JPS5970885A - Igniter of internal-combustion engine - Google Patents

Abstract

PURPOSE:To alarm any trouble in an igniter to a driver, by bringing an engine to a stop even if either a first or a second power transistor is broken due to short circuit. CONSTITUTION:When a first power transistor 4 is broken due to short circuit, a first ignition coil 6 remains in a condition that a current flows therethrough, a voltage, being higher than the voltage at a time when a first power transistor 4 is turned ON in normal operation, is produced at a primary current detecting resistor 12, a transistor 812 is turned OFF, and transistors 813 and 815 are brought to a complete ON-state. Thereby, a waveform at a point E is prevented from generation, a second power transistor 5 is brought to an OFF-state via a waveform shaping circuit 14 and a second drive circuit 3, and an engine is brought to a stop. When the second power transistor 5 is broken due to short circuit, the first power transistor 4 works in a normal manner, but since a timing signal to an electronic fuel injection device 15 is fed from the collector of the second power transistor 5, fuel injection is forced to a stop to stop the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an ignition device for an internal combustion engine that includes two ignition coils and generates high voltage almost simultaneously.

Conventionally, an ignition device that drives a plurality of ignition coils has been proposed in Japanese Patent Laid-Open No. 54-5223.

In the device proposed in JP-A-54-5223, when one of the two power transistors that controls the energization of the two ignition coils is destroyed by a short circuit, the short circuit is destroyed. The current determined by the coil primary winding resistance continues to flow through the ignition coil on the side, so no high voltage is generated, but the other power transistor operates normally, so the engine continues to run without stopping. is possible.

Therefore, the driver continues driving without noticing the abnormality in the ignition system. In such a case, there is a problem that the ignition coil on the side where the power transistor is destroyed generates abnormal heat and the ignition coil ruptures or burns out.

In order to solve the above two drawbacks, the present invention includes a closed angle control circuit that controls the energization time of the ignition coil, a first drive circuit that is controlled by the output signal of the closed angle control circuit, and a first power transistor controlled by a drive circuit; a first ignition coil driven by the power transistor; a first constant current control circuit that limits the primary current of the ignition coil to a predetermined current; a waveform shaping circuit that shapes the constant current controlled signal voltage in the first drive circuit; a second drive circuit that is controlled by the output signal of the waveform shaping circuit; and a second drive circuit that is controlled by the drive circuit. and a second ignition coil driven by the power transistor,
By supplying the voltage waveform of the collector of the second power transistor as a timing signal for the electric fuel injection device as necessary, if the first power transistor is short-circuited, the second power transistor is forcibly activated. If necessary, if the second power transistor is short-circuited, the engine can be stopped and started by stopping fuel injection from the electronic fuel injection device. The purpose is to inform people of abnormalities in the ignition system.

Hereinafter, embodiments of the present invention will be described without being shown in the drawings.

FIG. 1 shows an embodiment of an ignition device for an internal combustion engine according to the present invention. In FIG. 1, reference numeral 1 denotes a closed angle control circuit for controlling the energization time of the ignition coil, into which a signal obtained by shaping the signal from a signal generator or the like that generates a signal synchronized with the rotation of an internal combustion engine (not shown) is input; 2 is a first drive circuit for driving the first power transistor 4 by the output of the closed angle control circuit 1; 4 is the first power transistor driven by the drive circuit 2; 8 is the first power transistor 4; This is a first constant current control circuit for constant current control of the power transistor 4, and outputs a pulse having a time width for which the power transistor 4 is constant current controlled. 10 is a Zener diode for protection of the first power transistor 4; 6 is an IT
The first ignition coil is driven by the power transistor 4 of the first ignition coil. 14 is a waveform shaping circuit for shaping the signal voltage controlled by constant current in the drive circuit 1; 3 is a second drive for driving the second power transistor 5 with the output of the waveform shaping circuit 14; 5 is a second power transistor driven by the drive circuit 3; 9 is a second constant current control circuit for constant current control of the second power transistor 5; Outputs a pulse with a current-controlled time width. 11 is the second power transistor 5
A protective Zener diode 7 is a second ignition coil driven by a second power transistor 5.

15 is an electronic fuel injection device operated by a timing signal supplied from the collector of the second power transistor 5. 12.13 are resistors for detecting the current flowing through each power transistor 4.5.

Furthermore, - to describe the detailed configuration of each of the above parts, 101 is a ramp wave generation circuit that generates a ramp wave from a human input signal such as a rectangular wave, 102 is a comparator, and 103 is an F that flows a constant current proportional to the engine rotation speed. /I conversion circuit, 104 to 108 are transistors, 109 to 113 are resistors, and 114 and 115 are capacitors. 20-24 are resistors, 25.26 are transistors, 801-810 are resistors, 811 are diodes, 812-815 are transistors, 30-34 are resistors, 35.36 are transistors, 901-910 are resistors,
912 to 915 are transistors, 911 is a diode,
141 and 142 are resistors, and 143 is a comparator. In addition,
Vcc is connected to a constant voltage power supply (not shown). VB is connected to a knob (not shown). Go to Figure 2.
B, C, D, E, F, G.

11 and f are operational waveform diagrams of each part of the embodiment shown in FIG.

Next, the operation of the ignition system for an internal combustion engine having the above configuration will be explained. The output signal of a signal generator that generates a signal synchronized with the rotation of the internal combustion engine (not shown) is shaped into a rectangular wave signal by a waveform shaping circuit (not shown). ) is input to the closing angle control circuit 1. In response to the input signal, the ramp wave generating circuit 101 generates a ramp wave as shown at B in FIG. Figure 2 illustration ■3 ■! is controlled to be a constant value regardless of the engine speed. A comparator 1 compares the voltage determined by the engine rotational speed and the time period during which each of the power transistors 4.5 is controlled with a constant current (!Il!2 C shown in FIG. 2) and the ramp wave.
02, and the output signal shown in FIG. 2 is output. The output signal of the comparator 102 is sent to the first drive circuit 2, where it is amplified to a predetermined signal strength. A first power transistor 4 is connected to the first drive circuit 1 and 2, and drives a first ignition coil 6.

A primary current detection resistor I2 is connected to the emitter of the first basso transristor 4, and the voltage generated across the resistor 12 (G shown in FIG. 2) is detected by the first constant current control circuit 8, and a predetermined voltage is detected. When a predetermined voltage is reached, the base current of the first power transistor 4 is controlled via the first drive circuit 2 so as to maintain that state. Therefore, the current flowing through the primary coil of the first ignition coil 6 is controlled to be a constant current at a predetermined value. Further, the first constant current control circuit 8 outputs a constant current time pulse having a time width controlled by the first power transistor 4 at constant current. The signal voltage (E shown in FIG. 2) which is under constant current control in the first drive circuit 2 is shaped by the waveform shaping circuit 14 and outputted as a signal F shown in FIG. Waveform shaping circuit 1
The output signal of No. 4 is input to the second drive circuit 3. Below, the second drive circuit 3 and the second power transistor 5
, the second ignition coil 7, and the second constant current control circuit 9 operate in the same manner as the respective first corresponding circuits, and will therefore be omitted.

Each ignition coil 6.7 each has a respective power transistor 6.7.
A high voltage is generated when the cylinder 7 changes from a conductive state to a disconnected state, and this high voltage is supplied to two ignition flags in the same cylinder through a power distributor (not shown). Each constant current time pulse of each constant current control circuit 8.9 is fed back to the closing angle control circuit 1. The capacitor 114 of this closing angle control circuit 1 converts constant current time into voltage, and each constant current time pulse drives the transistor j04.105, and the capacitor 114
is charging. The capacitor 115 is charged with a constant voltage determined by the resistor 1'13 and the F/I current conversion circuit 103, and is also charged with a current proportional to the charging voltage of the capacitor 114.

(C in Figure 2) That is, the basic energization time of each ignition coil 6.7 is determined by the ramp wave shown in B in Figure 2, the F/V voltage determined by the resistor 113, and the F/1 current conversion circuit 103. On the other hand, it is necessary to shorten the time during which the constant current of each power transistor 4.5 is controlled (as shown in B in FIG. The comparison level for the ramp wave is corrected.

Since it is configured as described above, if the first power transistor 4 is short-circuited 1 (supposed to be broken by Si as shown in FIG. 2), current will continue to flow through the first ignition coil 6. , a voltage larger than that when the first power transistor 4 is turned on during normal operation is generated in the -order current detection resistor 12. Therefore, the transistor 812 is ○FFL,
, transistors 813 and 815 are completely turned on.

(It is active during normal constant current control). Therefore, E
The waveform at the point becomes E shown in FIG. 2, and the second power transistor 5 is turned off via the waveform shaping circuit 14 and the second drive circuit 3, and the engine stops.

Next, if the second power transistor 5 undergoes a steep failure, the first power transistor 4 will operate normally, but the timing signal to the electronic fuel injection device 15 will not be supplied from the collector of the second power transistor 5. As a result, fuel injection stops and the engine stops.

Note that in an internal combustion engine that does not have the electronic fuel injection device 15, a rotation detection pulse is supplied from the collector of the second power transistor 5 to the engine rotation needle to detect the rotation of the engine rotation needle when the internal combustion engine is rotating. Rotation display is Qrpm
The damage to the seat of the second power transistor 5 may be notified to the user.

As described above, the present invention includes one closing angle control circuit that controls the energization time of the ignition coil, a drive circuit for W41 that is controlled by the output signal of the closing angle Wi control circuit,
a first power transistor controlled by the drive circuit; a first ignition coil driven by the power transistor; a first constant current control circuit that controls the primary current of the ignition coil to a constant current; a waveform shaping circuit that shapes the constant current controlled signal in the first drive circuit; a second drive circuit that is controlled by the output signal of the waveform shaping circuit; and a second drive circuit that is controlled by the drive circuit. a second power transistor driven by the power transistor; and a second ignition coil driven by the power transistor; , first,
Even if any of the second power transistors undergoes initial failure, the engine can be stopped and the driver can be notified of an abnormality in the ignition system, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing one embodiment of the device of the present invention, and FIG.
The figures are waveform diagrams of various parts for explaining the operation of the apparatus shown in FIG. 1...Closing angle control circuit, 2.3...1st. Second drive circuit, 4, 5...first and second puff transistors, 6. 1-...first and second ignition coils,
8゜9...first and second constant current control circuits, 14...
Waveform shaping circuit, 15...electronic fuel injection device. Representative Patent Attorney Takashi Okabe

Claims (2)

[Claims] (1) One closed angle control circuit that controls the energization time of the ignition coil, a first drive circuit that is controlled by the output signal of the closed angle control circuit, and a first power that is controlled by the drive circuit. a first ignition coil driven by the power transistor; a first constant current control circuit that limits the primary current of the ignition coil to a predetermined current; and constant current control in the drive circuit of the ffi+. a waveform shaping circuit that shapes the waveform of the waveform shaping circuit, a second drive circuit controlled by the output signal of the waveform shaping circuit, a second bus sort transristor controlled by the drive circuit, and the power transistor. An ignition device for an internal combustion engine, comprising a driven second ignition coil. (2) The ignition device for an internal combustion engine according to claim 1, wherein a timing signal is supplied to the electronic fuel injection device from the collector of the second power transistor.