JPS60122281A - Igniter of internal-combustion engine - Google Patents

Abstract

PURPOSE:To provide a small sized, light weight igniter by arranging a film capacitor around the outer wall of an amplifier case of an igniter of an internal- combustion engine. CONSTITUTION:A printed circuit 3 is placed on the inner bottom surface of an amplifier case 1 made of insulating resin and a square, hollow film capacitor 2 which has a size slightly smaller than the inner space of the outer wall of the amplifier case 1 and formed by winding dielectric film and a pair of metal foils is fitted along the outer wall of the amplifier case 1. The, an lead wire 4 fixed by evaporation is soldered to the printed circuit 3 and resin 7 is poured in the case 1 and hardened. In this way, the use of insulating material of a capacitor simple substrate can be eliminated and also efficient capacity is secured. Consequently, small sized igniter is obtained with low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a capacitor discharge type internal combustion engine ignition system.

(Prior Art) In a conventional device of this type, a large solid capacitor is housed in a case along with various electrical components.

However, while efforts are being made to make devices smaller and lighter, capacitors, which are the largest in size, have become the biggest bottleneck in increasing the packaging density of amplifiers.

Therefore, as described in Japanese Utility Model Application Publication No. 56-126829, a method has been considered in which a hollow film capacitor is mounted on the core of the ignition coil, and the primary and secondary coils are wound on top of the hollow film capacitor. However, since the diameter of the iron core is relatively small, the number of turns of the capacitor mounted on the iron core is large in order to obtain a given capacity, and the number of turns of the capacitor mounted on the core is large.
Next, not only does the number of turns of the secondary coil increase, but additional terminals must be provided on the ignition coil to connect the capacitor to various electrical components, which increases the size of the ignition coil and significantly increases costs. It has the disadvantage of being amplified.

(Object of the Invention) In order to eliminate the above-mentioned drawbacks, the present invention significantly reduces the size of the amplifier case by arranging a hollow film capacitor along the outer wall surface of the amplifier case that houses various electric circuit components. The purpose is to be able to reduce costs and reduce costs.

(Example) The present invention will be described below with reference to embodiments shown in the drawings.

In Figures 1 and 2, 1 is an amplifier case made of insulating resin, 2 is a film capacitor formed into a rectangular cavity by alternately wrapping a dielectric film and a pair of metal foils; is formed to be slightly smaller than the inner side of the outer wall surface of the case 1, and is arranged along the outer wall surface of the case 1. 3 is a printed wiring board, which is placed on the inner bottom surface of the case (■).

4 is a lead fixed by vapor deposition to a pair of metal foils of the capacitor 2, and is fixed by soldering to a wiring copper foil of a printed wiring board 3. Reference numeral 5 indicates various electric circuit components soldered to the printed wiring board 3, and reference numeral 7 indicates casting resin injected into the case 1 and hardened.

The overall configuration of the electric circuit is as shown in Figure 3, where 8 is the generating coil of the magnet generator, 9, 10° 11.12
is a diode, 13, 14.15 is a resistor, 16.17 is a cyrisk, 18 is a transistor, 19 is an ignition coil,
20 is a spark plug, and 21 is a signal coil. Various electrical components surrounded by two-dot chain lines are housed in a case l shown in FIG.

In the above configuration, when an output is generated in the generator coil 1 in the direction of the arrow in FIG.
A base current is supplied to the transistor 18, which makes the transistor 18 conductive and short-circuits the output of the generator coil 8. When this short circuit current exceeds a predetermined value, it is detected by the resistor 13.14, the cyrisk 16 becomes conductive, and the transistor 18
short circuit the base current of. As a result, transistor 1
8 is cut off, a high voltage is induced in the generator coil 8, and the capacitor 2 is charged by this high voltage. After that, an output voltage is generated in the signal coil 21, so that the thyristor ■
7 becomes conductive, and the charge in the capacitor 2 is transferred to the ignition coil 19.
By discharging through the primary side of the spark plug 20, a high voltage is generated on the secondary side, causing the spark plug 20 to generate an ignition spark.

Here, since the hollow film capacitor 2 is arranged along the outer wall surface of the case 1, a sufficient surface area (capacitance) can be secured with a small number of turns, and its insulation is also provided by the cast resin 7. Since the capacitor 2 can be secured, the insulating agent for the capacitor 2 alone can be eliminated, resulting in a compact and inexpensive configuration.

FIG. 4 shows another embodiment of the present invention, in which a hollow film capacitor 1 is embedded and integrally molded inside the case 1 using its insulating resin material, which allows for further miniaturization. .

According to the embodiment described above, the present invention is applicable to a device in which the output of the generator coil 8 is short-circuited by the transistor 18 in advance, and the capacitor +2 is charged by the high voltage induced in the generator coil 8 when the transistor is cut off. However,
The present invention can also be applied to a device in which the capacitor 2 is directly charged by the output generated by the generator coil 8.

(Effects of the Invention) As described above, in the present invention, since a hollow film capacitor is arranged along the outer wall surface of an amplifier case that houses electric circuit components, a sufficient surface area can be obtained as a capacitor with a small number of turns. Since the insulation can be secured by the molded resin inside the case or the insulating material of the case, it is possible to eliminate the need for an insulating agent for the capacitor itself, and it has the excellent effect of being able to be constructed in a small size and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the device of the present invention, FIG. 2 is a partially exploded perspective view of the main structure of the above embodiment, and FIG.
The figure is an electric circuit diagram showing the overall configuration of the above embodiment, and FIG. 4 is a longitudinal sectional view showing another embodiment of the apparatus of the present invention. ■...Case, 2...Capacitor, 5...Electric circuit components, 8...Generating coil, 17...Sirisk,
19...Ignition coil. Representative Patent Attorney Takashi Okabe Figure 1 Figure 3 Figure 1

Claims (1)

[Claims] (11) An internal combustion engine in which a capacitor is charged by the generated output of a generating coil of a magnet generator, and the charge in the capacitor is discharged via the primary coil of an ignition coil by conduction of a cyrisk. The ignition device includes an amplifier case that houses electric circuit components including the thyristor and the capacitor, the capacitor being a hollow film capacitor, and the capacitor disposed along the outer wall surface of the amplifier case. (2) The internal combustion engine ignition device according to claim 1, wherein the capacitor is embedded and integrally molded in the case using an insulating resin material.