JPH08210232A - Ignition device for electronic distribution - Google Patents

Abstract

PURPOSE: To prevent the occurrence of rupture due to the overcurrent of an ignition device by a method wherein in a case ignition signals are simultaneously inputted to a plurality of the input terminals of the ignition device, simultaneous ON is detected and a whole power switching element is forcibly disconnected. CONSTITUTION: An ignition device comprises a plurality of power transistors 1 to connect and disconnect the primary current of a separately arranged ignition coil by means of an ignition signal from an individually arranged engine control unit; a current limit circuit 2 to prevent the flow of an overcurrent to the respective power transistor 1; and a simultaneous ON preventing circuit 3 to disconnect all the power transistors 1 when ignition signals are simultaneously inputted to a plurality of input terminals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating means of a current control circuit in an internal combustion engine ignition device.

[0002]

2. Description of the Related Art As described in Japanese Patent Application Laid-Open No. 1-174143, a conventional device is designed so that if an ignition signal from an engine control unit is input to a plurality of input terminals of the ignition device, the ignition signal All the power switching elements corresponding to the terminals to which was input were turned on at the same time.

[0003]

SUMMARY OF THE INVENTION In the above-mentioned prior art, if the engine control unit malfunctions,
When an ignition signal is simultaneously input to a plurality of input terminals of the ignition device, a plurality of power switching elements are simultaneously turned on to connect a hybrid IC or an internal circuit provided inside the ignition device and a package terminal. Since a large current of 12 to 50 A flows through the existing connecting member, the IC pattern and the connecting member may melt and the engine may stop.

An object of the present invention is to use a circuit for detecting simultaneous ON even if ignition signals are simultaneously input to a plurality of input terminals of an ignition device due to malfunction of an engine control unit provided separately. The purpose is to detect the on-state and forcibly turn off all the power switching elements to prevent a large current from flowing into the circuit and to prevent the ignition device from being destroyed.

[0005]

In order to achieve the above object, when an ignition signal is simultaneously input to a plurality of input terminals between an input terminal of an ignition device and a power switching element, the ignition signal is transmitted to all power switching elements. There is no circuit.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The ignition device for electronic distribution uses an ignition signal from an engine control unit, which is provided separately, to connect and disconnect a power switching element provided inside the ignition device, and a primary winding of a separately provided ignition coil. By interrupting the primary current flowing through the wire, a high voltage is generated at the secondary winding end of the ignition coil.

In the case where a plurality of power switching elements are built in the ignition device, when an ignition signal is simultaneously input to a plurality of input terminals of the ignition device, the primary current flowing through the power switching element in the conductive state. Of the total flow into the connecting member that connects the internal circuit with the terminals of the hybrid IC or package inside the ignition device. Although it depends on the number of cylinders and the current control method, a large current of about 12 to 50 A flows into the IC pattern and the connecting members may be melted by Joule heat, which may cause the engine to stop and become unable to restart. is there.

However, as in the present invention, when the ignition signals are simultaneously input to a plurality of input terminals in the logic circuit between the input terminal of the ignition signal and the power switching element, a circuit for turning off all the power switching elements. Therefore, even if an ignition signal is simultaneously input to the input terminals, all the power switching elements do not become conductive, so the primary current does not flow into the ignition device, so prevent the ignition device from being destroyed. You can

An embodiment of the present invention will be described below with reference to FIG. This embodiment is an embodiment of an ignition device for 6-cylinder independent ignition, and comprises 6 power transistors 1, a current limiting circuit 2 and a simultaneous ON prevention circuit 3, and B1 to B6 are input terminals for ignition signals. , C1 to C6 are connection terminals to the ignition coil, E is a connection terminal to the ground, and Vcc is a power supply terminal for the simultaneous ON prevention circuit.

In the simultaneous ON prevention circuit 3, when an ignition signal is independently input to the input terminals of B1 to B6, a signal is input to the base of the power transistor corresponding to each input terminal, and the power transistor becomes conductive. If an ignition signal is simultaneously input to a plurality of input terminals, the output of the NOR gate in the simultaneous ON prevention circuit 3 becomes "LOW", and the output of all AND gates in the final output stage of the simultaneous ON prevention circuit 3 becomes "L".
OW ”, all power transistors 1 are cut off. When all power transistors 1 are cut off, the primary current does not flow into the ignition device, so by any chance ignition to multiple input terminals simultaneously. Even if a signal is input, the ignition device will not be destroyed.

[0011]

According to the present invention, if an ignition signal is simultaneously input to a plurality of input terminals of the ignition device, all power switching elements are forcibly shut off, so that an abnormal primary current is generated in the ignition device internal circuit. Does not flow. Therefore, the ignition device is not destroyed by overcurrent.

[Brief description of drawings]

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

FIG. 2 is a system configuration diagram using the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Power transistor, 2 ... Current limiting circuit, 3 ... Simultaneous ON prevention circuit, 4 ... Ignition device, 5 ... Ignition coil, 6 ... Ignition plug, 7 ... Engine control unit.

Claims (1)

[Claims] 1. An electronic distribution ignition device having a plurality of power switching elements built-in, comprising a control circuit for shutting off all of the power switching elements when an ignition signal is simultaneously input to two or more input terminals. An ignition device for electronic power distribution characterized by the above.