JPS6131308B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-contact ignition device, and more particularly to a non-contact ignition device in which a signal amplification section is constructed of a hybrid integrated circuit.

Conventionally, there have been various types of structures in which a non-contact ignition device is attached to an ignition coil and integrated with the ignition coil. For example, US Patent No. 3260299 and 3395684
3902471 and 3941112. However, there are very few products that are integrated with a molded ignition coil, and when integrated with a molded ignition coil, it is difficult to effectively dissipate heat generated from the circuit and protect the circuit from high electric fields. is an absolute condition.

An object of the present invention is to provide a contactless ignition device that satisfies the above conditions so as to be integrated with a molded ignition coil.

The present invention connects a hybrid integrated circuit and a power transistor chip onto a single metal plate via a ceramic substrate, and connects the metal plate to a metal case that becomes a heat dissipation fin with a conductive adhesive, thereby forming the heat dissipation fin. By setting the metal case at the same potential as the ground potential of the hybrid integrated circuit, heat dissipation from the hybrid integrated circuit and the power transistor is improved, and at the same time, charging of the metal case, which serves as a heat dissipation fin, is prevented.

FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a side view, and FIG. 3 is a plan view.

The ignition device includes an ignition coil 1, an amplifier 2, a casing 3, mounting stays 4a, 4b, screws 5, spring washers 6, nuts 7, washers 8, lead wires 10a, 10b, 10c, shield wires 11,
It is composed of 12 bullets.

The outside of the ignition coil 1 is molded from synthetic resin, and a seat 1A for mounting the amplifier 2 is provided in a part of the coil. On the other hand, a casing 3 is provided for housing the amplifier 2, and a protrusion 3f is provided so as to surround the amplifier 2. A groove 1s that fits into this protrusion 3f is provided in the seat of the ignition coil 1, so that the casing 3 is integrated with the boss portion 1a of the ignition coil 1 when it is attached to the boss portion 1a of the ignition coil 1 with a countersunk screw 13 as shown in FIG. ing. In this case, an adhesive or a sealing member is placed in the groove 1s to maintain airtightness between the groove 1s and the protrusion 3f. Stays 4a and 4b for attachment to the vehicle body are attached to the ignition coil 1 using screws 5, spring washers 6, nuts 7, and washers 8. Further, lead wires 10a and 10b from the amplifier 2 are connected to terminals 1b and 1c attached to the ignition coil 1, respectively.
Connect to. A shielded wire 11 is used for connection to a non-contact pickup (not shown).

As shown in FIGS. 1 and 2, the casing 3 is
It is divided into a housing part for the amplifier 2 and a box part 3B for housing a group of lead wires. The casing 3 has a structure in which the entire surface is in contact with the casing surface of the ignition coil 1,
A box portion 1B is provided corresponding to the box portion 3B.
In this case, the box portion 3B is placed at a position away from the high-voltage line lead-out terminal, as shown in FIG.
By doing so, it is possible to prevent spark voltage from entering the pickup lead from the high voltage line. The lead wires 10a, 10b, 10c (earth wires) and the shield wire 11 are drawn out in opposite directions as shown in FIG. 1 to reduce the storage space. Since the box parts 3B and 1B are provided at the mounting base where the ignition coil 1 is least used, storage space for other equipment is not taken away.

FIG. 4 is an assembled front view showing the amplifier 2 housed in the casing. 5 is a sectional view of the embodiment shown in FIG. 4, and FIG. 6 is a sectional view of the embodiment shown in FIG.
FIG. 3 is a cross-sectional view of the embodiment shown in FIG.

The hybrid integrated circuit 13 is composed of a ceramic substrate 20, a monolithic IC 21, a thick film resistor, and the like. Further, a power transistor chip 22 is constructed on a ceramic substrate 23 with molybdenum 24 interposed therebetween. The hybrid integrated circuit 13 and the power transistor chip 22 are connected by bonding wires 25. The ceramic substrates 20, 23 are bonded onto a copper base 26, which is connected to the ground of the hybrid integrated circuit 13 by a ground connection wire 27 and maintained at the same potential. The copper base 26 is glued to the casing 3 by a conductive adhesive 28. Therefore, the casing 3 is at the same potential as the ground potential of the hybrid integrated circuit 13. The material of the casing 3 is aluminum die-casting, which is a good conductor of heat, and a protrusion 1s is provided all around the inside of the countersink 3d, and the hybrid integrated circuit 13 is mounted inside the casing 3 surrounded by the protrusion 1s. Hybrid integrated circuit 13
are connected by connection terminals 16 as shown in FIGS. 4 and 6. The connection terminal 16 is taken out by passing through the bush 17. The bush 17 is made of a highly elastic material such as rubber, and a portion thereof has a protrusion that matches the protrusion 3f of the casing 3, into which the lead wire 10a is inserted and soldered to the terminal 16. Further, the bush 18 is for drawing out the shielded wire 11 to the outside and is made of an insulating material.

As shown in FIG. 5, the copper base 26 and caning 3
By connecting them with a conductive adhesive 28, a thin copper base 26 can be used. Further, since the conductive adhesive 28 has a low thermal resistance, the heat generated by the hybrid integrated circuit 13 and the power transistor chip 22 can be efficiently conducted to the casing 3. As a result, thermal deterioration and destruction of each element can be prevented. Furthermore, since the potential of the casing 3 and the ground potential of the hybrid integrated circuit 13 are at the same potential, the hybrid integrated circuit can be protected from flashover of the ignition coil 1. Furthermore, since the casing 3 is at ground potential, the casing 3 will not be charged to a high potential due to the high electric field generated near the ignition coil 1, and in this respect as well, the hybrid integrated circuit can be protected. .

As is clear from the above, according to the present invention, the conditions for integrating a hybrid integrated circuit including a molded ignition coil and a power transistor chip with a simple structure are met, namely, more effective heat dissipation and protection from high electric fields. Sufficient protection can be ensured, and thereby the molded ignition coil and the ignition device can be reliably integrated.

[Brief explanation of the drawing]

FIG. 1 is a front view of the embodiment of the present invention, FIG. 2 is a side view of the embodiment of FIG. 1, FIG. 3 is a plan view of the embodiment of FIG. 1, and FIG. 4 is an amplifier according to the present invention. 5 is a plan view of the amplifier shown in FIG. 4, and FIG.
FIG. 6 is a cross-sectional view of the amplifier shown in FIG. 4. 2... Amplifier, 3... Casing, 13... Hybrid integrated circuit, 20, 23... Ceramic substrate, 21... Monolithic IC, 22... Power transistor chip, 26... Copper base, 27... Earth connection wire,
28...Conductive adhesive.

Claims (1)

[Claims] 1. An ignition coil integrally molded with synthetic resin, a metal container attached to a side surface of the molded ignition coil, and an amplifier housed in a space surrounded by the side surface of the molded ignition coil and the metal container. A non-contact ignition device comprising: a hybrid integrated circuit in which a signal amplification section for shaping the waveform of an ignition signal generated in synchronization with engine rotation and amplifying it to a predetermined value is integrated on a first ceramic substrate; and a power transistor chip which is formed on a second ceramic substrate and cuts off the primary current of the ignition coil based on the output signal of the hybrid integrated circuit, and these are formed on a common metal plate. In the non-contact ignition device housed in the metal container; the metal plate and the ground of the hybrid integrated circuit are connected to have the same potential, and the metal plate is attached to the metal container with a conductive adhesive. A non-contact ignition device characterized by being fixed.