfaces mutually facing each other in a lateral direction Y at a rear end of the central core. At least one of the second opposing surfaces and one of rear end surfaces of the central core contacting the least one of the second opposing surfaces collectively constitute a pair of oblique surfaces and come to close to the other one of the second opposing surfaces in the lateral direction Y as a portion of each of the oblique surfaces recedes further from the first opposing face in the coil axial direction X.

Ignition coil

An ignition coil includes a center core, a first core member, and a second core member. The first core member includes a first core-facing portion facing a front core surface of the center core and a first core side portion extending rearward from the first core-facing portion. The second core member includes a second core-facing portion facing a rear core surface of the center core and a second core side portion extending frontward from the second core-facing portion. The first core-facing portion has an end surface contacting a portion of the second core side portion to create a first contact region. Similarly, the second core-facing portion has an end surface contacting a portion of the first core side portion to create a second contact region. The first and second contact regions are shaped to approach frontward close to the first core side portion. This structure enhances productivity of the ignition coil.

In a control apparatus, a discharge control unit controls an igniter unit so that a flow of current from a primary coil towards a ground side is blocked, thereby generating a high voltage in a secondary coil, and controls a spark plug so that the spark plug generates electric discharge. An energy input control unit controls an energy input unit so as to input electrical energy to an ignition coil after the start of control of the spark plug by the discharge control unit. A control unit and an abnormality detecting unit detects an abnormality in the igniter unit or the ignition coil based on a first threshold and a first current value that is a value corresponding to a current detected by a current detection circuit at this time, when a first predetermined period elapses after the start of control of the spark plug by the discharge control unit.

Control apparatus and ignition apparatus

In an ignition coil for an internal combustion engine, a resistor is disposed in a tower insertion hole of a high-voltage tower section. A coil spring is inserted in the tower insertion hole. An inner diameter of a proximal end side portion of the tower insertion hole is larger than an outer diameter of a maximum outer diameter portion of the resistor. An inner diameter of the distal end side portion of the tower insertion hole is larger than an outer diameter of a proximal end side portion of the coil spring, and is smaller than the outer diameter of the maximum outer diameter portion. In a state where the coil spring is pulled out from the tower insertion hole, the maximum outer diameter portion is restrained by the distal end side portion of the tower insertion hole, and a gap is formed between the resistor and a high-voltage cap.

Ignition coil for internal combustion engine

A spark plug includes a tubular housing, a tubular insulator retained in the housing, a center electrode secured in the insulator with a distal end portion of the center electrode protruding outside the insulator, and an annular ground electrode fixed to a distal end of the housing. The housing has, at the distal end thereof, a small-inner diameter portion that has a smaller inner diameter than other portions of the housing. The annular ground electrode is arranged on a distal end surface of the small-inner diameter portion of the housing so that an inner circumferential surface of the ground electrode faces an outer circumferential surface of the distal end portion of the center electrode through a spark gap formed therebetween. The outer diameter of the ground electrode is less than the outer diameter of the distal end surface of the small-inner diameter portion of the housing.

Spark plug for internal combustion engine and method of manufacturing spark plug

An ignition coil, which includes a primary coil and a secondary coil, has an electrical insulating member. The electrical insulating member includes an insulating material being a base material. The electrical insulating member further includes a reactive agent being an additive added to the insulating material for causing dehydration-decomposition, so as to enhance durability when being applied with high voltage. Alternatively, a reactive agent is coated on a surface of the electrical insulating body for causing dehydration-decomposition, so as to enhance durability when being applied with high voltage.

Insulating member

An ignition coil includes a coil body, a primary resin molded body, and a secondary resin molded body. The coil body has a primary coil and a secondary coil. The primary resin molded body has the coil body therein in a fixed relation, and the primary resin molded body has a plurality of exposed side portions that hold the coil body therebetween. The secondary resin molded body is molded to have the coil body and the primary resin molded body embedded therein. The secondary resin molded body is configured to allow the plurality of exposed side portions of the primary resin molded body to be exposed to an exterior of the secondary resin molded body.

Ignition coil and method for manufacturing the same

An ignition coil includes a primary coil (), a secondary coil () disposed on an outer circumferential side of the primary coil and configured to be boosted by mutual induction with the primary coil, an outer periphery core () having an opposing surface (), which is opposed to an outer peripheral surface () of the secondary coil, and an insulating member () disposed between the outer peripheral surface and the opposing surface. The secondary coil and the outer periphery core are arranged such that a shortest distance between the outer peripheral surface and an outer edge () of the opposing surface is larger than a shortest distance between the outer peripheral surface and the opposing surface.

An ignition coil comprises a housing, a rod-shaped center corearranged substantially at the center within the housing, a thermal stress relaxing membercovering the outer circumferential surface of the center core, a cylindrical spoolarranged on the outer circumferential side of the thermal relaxing memberwith a gapin between and a resin insulating materialwith which the gapis filled and which hardens. The thermal stress relaxing memberis wound around the center coreand the thickness of the thermal stress relaxing memberis set to a thickness so that the thermal stress, which is caused by the thermal deformation of the center coreand is applied to the resin insulating material, is reduced and reaches a saturation value thereof.

Ignition coil with optimized thermal stress relaxing member

An ignition coil ( ) having a case ( ), a core ( ) installed in the case, a primary spool ( ) disposed substantially coaxially around an outer circumference of the core within the case, a primary coil ( ) comprising a wire wound around the primary spool, a secondary spool ( ) disposed substantially coaxially around the outer circumference of the core within the case, a secondary coil ( ) comprising a wire wound around the secondary spool and a resin insulating material ( ) filled within the case, the ignition coil being characterized in that the spool of the primary and the secondary spools which is disposed between the secondary coil and the core and/or which is disposed between the secondary coil and the primary coil comprises a base resin having an adhesive strength to the resin insulating material which is less than that provided by polybutylene terephthalate and an insulation breakdown voltage which exceeds that provided by polyphenylene sulfide.

Internal combustion engine ignition coil, and method of producing the same

An ignition coil according to the invention is an ignition coil having a case and a coil portion accommodated in the case. The case comprises a base resin whose dielectric breakdown voltage exceeds that of polyphenylene sulfide and whose spiral flow length exceeds that of polybutyrene terphthalate. As the base resin has a high fluidity, there is only a limited risk that a defect such as a weld line is caused when molding a thin case. In addition, while the thickness of the case and the electrical insulation properties are in proportion to each other, the case comprising the base resin can ensure sufficient electrical insulation properties even if the case is formed thin.

Growing community of inventors

Kariya, Japan

Junichi Wada