Denso Corporation

Norihito Fujiyama

Jyunichi Wada

Kengo Nakao

Kazutoyo Osuka

A primary coil of an ignition coil has a socket with a side wall having an opening, a center core having a body portion with a root located in the opening and a collar portion extending perpendicularly from the root, and a winding wound on the body portion while the socket catches start and end portions of the winding on respective winding start and end sides. The collar portion is held in the socket. The core is formed by compressing magnetic powder in two divided dies divided through dividing lines which extend along a diagonal line of a rectangle formed by projecting the collar portion on a plane perpendicular to a center axis of the core. The root on the diagonal line is exposed to the opening on the winding start side and is covered with the side wall on the winding end side.

Ignition coil with core formed of compressed powder

A housing of an ignition coil has an approximately rectangular shape. A central core is in parallel with both side surfaces of the housing. The peripheral core has a larger size than the central core in a direction of a height of the housing. A first and second side portions of the peripheral core are opposed to both axial end surfaces of the central core, respectively. A third and fourth side portions of the peripheral core interpose the central core, a primary coil and a secondary coil therebetween to magnetically connect the first side portion to the second side portion. A terminal treatment portion for electrically connecting the primary coil to an external electric power source is arranged above or below the first side portion of the peripheral core. The peripheral core is positioned off-center with respect to the central core in the direction of the height of the housing.

Ignition coil for internal combustion engine

An ignition coil is inserted into a plughole of an engine. The ignition coil includes a coil case accommodating a primary coil and a secondary coil, and extending to define a cylindrical mount portion on a high voltage side. The mount portion includes a high voltage terminal conductive with the secondary coil. A coil spring conducts the high voltage terminal with the sparkplug. A plug cap has a circumferential portion attached to the mount portion. The plug cap circumferentially surrounds the high voltage terminal, the coil spring, and the sparkplug. The mount portion has a substantially annular space communicating with an inner gap in the coil case, and charged with an infilling resin to have a first resin high voltage end located on the high voltage side with respect to a low voltage end of the circumferential portion of the plug cap on a low voltage side.

Ignition coil

An ignition coil includes a coil body, a connector, a coil case, a filling resin, and a vent groove. The coil body includes a primary coil, a secondary coil, and a center core. The secondary coil has a secondary spool and a secondary wire wound around the spool. The center core is provided on an inner peripheral side of the secondary spool. The connector is coupled with an end of the coil body. The connector has an aligning part adapted for centering the center core. An end of the secondary spool has a tubular shape adapted for engagement with an outer periphery of the aligning part. The vent groove is provided to facing surfaces of the aligning part and of the end of the second spool. The vent groove is adapted for releasing gas around the center core to an exterior of the secondary spool.

An ignition coil includes primary and secondary coils accommodated in a coil case extending to define a cylindrical mount portion on a high voltage side. The mount portion includes a high voltage terminal electrically connected with the secondary coil. A coil spring electrically connects the high voltage terminal with a sparkplug. An electrically insulative plug cap is attached to the mount portion. The coil spring has a low voltage end electrically connected with the secondary coil via the high voltage terminal. The coil spring has a high voltage end in contact with a terminal of the sparkplug. The coil spring has an intermediate portion between the low voltage end and the high voltage end. The plug cap has a spring support portion, which is partially defining the fitting hole and restricting the intermediate portion of the coil spring from being radially deformed.

Ignition coil having plug cap

An ignition coil includes primary and secondary coils. The primary coil includes a primary spool and a primary winding wound on the spool. The primary winding has a second winding layer wound around a first winding layer. The primary spool has first and second overhangs protruding radially outwardly from a first spool end portion of the primary spool. The first overhang is positioned away from the second overhang toward a second spool end portion. The first winding layer has a first winding end portion extending from the first winding layer through a space between the first overhangs, and being wound on the first spool end portion between the first and second overhangs. The second winding layer has a second winding end portion extending from the second winding layer between the first overhangs, and being wound on the first spool end portion between the first and second overhangs.

Ignition coil and method for manufacturing the same

A stick-type ignition coil comprises a coil part, an insulating ring-shaped terminal assembly and a control part. The coil part includes a central core, a primary coil and a secondary coil. The terminal assembly is press-fitted on the upper end part of a primary spool of the primary coil. The terminal assembly has a primary terminal for holding a pair of ends of the primary winding of the primary coil, and an on-voltage suppressing diode connected between the primary and the secondary windings. The control part includes an insulating upper case press-fitted on the terminal assembly and an igniter disposed in the upper case.

Stick-type ignition coil and terminal assembly therefor

An ignition coil is constructed of a center core, a primary coil, a secondary coil, and an outer circumferential core. The center core and the outer circumferential core are connected with each other via a first magnetoresistive member on one axial end side. The center core and the outer circumferential core are connected with each other via a second magnetoresistive member on the other axial end side. A permanent magnet is arranged in an axially central portion of the center core. A magnetic passage is formed of the center core, the permanent magnet, the first magnetoresistive member, the outer circumferential core, and the second magnetoresistive member. Magnetic flux generated by the primary coil is reduced through the first and second magnetoresistive members, and is reverse-biased by the permanent magnet.

Ignition coil having magnetic flux reducing inner structure

A small-diameter ignition coil includes a center core, a primary coil, a secondary coil, and a thin film tube. The primary and secondary coils are arranged on an outer circumferential side with respect to the center core. The thin film tube has a cylindrical shape. The thin film tube is arranged on an outer circumferential side with respect to one of the primary coil and the secondary coil that is arranged on an outer circumferential side with respect to the other of the primary coil and the secondary coil. The thin film tube is thermally resistive and electrically insulative. The thin film tube has wall thickness that is equal to or less than 0.35 mm. An electrically insulative resin is filled in a gap formed between the thin film tube and one of the primary coil and the secondary coil, which is radially adjacent to the thin film tube.

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Obu, Japan

Norihito Fujiyama