JPS5936109B2 - igniter - Google Patents

Description

[Detailed description of the invention] The present invention relates to an ignition device for an internal combustion engine.

FIG. 1 is a block diagram showing the configuration of a conventional ignition system for an internal combustion engine, and 1 is an input signal generator for determining ignition timing.

The input signal generator 1 supplies an axle-synchronous input signal, as shown in FIG. 2a, obtained, for example, from a magnetic induction pickup coil to the input detection circuit 2.

The input detection circuit 2 detects the set level of the input signal and supplies an output pulse as shown in FIG. 2 to the on/off duty control circuit 3.

This on/off duty control circuit 3 allows the output transistor 5 to flow through the ignition coil 4 for an appropriate time.
It generates a signal that determines the duty of the on period and off period, and supplies the signal to the output switch circuit 6.

In the output of the on-off duty control circuit 3 shown in FIG. 2C, the pulse that rises before the pulse shown in FIG. This is because there is.

The output switch circuit 6 actually performs switching control of the output transistor 5.

The current limiting circuit 7 detects the current flowing through the ignition coil 4 through a resistor 8 connected in series with the output transistor 5, and limits the collector current of the output transistor 5 to a constant value as shown in FIG. A signal for subsequent control is fed back to the duty control circuit 3.

FIG. 2e shows the spark current obtained by the falling current of the ignition coil 4.

FIG. 3 shows in detail the conventional ignition device shown in FIG. 1 above.

In FIG. 3, parts corresponding to those in FIG. 1 are designated by the same reference numerals and will be explained.

The output of the input signal generator 1 becomes an input signal at the input terminal (2) of the rectifying element 11, and is supplied to the smoothing capacitor 13 via the resistor 12.

The output terminal (1) of this capacitor 13 is connected to the base of a control transistor 15 of a current generating circuit 14, and the emitter of the transistor is connected to a ground potential point via a resistor 19.

The collector of the transistor 15 is connected to the collector and base of one transistor 17 of the mirror circuit 16, the emitter of the transistor 17 and the emitter of the other transistor 18 are connected to the constant voltage power supply E1, and the collector of the transistor 18 is connected to the collector of the transistor 17 of the mirror circuit 16. It is connected to the capacitor 20 for use.

The output terminal (■) of the input signal generator 1 is connected to the non-inverting input terminal of a comparator circuit 21, and the inverting input terminal of this comparator circuit 21 is connected to the set voltage output terminal of a voltage dividing circuit consisting of resistors 22 and 23. There is.

The output terminal (■) of the comparator circuit 21 is connected to the base of a discharge transistor 25 via a resistor 24.
The collector of No. 5 is connected to a charging capacitor 20.

A voltage output terminal (3) of this capacitor 20 is connected to a non-inverting input terminal of a comparison circuit 26.

The inverting input terminal of this comparator circuit 26 is connected to the set voltage output terminal (■) of a voltage dividing circuit consisting of resistors 27 and 28, and the end side of this resistor 27 is connected to a constant voltage power supply E1 via a resistor 29.
It is also connected to a battery power source E2 via a resistor 30.

The output terminal ■ of the comparison circuit 26 is connected to one input terminal of the OR circuit 31, and the other input terminal of this OR circuit 31 is connected to the comparison circuit 21.
Connected to the output terminal ■.

The output terminal (2) of the OR circuit 31 is connected to the input terminal of the output switch circuit 6.

The current limiting circuit 7 detects the collector current of the output transistor 5 with a resistor 8, and controls the base of the output transistor 5 via the output switch circuit 6 so that the current is constant.

Further, the current limiting circuit 7 is connected to a capacitor 33 of a charging control circuit 32 that performs charging only during a constant current period.

The output terminal of this capacitor 33 is connected to the ground potential point via a resistor 34, and is also connected to the collector and base of one transistor 38 of a mirror circuit 37 via an amplifier 35 and a resistor 36, and to the collector and base of the other transistor 39. The collector is connected to the output end of capacitor 20.

Note that 40.41 is a circuit for fixing the output level even if the input voltage fluctuates around the set value after the output of the comparison circuits 21.26 is inverted.

In the conventional ignition device shown in FIG. 3 above, first, the signal shown by the zero point waveform in FIG. Since the comparator circuit 21 outputs a pulse shown by the 0-point waveform in FIG. 4, the transistor 25 is turned on and the capacitor 20 is discharged.

In short, the input signal from the 0 point is rectified by the rectifier 11,
The signal is then smoothed by a capacitor 13 to obtain a signal shown by the zero point waveform in FIG.

As a result, the transistor 15 is controlled, and the mirror circuit 16
A smoothing capacitor 13 is connected to the collector of the transistor 18.
A current flows according to the output voltage of the capacitor 20, and the capacitor 20 is charged.

This charging occurs more rapidly as the rotational speed of the internal combustion engine increases.

When the charging voltage of the capacitor 20 becomes equal to or higher than the set voltage of the 0 point, the output of the comparison circuit 26 is inverted and supplied to the OR circuit 31, which turns on the output transistor 5 via the output switch circuit 6.

This state remains until the subsequent pulse is output from the comparator circuit 21 and the capacitor 20 is discharged. However, since the above pulse is supplied to the ON circuit 31 from the 0 point, the output transistor 5 is output from the 0 point. Continue until the pulse falls.

Although such an operation is repeated, since the charge level of the capacitor 20 is proportional to the rotational speed of the internal combustion engine, the comparator circuit 26 controls the off period of the output transistor 5.

Here, if the constant current period of the output transistor 5 is long, the charging voltage of the capacitor 33 becomes high, so the amount of charging of the capacitor 20 is controlled by controlling the mirror circuit 37.

In addition, a current equal to the sum of the current from the constant voltage power source E1 and the current from the battery power source E2 is passed through the resistors 27 and 28 that obtain the set voltage of the comparison circuit 26, thereby controlling the energization period of the ignition coil 4 caused by fluctuations in the voltage. It is something.

In the conventional ignition system configured as described above, when variations occur in the voltage obtained by the magnetic induction pickup coil of the input signal generator 1, variations also occur in the output current value of the mirror circuit 16. The drawback was that the ignition timing of the engine would deviate from the optimal ignition timing.

This invention was made in consideration of the above circumstances, and its purpose is to provide an ignition device that is not affected by variations in input signals and can always obtain optimal ignition timing. It is in.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 is a block diagram showing one embodiment of the ignition device of the present invention.

In FIG. 5, parts corresponding to those of the conventional circuit shown in FIG. 3 will be described with the same reference numerals.

The output terminal (■) of the input signal generator 1 is connected to the non-inverting input terminal of a comparator circuit 21, and the inverting input terminal of this comparator circuit 21 is connected to the set voltage output terminal of a voltage dividing circuit consisting of resistors 22 and 23. There is.

The output terminal (■) of the comparator circuit 21 is connected to the base of a discharge transistor 25 via a resistor 24.
The collector of 5 is connected to a capacitor 20.

A voltage output terminal (3) of this capacitor 20 is connected to a non-inverting input terminal of a comparison circuit 26.

It is connected to the inverting input terminal of this comparison circuit 26.

The inverting input terminal of this comparator circuit 26 is connected to the set voltage output terminal (2) of a voltage dividing circuit consisting of resistors 27 and 28, and the end side of this resistor 27 is connected to the constant voltage power supply E1 via a resistor 29.
It is also connected to a battery power source E2 via a resistor 30.

The output terminal (2) of the comparison circuit 26 is connected to one input terminal of an OR circuit 31, and the other input terminal of this OR circuit 31 is connected to the output terminal (2) of the comparison circuit 21.

The output terminal (3) of the OR circuit 31 is connected to the input terminal of the output switch circuit 6.

The current limiting circuit 7 detects the collector current of the output transistor 5 with a resistor 8, and controls the base of the output transistor 5 via the output switch circuit 6 so that the current is constant.

Further, the current limiting circuit 7 is connected to a capacitor 33 of a blow mold control circuit 32 that performs charging only during a constant current period.

The output terminal of this capacitor 33 is connected to the ground potential point via a resistor 34, and is also connected via an amplifier 35 and a resistor 36 to the collector and base of one transistor 38 of a mirror circuit 37, and the other transistor 39. The collector of is connected to the output terminal (2) of the capacitor 20.

Note that 40 and 41 are circuits for fixing the output level even if the input voltage fluctuates around the set value after the outputs of the comparison circuits 21 and 26 are inverted.

Further, one end of the resistor 50 is connected to the battery power source E2, and the other end of the resistor 50 is connected to the capacitor 51.

The other end of this capacitor 51 is connected to a ground potential point.

The connection point between the resistor 50 and the capacitor 51 is the comparison circuit 5.
Connected to the inverting input terminal of 2.

Further, the collector of a transistor 53 is connected to the inverting input terminal of the comparison circuit 52.

The emitter of this transistor 53 is connected to the ground potential point, and the base of this transistor 53 is connected to the output end of an inverter 54 whose input end is connected to the output end of the OR circuit 31.

Further, the non-inverting input terminal of the comparison circuit 52 is connected to a set voltage output terminal of a voltage dividing circuit made up of a resistor 5556.

The output terminal of the comparison circuit 52 is connected to one input terminal of an AND circuit 57, and the other input terminal of the AND circuit 57 is connected to the output terminal (2) of the OR circuit 31.

The output signal of the AND circuit 57 controls the opening and closing of the switch 58.

One end of this switch 58 is connected to a constant current source 59,
Furthermore, the other end of this switch 58 is connected to the other end of a capacitor 60 whose one end is connected to the ground potential point.

The output end of this capacitor 60 is connected to the ground potential point via a resistor 61 and also to the base of the transistor 15 of the current generating circuit 14.

Further, the emitter of this l-range disk 15 is connected to the ground potential point via a resistor 19.

The collector of the transistor 15 is connected to the collector and base of one transistor 17 of the mirror 41 path 16, the emitter of this transistor 17 and the emitter of the other transistor 18 are connected to the constant voltage power supply E1, and the collector of this transistor 18 is connected to the capacitor 20.

Next, the operation of the apparatus configured as described above will be explained.

First, the signal shown by the 0 point waveform in FIG. 4 is supplied to the signal input terminal (2), and while this signal level is within the set voltage of the comparator circuit 21, the comparator circuit 21 outputs the 0 point waveform in FIG. Since the pulse indicated by the waveform is output, the transistor 25 is turned on and the capacitor 20 is discharged.

On the other hand, when the output signal of the OR circuit 31 is at a high level and the voltage level of the capacitor 51 is equal to or higher than the set voltage of the comparator circuit 52, the output signal of the comparator circuit 52 becomes a high level.

When the output signal of comparison circuit 52 and the output signal of OR circuit 31 are both at high level, switch 58 is closed and capacitor 60 is thereafter charged by the output current of constant current source 59.

As a result, the transistor 15 is controlled and the mirror circuit 16
A current corresponding to the output voltage of the capacitor 60 flows through the collector of the transistor 18, and the capacitor 20 is charged.

Further, when the output signal of the OR circuit 31 is at a low level, the output signal of the impark 54 becomes a high level, and thereafter the transistor 53 is turned on and the output signal of the comparison circuit 52 becomes a low level.

At this time, the output signal of the AND circuit 57 also becomes low level,
Furthermore, the switch 58 opens and the charge in the capacitor 60 is discharged via the resistor 61.

The transistor 15 is controlled by the output voltage of the capacitor 60, and a current according to the output voltage of the capacitor 60 flows through the collector of the transistor 18 of the mirror circuit 16.
Capacitor 20 is charged.

This charging occurs more rapidly as the rotational speed of the internal combustion engine increases.

At this time, the capacitor 60 is charged by the output current of the constant current source 59, so even if the output voltage of the input signal generator 1 varies, the output current of the mirror circuit 16, that is, the charging current of the capacitor 20 varies. does not occur.

When the charging voltage of the capacitor 20 becomes equal to or higher than the set voltage of the 0 point, the output of the comparator circuit 26 is inverted and supplied to the OR circuit 31, which turns on the output transistor 5 via the output switch circuit 6.

This state remains until the subsequent pulse is output from the comparator circuit 21 and the capacitor 20 is discharged. However, since the above pulse is supplied to the OR circuit 31 from the 0 point, the output transistor 5 is output from the 0 point. Continue until the pulse falls.

Although such an operation is repeated, since the charge level of the capacitor 20 is proportional to the rotational speed of the internal combustion engine, the comparator circuit 26 controls the off period of the output transistor 5.

On the other hand, if the constant current period of the output transistor 5 is long, the charging voltage of the capacitor 33 becomes high, so the amount of charging of the cone capacitor 20 is controlled by controlling the mirror circuit 37.

As explained above, according to the present invention, there is provided an input detection circuit that detects a set level of an input signal and generates an output pulse, a first capacitor that is discharged in response to an output pulse of the input detection circuit, and a first capacitor that is discharged according to an output pulse of the input detection circuit. a first comparator circuit whose output is inverted by comparing the capacitor voltage of the first capacitor with a first set voltage; and the output of the first comparator circuit and the output pulse of the input detection circuit are input. OR circuit and a second circuit that is charged with a current that corresponds to the power supply voltage.
a second comparison circuit whose output is inverted by comparing the capacitor voltage of the second capacitor with a second set voltage, and an output of the second comparison circuit and an output of the OR circuit. a charging/discharging circuit whose charging/discharging operation is controlled according to the charging/discharging circuit; and a current generating circuit provided on the output side of the charging/discharging circuit, whose output current is controlled by the output of the circuit, and which charges the first capacitor with the output current. The circuit includes: an output switch circuit that controls energization to the ignition coil according to the output of the OR circuit; a current limit circuit that detects a current flowing through the ignition coil and controls a constant current period of the output switch circuit; a charge control circuit that controls the amount of charge to the first capacitor according to a constant current period of the current flowing through the ignition coil, and a charge control circuit that controls the amount of charge to the first capacitor according to the constant current period of the current flowing through the ignition coil, and By controlling the charging/discharging circuit and further controlling the output current of the current generating circuit according to the output of the charging/discharging circuit, an ignition device is provided that can always obtain the optimal ignition timing without being affected by variations in the input signal. can.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the configuration of a conventional ignition system;
The figure is a time chart showing the operation of the device, and Figure 3 is the first
A detailed configuration diagram of the block diagram shown in Figure 4.
FIG. 5 is a time chart showing the operation of the device shown in the figure, and FIG. 5 is a configuration diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Input signal generator, 4...Ignition coil, 5...Output transistor, 6...
...Output switch circuit, 7...Current control circuit, 14...Current generation circuit, 20, 51, 6
0...Capacitor, 21゜2652...
・Comparison circuit, 31...OR circuit, 32...
...Charging control circuit.

Claims (1)

[Scope of Claims] 1. An input detection circuit that detects a set level of a human input signal and generates an output pulse; a first capacitor that is discharged in response to an output pulse of the input detection circuit; a first comparator circuit whose output is inverted by comparing the capacitor voltage with a first set voltage;
an OR circuit whose inputs are the output of the first comparator circuit and the output pulse of the input detection circuit; a second capacitor charged with a current having a value corresponding to the power supply voltage; and a capacitor voltage of the second capacitor. a second comparator circuit whose output is inverted by comparing the output voltage with a second set voltage; and a charging/discharging operation whose charging/discharging operation is controlled according to the output of the second comparator circuit and the output of the OR circuit. a current generating circuit provided on the output side of the charging/discharging circuit, the output current of which is controlled by the output of the circuit, and charging the first capacitor with the output current; An ignition device equipped with an output switch circuit that controls energization to a coil. 2. An input detection circuit that detects the set level of a human input signal and generates an output pulse, a first capacitor that is discharged in response to the output pulse of the input detection circuit, and a capacitor voltage of the first capacitor and a first a first comparison circuit whose output is inverted by comparing it with a set voltage;
an OR circuit whose inputs are the output of the first comparator circuit and the output pulse of the input detection circuit; a second capacitor charged with a current having a value corresponding to the power supply voltage; and a capacitor voltage of the second capacitor. and a second comparison circuit whose output is inverted by comparing the voltage with a second set voltage; and a charging/discharging operation whose charging/discharging operation is controlled according to the output of the second comparing circuit and the output of the OR circuit. a current generating circuit provided on the output side of the charging/discharging circuit, the output current of which is controlled by the output of the circuit, and charging the first capacitor with the output current; an output switch circuit that controls energization to the coil; a current limit circuit that detects the current flowing through the ignition coil and controls a constant current period of the output switch circuit; An ignition device comprising: a charge control circuit that controls the amount of charge to the first capacitor.