JPH0355816Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a retard control signal that generates a retard control signal used to control the ignition timing of an internal combustion engine to be delayed as the rotational speed increases. This relates to the generation circuit.

[Prior Art] Generally, in internal combustion engines, the ignition timing is advanced in the mid-high speed range of the engine, but in some engines, the ignition timing is retarded at high speeds in order to improve performance at high speeds. In some cases, it may be necessary to retard the ignition timing at high speeds in order to limit the engine speed to below a set value.

Recently, electronically controlled ignition devices that electronically control the generation timing of an ignition timing signal that determines ignition timing have come into widespread use as ignition devices for internal combustion engines. Various types of conventional ignition devices have been proposed. One such device uses a signal coil to generate first and second signals at maximum and minimum advance positions of the engine, respectively, and the first and second signals trigger a flip-flop circuit. A rectangular wave-like ignition operation permissible section detection signal that continues from the maximum advance angle position to the minimum advance angle position (an interval during which ignition operation is permitted, i.e.,
This is a signal that detects the interval between the maximum advance angle position and the minimum advance angle position, and ignition operation is permitted only during the period when this signal is generated. ) occurs. Then, by controlling an integral circuit using this ignition operation permissible interval detection signal to obtain a control signal with a predetermined waveform, comparing the control signal with a reference signal and generating an ignition timing signal when both signals match, A predetermined advance or retard angle characteristic is obtained.

In addition, as an ignition device that obtains retard characteristics, as seen in Japanese Patent Application Laid-Open No. 143354/1983, signals generated at the maximum advance position and minimum advance position are used, and these signals are used to connect an integrator. By controlling a voltage comparator and a flip-flop circuit, an integrated voltage of a waveform that descends at a constant slope from the maximum advance angle position to a reference value and then rises at a constant slope is obtained, and this integrated voltage is used as a retard angle control signal. , an ignition signal is generated when this signal reaches a reference value.

Furthermore, in the device shown in JP-A-58-131361,
Using a signal coil that generates a positive voltage following a negative voltage, the signal coil rises at a predetermined slope from the position where the positive voltage is generated to the position where the negative voltage is generated, and the area where the negative voltage is generated is even larger. The integrated voltage that increases with a slope is obtained as a retard control signal, and when the voltage of the waveform (the waveform of the section where the signal coil is generating negative voltage) in the region of the steep slope of this integrated voltage matches the reference voltage. Retard characteristics are obtained by generating an ignition signal.

Furthermore, in the device shown in Japanese Patent Application Laid-Open No. 58-206875,
By controlling an integrator with the output of a signal coil that sequentially generates a negative voltage and a positive voltage, the signal coil rises at a constant slope from the position where it generated a positive voltage, and when the signal coil generates a positive voltage again. Obtain an integrated voltage with a waveform that returns to zero, use this integrated voltage as a retard control signal, and compare this retard control signal with a reference signal of a rectangular waveform that is generated only during the period when the signal coil is generating a negative voltage. By generating an ignition signal when both signals match, retard characteristics are obtained.

[Problem to be solved by the invention] A rectangular wave-like ignition operation permissible interval detection signal that continues from the maximum advance position to the minimum advance position is generated, and this detection signal is used to control an integral circuit for retard control. Conventional devices designed to obtain a signal of There was a problem that the price was high.

Furthermore, in the device shown in Japanese Patent Application Laid-open No. 56-143354,
In order to obtain the retard control signal, an integrator, a voltage comparator, and a flip-flop circuit are required, making the configuration unavoidably complicated.

Furthermore, in the device disclosed in JP-A-58-131361, the retard width is set in the section in which the signal coil generates a negative voltage, so there is a problem in that the retard width cannot be made very wide.

Furthermore, in the device shown in Japanese Patent Application Laid-Open No. 58-206875,
Since the retard width is defined as the section in which the signal coil generates a negative voltage, the retard width is limited by the output of the signal coil, and there is a problem in that the retard width cannot be increased.

The purpose of the present invention is to provide a retard control signal for an internal combustion engine ignition system that allows a retard control signal to be obtained with a simple configuration, and also allows the retard width to be easily determined by the configuration of a signal generator. An object of the present invention is to provide an angle control signal generation circuit.

[Means for Solving the Problems] The means for solving the above problems will be explained with reference to FIG. 1 showing an embodiment of the present invention. The first signal reaches the threshold level at angular position θ1
A signal coil that generates Vs1 and a second signal Vs2 that reaches the threshold level at the minimum advance position θ2 with different polarities, 2 is the first capacitor, 3 is the first signal
A first capacitor charging circuit which inputs Vs1 and charges the first capacitor 2 to one polarity with the first signal Vs1, 4 is the second capacitor, 5 is the first
a second capacitor charging circuit that instantaneously charges the second capacitor 4 to one polarity with the voltage across the capacitor 2; 6 is a discharging circuit that discharges the second capacitor at a constant time constant; 7 is a second capacitor charging circuit; This is a reset circuit which sequentially discharges the residual charge of the second capacitor 4 when the second signal becomes equal to or higher than the threshold level by inputting the signal Vs2 of the present invention. is configured.

[Operation of the invention] In the above circuit, when the signal coil 1 generates the first signal Vs1 at the maximum advance angle position θ1, the first capacitor 2 is charged to one polarity. When the first signal passes the peak, current flows from the first capacitor 2 to the second capacitor charging circuit 3, and the second
Capacitor 4 is charged instantly. When the second signal Vs2 is generated at the minimum advance angle position θ2, the reset circuit 7 instantly discharges the residual charge in the second capacitor 4. Therefore, as shown in FIG. 3B, the voltage at both ends of the second capacitor 4 rises at the maximum advance angle position θ1 and falls at a constant time constant from the maximum advance angle position to the minimum advance angle position θ2. It is possible to obtain a retard control signal Vc with a waveform that returns to zero at the minimum advance position.

Since the time during which the second capacitor 4 can be discharged through the discharge circuit 6 becomes shorter as the engine speed increases, the retard control signal
For example, as shown in Figure 4, the gradient of the downward slope of Vc is as follows:
It becomes more gradual as it rises from N3 to N4. Therefore, when the retard control signal Vc is compared with the reference signal Vr, the position where both signals match becomes delayed as the engine speed increases. This retard control signal
By comparing Vc with a reference signal Vr and generating an ignition timing signal when both signals match, the ignition timing signal changes as θa → θb → θc → θ2 as the engine speed increases. I'm getting late.
Note that the engine rotation angle positions θ1, θ2, θa, θb, and θc are measured toward the advance side with respect to top dead center.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Fig. 1 shows an embodiment of the present invention, in which a signal coil 1 is placed in a signal generator attached to the engine, and as the engine rotates, the signal coil 1 is moved as shown in Fig. 3A. , a first signal of negative polarity is generated at the maximum advance angle position θ1 and the minimum advance angle position θ2, respectively.
Vs1 and a second signal Vs2 of positive polarity are generated.

The first capacitor charging circuit 3 includes a diode 301 whose cathode is connected to one end of the first capacitor 2, and a diode 301 whose anode is connected to the other end of the first capacitor via a resistor 302 having a sufficiently small resistance value. and a diode 303 connected to the other end b of the signal coil 1.

The second capacitor charging circuit 5 includes a diode 3
01 and the first capacitor 2, and a diode 501 whose cathode is connected to one end of the second capacitor 4 and one end a of the signal coil 1, and the other end of the second capacitor 4. a resistor 502 (its resistance value is set sufficiently small), one end of which is connected to the resistor 502, and a diode 50 whose anode is connected to the other end of the resistor 502 and whose cathode is connected to the contact between the first capacitor 2 and the resistor 302.
3, and a Zener diode 504 connected between the anode of the diode 501 and the other end of the capacitor 4 with its cathode facing the anode side of the diode 501.

The discharge circuit 6 has a collector connected to the second capacitor 4.
an NPN transistor 601 connected to one end of the
The variable resistor 602 consists of a variable resistor 602 having one end connected to the emitter of the transistor 601, a resistor 603 connected between the collector and base of the transistor 601, and a resistor 604 having one end connected to the base of the transistor 601. and resistance 6
The other end of 04 is connected to the other end of second capacitor 4.

The reset circuit 7 includes an NPN transistor 701 whose emitter is grounded and whose collector c is connected to one end of a second capacitor 504;
A resistor 702 connected between the base and emitter of 01
, a resistor 703 whose one end is connected to the base of the transistor 701, and a diode 704 whose cathode is connected to the other end of the resistor 703 and whose anode is connected to the other end b of the signal coil 1.

In the above embodiment, the signal coil 1 generates the first and second signals Vs1 and Vs2 once per ignition cycle in synchronization with the rotation of the engine, as shown in FIG. 3A. When the first signal Vs1 is generated, a current flows from the signal coil through the diode 301, the first capacitor 2, the resistor 302 whose resistance value is set to be sufficiently small, and the diode 303, and the first capacitor 2 has the polarity shown. It will be charged. When the first signal Vs1 reaches its peak at the maximum advance angle position θ1, charging of the first capacitor 2 is finished,
The electric charge of the first capacitor 2 is transferred to the diode 50.
1. Discharge occurs through the second capacitor 4, the resistor 502 whose resistance value is set sufficiently small, and the diode 503. As a result, the second capacitor 4 is charged to the polarity shown, and the voltage Vc across the second capacitor 4 rises as shown in FIG. 3B. Since the Zener diode 504 is provided,
The charging voltage Vcm of the second capacitor 4 becomes constant. When the second capacitor 4 is charged, the resistor 6
The base voltage flows to the transistor 601 through 03, and the transistor becomes conductive. Therefore, a discharge current flows from the second capacitor 4 between the base and emitter of the transistor 601 and through the variable resistor 602, and the second capacitor 4 is discharged at a constant time constant. Therefore, the terminal voltage of the second capacitor 4 decreases at a constant slope. The slope of the drop in the terminal voltage can be adjusted by the resistance value of the variable resistor 602. When the second signal Vs2 is generated at the minimum advance angle position θ2, a base current flows to the transistor 701 through the diode 704 and the resistor 703, and the transistor 701 becomes conductive. At this time, the second capacitor 4 is instantaneously discharged through the collector-emitter of the transistor 701, and the second capacitor 4
The terminal voltage of capacitor 4 becomes zero. Therefore, the waveform of the voltage across the second capacitor 4 changes as shown in FIG. 3B with respect to the rotation angle of the engine, rises at the maximum advance position θ1, and moves from the maximum advance position to the minimum advance position θ2. A retard control signal Vc is obtained which descends at a constant gradient until the end and returns to zero.

When the above control signal Vc is obtained, the fourth
As shown in the figure, by comparing the control signal Vc with the reference signal Vr and generating an ignition timing signal when both signals match, the ignition timing is adjusted from θa→θb→θc as the engine speed increases. →Can be delayed like θ2.

In addition, since the above-mentioned retard control signal is a signal that is generated during the ignition operation permissible period from the maximum advance position to the minimum advance position, when controlling the ignition timing,
There is no need to separately generate an ignition operation permissible section detection signal. Therefore, the configuration of the control circuit of the ignition device can be simplified.

In the above embodiment, the Zener diode 50
If 4 is omitted, the rotation speed will be as shown in Figure 5.
When it rises like N1→N2→N3→N4, the second
The peak value of the voltage Vc across the capacitor 4 increases as the rotational speed increases. Comparing the control signal with such a waveform with the reference signal Vr shows that as the rotation speed increases, the ignition timing is continuously delayed from the maximum advance position to the minimum advance position as θa → θb → θc → θ2. I can do it.

Here, the retard width is the difference between the first signal Vs1 and the second signal
Determined by the interval between Vs2 occurrences. Generally, it is not easy to adjust the width of the signal obtained from a signal generator, and it is especially difficult to obtain a wide signal, but the interval between signal generation depends on the mechanical angle of a specific part of the signal generator's rotor. Can be set arbitrarily. For example, when the most common inductor type signal generator is used, the signal can be adjusted by changing the polar arc angle (circumferential length) of the reluctor (inductor) provided on the rotor side of the signal generator. You can change the occurrence interval. Therefore, according to the present invention, it is possible to easily generate a retard control signal to obtain an arbitrary retard width from a narrow retard width to a wide retard width, and the retard width can be adjusted using a signal generator. This can be easily done by adjusting the mechanical angle of specific parts of the rotor.

FIG. 2 shows the main part of another embodiment of the present invention, in which the discharge circuit 6 is comprised of a variable resistor 602 connected in parallel to the capacitor 4. Other points are similar to the embodiment shown in FIG. 1, and the same operation as in the embodiment shown in FIG. 1 is performed.

The ignition device that can be controlled using the retard control signal Vc obtained in each of the above embodiments controls the primary current of the ignition coil with a semi-inductive element such as a thyristor or transistor operated by an ignition timing signal to ignite. Any device may be used as long as it has a circuit for obtaining a high voltage on the secondary side of the coil, and the retard control signal can be used to control a known ignition device such as a capacitor discharge type or a current cutoff type.

[Effects of the invention] As described above, according to the invention, a retard control signal can be obtained with a simple circuit configuration consisting of a capacitor charging/discharging circuit. Further, since the retard control signal generated during the ignition operation permissible interval from the maximum advance angle position to the minimum advance angle position is obtained, there is no need to provide a separate circuit for detecting the ignition operation permissible interval.
Therefore, a flip-flop circuit or the like that was conventionally required for generating the ignition operation permissible interval detection signal is no longer necessary, and the circuit configuration of the ignition device can be simplified.

Furthermore, according to the present invention, since the retard width is determined by the generation interval between the first signal and the second signal obtained from the signal coil, the retard width of the ignition timing is determined by the mechanical angle of the signal generator. It has the advantage of being easy to configure.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, Fig. 2 is a circuit diagram showing main parts of another embodiment of the invention, and Fig. 3 explains the operation of the embodiment of Fig. 1. FIGS. 4 and 5 are waveform diagrams showing the waveform of the retard control signal obtained by the circuit of the present invention with respect to the rotation angle of the engine. 1... Signal coil, 2... First capacitor,
3...First capacitor charging circuit, 4...Second capacitor, 5...Second capacitor charging circuit,
6...discharge circuit, 7...reset circuit.

Claims (1)

[Claims for Utility Model Registration] The ignition timing increases by comparing the retard control signal with a reference signal of a certain level and performing the ignition operation when the retard control signal matches the reference signal. In the retard control signal generation circuit that generates the retard control signal of an internal combustion engine ignition system that obtains a retard characteristic that retards the ignition timing as the ignition timing increases, a signal coil that generates a first signal and a second signal that reaches a threshold level at the minimum advance position with different polarities; a first capacitor; a first capacitor charging circuit that charges the first capacitor to one polarity; a second capacitor; and a voltage across the first capacitor that charges the first capacitor to one polarity;
A second capacitor that instantly charges the capacitor to one polarity.
a discharge circuit for discharging the second capacitor at a constant time constant; and a discharging circuit for discharging the second capacitor at a constant time constant; A retard control signal generation for an internal combustion engine ignition system, comprising: a reset circuit that instantaneously discharges residual charge in a capacitor; and a voltage obtained across the second capacitor is used as the retard control signal. circuit.