JPH032711Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of an ignition signal generating device for a contactless ignition device.

Fig. 1 shows a conventional ignition device shown in, for example, Japanese Utility Model Publication No. 56-4858.
2 is a housing, 2 is a rotating shaft rotatably supported by the housing 1, 3 is a camshaft fitted to this rotating shaft 2, 4 is a rotor fixed to this camshaft 3, and a rotor electrode 4a is provided on the top surface. It is formed. Further, 5 is a fixed base plate fixed to the housing 1, 6 is a movable base plate rotatably attached to the fixed base plate 5, and the movable base plate 6 is rotated by the vacuum device. It is composed of 7 is a non-contact position detector attached to the movable plate 6, which detects the salient pole of the inductor 3a attached to the camshaft 3 and generates an ignition signal. It is composed of a magnet generator with. 8 is a cap attached to the housing 1, with a center electrode 8a in the center.
is formed with a required number of power distribution electrodes 8b on the periphery.

With this configuration, when the rotating shaft 2 rotates, a signal voltage is induced in the signal coil 7b by the inductor 3a, and an ignition voltage is formed on the secondary side of the ignition coil based on this signal voltage. , furthermore, this ignition voltage is guided to the center electrode 8a, and the rotor electrode 4a
Power is then distributed to the spark plug through a predetermined power distribution electrode 8b.

Here, the position detector 7 is provided inside the housing 1, while the control circuit for forming the ignition voltage is provided outside the housing 1. Therefore, as shown in FIG. It will be connected to the circuit via lead wires 9a, 9b, whose intermediate portions are supported by the housing 1 via grommets.

By the way, it is desirable that the position detector 7 can be commonly applied to many types of ignition devices, and for this reason,
The lengths of the lead wires 9a and 9b are selected to have a sufficient length. Moreover, since the movable base plate 6 is rotated by the vacuum device, it is necessary to select the lengths of the lead wires 9a and 9b in consideration of the amount of rotation. Therefore, the lead wires 9a, 9b are installed with sufficient room in the housing, and the movable base plate 6 is attached to the lead wires 9a, 9.
If the lead wires 9a,
9b may rise and come close to the rotor electrode 4a.

Under such conditions, when ignition is performed in a state where the rotor electrode 4a and the power distribution electrode 8b of the cap 8 are not properly adjacent to each other, the lead wires 9a, 9
A high ignition voltage of tens of thousands of volts, which exceeds the dielectric strength voltage of the lead wire coating, is applied between the lead wire and the lead wire, and a large current instantly flows through the lead wire and the control circuit connected to the lead wire. This has the disadvantage that the control circuit connected to the outside may be destroyed and the reliability of the ignition system is significantly reduced. The cause of such high ignition voltage being applied is when an ignition timing abnormality actually occurs due to incorrect assembly of the drive gear that is a component part during repair or adjustment of a switchboard in the market, or when a similar situation occurs. When replacing the power distributor, there may be a case where cranking is performed while forgetting to connect the high voltage cord to the power distribution electrode 8b.

This idea was made to eliminate the drawbacks of the conventional ones as described above, and by winding a conductive member in the form of a coil spring with one end grounded around the lead wire connected to the position detector,
It is an object of the present invention to provide an engine ignition signal generating device that can prevent destruction of an ignition device even when ignition high voltage is not normally distributed.

This invention will be explained below with reference to a figure which is an example. In FIG. 3, 10 is wound around lead wires 9a and 9b connected to the position detector 7,
It is a coil spring-shaped conductive member whose one end is grounded through the housing.

In the above configuration, if a high ignition voltage is generated in a state where the rotor electrode and the power distribution electrode of the cap do not maintain a normal positional relationship inside the power distribution device, this ignition high voltage will be generated by a conductive coil spring with one end grounded. Since the voltage is applied to the member 10,
High voltage is no longer applied to the lead wires 9a and 9b of the position detector 7, and as a result, the lead wire 9
It is possible to eliminate the fear that the control circuit connected to a and 9b will be destroyed.

Note that when a high voltage is applied to the conductive member 10,
Although it is possible that some voltage is applied to the lead wires 9a and 9b due to induction, most of the power is grounded through the conductive member 10 close to the rotor electrode, so the voltage is applied to the lead wires 9a and 9b. The amount of power consumed is extremely small and will not damage the control circuit.

Further, if the lead wires 9a and 9b are located at a position lower than the upper end of the opening of the housing, the high voltage will be grounded through the housing rather than the conductive member 10, and the control circuit will not be affected.

In the above embodiment, a magnetic generator type position detector is described, but a Hall IC type, photoelectric type, or other non-contact type position detector may be used, and the same effects as described above can be obtained.

As described above, according to this invention, by wrapping a coil spring-like conductive member whose one end is grounded around the lead wire of a non-contact position detector, the possibility of high ignition voltage being applied to the control circuit is eliminated. This makes it possible to provide a highly reliable ignition device at a low cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing the structure of a conventional ignition device, FIG. 2 is a block diagram showing a conventional engine ignition signal generating device, and FIG. 3 is a block diagram showing an embodiment of this invention. In the figure, 7 is a non-contact position detector, 9a and 9b are lead wires, and 10 is a coil spring-like conductive member. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A non-contact position detector that detects the rotational position of the engine and generates an ignition signal, a lead wire with one end connected to the non-contact position detector and the other end connected to the control circuit, and the outer circumference of this lead wire. 1. An open ignition signal generating device comprising: a coil spring-shaped conductive member wound around a coil spring; one of the conductive members being grounded;