JPH0726604B2 - Ignition device for internal combustion engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ignition device for an internal combustion engine having an advance angle function.

[Prior Art] In order to operate an internal combustion engine efficiently, in many cases, an ignition device having a characteristic of advancing the ignition position in accordance with an increase in rotation speed is required. It usually varies depending on the model.

By the way, as an ignition device for an internal combustion engine having an advance angle characteristic, a signal coil that generates first and second signals at a maximum advance position and a minimum advance position of the engine, respectively, and an output of this signal coil as an input An ignition position control circuit that generates an ignition signal whose generation position appropriately changes between the advance position and the minimum advance position according to the rotation speed is known. In this type of ignition device, the maximum advance angle position and the minimum advance angle position are respectively determined by the first signal and the second signal generated by the signal coil, and the second signal is generated after the first signal is generated. The interval until the occurrence is the advance width.

[Problems to be Solved by the Invention] As described above, in the conventional ignition device for an internal combustion engine, the angle width from the generation of the first signal to the generation of the second signal by the signal coil is advanced. Since the width of the signal generator is different, it is necessary to change the configuration of the signal generator each time the advance angle width required by the internal combustion engine is different, and the signal generator cannot be shared by the ignition devices for internal combustion engines having various characteristics. Therefore, it is necessary to remake the signal generator each time the required advance angle width is different, and there is a problem that the cost of the ignition device increases.

An object of the present invention is to provide an ignition device for an internal combustion engine, which can obtain various advance widths with one type of signal generator.

[Means for Solving the Problems] The present invention is directed to the operation of the ignition coil by the operation of the semiconductor switch.
An ignition circuit that suddenly changes the secondary current to generate a high voltage for ignition on the secondary side of the ignition coil; a first signal that becomes a threshold level or more at a first rotational angle position of the internal combustion engine; A signal coil for generating a second signal having a threshold level or higher at a second rotation angle position whose phase is delayed from the first rotation angle position, and a first rotation using the first and second signals as inputs. In an ignition device for an internal combustion engine, which includes an ignition position control circuit that generates an ignition signal for operating a semiconductor switch between an angular position and a second rotational angular position, an advance width can be electrically adjusted. It was done like this.

Therefore, in the present invention, the ignition position control circuit is composed of the following elements.

I. Initial integration operation of initially charging the first integrating capacitor with the first charging current from the first rotation angle position to the position where the terminal voltage of the first integrating capacitor reaches the set value, and the terminal of the first integrating capacitor. A first integrating circuit performing an additional integrating operation of additionally charging the first integrating capacitor with a second charging current smaller than the first charging current from a position where the voltage reaches a set value.

B. A second integration circuit that performs an integration operation of charging the second integration capacitor from each second rotation angle position with a constant time constant.

C. The first integrated voltage obtained across the first integrating capacitor is compared with the second integrated voltage obtained across the second integrating capacitor, and the first integrated voltage exceeds the second integrated voltage. An ignition signal generation circuit that sometimes generates an ignition signal.

D. A reset circuit that discharges each of the first integration capacitor and the second integration capacitor from a position where the first integrated voltage exceeds the second integrated voltage to a second rotation angle position.

[Advantageous Effects of Invention] According to the above configuration, the angle at which the terminal voltage of the first integrating capacitor is equal to the terminal voltage of the second integrating capacitor during the period when the initial integrating operation is performed is the first integrating capacitor. Is determined by the first and second charging currents and the charging current of the second integrating capacitor, and the rotation speed (rpm)
Become irrelevant to. That is, the position where the terminal voltage of the first integrating capacitor becomes equal to the second integrating voltage during the period when the initial integrating operation of the first integrating circuit is performed is the maximum advance position, and this maximum advance position is It can be appropriately set by the first and second charging currents of the first integrating capacitor and the charging current of the second integrating capacitor. Therefore, the advance width can be changed without changing the structure of the signal generator provided with the signal coil.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

[I] Configuration of the embodiment of FIG. 1 a. Ignition circuit 4 FIG. 1 shows the basic configuration of one embodiment of the present invention.
In the figure, 1 is a primary coil 1a with one end commonly connected.
An ignition coil 2 having a secondary coil 1b is attached to a cylinder of an engine (not shown), and an ungrounded terminal is connected to the other end of the secondary coil of the ignition coil via a high voltage cord. The common connection point of one ends of the primary coil and the secondary coil of the ignition coil 1 is connected to the collector of the transistor 3 as a primary current controlling semiconductor switch whose emitter is grounded, and the other end 1a1 of the primary coil has a negative terminal. It is connected to the positive electrode terminal of a grounded battery (not shown).
As the transistor 3 in this example, a composite transistor in Darlington connection is used. The ignition coil 1, the ignition plug 2, and the transistor 3 constitute an ignition circuit 4.

In the ignition circuit, a transistor (hereinafter also referred to as a semiconductor switch) 3 is turned on by a control circuit, which will be described later, at a position ahead of the ignition position of the engine by a base current supplied from a power source (not shown) through a resistor Rs. ,
At the ignition position, the base current is cut off and the transistor 3 is cut off. When the transistor 3 is turned off, the primary current that has been flowing between the primary coil 1a of the ignition coil and the collector-emitter of the transistor 3 is cut off, so that the primary current is passed through the primary coil. A high voltage that tends to continue is induced. At this time, a large magnetic flux change occurs in the iron core of the ignition coil, and this magnetic flux change induces a high voltage in the secondary coil. Since this high voltage is applied to the spark plug 2, spark discharge is generated in the spark plug 2 and the engine is ignited. That is, in the ignition circuit of this example, the position where the semiconductor switch 3 performs the breaking operation is the ignition position.

The control circuit that controls the transistor (semiconductor switch) 3 includes a signal coil 5, a rectangular wave generation circuit 6, a pulse shaping circuit 7, a first integration circuit 8, and a second integration circuit 9.
A reset circuit 10 and an ignition signal generation circuit 11. Each of these parts will be described below.

b. Signal coil 5 The signal coil 5 is arranged in the signal generator that rotates in synchronization with the rotation of the engine, and one end thereof is grounded. As shown in FIG. 2A, the signal coil 5 exceeds the threshold level Vt at the first rotation angle position θ1 of the engine and at the second rotation angle position θ2 whose phase is behind that of the first rotation angle position, respectively. A first signal Vs1 and a second signal Vs2 are generated. The horizontal axis of FIG. 2 represents the engine rotation angle. The angles at the first rotation angle position and the second rotation angle position are measured from the top dead center TDC of the engine to the advance side. ing.

In this type of ignition device, the second signal Vs2 is set to be larger than the first signal Vs1 when the engine speed is extremely low, and the second signal Vs2 is set to the second signal Vs1 when the engine is started. Signal becomes higher than the threshold level before the first signal.

b. Rectangular wave generation circuit 6 The rectangular wave generation circuit 6 receives the output of the signal coil 5 as an input,
As shown in FIG. 2B, the rectangular wave signal Vq that continues from the first rotation angle position to the second rotation angle position is output, and the pulse shaping circuit 7 outputs the second waveform signal Vq as shown in FIG. 2C. Signal Vs2
Is shaped to output a pulse Vp rising at the second rotation angle position θ2.

c. First integrating circuit 8 The first integrating circuit 8 includes a first integrating capacitor 8a, an initial charging circuit 8A and an additional charging circuit 8B, and the first integrating capacitor 8a is connected to the first rotation angle. Position θx at which the terminal voltage of the first integrating capacitor 8a reaches the set value Vo from position θ1
Until the first charging current I11 is initially charged with the first charging current I11 and the terminal voltage of the first integrating capacitor 8a reaches the set value.
An additional integration operation of additionally charging with a second charging current I12 smaller than I11 is performed.

d. Second integrating circuit 9 The second integrating circuit 9 includes a second integrating capacitor 9a and a constant current.
A charging circuit 9A for charging the capacitor 9a with I2 is provided, and a second integrating capacitor is connected to each second rotation angle position θ2.
Performs an integration operation that charges from a constant time constant.

e. Reset circuit 10 The reset circuit 10 includes the first integration capacitor between the position where the terminal voltage of the first integration capacitor 8a exceeds the terminal voltage of the second integration capacitor and the second rotation angle position θ2.
8a and the second integrating capacitor 8b are respectively discharged. In this example, the pulse signal Vp rising at the second rotation angle position θ2 is input, and the first and the second rotation angle position θ2 are supplied. The integrating capacitors 8a and 9a are designed to be discharged almost instantly. Therefore, the first integrating capacitor 8a
The first integrated voltage Vc1 obtained at both ends of the waveform has a waveform as shown by the solid line in FIG. 2D, and the waveform of the second integrated voltage Vc2 obtained at both ends of the second integrating capacitor 9a is shown in FIG. As shown by the broken line in D.

The terminal voltages of the first and second integrating capacitors are used to generate a signal that determines the position at which the semiconductor switch 3 is operated (interruption operation in the above example) to perform the ignition operation. Since it is not necessary after the signal is generated, the reset of the first and second integration circuits does not necessarily have to be performed at the second rotation angle position. Therefore, the reset circuit 10 includes the first integration capacitor 8a and the second integration capacitor 8a between the position where the first integrated voltage Vc1 exceeds the second integrated voltage Vc2 and the second rotation angle position θ2.
Any circuit that discharges 8b may be used.

f. Ignition signal generation circuit 11 The ignition signal generation circuit 11 includes a first integration voltage Vc1 and a second integration capacitor 9a obtained at both ends of the first integration capacitor 8a.
Comprising a comparator 11a for comparing with a second integrated voltage Vc2 obtained at both ends of the comparator 11a, the output voltage V11 of the comparator 11a is the second
As shown in FIG. E, when the first integrated voltage Vc1 becomes equal to or higher than the second integrated voltage Vc2, it becomes zero (the output terminal of the comparator 11a is in the ground state), and the semiconductor switch 3 is cut off. It is designed to let you.

In this embodiment, since the ignition operation is performed when the semiconductor switch 3 of the ignition circuit 4 is shut off, the comparator 11a operates as shown in FIG. 2 when the first integrated voltage Vc1 becomes equal to or higher than the second integrated voltage Vc2. As shown in E, the output voltage V11 is set to zero, but when the ignition operation is performed by the conduction of the semiconductor switch of the ignition circuit, the first integrated voltage Vc1 becomes the second integrated voltage Vc1. Comparator 11a when the voltage exceeds Vc2
The output terminal of is brought into a non-grounded state (the output voltage of the comparator 11a becomes high level).

[II] Operation of the Embodiment of FIG. 1 The waveforms a, b and c shown in FIG. 2 (D) are the waveforms when the engine speed N is Na, Nb and Nc (Na <Nb <Nc), respectively. 1 shows the change of the integrated voltage Vc1 with respect to the rotation angle θ, and the waveforms a ′, b ′ and c ′ show the changes with respect to the rotation angle θ of the second integrated voltage Vc2 when the engine speed N is Na, Nb and Nc, respectively. Shows changes. Here, the rotation speed Nb is the rotation speed at which the advance angle ends (advance angle end rotation speed). Engine speed N (rp
When m) is low, the time for charging the second integration capacitor 9a is sufficiently long, so that the first integration voltage Vc1 reaches the second rotation angle position (minimum advance position) θ2 and the second integration voltage Vc2 Can't be more. In this state, there are many methods of turning off the transistor 3 to perform the ignition operation. In the example of FIG. 1, for example, in the reset circuit 10, the discharge of the first integrating capacitor 8a is changed to the discharge of the second integrating capacitor 9a. Capacitor 8a and
By setting the discharge time constant of 9a, it is possible to make the output voltage of the comparator 11a zero at the second rotation angle position θ2 and perform the ignition operation. Further, by configuring the comparator so that the output terminal of the comparator 11a is grounded when both input voltages of the comparator 11a are zero, the ignition operation can be performed at the second rotation angle position at low speed. it can.

Although not shown in FIG. 1, the second rotation angle position θ2
A switching circuit that conducts in response to a pulse signal Vp rising at is provided in parallel between the base and emitter of the transistor 3, and the transistor 3 is cut off by conduction of the switching circuit, so that the ignition operation at low speed is performed by the second rotation. It is also possible to perform it at an angular position.

The time for which the second integration capacitor 9a is charged during one revolution of the engine becomes shorter as the engine speed N (rpm) increases, so the second integrated voltage Vc2 increases the engine speed. It becomes lower with. Therefore, as the engine speed increases, the first position θi, which is advanced from the second rotational angle position, is first obtained, as indicated by the waveforms a and a ′ shown in FIG. 2D.
The gently-sloped portion of the additional charging period of the integrated voltage Vc1 of becomes the second integrated voltage Vc2 or more. In such a state, the ignition operation is performed at the position θi, which has a phase advanced from the second rotation angle position θ2, and the ignition position advances as the rotation speed increases.

As the ignition position advances, the waveform in Fig. 2 (D)
Like b and b ', the ignition operation is performed at the position θm where the steep slope portion of the initial charging period of the first integrated voltage Vc1 becomes equal to the second integrated voltage Vc2. Generally, when comparing two integrated voltages obtained by charging the two capacitors from the state where their respective electric charges are zero, the rotation angle position where the two integrated voltages are equal becomes constant regardless of the number of rotations. The position θm where the steep slope portion of the first integrated voltage Vc1 at the time of initial charging matches the second integrated voltage Vc2 becomes constant regardless of the rotation speed, and even if the rotation speed further rises above Nb. The position (ignition position) where Vc1 = Vc2 remains (θm (constant)) remains (even if N = Nc, for example). Therefore, the position of θm is the maximum advance position.

In this case, the maximum advance position θm is determined by the charging currents I11 and I12 of the first integrating capacitor, the charging current I2 of the second integrating capacitor, and the capacitances of the capacitors 8a and 9a, as shown below. It

In the above embodiment, the first integrating capacitor 8a and the second integrating capacitor 8a
Let C1 and C2 be the electrostatic capacities of the integrating capacitors 9a, respectively, and the first rotation angle position θ1 to the second rotation angle position θ
2 is α, the time measured from the charging start time of the first integrating capacitor 8a is t, and the engine speed is N, O <t ≦ to (to is the charging of the first integrating capacitor 8a). The first and second integrated voltages Vc1 and Vc2 during the period from the start until the terminal voltage of the capacitor 8a reaches the set value Vo) are given by the following equations.

Vc1 = (I11 + I12) (t / C1) (1) Vc2 = (I2 / C2) (A + t) (2) where A = (360−α) / (6N) (3) where Vc1 = Vc2 Tm = (I2 × A) / B ... (4) where B = (C2 / C1) (I11 + I12) -I2 ... (5) When the above tm is converted to the angle θm, θm = 6Nt = I2 (360−α) / B (6) From this, the angle θm is constant regardless of the rotation speed N, and the first
And the second charging currents I11 and I12, the charging current I2, and the capacitances C1 and C2 of the capacitors 8a and 9a. That is, it is possible to change the advance width by appropriately setting the position of the angle θm by appropriately selecting I11, I12 and I2.

Further, the advance end rotation speed Nb is the second integrated voltage Vc2 at t = to.
Is the number of revolutions that is equal to the set voltage Vo, so if N = Nb and Vc2 = Vo, then (I2 / C2) (A ′ + to) = Vo (7) where A ′ = (360−α ) / (6Nb)… (8) Moreover, according to the equation (1), (I11 + I12) (to / C1) ＝ Vo… (9) If we find Nb from the equations (8) to (9), we get ) / (6VoK) (10) However, K = (C2 / I2)-{C1 / (I11 + I12)} (11) From this, it can be seen that the advance end rotation speed Nb can be arbitrarily determined.

[III] Configuration of Embodiment of FIG. 3 Next, a more specific embodiment of the present invention will be described with reference to FIG. In this embodiment, a third integration circuit 12 and a comparison circuit 13 are added to control the conduction angle of the transistor 3 of the ignition circuit 4 (the conduction angle of the primary current of the ignition coil). The structure of each part of this embodiment is as follows.

a. Pulse shaping circuit 7 The pulse shaping circuit 7 includes a diode 7a whose cathode is connected to the non-grounded side terminal of the signal coil 5, a capacitor 7b whose one end is connected to the anode of the diode 7a and whose other end is commonly connected, and A resistor 7c, an NPN transistor 7d as a waveform shaping switch whose base is connected to the common connection point of the other ends of the capacitor 7b and the resistor 7c, and the emitter is grounded, and the anode is grounded between the base and ground of the transistor 7d. The diode 7e connected to the resistor 7f and the resistor 7f and 7g whose one end is connected to the base and collector of the transistor 7d, respectively.
It consists of

In this pulse shaping circuit 7, when the second signal Vs2 generated by the signal coil 5 exceeds the threshold level at the second rotation angle position, the transistor 7d is extremely short due to the voltage drop across the diode 7e. The time cutoff state occurs, and the pulse signal Vp is output between the collector and emitter of the transistor 7d at the second rotation angle position θ2.

b. Rectangular wave generating circuit 6 The rectangular wave generating circuit 6 includes a diode 6a whose anode is connected to the non-ground side terminal of the signal coil 5 and a capacitor whose one end is connected to the cathode of the diode 6a and whose other end is commonly connected. 6b and a resistor 6c, a base connected to a common connection point of the capacitor 6b and the resistor 6c via a resistor 6d and an emitter grounded, and a base connected to the collector of the transistor 6e via a resistor 6g. PNP transistor 6h, resistor 6i connected between the base and emitter of transistor 6h, signal storage capacitor 6j connected between the collector of transistor 6h and ground, the emitter is grounded and the collector is connected to the collector of transistor 6h. NPN
It consists of a transistor 6k and a resistor 6m whose one end is connected to the base of the transistor 6k. The emitter of the transistor 6h is an output terminal of a DC constant voltage power supply (not shown), and the base of the transistor 6k is a resistor 6m through a resistor 6m. Each of them is connected to the collector of the transistor 7d (the output terminal of the pulse shaping circuit 7).

In the rectangular wave signal generating circuit 6, when the signal coil 5 generates the first signal Vs1 at the first rotation angle position, the period during which the first signal Vs1 is equal to or higher than the predetermined threshold level Vt. The transistor 6e is triggered and the transistor 6h becomes conductive, and the signal storage capacitor 6j is instantly charged to the power supply voltage E1 with the polarity shown through the collector and emitter of the transistor 6h. When the pulse signal Vp is obtained at the collector of the transistor 7d of the pulse shaping circuit 7, the transistor 6k becomes conductive and the capacitor 6j is instantaneously discharged through the collector and emitter of the transistor 6k. Therefore, as shown in FIG. 4B, a rectangular wave signal voltage Vq having a peak value E continuing from the first rotation angle position θ1 to the second rotation angle position θ2 is obtained at both ends of the signal storage capacitor 6j. To be

c. First integrating circuit 8 Next, the first integrating circuit 8 includes a first integrating capacitor 8a,
A voltage divider circuit consisting of a series circuit of resistors 8b and 8c, a transistor 8d, a speed-up capacitor 8e, and resistors 8f and 8g.
And a voltage divider circuit composed of resistors 8b and 8c is connected in parallel to both ends of the signal storage capacitor 6j. The base of the transistor 8d is connected to the voltage dividing point of the voltage dividing circuit, and the collector is connected to the non-ground side terminal of the signal storage capacitor 6j via the resistor 8g. The speed-up capacitor 8e is connected between the base and collector of the transistor 8d, and the resistor 8f is connected between the collector and emitter of the transistor 8d. The first integration capacitor 8a is connected between the emitter of the transistor 8d and the ground, and the rectangular wave signal voltage Vq obtained across the signal storage capacitor 6j causes the first integration capacitor 8a to pass between the resistor 8g and the collector-emitter of the transistor 8c and the resistor 8f. The integrating capacitor 8d is charged.

That is, when the rectangular-wave signal voltage Vq is generated across the signal storage capacitor 6j, a base current flows through the transistor 8d and the transistor 8d becomes conductive, and the resistor 8g and the transistor 8g
The first integrating capacitor 8a is charged with the first charging current I11 to the illustrated polarity through the collector-emitter of 8d and the resistor 8f, and the initial integrating operation is performed. First integrating capacitor
The terminal voltage of 8a changes the voltage Vq across capacitor 6j to resistor 8b and
Set voltage obtained by dividing by 8c (voltage across resistor 8c) Vo
Then, the base current stops flowing in the transistor 8d and the transistor 8d is cut off. After that, the terminal voltage of the capacitor 6j causes the capacitor 8a to pass through the resistor 8f and the second
Is additionally charged by the charging current I12 (<I11) of and the additional integration operation is performed. The waveform of the first integrated voltage Vc1 obtained across the first integrating capacitor 8a is as shown by the solid line in FIG. 4E.

In this embodiment, the set voltage Vq obtained by dividing the voltage Vq obtained across the signal storage capacitor 6j by the resistors 8b and 8c.
The magnitude of o is given by the following equation, where the peak value of the voltage Vq is E and the resistance values of the resistors 8b and 8c are R1 and R2, respectively.

Vo = (ER2) / (R1 + R2) (12) d. Second integrating circuit 9 The second integrating circuit 9 includes a second integrating capacitor 9a whose one end is grounded, and a non-grounded terminal of the capacitor 9a. It is composed of a resistor 9b connected between the output terminal of a DC constant voltage power supply (not shown).

The capacitor 9a of the second integrating circuit 9 is charged with a constant time constant through the resistor 9b by the output of a DC constant voltage power source (not shown), and the both ends of the capacitor 9a are as shown by the broken lines in FIGS. The second integrated voltage Vc2 is obtained.

e. Reset circuit 10 The reset circuit 10 is a reset circuit 10A for the first integrating circuit.
And a second reset circuit for integration circuit 10B. The first integrator reset circuit 10A has a reset transistor (NPN transistor) 10a whose emitter is grounded and whose collector is connected to the non-grounded side terminal of the first integrating capacitor 8a, and one end of which is connected to the base of the transistor 10a. And a resistor 10b having the other end connected to the collector of the transistor 7d, and when the pulse signal Vp is generated at the second rotation angle position θ2, the transistor 10a becomes conductive and instantly discharges the first integrating capacitor 8a. Let Therefore, the first integrated voltage Vc1 obtained across the first integrating capacitor 8a becomes zero at the second rotational angle position θ2 as shown in FIG. 4E.

The second reset circuit 10B for the integrating circuit includes a discharging transistor (NPN transistor) 10c whose collector is connected to the non-grounded side terminal of the capacitor 9a and whose emitter is grounded.
It is composed of a resistor 10d connected between the base of the transistor 10c and the collector of the transistor 7d, and is a transistor when the pulse signal Vp is generated at the second rotation angle position θ2.
10c becomes conductive and instantly discharges the second integrating capacitor 9a. Therefore, as shown in FIGS. 4D and 4E, the second integrated voltage Vc2 becomes zero at the second rotational angle position θ2.

f. Third integrating circuit 12 The third integrating circuit 12 includes a third integrating capacitor 12a whose one end is grounded, and a discharging transistor whose collector is connected to the non-grounded terminal of the capacitor 12a and whose emitter is grounded ( NPN transistor) 12b, a resistor 12c whose one end is connected to the base of the transistor 12b, a resistor 12d which is connected between the base and emitter of the transistor 12b, the other end of the resistor 12c and the non-ground terminal of the signal storage capacitor 6j. A capacitor 12e connected between the resistor 12h, a resistor 12h having one end connected to the non-ground terminal of the third integrating capacitor 12a, a cathode connected to the other end of the resistor 12h, and an anode serving as a signal storage capacitor.
The third integration capacitor 12a is composed of a diode 12i connected to the non-ground terminal of 6j, and the third integration capacitor 12a is a signal storage capacitor 6
The voltage Vq across j charges the diode 12i and the resistor 12h with a constant time constant.

In this embodiment, the differentiation circuit 12g is composed of the resistors 12c and 12d and the capacitor 12e. The differentiating circuit 12g differentiates the rising of the rectangular wave signal Vq obtained at both ends of the signal storage capacitor 6j and outputs a pulse current If, and while the pulse current is generated, the transistor 12b is turned on to turn on the third current. The integrating capacitor 12a is discharged. The waveform of the third integration voltage Vc3 obtained across the third integration capacitor 12a is the fourth
It becomes as shown by the solid line in FIG.

g. Ignition signal generation circuit 11 The ignition signal generation circuit 11 is composed of a voltage comparator 11a composed of an IC, and the output terminal of the comparator 11a is connected to the base of the transistor 3. The first is connected to the negative phase input terminal of the comparator 11a.
The first integrated voltage Vc obtained across the integrating capacitor 8a of
1 is input, and the second integrated voltage Vc2 obtained across the second integrating capacitor 9a is input to the positive phase input terminal of the comparator 11a.

h. Comparison circuit 13 The comparison circuit 13 is composed of an IC voltage comparator 13a and a comparator 13a.
The output terminal of the comparator 13a is connected to the base (control signal input terminal) of the transistor 3 of the ignition circuit. The third integrated voltage Vc3 obtained at both ends of the third integrating capacitor 12a is input to the negative phase input terminal of the comparator 13a,
The second integrating capacitor 9a is connected to the positive phase input terminal of the comparator 13a.
The second integrated voltage Vc2 obtained at both ends of is input.

i. Self-ignition prevention resistor 14 In this embodiment, a self-ignition prevention resistor 14 is provided between the connection point between the resistor 12h of the third integrating circuit 12 and the diode 12i and the collector of the transistor 7d of the pulse shaping circuit 7. Is connected, and the transistor 7d is conducting, the transistor 7d passes from the third integrating capacitor 12a through the resistors 12h and 14.
The discharge circuit of the capacitor 12a is configured by the circuit up to. The resistance value of the resistor 14 is set to a sufficiently large value so that normal charging of the third integrating capacitor 12a is not hindered during steady operation.

[IV] Operation of the embodiment shown in FIG. 3 a. Operation when normal starting operation is performed In normal operation of the engine, the engine starting operation is performed immediately after the power switch (not shown) is closed. When the engine starting operation is performed, the signal coil 5 causes the first and second signals Vs1 and Vs
Output s2. At the very low speed of the engine, the first signal Vs
1 does not exceed the threshold level and the second signal Vs2
Only are set above the threshold level. Therefore, at an extremely low speed of the engine, it is not possible to obtain a signal having a magnitude capable of triggering the transistor 6e of the rectangular wave generating circuit 6.

In the pulse shaping circuit 7, a resistor from a power source (not shown)
A base current flows through the transistor 7d through the transistor 7f, and the transistor 7d becomes conductive. When the second signal Vs2 is generated, a current flows through the diode 7e, the resistor 7c, the capacitor 7b, and the diode 7a of the pulse shaping circuit 7, and when the voltage across the diode 7e reaches a predetermined value at the second rotation angle position θ2. (When the second signal Vs2 becomes equal to or higher than the threshold level Vt), the base and emitter of the transistor 7d are reverse biased, and the transistor 7d is cut off. Second
When the signal Vs2 of Vs2 falls below the threshold level, the transistor 7d becomes conductive again. Therefore transistor 7d
A pulse signal Vp having a pulse width corresponding to the period during which the second signal Vs2 is at or above the threshold level is obtained between the collector and emitter of the.

In this way, when the engine is extremely low speed, only the pulse signal Vp is generated and the transistor 6e of the rectangular wave generation circuit 6 is not triggered. Therefore, the transistor 6h does not conduct and the capacitor 6j is not charged. Therefore, the first integrating capacitor 8d and the third
The integration capacitor 11a of is not charged.

In the second integration circuit, the second integration capacitor 9a is charged from the power supply through the resistor 9b to the polarity shown in the figure, and the pulse signal Vp
As a result, the capacitor 9a is discharged when the transistor 9b becomes conductive. Therefore, as shown in FIGS. 4D and 4E, both ends of the second integrating capacitor 9a rise with a constant gradient from each second rotation angle position θ2. At the next second rotation angle position θ2, the second integrated voltage Vc2 that returns to zero is obtained.

As described above, the third integration capacitor 12a is not charged by the rectangular wave signal Vq at the extremely low speed, but the second signal Vs
When the transistor 7d of the pulse shaping circuit 7 is cut off during the period when 2 is above the threshold level, the charging current flows from the power source (not shown) to the third integrating capacitor 12a through the resistor 7g and the resistors 14 and 12h. Therefore, the third integration capacitor is slightly charged while the second signal Vs2 is at the threshold level or higher, and its terminal voltage is increased.
Vc3 rises slightly.

The first comparison circuit 12 compares this voltage Vc3 with the second integrated voltage Vc2. When the voltage Vc2 becomes higher than the voltage Vc3, the output voltage Vd of the comparison circuit 13 becomes high level. Further, since the first integrated voltage Vc1 is not generated, the output voltage Vb of the comparator 11a remains at the high level. Therefore, the output voltage Vd of the comparison circuit 13
Becomes high level, the base-emitter voltage V11 of the transistor 3 becomes high level as shown in FIG. 4F. As a result, a base current flows through the transistor 3, the transistor 3 becomes conductive, and the primary current I1 flows through the ignition coil 1. Next, when the second integrated voltage Vc2 becomes zero at the second rotation angle position, the potential of the output terminal of the comparison circuit 13 becomes the ground level, so that the transistor 3 is cut off and the primary current I1 is suddenly cut off. . As a result, a large magnetic flux change occurs in the iron core of the ignition coil, and a spark is generated in the ignition plug 2. As described above, in the present embodiment, the ignition operation is performed at the minimum advance position θ2 even at the extremely low speed of the engine in which the first signal Vs1 does not exceed the threshold level, so that the engine startability is improved. You can

If the rotation speed increases to some extent due to the start of the engine, the first
Signal Vs1 also goes above the threshold level. At this time, the rectangular wave generation circuit 6 generates a rectangular wave voltage Vq that continues from the first rotation angle position θ1 to the second rotation angle position θ2 as shown in FIG. 4B.

When the rectangular wave signal Vq is generated, the first integration circuit 8 performs the initial integration operation and the additional integration operation as described above,
A first integration voltage Vc1 is obtained across the first integration capacitor 8a as shown in FIG. 4E.

In the second integrating circuit 9, the second integrating capacitor 9a is connected to both ends of the second integrating capacitor 9a as shown in FIGS.
The integrated voltage Vc2 of is obtained.

In the third integrating circuit 12, the output pulse current If of the differentiating circuit 12g that differentiates the rising edge of the rectangular wave signal Vq disappears and the transistor 12b cuts off the position θ3 to the second rotational angle position θ.
Up to 2, the third integration capacitor 12a is charged with the signal rectangular wave signal voltage Vq with a constant time constant, and after the rectangular wave signal voltage Vq disappears, the terminal voltage of the third integration capacitor is changed to the first
The rotation angle position θ1 is maintained. When the rectangular wave signal Vq rises at the first rotation angle position θ1 and the differentiating circuit 12g outputs the pulse current If, the transistor 12b becomes conductive and discharges the capacitor 12a. Therefore, the third integrating capacitor 1
At both ends of 2a, as shown in FIG. 4D, ascending at a constant gradient from a position θ3 delayed by an angle β from each first rotation angle position θ1 to a second rotation angle position θ2, the next maximum advance is made. A third integrated voltage Vc3 that holds the voltage up to the angular position θ1 is obtained.

The second integrated voltage Vc2 and the third integrated voltage Vc3 are input to the comparison circuit 13. In the comparison circuit 13, the third integrated voltage Vc
When 3 is equal to or higher than the second integrated voltage Vc2, the output stage of the comparator 13a is in a conductive state and the ground voltage Vd at its output terminal is at zero level. When the second integrated voltage Vc2 exceeds the third integrated voltage Vc3, the output stage of the comparator 13a is cut off and the voltage Vd at its output terminal becomes high level. Comparison circuit
While the output voltage Vd of 13 is zero, the potential of the base of the transistor 3 is kept at the ground level and the conduction of the transistor 3 is prohibited, and the conduction of the transistor 3 is allowed only while the voltage Vd is at the high level. .

The first integrated voltage Vc1 and the second integrated voltage Vc2 are compared by the comparator 11a.
Entered in. The first integrated voltage Vc1 is the second integrated voltage Vc2
In the following cases, the output stage of the comparator 11a is in the cutoff state, and when the first integrated voltage Vc1 exceeds the second integrated voltage Vc2, the output stage of the comparator 11a is in the cutoff state. Therefore, as shown in FIG. 4E, when the first integrated voltage Vc1 is equal to or lower than the second integrated voltage Vc2, the ground voltage Vd at the output terminal of the comparator 11a is increased.
Becomes high level, and the ground voltage at the output terminal of the comparator 11a becomes zero while the first integrated voltage Vc1 exceeds the second integrated voltage Vc2. Therefore, the second integrated voltage Vc2 exceeds the third integrated voltage Vc3 (allowing conduction of the transistor 3), and the first integrated voltage Vc1 is the second integrated voltage Vc2.
In the following cases, the comparator 11a allows the base current to flow through the transistor 3 as the primary current control semiconductor switch to make the transistor 3 conductive, and as shown in FIG. Pass the next current I1. When the first integrated voltage Vc1 exceeds the second integrated voltage Vc2 at the angle θi, the output voltage Vb of the comparator 11a becomes zero (ground potential), so that the transistor 3 is turned off. When the transistor 3 is switched from the conductive state to the cutoff state in this way, the primary current I1 of the ignition coil changes rapidly, so that the high voltage Vh is induced in the secondary coil 1b of the ignition coil as shown in FIG. 4H. .
As a result, the spark plug 2 attached to the cylinder of the engine
A spark discharge occurs in the engine and the engine is ignited.

Angle θ at which the first integrated voltage Vc1 exceeds the second integrated voltage Vc2
Since i advances as the rotation speed of the engine increases, the ignition position (θi) of the engine advances as the rotation speed increases.

As described above, the second integrated voltage Vc2 is changed to the third integrated voltage Vc3.
When the transistor 3 (switch for primary current control) is turned on at the time of exceeding, the constant of the differentiation circuit 12g (time constant determined by the resistors 12c and 12d and the capacitor 12e) and the integration constant of the third integration circuit 12 (Capacitor 12a and resistor 1
By appropriately setting the time constant determined by 2h), the position where the primary current control switch starts conducting can be arbitrarily set. Therefore, by setting the integral constant of the third integrator circuit so that the energization period of the primary current of the ignition coil is minimized when the engine speed is low,
The loss can be minimized, and the temperature rise of the switch element forming the primary current control switch can be suppressed. Further, the position θ3 at which the charging of the third integration capacitor is started is delayed as the rotation speed of the engine increases, and the position where the second integration voltage exceeds the third integration voltage is
Since the engine speed increases as the engine speed increases, the primary current energization time increases as the engine speed increases. Therefore, it is possible to prevent the breaking current value from decreasing at a high speed of the engine, and prevent the ignition performance from decreasing at a high speed.

b. Operation when the engine starting operation is abnormal (action of the spontaneous combustion preventing resistor 14) When the power switch is kept closed when the engine is stopped in the above-mentioned embodiment, that is, the power switch is closed. Consider the case where the starting operation is not performed immediately after the start.

Since the signal coil 5 does not output the first and second signals Vc1 and Vc2 when the engine is stopped, neither the rectangular wave signal Vq nor the pulse signal Vp is generated. Therefore, the rectangular wave signal Vq does not charge the first and third integrating capacitors 8a and 12a. However, the second integrating capacitor 9a has a resistor 9b
Is charged from a power source (not shown), the terminal voltage Vc2 thereof rises at a predetermined gradient and is eventually saturated. Comparator by the terminal voltage of this second integrating capacitor
Since the potential of the output terminal of 13a becomes high, transistor 3
Is supplied with a base current, the transistor 3 is turned on, and a primary current flows through the ignition coil 1.

At this time, in the second comparison circuit 13, a weak current flows from the power source through the inside of the comparator 13a to the negative phase input terminal and the positive phase input terminal of the comparator.

Assuming that the spontaneous combustion preventing resistor 14 is not present in FIG. 3, the third integrating capacitor 12a is charged by the weak current flowing out from the negative-phase input terminal of the comparator 13a.
The terminal voltage Vc3 of the integrating capacitor 12a of No. 2 rises until the terminal voltage Vc3 of the third integrating capacitor 12a becomes the second value.
Exceeds the integrated voltage Vc2 of. Thus, when the third integrated voltage Vc3 exceeds the second integrated voltage Vc2, the output terminal of the comparator circuit 12 becomes the ground potential, so that the transistor 3
Is cut off, and the primary current I1 is cut off. Therefore, a large magnetic flux change occurs in the iron core of the ignition coil 1, and a high voltage is induced in the secondary coil of the ignition coil. Since this high voltage is applied to the spark plug 2, a spark is generated in the spark plug,
So-called spontaneous combustion occurs.

On the other hand, as in the above embodiment, the spontaneous combustion prevention resistor
When 14 is provided, the resistor 12h, the spontaneous combustion prevention resistor 14 and the transistor 7d of the pulse shaping circuit 7 in the conductive state are held when the power switch is kept closed while the engine is stopped. Since the third integration capacitor 12a is discharged through, the terminal voltage of the third integration capacitor is prevented from rising and spontaneous ignition is prevented.

[V] Embodiment of FIG. 5 FIG. 5 shows a main part of another embodiment of the present invention. In this embodiment, a capacitor discharge type circuit is used as an ignition circuit, and an ignition signal generating circuit 11 is provided. A programmable unijunction transistor (PUT) P1 is used as a comparator. In this embodiment, a capacitor C1 is provided on the primary side of the ignition coil 1, and the capacitor C1 is an exciter coil provided in a magnet type AC generator that rotates in synchronization with the engine.
The output of Le charges the diode D1 to the polarity shown. Thyristor Th is provided between the connection point of capacitor C1 and diode D1 and ground.
A protective resistor R1 is connected between the gate and cathode of the. Ignition coil 1, spark plug 2, capacitor C1, exciter coil Le, diode D1, thyristor Th and resistor R1
The ignition circuit 4 is constituted by.

This ignition circuit 4 is well known as a capacitor discharge type circuit, and the charge of the capacitor C1 is discharged to the primary coil 1a of the ignition coil 1 by the conduction of the thyristor Th.
A high voltage is induced in the secondary coil 1b to perform an ignition operation.

Further, in this embodiment, the first integrated voltage Vc1 across the first integrating capacitor 8a is applied to the anode of the programmable unijunction transistor P1, and the second integrated voltage Vc2 across the second integrating capacitor 9a is applied to the resistor 15. Is applied to the gate of the programmable unijunction transistor P1 via.

The cathode of the programmable unijunction transistor P1 is connected to the gate of the thyristor Th of the ignition circuit,
An ignition signal is supplied to the thyristor Th through the programmable unijunction transistor.

When the first integrated voltage Vc1 is lower than the second integrated voltage Vc2, the programmable unijunction transistor P1 is cut off and the firing signal is not supplied to the thyristor Th.
When the first integrated voltage Vc1 becomes equal to or higher than the second integrated voltage Vc2, the programmable unijunction transistor P1 becomes conductive, so that a firing signal is given to the thyristor Th and the thyristor Th becomes conductive to perform the ignition operation.

Further, in the embodiment shown in FIG. 5, the pulse signal Vp is supplied to the gate of the thyristor Th via the resistor 16, and the ignition signal is given to the thyristor Th by this pulse signal when the engine is at a low speed.

Although the reset circuit for discharging the first integrating capacitor 8a is not shown in FIG. 5, the reset circuit for the first integrating capacitor is the one used in the embodiment of FIG. Similar circuits can be used.

In the above embodiment, the rectangular wave signal is output by the output of the signal coil.
Although Vq and the pulse signal Vp are generated and the first integrator circuit and the second integrator circuit are controlled by these signals, the control method of both integrator circuits is limited to the above embodiment. is not. In the first integration circuit, the start position of the initial integration operation may be determined by the first signal, and the end position of the additional integration operation may be determined by the signal indicating the ignition position or the second signal. Further, the second integration circuit may determine the start position of the integration operation by the second signal, and the end position of the integration operation by the signal indicating the ignition position or the second signal.

As described above, according to the present invention, the position where the terminal voltage of the first integrating capacitor is equal to the second integrating voltage during the period when the initial integrating operation of the first integrating circuit is being performed. Is set as the maximum advance angle position, and the maximum advance angle position can be appropriately set by the first and second charging currents of the first integrating capacitor and the charging current of the second integrating capacitor. There is an advantage that the advance width can be changed without changing the configuration of the signal generator provided with the signal coil, and a common signal generator can be used for various engines having different ignition characteristics.

Further, according to the present invention, the first integrating circuit may perform the initial charging and the additional charging of the first integrating capacitor, and the second integrating circuit charges the second integrating capacitor with a constant time constant. Since it is sufficient to perform the operation, there is an advantage that a function of adjusting the advance angle width can be provided without complicating the configurations of the first and second integrating circuits.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a signal waveform diagram of each part of FIG. 1, FIG. 3 is a circuit diagram showing a more concrete embodiment of the present invention, and FIG. Is a signal waveform diagram of each part of FIG. 3, and FIG. 5 is a circuit diagram showing an essential part of still another embodiment of the present invention. 1 ... Ignition coil, 2 ... Ignition plug, 4 ... Ignition circuit, 5 ... Signal coil, 6 ... Rectangular wave generation circuit, 7 ...
Pulse shaping circuit, 8 ... First integrating circuit, 9 ... Second integrating circuit, 10 ... Reset circuit, 11 ... Ignition signal generating circuit.

Claims (1)

[Claims] 1. An ignition circuit for suddenly changing a primary current of an ignition coil by an operation of a semiconductor switch to generate a high voltage for ignition on a secondary side of the ignition coil, and a first rotation angle position of an internal combustion engine. A signal coil for generating a first signal having a level equal to or higher than a threshold level and a second signal having a phase equal to or higher than a threshold level at a second rotation angle position having a phase delayed from the first rotation angle position; An ignition position control circuit which receives the first and second signals and generates a signal for determining a position for operating the semiconductor switch between the first rotation angle position and the second rotation angle position. In the ignition device for an internal combustion engine, the ignition position control circuit may charge the first integration capacitor from the first rotation angle position to a position where the terminal voltage of the first integration capacitor reaches a set value. Electric Initial integration operation for initial charging with and additional integration for additionally charging the first integrating capacitor with a second charging current smaller than the first charging current from the position where the terminal voltage of the first integrating capacitor reaches a set value. A first integrating circuit for performing an operation, a second integrating circuit for performing an integrating operation for charging the second integrating capacitor from each second rotation angle position with a constant time constant, and The semiconductor switch is operated when the first integrated voltage exceeds the second integrated voltage by comparing the first integrated voltage obtained across the second integrated voltage with the second integrated voltage obtained across the second integrating capacitor. An ignition signal generating circuit for generating a signal for determining a position to be made to operate, and the first integrating capacitor between a position where the first integrated voltage exceeds a second integrated voltage and the second rotational angle position. And the second integral controller An ignition device for an internal combustion engine, comprising: a reset circuit that discharges each capacitor.