JPH0693944A - Ignition device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve resistance of leak from a high pressure distributing part to the head part of a screw. CONSTITUTION:An ignition device for an internal combustion engine comprises a central electrode 13 arranged at the central part of a cap 2, a drive shaft 4 arranged on the same axis of that of the central electrode 13, an ignition coil 3 disposed on the periphery of the drive shaft 4 and applying a high voltage on the central electrode 13, a heat sink 20 located between the ignition coil 3 and the central electrode 13, a power switch arranged to the heat sink 20, and a crank angle sensor body 22 to detect the rotation angle of a crank adhered to the heat sink 20. Further, the heat sink 20 is fixed directly to a housing 1 by means of a screw 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine ignition device for sequentially igniting a secondary voltage generated in an ignition coil to an ignition plug of each cylinder.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing an example of a conventional ignition device for an internal combustion engine, wherein 1 is a housing, 2 is a cap,
Reference numeral 3 denotes an ignition coil attached to the housing 1, and 4 denotes a drive shaft supported by the housing 1, which rotates in synchronization with a crankshaft (not shown) of the internal combustion engine.

Reference numeral 5 denotes a crank angle sensor main body fixed to the housing 1 by screws 6, which are first and second Hall IC sensors (not shown) which are magnetic sensors, and first and second.
Magnets (not shown) are molded by thermosetting resin. 7 and 8 are respectively fixed to the drive shaft 4 through the blank 9 with screws 10 and the drive shaft 4
First and second vanes made of a magnetic material that rotate integrally with the first and second vanes 7 and 8 are disc-shaped, and the tip of the vanes 7 and 8 are bent at an angle of 90 °. Music part 7
a and 8a are formed. The bent portions 7a and 8a pass through a first gap 11 and a second gap (not shown) formed between the Hall IC sensor and the magnet.

Reference numeral 12 denotes a power distribution rotor which is attached to the tip of the drive shaft 4 and rotates integrally with the drive shaft 4. On the power distribution rotor 12, a rotor electrode 14 slidably contacting a center electrode 13 provided on the cap 2 is provided. It is provided. Reference numeral 15 denotes a spark plug of each cylinder of an internal combustion engine (not shown) on the periphery of the cap 2.
Secondary electrodes of an ignition coil (not shown) are sequentially distributed via the rotor electrode 14 by a plurality of peripheral electrodes provided corresponding to (not shown), and the ignition plug is ignited.

Reference numeral 16 is a heat sink joined to the crank angle sensor main body 5, on which a hybrid integrated circuit (HIC is abbreviated as HIC) for controlling the primary current flowing in the primary coil of the ignition coil 3. (Not shown) and a power transistor (not shown) for cutting off and energizing the primary current flowing through the primary coil of the ignition coil 3 are bonded.

In the internal combustion engine ignition device having the above structure, when the drive shaft 4 rotates due to the rotation of the crank shaft of the internal combustion engine, the first and second vanes 7, 8 fixed integrally with the drive shaft 4 also rotate. , The bent portions 7a and 8a have the first gap 11
The bent portions 7a and 8a block the magnetic flux passing from the magnet toward the first and second Hall IC sensors each time the first and second Hall IC sensors are crossed. The change of the magnetic flux according to the rotation of 4 is given. In this first Hall IC sensor, the change in magnetic flux is converted into an electric signal, and this electric signal is processed by a computer and then sent to a power switch composed of a HIC and a power transistor, and as a result, the ignition coil 3
The primary current is controlled, and a secondary voltage is generated in the ignition coil 3 at the ignition timing. This secondary voltage is sequentially distributed to the peripheral electrode 15 via the center electrode 13 and the rotor electrode 14 as the distribution rotor 12 rotates, the ignition plugs of each cylinder are sequentially ignited, and the internal combustion engine is continuously operated. Also, the second
The Hall IC sensor converts the change in magnetic flux into an electric signal, and the electric signal is used for the discrimination function of each cylinder.

[0007]

In the conventional ignition device for an internal combustion engine configured as described above, the molded crank angle sensor body 5 is fixed to the housing 1 by the screw 6 together with the heat sink 16 via the bush 17. However, there is a problem in that the head of the screw 6 is close to the power distribution rotor 12 that is a high-voltage power distribution unit, and the head of the screw 6 may be struck by lightning from the power distribution rotor 12. There is also a problem that a new mold must be prepared every time the position of the screw hole in the crank angle sensor body 5 changes.

The present invention has been made to solve the above problems, and provides an ignition device for an internal combustion engine, which can improve the leakage resistance from the high-voltage power distribution section to the head of the screw and can eliminate the bush. The purpose is to provide.

[0009]

In the ignition device for an internal combustion engine according to the present invention, the heat sink is directly fixed to the housing by screws.

[0010]

In the present invention, since the heat sink is directly fixed to the housing by using the screw, the distance between the head of the screw and the high voltage power distribution unit becomes large.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the present invention. The same or corresponding parts as in FIG. 2 are designated by the same reference numerals and the description thereof is omitted.

In the figure, 20 is a housing 1 with screws 2
A heat sink fixed by using 1 and a crank angle sensor main body 22 bonded to the heat sink 20 and integrated with the heat sink 20.

In the ignition device for an internal combustion engine constructed as described above, the heat sink 20 is fixed to the housing 1 by the screw 21.
Is directly fixed to the screw 21, the distance between the head of the screw 21 and the high-voltage distribution unit is increased, and the leakage resistance from the high-voltage distribution unit to the head of the screw 21 is improved. Further, in the conventional case, a bush is provided in the screw hole of the crank angle sensor main body 5 formed by molding in order to prevent the occurrence of the resin creep phenomenon and the decrease in the fastening force of the screw. However, the fastening of the crank angle sensor main body 22 with the screw 21 is eliminated, and the bush 17 can be inevitably abolished. In the above embodiment, the Hall effect type sensor device has been described as the crank angle sensor, but it is not limited to this, of course, and it may be an optical type sensor device using a photodiode, for example.

[0014]

As described above, according to the ignition device for an internal combustion engine of the present invention, since the heat sink is directly fixed to the housing by the screw, the distance between the head of the screw and the high-voltage distribution unit becomes large. , The leakage resistance from the high-voltage distribution unit to the screw head is improved. In addition, since the previously required bush can be eliminated, the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a conventional ignition device for an internal combustion engine.

[Explanation of symbols]

 1 Housing 2 Cap 3 Ignition Coil 4 Drive Shaft 13 Center Electrode 20 Heat Sink 21 Screw 22 Crank Angle Sensor Main Body

Claims (1)

[Claims] 1. A cap, a center electrode provided in the center of the cap, a drive shaft coaxial with the center electrode and rotating in synchronization with a crankshaft, and provided around the drive shaft. An ignition coil for applying a high voltage to the center electrode, a heat sink provided between the ignition coil and the center electrode, and power for intermittently energizing a current flowing through a primary coil of the ignition coil provided on the heat sink. An ignition device for an internal combustion engine comprising a switch and a crank angle sensor main body which is adhered to the heat sink and detects a rotation angle of a crank. The ignition device for an internal combustion engine, wherein the heat sink is directly fixed to a housing by a screw. apparatus.