JP2770602B2 - Ignition position control method and apparatus for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition position control method for an internal combustion engine for controlling the ignition position of an internal combustion engine, and an ignition position control device used for implementing the method.

[0002]

2. Description of the Related Art The ignition position of an internal combustion engine is determined by the number of revolutions [rpm].
The ignition position control device controls the ignition position by performing a predetermined integration operation and a comparison operation in synchronization with the rotation of the engine, and generates an ignition signal at the calculated ignition position. Various types are known.

In such a conventional ignition position control method, a signal generator which generates a maximum advance position signal and a minimum advance position signal at the maximum advance position and the minimum advance position of the engine, respectively, is used. By controlling the integration operation by the signal, the ignition position is calculated so that the section from the position where the maximum advance position signal is generated to the position where the minimum advance position signal is generated is set as the advance range.

FIG. 8 shows signal waveforms when the ignition device is controlled by this type of conventional ignition position control method. FIG. 8A shows a maximum advance position signal P1 'and a minimum advance position signal. P2 ', and FIG. 4B shows the waveform of the primary current I1 of the ignition coil. FIG. 3C shows the ignition high voltage Vh obtained on the secondary side of the ignition coil when the engine rotates forward, and FIG. 3D shows the ignition high voltage obtained on the secondary side of the ignition coil when the engine rotates in reverse. The high voltage Vh is shown. FIG.
In (B) to (D), the waveform of the broken line indicates a waveform at a low speed lower than the rotation speed at which the advance of the ignition position is started, and the waveform of the solid line indicates the waveform in the rotation speed region equal to or higher than the rotation speed at which the advance is completed. Is shown.

[0005] Incidentally, θ on the horizontal axis in FIG. 8 indicates the rotation angle of the engine. BTDC indicates that the phase is ahead of the top dead center TDC of the engine, and ATDC indicates that the phase is behind the top dead center.

In the example shown in FIG. 8, the maximum advance position signal P1 'is generated at the maximum advance position θa of the engine (a position advanced by an angle θa from the top dead center TDC of the engine), and the minimum advance position θb (A position advanced from the top dead center by the angle .theta.b), the minimum advance position signal P2 'is generated. Then, the calculation of the ignition position is performed with the angle θa-θb section from the position where the maximum advance position signal P1 'is generated to the position where the minimum advance position signal P2' is generated as the advance range. At low engine speeds,
At the minimum advance position θb, the primary current I1 of the ignition coil is cut off to generate a high voltage Vh on the secondary side of the ignition coil, and this high voltage is applied to the ignition plug to perform an ignition operation. The ignition position is advanced with an increase in the engine speed, and at the high speed of the engine, the primary current I of the ignition coil is set at the maximum advance position θa.
Cut off 1 and perform ignition operation. FIG. 9 shows a typical example of the characteristic of the ignition position with respect to the rotation speed N obtained by this type of ignition position control device.

[0007]

In a conventional ignition position control method for calculating an ignition position at each rotation speed by performing an integration operation and a comparison operation, a signal generator generates a maximum advance position signal P1 '. Since the angle between the generation of the minimum advance position signal P2 'and the advance angle width is defined as the advance angle width, the advance angle width is determined by the configuration of the signal generator. Therefore, it is necessary to prepare a different signal generator every time the advance width is different,
The costs were inevitable. Further, as shown in FIG. 9, when the ignition position at a low speed of the engine is constant,
Depending on the characteristics of the engine, when the throttle is opened and returned from the idling state of the engine for a short time, the engine may stop if the load suddenly increases in the process of decreasing the engine speed. For example, suppose that in the characteristics of FIG. 9, N1 and N2 are the engine start speed and the idling speed, respectively, and the throttle is suddenly opened from the idling state and immediately returned. At this time, the engine speed is, for example, N
3 (e.g., 3000 rpm) and then decrease, but if the engine load suddenly increases due to the turning on of headlamps etc. during the process of decreasing the engine speed, the engine output becomes insufficient and the engine speed decreases. The engine dropped below N2 and the engine stopped. This phenomenon is called snap stalling.

In the case of the conventional control method, FIG.
As shown by the solid line in (D), at the time of reverse rotation of the engine, the ignition operation is performed near the top dead center TDC (angle θb).
In the case of a two-stroke engine, when the engine is reversed for any reason, the reversal state may be maintained, which is dangerous. For example, in a motorcycle, when the engine is reversed by applying a reverse rotational force to the engine at the time of starting on a slope, the engine may not be stopped and the reverse rotation state may be maintained. However, there is a danger of causing personal injury as the vehicle starts suddenly backwards.

An object of the present invention is to make it possible to adjust an advance width by a circuit constant regardless of a signal generation interval of a signal generator, and to realize ignition characteristics of various advance widths without changing the signal generator. And an ignition position control device for implementing the method.

Another object of the present invention is to provide an ignition position for an internal combustion engine in which the occurrence of snap stalling is prevented by making it possible to advance the ignition position with a decrease in the rotational speed in a low speed region of the engine. It is to provide a control method and a control device.

Still another object of the present invention is to provide an ignition for an internal combustion engine in which the ignition position at the time of reverse rotation of the engine is greatly delayed from the top dead center, so that the possibility that the reverse rotation state of the engine continues can be eliminated. A position control method and apparatus are provided.

[0012]

According to the ignition position control method of the present invention, a circuit for charging an integrating capacitor with a predetermined time constant and a circuit for discharging the integrating capacitor with a predetermined time constant are provided. The period from the set position where the phase is advanced from the advanced position to the maximum advanced position is defined as the charging period of the integrating capacitor, and the period from the maximum advanced position to the next set position is defined as the discharging period of the integrating capacitor. An integrated voltage is generated across the capacitor, and when the integrated voltage falls below a reference voltage, an ignition signal for determining an ignition position is supplied to an ignition device for an internal combustion engine.

In the ignition position control method of the present invention, when the ignition position is fixed at the maximum advance position when the engine is running at a high speed, the following is performed. That is, in a rotation speed region lower than the set rotation speed at which the integrated voltage falls below the reference voltage at the maximum advance position, the ignition position is determined by the internal combustion engine ignition device when the integrated voltage falls below the reference voltage. Signal is supplied to the internal combustion engine ignition device at the maximum advance position in a rotation speed region equal to or higher than the set rotation speed.

In the above method, the charging time constant of the integrating capacitor is set so that the charging voltage of the integrating capacitor is saturated at a position before the maximum advance position .

The ignition position control apparatus of the present invention for implementing the above method detects, for example, a maximum advance position of the engine and a set position whose phase is advanced from the maximum advance position in synchronization with the rotation of the internal combustion engine. A control signal generator for generating a control signal for holding a first state in a section from the set position to the maximum advance position and receiving a second state in other sections from an output of a signal generator for generating a signal to generate A charging circuit for charging the integration capacitor with a predetermined time constant in a period in which the circuit, the integration capacitor and the control signal are in the first state, and a charging circuit in which the period in which the control signal is in the second state is a discharging period. The discharge circuit for discharging at a predetermined time constant and the control signal
And a reset circuit that instantaneously discharges the residual charge of the integration capacitor when the state changes from the state (1) to the state (1). The integration voltage obtained at both ends of the integration capacitor is compared with a reference voltage to determine the integration voltage. A first ignition position determination signal for generating a first ignition position determination signal for a low-to-medium-speed region when the voltage falls below a reference voltage;
And a second ignition position determination signal generation circuit that outputs a second ignition position determination signal for a high-speed region that is generated at the maximum advance position and disappears by the next set position. An ignition signal generation circuit for generating an ignition signal when a condition that both the ignition position determination signals are simultaneously present is satisfied by inputting the first ignition position determination signal and the second ignition position determination signal. can do.

Also in this case, the charging time constant of the integrating capacitor is set so that the charging voltage of the integrating capacitor is saturated at a position before the maximum advance position .

The signal generating device includes a rotor having an inductor and rotating synchronously with the internal combustion engine, and a signal generator having a signal coil wound around a magnetic path to which a magnetic flux is given by the inductor. A known signal generator can be used. In this case, the positional relationship between the rotor and the signal generator is set so that pulse-like signals having different polarities are generated at the set position and the maximum advance position where the phase is advanced from the maximum advance position of the engine. Keep it.

Further, instead of a signal generator having a signal coil, a signal generator using a Hall element or a Hall IC as an element for detecting a change in magnetic flux on the signal emitting side can be used.

[0019]

With the above construction, the integrated voltage rises at a constant gradient from the set position where the phase is advanced from the maximum advance position to the maximum advance position or a position just before the maximum advance position, and the integrated voltage is increased to the maximum advance angle. The waveform has a constant gradient from the position to the next set position. If an ignition signal is generated when this integrated voltage falls below the reference voltage, the integrated voltage becomes the integration time (charge time of the integration capacitor) accompanying the increase in the rotation speed.
As the rotation speed increases, the phase at which the integrated voltage falls below the reference voltage advances as the rotation speed increases, so that the ignition position can be advanced as the rotation speed increases. In this case, since the advance angle width can be variously adjusted by adjusting the integration constant, the signal generator can be shared with the igniter that obtains various ignition characteristics, and the signal generator can be standardized to reduce the cost. Reduction can be achieved.

Further, when the charging time constant of the integrating capacitor is set so that the charging voltage of the integrating capacitor is saturated at a position just before the maximum advance position as in the present invention , the integrated voltage becomes a reference when the engine is running at a low speed. Since the time until the voltage drops below a constant value, it is possible to obtain a characteristic that the ignition position is delayed with an increase in the rotational speed (the ignition position is advanced with a decrease in the rotational speed). If such characteristics are obtained at low speeds, the throttle will be opened immediately after the throttle is opened for a short time in the idling state of the engine, and if the load suddenly becomes heavy in the process of decreasing the number of revolutions, Since the output of the engine can be increased by advancing the ignition position, it is possible to prevent the engine from stopping (snap stalling).

Further, with the above configuration, the ignition position at the time of reverse rotation of the engine can be set to a position that is significantly delayed from the top dead center, so that when the engine is reversely rotated for some reason, , Can be prevented from continuing, and safety can be improved.

[0022]

FIG. 1 shows an example of the configuration of an apparatus for implementing an ignition position control method according to the present invention. In FIG. 1, reference numeral 1 denotes a signal generator 2, a waveform shaping circuit 3, and a flip-flop (F).
/ F) a control signal generation circuit comprising a circuit 4, 5 an integration circuit, 6 a reference voltage generation circuit for generating a reference voltage, 7 a first ignition position determination signal generation circuit, and 8 a second ignition position determination circuit. A signal generation circuit 9 is an ignition signal output circuit.

The signal generator 2 is composed of a signal generator attached to the internal combustion engine. As shown in FIG. 2A, the signal generator 2 is shifted from the maximum advance position of the engine in synchronization with the rotation of the internal combustion engine. A signal Po for detecting the set position θo with advanced phase and a signal P1 for detecting the maximum advance angle θ4 are generated. The waveform shaping circuit 3 shapes these signals Po and P1 into waveforms suitable for signal processing, such as pulse waveforms, and outputs the signals Po and P1.
To generate signals Vpo and Vp1, respectively.

The flip-flop circuit 4 outputs signals Vpo and V
The first state (for example, a high-level state) from the set position θo where the phase is advanced from the maximum advance position to the maximum advance position θ4, which is set and reset by p1, respectively, is held. A rectangular wave signal holding the second state (for example, a low level or a zero level state) is output as a control signal Vq (FIG. 2B).

The integrating circuit 5 includes an integrating capacitor, a charging circuit for charging the integrating capacitor with a predetermined time constant according to the control signal Vq, and a discharging circuit for discharging the integrating capacitor with a predetermined time constant according to the control signal Vq. And a reset circuit that instantaneously discharges the residual charge of the integrating capacitor when the control signal Vq changes from the second state to the first state, and the control signal holds the first state. The period during which the control signal is maintained in the second state is defined as the period during which the integration capacitor is charged.
An integrated voltage is obtained across the integrating capacitor.

Therefore, as shown in FIG. 2 (C), both ends of the integrating capacitor of the integrating circuit 5 rise at a predetermined inclination from the set position θo to the maximum advance position θ4 or a position just before the maximum advance position θ4. Then, an integrated voltage Vi having a waveform falling from the maximum advance position θ4 to the next set position θo with a predetermined inclination is obtained.

The reference voltage generation circuit 6 divides the output voltage of the low-voltage DC power supply and divides the output voltage into a predetermined reference voltage Vr (FIG.
C) is output. The first ignition position determination signal generating circuit 7 compares the integrated voltage Vi obtained at both ends of the integrating capacitor of the integrating circuit 5 with the reference voltage Vr, and when the integrated voltage Vi falls below the reference voltage Vr, the first ignition Positioning signal V
Generate f1.

The second ignition position determination signal generating circuit 8 receives the control signal Vq as input and generates a second ignition position determination signal Vf2 which is generated at the maximum advance position and disappears by the next set position.

The ignition signal output circuit 9 receives the first ignition position determination signal Vf1 and the second ignition position determination signal Vf2 as inputs and generates both ignition position determination signals simultaneously (first condition).
When both the second ignition position determination signal and the second ignition position determination signal are high level signals, the ignition signal Vf is output when the AND condition of both ignition position determination signals is satisfied.

Here, as shown by a solid line in FIG. 2C, assuming that an integrated voltage Vi that rises at a predetermined inclination from the set position θo to the maximum advance position θ4 is obtained, this integrated voltage is Since the charging voltage decreases as the charging time decreases as the engine speed increases, the phase in which the integrated voltage falls below the reference voltage Vr advances as the engine speed increases.
The phase at which the ignition position determination signal is generated continuously advances as the engine speed increases. When the engine speed reaches the set value, the integrated voltage becomes lower than the reference voltage at the maximum advance position, and the first ignition position determination signal is constantly generated.

Therefore, in the low and medium speed range where the engine speed is equal to or less than the set value, when the first ignition position determination signal is generated (the second ignition position determination signal has already been generated at the maximum advance position. ), The condition that the first ignition position determination signal and the second ignition position determination signal exist at the same time is satisfied, and the ignition signal is generated. This ignition signal is supplied to an ignition circuit not shown in FIG. The ignition circuit controls so that the primary current of the ignition coil changes suddenly when an ignition signal is given, and generates a high voltage Vh (FIG. 2D) for ignition on the secondary side of the ignition coil.

The position at which the ignition signal is generated when the integrated voltage falls below the reference voltage advances as the rotational speed increases. After the rotation speed reaches the set value and the ignition position is advanced to the maximum advance position, the first ignition position determination signal is always generated, so that the second ignition position is at the maximum advance position. The ignition signal is generated at the same time as the decision signal is generated. Also, as shown by the broken line in FIG. 2C, if the circuit constant of the integration circuit is set so that the charging voltage of the integrating capacitor is saturated at a low speed, the charging voltage of the integrating capacitor is saturated while the charging voltage of the integrating capacitor is saturated. Since the time required for the integrated voltage Vi to fall below the reference voltage becomes constant, the position where the integrated voltage Vi falls below the reference voltage is delayed as the rotational speed increases. Therefore, in a low-speed region where the charging voltage of the integration capacitor is saturated, a characteristic is obtained in which the ignition position is delayed with an increase in the rotational speed (the ignition position is advanced with a decrease in the rotational speed).

The ignition position θ obtained by the above ignition device
FIG. 3 shows an example of the characteristics of f with respect to the rotation speed N. FIG.
In FIG. 2, the characteristic indicated by the broken line below the rotational speed N2
This is a characteristic when the integrated voltage is saturated as shown by the broken line in FIG.

With the above configuration, the advance angle width θ4−θ
2 is a generation interval Δθ between the output signals Po and P1 of the signal generator.
, But not by the circuit constant of the integrating circuit and the magnitude of the reference voltage. Therefore, a signal generator can be shared when obtaining ignition characteristics having different advance angle widths,
The cost can be reduced by standardizing the signal generator.

With the above configuration, the circuit constant of the integration circuit is set so as to saturate the charging voltage of the integration capacitor when the engine is running at a low speed. Can be obtained, so that the above-mentioned snap stalling can be prevented from occurring.

For example, in FIG. 3, it is assumed that N1 and N2 are a starting rotational speed and an idling rotational speed, respectively, and the throttle is opened for a short time in the idling state and then returned immediately. At this time, the number of revolutions of the engine starts decreasing immediately after increasing to, for example, N3. If the engine load becomes heavier due to the lighting of headlamps or the like in the process of lowering the rotational speed, the rotational speed will be lower than the idling rotational speed N2, but if the rotational speed falls below the idling rotational speed N2, the ignition position will advance. As a result, the output of the engine is increased and the stop of the engine is prevented. This can prevent the occurrence of snap stalling.

In the above configuration, if the engine is reversed for some reason while the engine is rotating at the maximum advance position at high speed, the maximum advance position signal P1 at the time of reverse rotation is θ
Since it occurs at the position of o, the ignition position at the time of reverse rotation is the position of θo. Therefore, by setting the generation interval Δθ of the signals Po and P1 to be sufficiently large, the ignition position θo at the time of reverse rotation of the engine can be set to a position that is significantly delayed from the top dead center, and the engine speed can be reduced. When the engine is reversed for some reason during operation, the reverse state can be prevented from continuing.

When an ignition circuit of a capacitor discharge type is used in the ignition device for an internal combustion engine, the ignition operation can be performed only by giving an ignition signal at the ignition position. Therefore, the ignition signal is a pulse rising at the ignition position. Shaped waveform is acceptable.

However, when a current cutoff type ignition circuit is used, a short-circuit current is applied to the ignition power supply coil at a position where the phase is advanced from the ignition position, and the current is cut off at the ignition position to induce a high voltage. The ignition signal is
The signal must include information for determining a position at which the short-circuit current starts to flow and information of a position (ignition position) at which the short-circuit current is interrupted. In such a case, it is necessary to perform a predetermined calculation in the ignition position determination signal generation circuit 8 to calculate a position at which the primary current starts flowing through the ignition coil. A specific example of this calculation will be described in an embodiment described later.

In the above-described embodiment, the second ignition position determination signal generation circuit is provided to provide an ignition signal in a rotation speed region equal to or higher than the rotation speed at which the advance is completed. In some cases, it is sufficient to obtain the characteristic of continuously advancing the ignition position from a low speed to a high speed. In such a case, without generating the second ignition position determination signal,
The ignition signal may be given only by the first ignition position determination signal. In this case, since the ignition signal cannot be obtained when the rotation speed of the engine reaches the set value and the ignition position is advanced to the maximum advance position, the engine is misfired. Therefore, it is possible to prevent the engine from over-rotating without providing a special over-rotation preventing circuit.

FIG. 4 shows an embodiment of the present invention which is used when a current cutoff type ignition device for an internal combustion engine is used. In FIG. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals. I have. In FIG. 4, reference numeral 10 denotes an ignition circuit of a current interruption type. This ignition circuit includes an ignition coil IG, a composite transistor T1 serving as a Darlington-connected primary current control switch, and an interruption control for interrupting the transistor TR1 at the ignition position. Transistor T2 as a switch for
, A resistor R1, and a spark plug PL attached to a cylinder of the engine. One end of a primary coil and one end of a secondary coil of the ignition coil IG are commonly connected, and the common connection point is connected to a positive terminal of a battery (not shown) having a negative electrode grounded. Therefore, the battery voltage Eb is applied to both ends of the series circuit of the collector-emitter circuit of the transistor TR1 and the primary coil of the ignition coil.

In this ignition circuit, the transistor T2
When the ignition signal Vf is not given to the base of
A base current is applied to the transistor T1 from the DC power supply through the resistor R1, and the transistor T1 conducts. When the transistor T1 is turned on, a short-circuit current (primary current) i1 flows from the battery through the primary coil of the ignition coil and the collector and emitter of the transistor T1. When the ignition signal Vf is applied to the base of the transistor T2, the transistor T2 is turned on, so that the base potential of the transistor T1 is reduced to almost the ground potential and the transistor T1 is turned off. As a result, the ignition coil 1
The primary current i1 is cut off and the primary coil of the ignition coil
A voltage having a high polarity is induced to keep flowing the next current i1. Since this voltage is further boosted by the ignition coil, the ignition high voltage Vh is applied to the secondary coil of the ignition coil IG.
Is induced. Since this high voltage is applied to the spark plug PL, a spark is generated in the spark plug and the engine is ignited.

The signal generator comprises an inductor type signal generator mounted on the internal combustion engine, and the signal coil 2a of the signal generator has a set rotation angle of the engine as shown in FIG. Pulse-like signals Po and P1 having different polarities are generated at the position (set position) θo and the maximum advance position θ4. In the illustrated example, the signal Po has a positive polarity, and the signal P1 has a negative polarity. Here, θ4 is set to coincide with the maximum advance position of the internal combustion engine. The generation interval Δθ = θo-θ4 between the signals Po and P1 corresponds to the polar arc angle of the inductor of the signal generator. In FIG. 5, angles such as θo and θ4 are measured on the advance side with respect to the top dead center TDC of the engine.

The waveform shaping circuit 3 includes a transistor T3,
It comprises diodes D1 to D3, resistors R2 to R5 and capacitors C1 and C2. Signal coil 2
When a generates a signal Po of positive polarity, the pulse signal Vpo is passed through the resistor R2 for a short period during which the signal Po exceeds the voltage across the capacitor C1 (a period during which the signal Po is higher than a predetermined threshold level). Is output. When the signal P1 is input, the signal P1 is
Short period during which the voltage between both ends of 2 is exceeded (period during which the signal P1 is at or above a predetermined threshold level)
A current flows through the diode D3, the resistor R3, and the diode D2. At this time, the forward voltage drop across the diode D3 causes a reverse bias between the base and the emitter of the transistor T3, and the transistor T3 is turned off. During a short time when the transistor T3 is in the cut-off state, the potential of the collector of the transistor T3 rises almost to the power supply voltage. Therefore, when the signal P1 is generated, a pulse signal Vp1 is obtained at the collector of the transistor T3.

The flip-flop circuit 4 comprises transistors T4 to T6, a resistor R6, and a capacitor C3. When the pulse signal Vpo is supplied from the waveform shaping circuit 3, the transistor T4 is turned on and the transistor T5 is turned on, and the capacitor C3 is instantaneously charged from the DC power supply circuit (not shown) through the transistor T5 (the flip-flop circuit is set). ). When the waveform shaping circuit 3 generates the pulse signal Vp1, the transistor T
6 becomes conductive, the electric charge of the capacitor C3 is discharged instantaneously through the transistor T6 (the flip-flop circuit is reset). Therefore, at both ends of the capacitor C3, as shown in FIG. 5B, a high level state (first state) is maintained from the set position .theta.o to the maximum advance position .theta.4, and the next setting from the maximum advance position .theta.4. The control signal Vq in the form of a rectangular wave that maintains the low-level state (second state) up to the position θo is obtained.

The integrating circuit 5 includes a transistor T7, a comparator CM1, a diode D4, a capacitor C4 for differentiating a control signal, an integrating capacitor C5, and a resistor R
7 or R11. In the integrating circuit 5, the control signal V is controlled by the diode D4 and the resistor R11.
A charging circuit is configured to charge the integrating capacitor C5 with a constant time constant with a period in which q is in a high level state (first state) as a charging period, and the comparator CM1 and the resistors R8 to R8.
A discharge circuit is constituted by 10 in which the integration capacitor C5 is discharged with a constant time constant with a period in which the control signal Vq is in a low level state (second state) as a discharge period.
The transistor T7, the capacitor C4, and the resistor R7 form a reset circuit for the integrating capacitor. The operation of this integration circuit is as follows.

When the control signal Vq is generated, a base current is instantaneously applied to the transistor T7 through the capacitor C4 at the rise thereof, so that the transistor T7 constituting the reset circuit is instantaneously turned on, and the integrating capacitor C7 is turned on.
5 is discharged instantaneously. After the discharging of the integrating capacitor C5, the transistor T7 returns to the cut-off state. During the period in which the control signal Vq is generated, the non-inverting input terminal (+
The level of the control signal Vq applied to the
9 is higher than the set voltage obtained at both ends of the comparator C.
The output stage of M1 is shut off. Therefore, during the period when the control signal Vq is generated, the capacitor C5 is connected to the resistor R10.
There is no discharge through the output stage of the comparator CM1. When the transistor T7 is turned off, the integration capacitor C5 is charged to the polarity shown in the figure at a predetermined time constant through the diode D4 and the resistor R11 by the control signal Vq. Therefore, the integrated voltage Vi across the integrating capacitor C5 increases as shown in FIG. 5 during the period when the control signal Vq is generated. The waveform of the integrated voltage is such that the engine speed changes from N1 to N1.
4 (N1 <N2 <N3 <N4). In this example, as seen from the integrated voltage at the rotation speed N1 shown in FIG. 5C, the charging voltage of the integrating capacitor C5 is saturated at a low speed of the engine before the control signal Vq disappears. , Integrating capacitor C5
Is set.

When the control signal Vq disappears at the maximum advancing position θ4, the output stage of the comparator CM1 becomes conductive and the output terminal of the comparator CM1 is connected to the ground, so that the electric charge of the integrating capacitor C5 is connected to the resistance R10. Discharge is performed at a constant time constant through the output stage of the comparator CM1. Therefore, the integral voltage V
As shown in FIG. 5 (C), i decreases with a predetermined inclination from the maximum advance position θ4 to the next set position θo. When the control signal Vq is generated at the set position, the transistor T7 is instantaneously turned on by the above-described operation to discharge the capacitor C5, and the integrated voltage Vi returns to zero.

The reference voltage generating circuit 6 includes resistors R12 and R13.
The reference voltage Vr is generated across the resistor R13 by dividing the power supply voltage.

The first ignition position determination signal generating circuit 7 comprises a comparator CM2, which generates a high-level first ignition position determination signal Vf1 when the integrated voltage Vi falls below the reference voltage Vr. .

When the engine speed is low (for example, at N1)
Because the charging voltage of the integrating capacitor is saturated,
The time required for the integrated voltage Vi to fall below the reference voltage Vr is constant. Therefore, the position where the integrated voltage Vi becomes lower than the reference voltage is delayed as the rotation speed increases. As the rotation speed increases, the time required to charge the integration capacitor decreases, and when the rotation speed increases to a certain rotation speed N2,
The charging voltage of the integration capacitor is no longer saturated. When the rotation speed further increases from this rotation speed, the charging time of the integration capacitor becomes shorter, so that the peak value of the integration voltage Vi becomes lower and the position where the integration voltage Vi becomes lower than the reference voltage Vr (lower position). The ignition position in the medium speed range) advances.

The second ignition position determination signal generating circuit 8 includes transistors T8 and T9, a comparator CM3, signal differentiation capacitors C6 and C8, integration capacitors C7 and C9, resistors R14 to R18, and a diode D5. The signal Vp1 obtained from the waveform shaping circuit 3 is supplied to the base of the transistor T8 through the capacitor C6.

In the second ignition position determination signal generating circuit 8, when the signal Vp1 is generated from the waveform shaping circuit 3 at the maximum advance position, the base current is instantaneously applied to the transistor T8 through the capacitor C6.
8 instantaneously conducts, and the charge of the integrating capacitor C7 is discharged instantaneously through the transistor T8. Thereafter, the capacitor C7 is charged with a constant time constant through the resistor R15 by the power supply voltage. Therefore, an integrated voltage Vc1 as shown in FIG. 5E is obtained at both ends of the integrating capacitor C7.

When the control signal Vq rises at the set position θo, a base current is supplied to the transistor T9 through the resistor R16 and the capacitor C8. As a result, the transistor T9 conducts, and the integrating capacitor C9
To discharge. When a certain period of time has elapsed since the generation of the control signal Vq at the set position, the charging of the integrating capacitor C8 ends, and the transistor T9 is turned off. Therefore, the integration capacitor C9 is charged to the shown polarity through the diode D5 and the resistor R18 by the control signal Vq. Therefore, as shown in FIG.
An integrated voltage Vc2 having the waveform shown in FIG.

The above-mentioned integrated voltages Vc1 and Vc2 are output from the comparator C
It is input to M3 and compared. The comparator CM3 is shown in FIG.
As shown in (F), a second ignition position determination signal that rises to a high level when the integral voltage Vc2 exceeds the integral voltage Vc1, and falls to a low level when the integral voltage Vc2 falls below the integral voltage Vc1. Outputs Vf2. The rising position of the second ignition position determination signal Vf2 always coincides with the maximum advance position θ4, but its falling position advances with an increase in the rotational speed. The rising of the second ignition position determination signal Vf2 is used as a signal for determining the ignition position at high speed. Further, the fall of the signal is used as a signal for determining a position where the primary current starts flowing through the ignition coil.

The ignition signal output circuit 9 is connected to the comparator CM2
A circuit for connecting the output terminal of the comparator CM3 and the output terminal of the comparator CM3 together so as to form an AND circuit, and a resistor R19 for connecting a common connection point of the output terminals of both comparators to a DC power supply. As shown in FIG. 5 (G), the ignition signal output circuit rises when a condition that the first ignition position determination signal Vf1 and the second ignition position determination signal Vf2 are simultaneously present is established. Outputs an ignition signal Vf which falls when the signal disappears. The rising position (ignition position) of the ignition signal Vf is delayed as the engine speed increases below the set value N2 when the engine speed is equal to or lower than the set value N2, and increases when the engine speed exceeds the set value N2. It goes along with. When the rotational speed exceeds the set value N4, the rising position of the ignition signal Vf is fixed at the maximum advance position θ4. The fall position of the ignition signal (the position where the primary current starts to flow) advances with an increase in the rotational speed.

When the ignition signal Vf is applied to the base of the transistor T2 of the ignition circuit 10, the transistor T2
2 is turned on, the transistor T1 is turned off. As a result, the primary current i1 is cut off as shown in FIG.
The high voltage Vh shown in (I) is induced. Since this high voltage is applied to the spark plug PL, a spark is generated in the spark plug and the engine is ignited. When the ignition signal Vf is extinguished, the transistor T2 is turned off.
And the primary current flows through the ignition coil. Since the position at which the primary current starts to flow in the ignition coil advances with an increase in the number of revolutions, it is necessary to prevent the time during which the primary current flows during the high-speed rotation from becoming too short, and to secure ignition performance at a high speed. Can be.

In the above embodiment, the characteristic that the ignition position is delayed as the engine speed increases at low speed of the engine is obtained. However, the circuit constant is set so that the charging voltage of the integrating capacitor is not saturated at low speed. Thus, it is possible to obtain a characteristic that the ignition position is advanced with the increase in the rotation speed from a low speed.

FIG. 6 shows an embodiment of the present invention which is applied to the case where a capacitor discharge type ignition circuit 11 is used. In FIG. 6, the same parts as those in FIG. 4 are denoted by the same reference numerals. It is.

The ignition circuit 11 includes an ignition coil IG, an ignition plug PL, an ignition energy storage capacitor C10,
This is a known circuit including diodes D11 and D12, a thyristor S1, and a capacitor charging power supply circuit (not shown) for supplying a charging current to the capacitor C10 to charge the capacitor C10 to the illustrated polarity.

In this ignition circuit, the ignition energy storage capacitor C10 is charged to the illustrated polarity by a power supply circuit (not shown) that uses an exciter coil or the like provided as a power source in a magnet generator attached to the internal combustion engine. This charging current is from the power supply circuit → capacitor C10 → diode D11
And the primary coil of the ignition coil → the power supply circuit. When the ignition signal Vf is applied to the thyristor S1 at the ignition position of the engine, the thyristor conducts and discharges the charge of the capacitor C10 to the primary coil of the ignition coil. As a result, a large magnetic flux change occurs in the iron core of the ignition coil, so that a high voltage is generated in the secondary coil of the ignition coil, and the ignition plug PL
Sparks fly.

When such a capacitor discharge ignition circuit is used, the thyristor S1 is placed at the ignition position of the engine.
May be given a pulse-like ignition signal. Therefore, in this case, the operation for determining the conduction start position of the primary current of the ignition coil is not necessary, and the second ignition position determination signal generation circuit generates the signal at the maximum advance position and reaches the next set position. It is sufficient to generate a second ignition position determination signal that disappears at the end.

Therefore, in this embodiment, the comparator CM3
And resistors R20 and R21 for dividing the power supply voltage.
The control signal Vq is applied to the inverting input terminal (-terminal) of the comparator CM4, and the reference voltage obtained across the resistor R21 is applied to the non-inverting input terminal of the comparator CM4. Each has been entered.

The ignition signal output circuit 9 further includes a comparator CM2
A differential capacitor C11 for outputting a pulsed ignition signal Vf when the potential at the common connection point between the output terminals of the first and CM3 rises to a high level. Other configurations are shown in FIG.
This is the same as the embodiment. The voltage or current waveform of each part of this embodiment is shown in FIGS. 7 (A) to 7 (H).

In the embodiment of FIG. 4, the comparator CM3 is
As shown in FIG. 7E, the control signal V at the maximum advance position
When the control signal Vq rises at the set position, the second ignition position determination signal Vf2 in the form of a rectangular wave is output, which rises to zero when the control signal Vq rises at the set position.

In the region where the rotational speed is equal to or lower than N4, the condition that the first ignition position determination signal Vf1 and the second ignition position determination signal Vf2 are simultaneously present when the first ignition position determination signal Vf1 is generated is satisfied. Therefore, the first ignition position determination signal Vf1
At the common connection point of the output terminal of the comparator CM2 and the output terminal of the comparator CM3, a signal Vf 'having a rectangular waveform as shown in FIG. 7F is generated, and the rising edge of the signal Vf' causes the capacitor C11 to rise. , An ignition signal Vf (FIG. 7G) is output.

In the region where the number of revolutions exceeds N4, the first ignition position determination signal Vf1 maintains a high level state.
At the maximum advance position, the ignition signal Vf is generated simultaneously with the generation of the second ignition position determination signal Vf2.

In the above embodiment, the control signal Vq maintains a high level from the set position to the maximum advance position, and maintains a low level from the maximum advance position to the next set position. This control signal may be a signal that can distinguish the section from the set position to the maximum advance position and another section,
Depending on the configuration of the integration circuit or the like, the signal may be a signal that holds a low level from the set position to the maximum advance position and holds a high level from the maximum advance position to the next set position. In other words, the control signal may be a signal that holds the first state from the set position to the maximum advance position and holds the second state from the maximum advance position to the next set position.

In the above embodiment, both the first ignition position determination signal and the second ignition position determination signal are high-level signals. However, depending on the configuration of a subsequent circuit that receives these signals as input, These signals can be low-level signals or signals having polarities different from each other.

[0070]

As described above, according to the present invention, the maximum ascends at a constant inclination from the set position where the phase is advanced from the maximum advance position to the maximum advance position or a position immediately before the maximum advance position. An integrated signal having a waveform that descends with a constant slope from the advanced position to the next set position is obtained, and when this integrated voltage falls below the reference voltage, an ignition signal for obtaining advanced characteristics is generated. By adjusting the constant, the advance angle width can be variously adjusted. Therefore, the signal generator can be used in common with the ignition device that obtains various ignition characteristics, and the cost can be reduced by standardizing the signal generator.

In the present invention, by setting the charging time constant of the integrating capacitor so that the charging voltage of the integrating capacitor is saturated at a position just before the maximum advance position, the rotational speed increases at low speed. The characteristic that the ignition position is delayed (i.e., the ignition position is advanced as the rotation speed decreases) can be obtained. If such characteristics are obtained at low speeds, the throttle will be opened immediately after the throttle is opened for a short time in the idling state of the engine, and if the load suddenly becomes heavy in the process of decreasing the number of revolutions, Since the ignition position can be advanced to increase the output of the engine, it is possible to prevent the engine from stopping.

Further, according to the present invention, the ignition position when the engine reverses can be set to a position that is significantly delayed from the top dead center, so that the engine can be reversed during operation for some reason. In this case, there is an advantage that the reverse state can be prevented from continuing.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of an apparatus that implements a control method according to the present invention.

FIGS. 2A to 2D are signal waveform diagrams for explaining a control method of the present invention.

FIG. 3 is a diagram showing an example of ignition characteristics obtained by the present invention.

FIG. 4 is a circuit diagram showing an embodiment in which each part of the apparatus of FIG. 1 is concretely illustrated;

5 (A) to 5 (I) are waveform diagrams showing voltage or current waveforms at various parts in FIG. 4;

FIG. 6 is a circuit diagram showing another embodiment in which each part of the device of FIG. 1 is concretely illustrated;

7 (A) to 7 (H) are waveform diagrams showing waveforms of voltages or currents of respective parts in FIG. 4;

8 (A) to 8 (D) are signal waveform diagrams for explaining a conventional ignition position control method.

FIG. 9 is a diagram showing ignition characteristics obtained by a conventional ignition position control method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Control signal generation circuit, 2 ... Signal generation device, 4 ... Flip-flop circuit, 5 ... Integration circuit, 6 ... Reference voltage generation circuit, 7 ... First ignition position determination signal generation circuit, 8 ... Second ignition position Decision signal generation circuit, 9 ... Ignition signal output circuit.

Claims (3)

(57) [Claims] A circuit for charging an integration capacitor with a predetermined time constant and a circuit for discharging the integration capacitor with a predetermined time constant are provided. An integration voltage is generated at both ends of the integration capacitor by taking a period from the maximum advance position to a charge period of the integration capacitor, and a period from the maximum advance position to a next set position as a discharge period of the integration capacitor. ignition position but to supply an ignition signal for determining the ignition position on an ignition device when lower than the reference voltage
In the position control method, the integration capacitor is located at a position before the maximum advance position.
Charge of the integrating capacitor so that the charging voltage of the
An ignition position control method for an internal combustion engine, wherein a time constant is set . 2. A circuit for charging an integrating capacitor with a predetermined time constant and a circuit for discharging the integrating capacitor with a predetermined time constant. An integration voltage is generated at both ends of the integration capacitor during a period from the maximum advance position to a next set position during a period from the maximum advance position to a next set position. In a rotation speed region lower than a set rotation speed at which the integrated voltage falls below the reference voltage at the position, when the integrated voltage falls below the reference voltage, an ignition signal for determining an ignition position in the internal combustion engine ignition device is set. In the internal combustion engine ignition position control method for supplying an ignition signal to the internal combustion engine ignition device at the maximum advance position in the rotation speed region at or above the set rotation speed.
The integration capacitor at a position before the maximum advance position.
Charge of the integrating capacitor so that the charging voltage of the
An ignition position control method for an internal combustion engine, wherein a time constant is set . 3. An ignition signal for determining an ignition position of an internal combustion engine.
Ignition position for controlling the position of occurrence according to the speed of the internal combustion engine
In the control device, the maximum advance position of the engine and the maximum advance position are synchronized with the rotation of the internal combustion engine.
A signal that detects a set position whose phase is advanced from the advance position
The output of the signal generator that generates
Hold the section first state from the position to the maximum advance position,
In other sections, control for generating a control signal for maintaining the second state is performed.
A control signal generating circuit, an integrating capacitor, and a period in which the control signal is in the first state.
Charge the integration capacitor with a predetermined time constant.
A charging circuit for charging and a period when the control signal is in the second state.
A predetermined time constant with the integration capacitor as a discharge period.
A discharge circuit for discharging at a time, and whether the control signal is in the second state.
When the first state is reached, the residual charge of the integrating capacitor is instantaneously
An integration circuit having a reset circuit that discharges the integrated voltage at a time, and an integrated voltage obtained across the integration capacitor as a reference voltage.
Voltage when the integrated voltage falls below the reference voltage.
A first ignition position determination signal for generating a first ignition position determination signal
The signal is generated at the maximum advance position and disappears by the next set position.
A second ignition position determination signal for outputting a second ignition position determination signal
A constant signal generation circuit, the first ignition position determination signal and the second ignition position determination signal
That both ignition position determination signals exist at the same time
An ignition signal output that outputs the ignition signal when the condition is satisfied.
A power circuit, and the integration capacitor at a position before the maximum advance position.
Charge of the integrating capacitor so that the charging voltage of the
An ignition position control device for an internal combustion engine, wherein a time constant is set .