JPS608466A - Ignition apparatus of internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Technical Field The present invention compares voltages from ignition devices between internal combustion engines, more specifically rotation angle sensors, and controls the time that current flows through the ignition coil according to on/off thresholds. The present invention relates to an ignition device for an internal combustion engine, which includes a first comparison circuit that has a positive off value (iIj) and activates a time signal generation circuit when that value is reached.

(b) Prior art Such an ignition device is disclosed in, for example, German Patent Publication Section 32.
No. 15728, in which current interruption during non-operation is effected by a time signal generation circuit operated by a second comparator circuit.

That is, after expiration of a hold period provided by the time signal generator, the ignition coil current is cut off, thereby preventing overheating of the ignition coil and unnecessary power losses.

This interruption of the ignition coil current is useful, inter alia, when stopping an internal combustion engine that is not driven even though the ignition system has been switched off, or when the engine speed is very low and does not reach the off threshold of the first comparison point. This is especially necessary for 111f.

In conventional devices, the circuit for cutting off the current is an analog circuit, which increases the cost, and since a capacitor is used in the time signal generating circuit, it is difficult to integrate the circuit.

(c) Purpose Therefore, the present invention has been made to solve these conventional drawbacks, and it is possible to integrate circuits in a simple manner without providing additional circuits, and is particularly suitable for digital technology. An object of the present invention is to provide an ignition device for an internal combustion engine that can perform good ignition over various rotational speed ranges by operating the ignition device according to the present invention.

(2) Examples Hereinafter, the present invention will be explained in detail according to examples shown in the drawings.

In FIG. 1, an inductive rotation angle sensor 10 is provided which is driven by the camshaft or crankshaft of an internal combustion engine, the two terminals of which are each connected to two resistors 11.
12 to 13.14 are connected to the respective inverting and non-inverting input terminals of a differential amplifier configured as a comparison circuit 15.16. The first comparator circuit 15 is fed back to the non-inverting input terminal via a series circuit of a resistor 17 and a Zener diode 18, and the second comparator circuit 16 is similarly fed back via a resistor 19. The power supply voltage terminal 20 is connected to ground via a voltage divider circuit consisting of resistors 21 and 22. The voltage dividing point between the two resistors 21 and 22 is connected to the connection point between the rotation angle sensor 10 and the resistor 14 and 12, and the inverting input terminal of the second comparison circuit 16 is connected to ground via the resistor 23. There is.

Both comparison circuits with an inductive angle of rotation sensor 10 essentially correspond to the one described in DE 32 15 728 A1. Further, the circuit described in the publication further describes configurations related to a safety circuit, a protection circuit from disturbance, and a voltage stabilization circuit, but these are omitted here for the sake of simplicity.

The output of the first comparison circuit 15 is connected to the power supply terminal 20 via a resistor 24 and to the base of a transistor 26 via a diode 25. The base and collector of transistor 26 are connected to power supply terminal 20 via resistors 27 and 28, respectively. Its emitter is also connected to ground via the base-emitter circuit of transistor 29. The collector of the transistor 29 is connected to the power supply terminal 20 via a resistor 30 and the output transistor 3
It is also connected to the base of 1. The emitter of the output transistor 31, preferably configured with a Darlington connection, is connected to ground and its collector is connected to the ignition coil arrangement 32. This ignition coil arrangement 32 supplies a high-voltage ignition signal to the ignition plug in a well-known manner. The output of the second comparator circuit 16 is connected to the power supply terminal 20 via a resistor 33, to the clock input terminal T of a D flip-flop 35 via an inverter 34, and to an exclusive-OR gate (EXOR) 36 and a D flip-flop 35. It is connected to the clock input terminal T of the pin 37. The clock frequency generator 38 is turned on and off by the output of the exclusive OR game 1.36, and the counter 39 is reset via the reset input terminal R. The clock frequency 1 fraction generator 38 and the counter 39 function as a time signal generating circuit. The clock frequency of clock frequency generator 38 can be controlled by power supply voltage Ub. Further, the frequency of the clock frequency generator 38 is input to the clock input terminal T of the counter 39. This counter has four output terminals, each with a predetermined count value B1.
A signal is generated when the poem reaches B4. The output terminal associated with count value B3 is connected to the reset input terminal R of flip-flop 37, and the output Q of this flip-flop is connected to the D input terminal of flip-flop amplifier 35. The output terminal of the counter 39 related to the count value B4 is connected to the clock input T of the D flip-flop 40, and the output Q of the flip-flop 40 is connected to the exclusive OR gate 36.
The other input terminal of the transistor 29 is connected to the input terminal of the antenna gate 1.41, and is also connected to the base of the transistor 29 via a resistor 42.

On the other hand, the output of the counter 39 related to the count value Bl is connected to the other input terminal of an AND gate 41, and the output of this gate is connected to the reset input terminal of the flip-flop 4o. Furthermore, the output of the counter 39 associated with B2 is connected via an AND gate 43 to the clock input terminal T of a D flip-flop 44, and the inverted output Q of this flip-flop is connected via a diode 45 to the transistor 26.
connected to the base of Further, the output Q of the flip-flop 35 is connected to the other input terminal of the AND gate 43. The output of the first comparison circuit 15 is connected to the reset input terminal R of the flip-flop 44 via an inputter 46. Further, a power supply voltage is supplied to the D input terminals of the flip-flops 37, 40, and 44 through the power supply terminal 20, respectively, and the output cuff L pressure U from the rotation angle sensor 10 is shown in FIG.
g is illustrated. Since both comparison circuits 15, 16 equalize the same on-threshold values Ue1 and Ue2, both comparison circuits operate together. That is, the output signal changes from a "1" signal to an rQJ signal. The second comparator circuit 16 has a positive off-threshold, thus reaching the off-threshold 4 more quickly.
ti U a 2, while comparator circuit 15 has a negative off-threshold and therefore a slow off-threshold Ual. When both comparison circuits are turned off, the corresponding output signal becomes rO.
The signal changes from J to "1" signal. Feedpa5. circuit 1
The on threshold value and the off threshold value differ depending on the input circuits 7.18 to 19 and the comparator circuits 15 and 16. Under normal conditions, that is, when the rotation speed is the average rotation speed, the closing time TS, that is, the primary @ of the ignition coil
The period during which current is present in the line is determined by the comparator circuit 15. The ignition point is determined when the off-threshold Ual is reached, ie when the closing time Ts ends. Time t
1, the second comparator circuit 16 sets its off threshold value Ua
2, the time processing circuit formed by the clock frequency generator 18 as well as the counter 39 is activated.

When the standby time (hold time) determined by this time processing circuit ends at time t2, the current flowing to the primary side is interrupted (usually this has already been done), thereby interrupting the current during non-operation. Emergency ignition is performed when the engine speed is low and the rotational speed is very low, that is, when the signal level is so low that it does not reach the threshold value Ua1.

Next, three cases will be explained with reference to the signal waveform diagram shown in FIG. First, it is assumed that the internal combustion engine has an average rotational speed, for example, 2000 to 3000 rpm.

As already explained in connection with FIG.
From 5.16 onwards, the output signal U15. U16 is output.

When the comparator circuit 16 is off, that is, its output is "0"
When the signal changes to a "1" signal, a "1" signal is generated at the output of the exclusive OR gate 36 during this "1" signal (a "0" signal is generated at the other input terminals of the exclusive OR gate). ” signal is applied). Thereby, the clock frequency generator 38 operates, and its clock signal U
3B is counted by counter 39 (Z 39)
. The next edge of signal U16 resets counter 39 again. The average rotation speed means that the counting state is the count value B3 and B.
It can be defined as the rotation speed between 4 and 4. Since the count value B4 is not reached, the flip-flop 40 remains reset S and does not perform any operation. As will be explained in detail later, in this rotation speed range, the output of the flip-flop 35 is also at the 0 level, so the flip-flop 44 also has no effect. In this rotational speed range, therefore, the time during which current flows through the ignition coil 32, ie the closing time, is determined primarily by the comparator circuit 15 and its output signal U15.

Next, a case in the low rotational speed region will be explained.

When the rotational speed is 2000 rpm or 1500 rotation/rotor, it is considered to be a low rotational speed. This limit rotation speed is determined by the count value B4. In FIG. 3, the signal waveforms of low rotational speeds are shown as the fifth to tenth signals. Since the rotational speed is in the low range, the counter 39 reaches its count value B4, which causes a signal of "1" to be generated at its output, thereby setting the flip-flop 40. The counter 39 is reset and closed by the output signal U40 of the flip-flop 40 via the exclusive OR gate 36. When the output signal of the comparator circuit 16 changes to a 0 signal, the counter 39 starts counting again because a signal of "1" is applied to the input of the exclusive OR gate 36 via the output of the flip-flop 40. . When the count value reaches B1, the fritter flop 40 is reset via the AND gate 41, thereby blocking the transistor 29 and allowing current to flow via the transistor 31. The counter 39 is reset again via the exclusive OR gate 36 and starts counting again from the next rising edge of the signal U16. In this way, the time Tv is obtained from the count value B1, and the start of current flowing into the ignition coil is delayed by that amount.

In this way, the cam angle is small at low rotational speeds, and power loss in this region can be effectively reduced.

In FIG. 4, the variation of this cam angle at 1500 revolutions per minute is illustrated by a solid line. What is shown by the dotted line is the characteristic when this cam angle does not decrease. FIG. 4 shows the duty ratio STV of the signal of the output transistor 31 with respect to the rotational speed.

The reaching of the count value B4 means at the same time the end (T2) of the waiting time obtained by the time signal generator starting at time t1 and constituted by circuit 38.39. If the signal from the comparator circuit 15 does not reach the off-threshold Ua1 for the reasons mentioned at the outset, or if the comparator circuit is not turned off for other reasons, the ignition coil 32 can be turned off without generating an ignition spark. Current will continue to flow. However, at time t2, flip-flop 40 is set, so that transistor 29
Since the rlJ signal is formed at the base of , the transistor 31 is cut off and the current flowing through the coil is cut off. This results in a non-operating current interruption when the internal combustion engine is stopped, while an auxiliary ignition spark is generated when the rotation speed is in the low range. The fact that the off-threshold value Ua2 is positive ensures that the time signal generation circuits 38, 39 are operated in any case when the internal combustion engine is stopped.

When the rotational speed is in the average value or in the low range region, the count value of the counter 39 becomes larger than B3, so that the flip-flop 37, which is set by the rising edge of the signal U16, starts counting (IIi When reaching B3, the count value of the counter 39 becomes larger than B3. It is reset by the flip-flop 37.
A signal sequence U37 is obtained at the output. Since in the flip-flop 35 the inverter 34 inherits the output signal of the flip-flop 37 at the end of the signal U16 (always zero at this point), the output signal of the flip-flop 35 is zero. Therefore, the AND gate 43 is in a blocked state. Therefore flip-flop 4
4 has no effect in the low range and average rotational speed range.

Next, the case of a high rotation speed, for example 3000 rotations/rotating ball, will be explained. This example is shown in FIG. 3 as the 11th to 15th signal strings. Since the count value does not reach B3 at high rotational speeds, the flip-flop 3
7 will no longer be reset. Therefore, the signal rlJ is always obtained on the output side, so that the signal "1" always appears in the flip-flop 35, and therefore, the AND gate 43 receiving the output B2 from the counter 39 is opened. When the count value reaches B2, the flip-flop 44 is set (a zero signal appears at the inverted output) and reset by the rising edge of the signal string U15 (the rlJ signal appears at the inverted output).

The signal train U44 appearing at the output of the flip-flop 44 obtained in this way acts on the base of the transistor 26, and while a zero field appears at the output of the flip-flop 44, no signal is present at the output signal of the comparator circuit 15. Regardless of whether it appears, transistor 26 is turned off. When the transistor 26 is cut off, the ignition coil 3
A current flows through 2. If the flip-flop 44 is not provided, the current starts to flow for the first time at time t3, so if the flip-flop 44 is provided, the cam angle Tg increases at high rotational speeds. 350 in Figure 4
It is shown that the cam angle is increasing due to the variation of the curve shown by the solid line at 0 revolutions per minute.

Instead of increasing the cam angle only once in the high rotational speed region, it is also possible to increase the cam angle several times at different rotational speeds. This is illustrated in dotted lines in FIG. When using the same counter 39, B2. Other output terminal B instead of output terminal B3
5. B6 is provided, and the circuits 34 and 35 are connected through it.
The circuit corresponding to ゜37.43 is driven. When a plurality of AND gates 43 are provided in multiple stages in this way, the output is sent to the flip-flop 44 via a circuit.
must be input to the clock input of In this way, it is possible to increase the cam angle finely and stepwise in a high rotation range using a small number of circuits and an inexpensive circuit.

By providing one counter 39 in the time signal generation circuit, current is cut off during non-operation, and
It can be seen that auxiliary ignition is possible at low engine speeds or when a failure occurs, and furthermore, it is possible to reduce the cam angle at low engine speeds and increase the cam angle at high engine speeds. For this purpose, it is only necessary to provide a relatively simple and inexpensive circuit for the counter 39.

The characteristics shown by the dashed line in FIG. 4 show the characteristics when the power supply voltage becomes large (for example, when the charge value of the battery is large). The curve can be shifted because the clock frequency of the clock frequency generator 38 can be controlled according to the supply voltage Ub. Thereby, it is possible to reach the values of the count values B1 to B4 at different times, and it is possible to functionally match the range in which the characteristics vary not only with respect to the rotation speed but also with respect to the power supply voltage. Furthermore, current interruption during non-operation can be performed functionally correctly. In other words, when the power supply voltage increases, the operation can be performed more quickly.

For the counter 39, for example, the circuit element 74C161
However, circuit elements 4013 (eg, Motorola, National) can also be used for flip-flops.

(E) Effects As explained above, according to the present invention, processing is performed digitally, which simplifies processing, allows for circuit integration, and can also be realized by a microcomputer. Become. In particular, the cam angle can be reduced in the low rotational speed range using a time signal generator configured as a digital counter, the advantage being that no additional circuitry is required.

Furthermore, in the embodiment of the present invention, the time signal generation circuit and the rotation speed information obtained by the time signal generation circuit are used to increase the cam angle in the high rotation speed region, thereby requiring an even more expensive circuit. This means that the counter used as the time signal generation circuit is used three times as much. Furthermore, in the present invention, the clock frequency input to the counter can be controlled in relation to the power supply voltage, so that the recum angle can be functionally matched not only to the rotational speed but also to the power supply voltage. It is possible to reduce power loss in the region, and it is also possible to obtain a sufficient cam angle in the high rotation speed region.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the schematic configuration of the ignition device according to the present invention, Fig. 2 is a characteristic diagram showing the characteristics of the signal obtained from the rotation angle sensor, and Fig. 3 shows the operation of the circuit in Fig. 1. FIG. 4 is a signal waveform diagram for explaining the characteristics of the cam angle. 10...Rotation angle sensor 15.16...Comparison circuit 31...Output transistor 32...Ignition coil 38...Clock frequency generator 39...Counter FIG, 2 FIG, 3

Claims (1)

[Claims] (1) Compare the voltage from the rotation angle sensor (10) and turn on;
A first comparator circuit (15) that controls the time during which current flows through the ignition coil (32) according to an off threshold, and a positive off threshold that generates a time signal when the threshold is reached. a second comparison circuit (16) for activating the circuit (38, 39), and in which the ignition coil current is cut off after a predetermined standby time determined by the time signal generation circuit has elapsed. , the time signal generating circuit (38, 39) is configured as a counter that periodically counts the clock frequency, and when the counter reaches the first 5-1 value (B4), the bistable switching circuit (40
) is in the first (7) switching state, thereby interrupting the ignition coil current, and the bistable switching circuit is in the first (7) switching state, and at the same time the counter (3) is in the first (7) switching state.
9) is the second count value (B4) smaller than the first count value (B4)
An ignition device for an internal combustion engine, characterized in that a logic coupling circuit (41) is provided that causes current to flow through an ignition coil when the condition becomes Bl). (2) The ignition device for an internal combustion engine according to claim 1, wherein current is caused to flow through the ignition coil by setting the bistable switching circuit (4o) to the second switching state. (3) Operation of clock frequency generator and counter (3)
Claim 9) The resetting is performed only when the bistable switching circuit (4o) enters the first switching state through the gate circuit or when the comparator circuit $2 is turned off. 4) When the count value of the counter (39) does not reach the count value (B3) that corresponds to the high rotation speed, the bistable switching circuit (44) is enabled by increasing the cam angle, and the counter ( 3
9) The ignition system for an internal PN engine according to claim 1, 2 or 3, wherein a current is caused to flow through the ignition coil when the other count value (B2) of 9) is reached. (5) A bistable switching device (34, 35,
37) is provided, and the internal combustion engine according to claim 4 is switched to the second switching state when the count value of the counter (39) does not reach the count value (B3) corresponding to the high rotation speed. igniter. (6) The bistable switching device consists of two flip-flops (35, 37), each flip-flop being set by a different signal end of the second comparison circuit (16), the first flip-flop. The flip-flop (37) is reset when the count value of the counter (39) reaches the count value corresponding to the high frequency rotation speed, and when the set signal appears in the output signal of the first flip-flop (37), the second flip-flop (37) is reset. An ignition device for an internal combustion engine according to claim 5, wherein the ignition device is sent to a flip-flop (35). (7) The ignition device for an internal combustion engine according to claim 4, wherein the bistable switching circuit (44) is resettable by an ignition signal. (8) The output of the bistable switching circuit (40, 44) is connected to the base of a transistor connected upstream of the output transistor (31), thereby controlling the current flowing to the ignition coil. An ignition device for an internal combustion engine according to any one of items 1 to 7. (9) Ignition of an internal combustion engine according to any one of claims 1 to 8, wherein the cross-shift frequency of the clock frequency generator can be adjusted according to the power supply voltage (Ub). Device.