JPS6017943B2 - Internal combustion engine spark ignition device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spark ignition device for an internal combustion engine,
More specifically, the present invention relates to a reliable spark ignition device using a known variable reluctance pickup.

In the past, variable reluctance pickups have had the fundamental drawback that the duration and amplitude of their output waveforms vary significantly with changes in engine speed.

That is, when the engine is rotating at low speed, the output waveform of the pickup has a relatively small amplitude, but its duration is long.
On the other hand, when rotating at high speed, the amplitude is large, but the duration is relatively short. Therefore, when a variable reluctance pickup is used in a spark ignition system, it cannot be determined that the engine crankshaft has reached a particular position using a conventional simple threshold level detector. That is, when the engine is running at low speeds, the output voltage of the detector never reaches the threshold level, and at high speeds, it quickly reaches that level. As a known example of the present invention, for example, U.S. Pat.
A device disclosed in No. 791364 is known.

This device discloses a monostable circuit driven by a detector circuit. In the monostable circuit, for example, flip
The bases of the two transistors are cross-connected so that they can be reswitched as in a flop circuit. Therefore, the spark ignition circuit is activated only when the monostable circuit is in a semi-stable state, and is not activated at other times. In this device, the actual timing at which the spark should be generated depends purely on when the impulse (output signal) passes through the diode 22. However, such a configuration has the drawback that malfunctions due to spurious signals such as spike noise are very likely to occur. The present invention has therefore been devised in view of the above-mentioned disadvantages, and in particular, the output of the variable reluctance transducer is zero voltage at a particular position on the crankshaft and the time integral of each half cycle of the output is equal to the engine rotational speed. The focus is on the fact that it remains constant regardless of. In this regard, the present invention discloses two circuit configurations. The present invention provides a variable magnetic resistance pick-up that generates an output signal whose polarity changes at the moment when an ignition spark is to be generated, an ignition spark generation circuit driven by the output signal, the variable magnetic resistance pickup, and the ignition spark generation circuit. In the spark ignition layer of an internal combustion engine, the control circuit includes an inverting amplifier, an input resistor directly connecting the pickup and an input of the inverting amplifier, and a series connection. The AC connected between the input and output of the inverting amplifier consists of a resistor and a capacitor, and has negative feedback, and when the inverting amplifier changes from the saturated state to the conductive state, the spark ignition circuit generates a spark. It is configured to occur.

The present invention will be explained in detail below using the accompanying drawings. In FIGS. 1 and 2, a battery 101 mounted on a vehicle
Its negative side is connected to the ground wire 102, and its positive side is connected to the feeder line 10.
3, and the positive one is further connected to a resistor 104.
The ground wire 10 is connected to the
It is connected to 2. Power is supplied from the junction between the resistor 104 and the Jenner diode 105 to the positive feed line 106 . The feed line 106 is connected to n-p- through a resistor 107.
It is connected to the collector of an n-transistor 108, and the emitter of the transistor is connected to the ground wire 1 via a resistor 109 and a variable magnetoresistive pickup 110 connected in series with the resistor 109.
It is connected to 02. The base of the transistor 108 is connected to the ground line 102 via a resistor 111, and also to the p-n-p
It is connected to the collector of transistor 112 and the base of npn transistor 113, respectively, and the emitter of transistor 113 is connected to ground line 102 via resistor 114. The base of the transistor 12 is connected to the base and collector of a p-n-p transistor 115, and the transistor 112.115
Both emitters are connected to a power supply line 106.
The collector of the transistor 113 is connected to the power supply line 106 through the resistor 116, and further to the base of the npn transistor 117, and the emitter of the transistor is connected to the base of the npn transistor 18. The collectors of both transistors 117 and 118 are connected to the power supply line 106.
The collector of 8 is connected to the collector of n-p-n transistor 119, and the emitter of the transistor is connected to n-p-n transistor 119.
It is connected to the base of transistor 121. Further, the collector of the transistor 121 is connected to the power supply line 106 via a resistor 122. The base of transistor 119 is connected to the collector of transistor 108, and the base of transistor 119 is connected to the collector of transistor 108.
The emitter of transistor 123 is connected to the collector and base of an n-p-n transistor 123 via a resistor 125, and the emitter of transistor 123 is connected to the ground line 102. P-n
At the base of the transistor 124, the transistor 124
Its emitter is connected to ground line 102, and its collector to the bases of transistors 12 and 115. The collector of transistor 121 is further connected to the base of n-p-n transistor 131 and resistor 132 to capacitor 13.
3 to the ground wire 102.

The collector of the transistor 131 is connected to the power supply line 106 through a resistor 134 and to the n-p-n transistor 37.
It is connected to the base of Power supply line 106 and ground line 10
A pair of resistors 138 and 139 are further connected in series between 2, and the junction of both resistors is connected to the base of an npn transistor 141, the collector of which is connected to the feed line 106. There is. transistor 131
, 141 are connected to the ground wire 10 via a resistor 142.
2, a capacitor 143 and a resistor 144 connected in series
via the emitters of transistors 108, respectively. The emitter of the transistor 137 is connected to the power supply line 10
6, and its collector is connected to the ground wire 102 via a resistor 151. The collector of transistor 137 provides an input to ignition circuit 186.

Resistor 151 is bridged between capacitor 152 and resistor 153. The junction between capacitor 152 and resistor 153 is p-
connected to the base of the n-p transistor 154;
The emitter of the transistor is connected to the power supply line 106, and the collector thereof is connected to the ground line 102 through series-connected resistors 155 and 156. The junction of the resistors 156, 156 is connected to the base of an n-p-n transistor 57, the emitter of which is connected to the ground line 10.
2, and its collector is connected to the feed line 1 through a resistor 158.
It is connected to 03. The collector of the transistor 157 is further connected to the base of an npn transistor 159, the emitter of which is connected to the ground line 102, and the collector is connected to the feed line 103 via a resistor 161. be. Further, the collector of transistor 159 is connected to the base of n-p-n transistor 162, whose emitter is n
- connected to the base of the Pn transistor 163;
The emitter of the transistor 63 is connected to the ground line 102. The collectors of the transistors 162 and 163 are connected to the power supply line 103 via the primary winding 164 of an ignition transformer 165, and the collector of the transformer 165 is
is connected to the engine plug via a known distributor. The pickup 110 is the second
As shown in Figure a, an output consisting of a positive half cycle followed by a negative half cycle is generated.

The noise signal detected by the pickup 110 is always a large amplitude, oscillating spike signal of very short duration. Such a spike signal is superimposed on the waveform shown in FIG. 2a. By integrating the output of the pickup 110 using an inverting integrator with a sufficiently long integration time constant, a waveform as shown in FIG. 2b is obtained.
What should be noted here is that by time-integrating any noise signal (spike signal) superimposed on the pickup output waveform, it becomes so small that it cannot be recognized from the overall integrated waveform. . The integrator is a known operational amplifier (transistors 108, 112
,113,115,117,118,119,121,
123, 124, 131 and related elements).

Transistors 117, 118, 119, and 121 form a differential amplifier that is part of an operational amplifier.

Transistors 108 and 113 form the input stage of the operational amplifier, and transistor 131 forms the output stage. Transistors 112, 115, 123 and 124 supply bias current to the input stage and differential amplifier stage. The emitter of transistor 108 forms the inverting input of the operational amplifier and is connected in series with capacitor 1.
43 and resistor 144 form feedback for the input. Resistors 109, 144 and capacitor 14
A value of 3 operates at low frequencies, ie, the pickup output frequency, as an integrator with a time constant determined by the resistance of resistor 109 and the capacitance of capacitor 143.
At these frequencies, resistance 144 can be ignored. However, at high frequencies, such as spark noise frequencies, capacitor 143 has a very low impedance, so the operational amplifier is determined by the ratio of resistors 144 and 109 (this value is It operates as an AC proportional amplifier with a gain (which is determined to be very small in some cases). In a static state, that is, when the output of pickup 110 is zero, no DC negative feedback loop is applied to the operational amplifier, so transistor 131 at the output of the operational amplifier is fully turned on, so that transistor 137 completely turn on. Therefore capacitor 15
The left plate of 2 is charged to approximately the voltage of line 106 via the emitter-collector of transistor 137, and its right plate is charged to a voltage slightly lower than the voltage determined by the base-emitter voltage of transistor 54. Ru. Transistor 154 is kept conductive by the current flowing through resistor 153, so transistor 57 is kept conductive and transistor 159 is kept non-conductive. Transistors 62 and 163 are adapted to conduct current through primary winding 164. When the positive half cycle of the signal from the pickup is input, the operational amplifier starts operating as an integrating amplifier.

That is, as current flows from winding 110 to resistor 109, transistor 108 tends to turn off (and thus promotes the conductivity of transistors 119 and 121), due to well-known operational amplifier behavior. , so the base current of transistor 131 decreases.Thus, transistor 131 turns off and turns off.) The output of the operational amplifier obtained from the emitter of transistor 131 is such that the current flowing through capacitor 43 flows through resistor lo9. The voltage across capacitor 143 increases over time according to the time integral of the voltage generated by pickup 11. The emitter voltage of transistor 131 thus drops until it reaches the clamp level determined by resistors 138 and 139.

When this clamp level is reached, transistor 141
is conductive and maintains a constant current in resistor 142 regardless of the state of transistor 131. When the output of the operational amplifier is clamped, no further negative feedback is applied to the emitter of transistor 108, so the voltage change ratio at the emitter of transistor 31 is no longer compensated for by feedback, and transistor 131' Well, it's completely turned off.

The emitter voltage and collector current of transistor 31 are shown in FIGS. 2c and 2d. Even when transistor 131 is turned off and transistor 137 is also turned off, the voltage at the collector of transistor 137 does not suddenly drop to zero.

This is because there is a slight voltage across capacitor 152 as described above. However, the capacitor 52 is discharged through the resistor 151 until the electrode on the resistor 151 side reaches the voltage of the line 102 shown in FIG. The collector voltage of transistor 137 is shown in FIG. 2e. Even if the transistor 41 is conductive, the capacitor 143
The voltage changes such that the left side plate has little delay with respect to the output voltage of the pickup 110, that is, the voltage reaches a peak and then goes to zero.

When the characteristic of the signal generated by the pickup 1101 is reversed from positive to negative, the transistor 131 is turned on again rapidly and the amplifier operates as an integrating amplifier.

When the transistor 131 turns on, the current flows through the resistor 13.
4. It flows between the collector and emitter of the transistor 131 and through the resistor 142, but at this time, the potential at the junction between the resistor 142 and the emitter of the transistor 141 is higher than the clamp level, and the output of the transistor 131 is in a saturated state. On the other hand, since the operational amplifier itself operates as an integrator, the saturated output state of the transistor 131 is reliably guaranteed.

That is, the operational amplifier operates as an integrator for the input signal independently of its output state. Transistor 131 turns on and transistor 13
When 7 is turned on, transistor 137 charges the left plate of capacitor 52 to a voltage approximately equal to line 106, so transistor 154 is reverse biased. The charge on the right plate of capacitor 152 then begins to discharge through resistor 153, and transistor 154 turns on at the end of this discharging process. Therefore, the current in the ignition coil primary winding 164 is
31 is turned on (transistor 154 is turned on), this state is interrupted when capacitor 15
2 is maintained until it is discharged. At the beginning of this interruption, an ignition spark is generated in the primary winding. Even when the signal generated by the pickup 110 changes from negative to zero, the output transistor 131 of the operational amplifier remains fully turned on, and the transistor 137 also remains fully turned on.

Then, when a signal transitioning from zero to positive is supplied again from the pickup, the operation of the operational amplifier described above is repeated.

In the frequency response of the amplifier mentioned above, the pickup 11
The periodically occurring high frequency spike signal superimposed on the zero output has no effect on the operation of the ignition system.

That is, the spike signal that occurs when the output of pickup 1 10 is zero is such that the time integral of that signal is so large that it displaces the emitter of transistor 131 negatively enough to switch on transistor 41. I can't. Furthermore, while the amplifier is operating as an integrator, that is, when the pickup is generating output, the integral value of the spike noise is negligibly small compared to the integral value of the pickup, and the A of the amplifier is small.
The C gain is very small, so the spike noise voltage is completely recessive.

On the other hand, transistor 31 is completely turned off during the saturation period of the amplifier, so it is not affected by spike noise. In the configuration shown in FIG. 1, the connection between the ignition circuit and the device can be made simple by grounding the pickup 110.

FIG. 2f shows the base voltage of transistor 154, while FIG. 2g shows the collector voltage of the same transistor 154.

The ignition spark occurs when transistor 154 switches off. Next, referring to FIG. 3, the battery 201 has its positive terminal connected to the power supply line
06, the negative electrodes thereof are connected to the ground wire 202, respectively.

A Zener diode 205 is arranged between both lines 206 and 202, and the voltage of the power supply line 206 is regulated by this. One end of the variable magnetoresistive pickup 210 is connected to the ground line, the end of the variable magnetoresistive pickup 210 is connected to the cathode of a diode 271 via a resistor 270, and the anode of the diode is connected to the ground line 202. The cathode of the diode 272 is connected to the cathode of the diode 271, and the anode of the diode 272 is n-
Connected to the base of pn transistor 274.
Further, a resistor 273 is connected in parallel with the diode 272. This diode 272 can be a diode-connected transistor. The base of the transistor 274 is connected to the power supply line 206 through a resistor 275, its collector is connected to the power supply line 206 through a resistor 276, and its emitter is connected to the ground line 202. The base of transistor 277 is connected to the collector of transistor 274, the collector of transistor 277 is connected to power supply line 206 through series-connected resistors 278 and 279, and its emitter is connected to ground line 202 through resistor 280. . The amplifier constituted by transistors 274 and 277 consists of a capacitor 281 and an A. C. It has a negative feedback circuit. The anode of the diode 283 is the transistor 27
The emitter and cathode of transistor 7 are connected to the base of transistor 274, respectively. p-n-p transistor 2
The collectors of the 84 external power supply lines 206 are connected to the ground line 202 via a resistor 285. The base of the transistor 284 is connected to resistors 278 and 279.
The collector is further connected to a spark generating circuit 286 having a construction similar to that shown at 186 in the embodiment shown in FIG. diode 2
72 and transistor 274 are biased through resistor 275, and when pickup 210 is not producing an output, transistors 274 and 277 are in a conductive state.
Transistor 284 is maintained in saturation.

The emitter of the transistor 277 is connected to the resistor 280 via a diode 283.
Connected to the base of 4. When a positive half cycle signal is input from the pickup 210, the diode 27
2 becomes reverse biased, so the operating point of transistor 274 moves to the saturated state and operates as a saturated amplifier.

Therefore, since the base potential of transistor 277 decreases, the operating point moves in the direction of turning off, and similarly transistor 284 tends to turn off. Therefore,
The potential at the connection point between the emitter of the transistor 277 and the resistor 280, which had guaranteed the conductivity of the transistor 274, drops, and the diode 283 enters the cut-off state. The negative loop circuit composed of the capacitor 281 and the resistor 282 operates to prevent changes in the transistors 274 and 277, but in the end, the transistor 274
saturates and transistors 277 and 284 are turned off. Then, a negative rising pulse is generated on the resistor 285. Hereinafter, the spark ignition circuit 286 operates in the same manner as explained in FIG. 1, but the explanation using FIG. 3 will be omitted. Next, when the output from the pickup 210 changes from the positive half cycle through zero to the negative half cycle, the diode 272 becomes forward biased and the resistor 273 is shorted. Therefore, the operating point of transistor 274 rapidly moves in the direction of cutting off (from a saturated state to a conductive state), and transistors 277 and 284 are therefore rapidly turned on. At this time, the voltage of the capacitor 281 increases according to the integration time constant of the AC negative feedback circuit provided so that the obeamp operates as an integrator. A positive rising pulse then appears on resistor 285. When the voltage on resistor 280 exceeds the base voltage of transistor 274, the base voltage of transistor 274 is clamped as diode 283 turns on, ensuring that transistor 274 remains conductive. In the above configuration, the function of the operational amplifier changes depending on the state of diode 272.

That is, when diode 272 is forward biased and resistor 273 is shorted, the operational amplifier operates as a proportional amplifier proportional to the output of pickup 210, while when reverse biased, it operates as an integrator. and operates as a low gain amplifier. This transfer function change occurs when the pickup output crosses the zero point, and this is the moment when the spark output is required. Second, even though the pickup 210 output signal goes from negative to zero, the operational amplifier operates as an integrator and low gain amplifier because diode 272 is slightly reverse biased by the current flowing through resistor 275. The transistors 274 and 277 are maintained in a conductive state, and the transistor 284 is maintained in a saturated state. Then, when the potential at the connection point between the emitter of the transistor 277 and the resistor 280 exceeds the base potential of the transistor 274, a direct current negative feedback loop is applied by the diode 283, and the conductive state of the transistor 277 is guaranteed. As described above, in the present invention, when the output signal from the pickup is within one channel, that is, during a positive half cycle, the output of the inverting amplifier increases relatively slowly toward saturation.
When the output signal of the pickup changes after being saturated, it is configured to be driven relatively quickly, and the change signal of the parentheses is
By supplying the ignition spark circuit, the inverting amplifier generates a spark that changes when it is not in saturation, i.e. in response to the pickup output transitioning from a positive half cycle to a negative half cycle. This is something that works.

Although the present invention has been described above using two embodiments, the present invention is not limited to these embodiments, and can be modified in various ways without departing from the scope of the claims.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing waveforms at various parts of the circuit shown in FIG. 1, and FIG. 3 is a circuit diagram showing another embodiment of the present invention. FIG. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A variable magnetic resistance pickup that generates an output signal whose polarity changes at the moment when an ignition spark is to be generated, an ignition spark generation circuit driven by the output signal, and the variable magnetic resistance pickup and the ignition spark generation circuit. In the spark ignition device for an internal combustion engine, the control circuit is connected in series with an inverting amplifier and an input resistor directly connecting the pickup and the input of the inverting amplifier. A. which consists of a resistor and a capacitor and connects the input and output of the inverting amplifier. C. 1. A spark ignition circuit for an internal combustion engine, having negative feedback, wherein the spark ignition circuit generates a spark when the inverting amplifier changes from a saturated state to a conductive state.