Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Denki Kabushiki Kiasha

Tomokazu Umezaki

Shinji Baba

Fumito Uemura

Nobuyuki Sawazaki

Tadao Takaishi

Yoshihide Masumoto

An internal combustion engine ignition coil apparatus includes: a case; a center core disposed in the case; a primary coil and a secondary coil disposed outside the center core inside the case; a high-voltage cord having: a first end portion electrically connected to the secondary coil; and a second end portion electrically connected to a spark plug; and a protective tube covering an outer peripheral surface of the high-voltage cord, a rim portion projecting away from a high-voltage terminal being formed so as to surround an insertion aperture in a bottom portion of the case, and a leading end portion of the protective tube covering and elastically engaging with the rim portion, wherein: a receiving portion having a radially-outwardly-projecting V-shaped cross-sectional shape when sectioned axially is formed on an end portion of the rim portion.

Internal combustion engine ignition coil apparatus

An ignition coil apparatus for an internal combustion engine can suppress an increase in the manufacturing cost of a terminal of a low-tension side connector resulting from variation in a wire diameter of an one end of a primary winding, and can ensure a stable fusing state. The positive terminal side fusing portion is composed of a planar portion and a turned portion that is inversely turned back from the planar portion to cooperate therewith to clamp a winding start conductor portion. A first bent portion of a radius of curvature R is formed at a base end portion of the turned portion. A second bent portion with its tip end tilted toward a planar portion is formed at an intermediate portion of the turned portion.

Ignition coil apparatus for an internal combustion engine

A magneto-generator, a method of manufacturing the same and a resin molding die for manufacturing the same. In the magneto-generator, a guard ring is omitted with the performance of the magneto-generator being enhanced. The magneto-generator is manufactured by making use of a resin molding die () having an outer peripheral surface () to be positioned in opposition to an inner peripheral surface of a flywheel () and projections () provided in the outer peripheral surface () for holding a plurality of magnets () at predetermined positions, respectively. The magnets () are positioned and held stationarily at predetermined positions by the aforementioned projections, respectively, and spaces defined between the resin molding die () and the inner peripheral surface of the flywheel () are filled with a resin. After hardening of the resin, the resin molding die () is detached from the flywheel ().

Method of manufacturing a magneto-generator

Magneto-generator, method of manufacturing the same and resin molding die assembly for manufacturing the same

Power generation efficiency of a magneto generator is improved. A guard ring made of a material of high magnetic permeability such as carbon steel plate is arranged inside a flywheel for the purpose of holding and guarding magnets . the guard ring is provided with opening portions at positions where the guard ring coincides with adjacent two end portions of the neighboring magnets . Magnetic flux is prevented from flowing into the neighboring magnets 12 through the guard ring at the time of power generation. The magnetic flux flows into an iron core of a magneto coil , and generation efficiency is effectively improved.

Magneto generator

Ventilation efficiency inside a flywheel is improved. Plural vent holes are formed on a side wall portion of a flywheel formed by a circumferential wall portion and the side wall portion on one end side of the circumferential wall portion, and fins protruding toward inside of the flywheel are formed between the neighboring vent holes The fins are formed integrally at the time of filling with a resin with which a space between a guard ring for guarding plural magnets arranged inside the circumferential wall portion of the flywheel and the flywheel is filled, and the magnets are embedded in the resin In generating electric power, the fins rotate synchronously with the flywheel a negative pressure is generated at the vent hole portions, and outside air is introduced into the flywheel and ventilation is performed.

An ignition coil unit for an internal combustion engine comprising a magnetic iron core, a primary coil wound around the iron core, a secondary coil electromagnetically coupled with the primary coil, a control circuit for controlling a primary electric current, and a case containing the iron core, the primary coil, the secondary coil and the control circuit therein. The ignition coil unit may further comprise a heat sink attached to the iron core, and the mold case may contain and integrally support the iron core and the heat sink, with at least part of the heat sink exposed to exterior of the mold case. The mold case defines a cavity containing therein the primary coil and the secondary coil wound around the iron core, and the space around the primary and second coils within the cavity is filled by a resin material.

Ignition coil unit for an internal combustion engine

Ignition coil for internal combustion engine

A high-voltage transformer is provided which includes a primary coil and a secondary coil disposed in a coil case, and a support member attached to the coil case and having a high-voltage terminal for electrically connecting a lead wire of the secondary coil with an external electrical device. The primary and secondary coil are first accommodated in the coil case, and the lead wire of the secondary coil is temporarily connected with the high-voltage terminal while the support member is separated from the coil case and freely moved to an appropriate location. Then, the lead wire of the secondary coil thus temporarily connected is soldered to the high-voltage terminal. Thereafter, the support member having the high-voltage terminal thus soldered to the secondary coil lead wire is attached to the coil case. Finally, a resin is filled into the coil case so as to firmly secure the primary and secondary coils and the support member to the coil case.

Method of making a high-voltage transformer

A housing structure of an ignition coil assembly for an internal combustion engine is disclosed, in which the coil assembly and the igniter are accommodated in a single casing. The coil assembly is wound around a leg of a rectangular core having a yoke portion running parallel to it. The casing accommodates the coil assembly and the leg of the core carrying it, leaving exposed to the outside the yoke of the core; a space is formed between a side of the coil assembly and a side wall of the casing. A plate-shaped heat sink abutting on the yoke of the core at its lower end extneds witin the casing between the coil assembly and the casing through said space, forming within the space a hollow receptacle between opposing surfaces of the coil assembly and the casing. The igniter is mounted to the heat sink within the hollow receptacle. The housing structure is attached to the body of an automobile, etc., at a surface of the heat sink abutting on the yoke of the core.

Ignition coil assembly structure for an internal combustion engine

In a high-voltage transformer such as an ignition coil for internal combustion engines, a resin-crack preventing member is provided between an iron core and a resin which is impregnated into a coil case for electrically insulating a primary coil and a secondary coil in the coil case from the iron core as well as for firmly securing these coils and the iron core to the coil case. The resin-crack preventing member is moulded from a resinous material which is highly adhesive to the impregnated resin and which has a coefficient of thermal expansion similar to that of the impregnated resin. The resin-crack preventing member serves to prevent direct contact of the impregnated resin with the corners, side surfaces and inner surface of the iron core which has a coefficient of thermal expansion substantially different from that of the impregnated resin, thereby avoiding peeling off and cracking in the impregnated resin which would otherwise be caused by severe temperature changes. As a result, degradation of the electrical insulation of the transformer is effectively prevented.

Resin-crack prevented high-voltage transformer

An ignition coil have a secondary winding wound on and around a secondary bobbin, have one end of the secondary winding connected to a high voltage terminal, and have a portion of the secondary winding close to the connected end engaged with a binding portion formed on a circumferential edge of one end of the secondary bobbin, wherein the binding portion comprises a winding piece which projects outwardly in the radial direction of the secondary bobbin and around which an end portion of the secondary winding is wound in several turns, and an engaging piece which is formed to extend from the leading edge of the winding piece along the central axis of the secondary bobbin and which has a side surface formed with a groove for inserting the secondary winding for clipping.

Growing community of inventors

Tokyo, Japan

Tomokazu Umezaki