Mitsubishi Denki Kabushiki Kaisha

Takafumi Narishige

Mitsuru Koiwa

Shingo Morita

Takeshi Shimizu

Shigemi Murata

Yutaka Ohashi

Nobuyuki Sawazaki

A plurality of ignition coils and a plurality of switching assemblies are accommodated in one case, and a wire harness which interconnects the winding, connectors, and the switching assembly is formed as a unit using a plurality of conductors by means of a resin. In addition, respective electrical connections are established by welding, and soldering is disused. Thereby, it is provided an ignition device in which troublesome wiring between a coil and a switching assembly is eliminated and the reliability of electrical connections is improved, and which is compact and lightweight.

Ignition coil for internal combustion engine

The purpose of the present invention is to obtain a low-cost and easy-to-produce ignition coil for an internal combustion engine. A lead wire 13a of an electronic part 13 is connected to a terminal 12a and a terminal 7a of an intermediate conductor 12 by means of caulking or press fitting. Since the end cut face of the lead wire 13a of the electronic part 13 is sharp, a wall material 71 and a cover 81 as crack spread preventing materials are arranged so as to encircle that end cut face. Further, an opening portion 92 is closed by the intermediate conductor 12, and high voltage is output via a spring 11 directly contacted to the intermediate conductor 12. The number of components may thus be reduced, and cracks generating in an insulating resin may be prevented from spreading.

A capacitor discharge ignition device for an internal combustion engine includes a booster coil 21 and a transistor 22 for generating a boosted voltage; a circuit 15A for generating a switching signal for the transistor in response to an ignition signal; first and second condensers 7, 8 for charging with the boosted voltage; an ignition coil 10 to whose secondary a spark plug is connected; a thyristor 13 forming a first closed discharge circuit with the first condenser and the ignition coil primary, which is turned on in synchronism with the ignition signal; and an inductor 9 forming a second closed circuit with the second condenser, the ignition coil primary and the thyristor. The discharge energy of the second condenser stored in the inductor is supplied to the ignition coil primary to extend the discharge time at the spark plug. A delay circuit 16 prevents the transistor from turning on during the extended discharge time, thus establishing a third closed inductor discharge path through the booster coil.

Capacitor discharge ignition system with inductively extended discharge

An LCDI-type ignition apparatus for an internal combustion engine includes first and second capacitors connected to an ignition coil and a voltage source for generating a charging voltage for the capacitors. The first capacitor is for producing an initial discharge of a spark plug, and the second capacitor is for lengthening the discharge of the spark plug after discharge has been initiated by the first capacitor. In one form of the invention, the second capacitor is charged only after the first capacitor has been charged by the voltage source to a prescribed voltage sufficient to produce a suitable discharge of the spark plug. As a result, even when the engine is operating at a high rotational speed and the time between consecutive firings of the engine is small, an adequate ignition voltage can be obtained. In another form of the invention, the charging voltage(s) of one or both of the capacitors is or are varied in accordance with the one or more engine operating conditions. Each charging voltage can be controlled to the minimum necessary value based on the present engine operating conditions.

Growing community of inventors

Himeji, Japan

Takafumi Narishige