JPS6160982B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition signal generation device used in connection with a non-contact ignition device for an internal combustion engine, and more particularly to an ignition signal generation device used when controlling the ignition position according to the rotational speed of the engine. It is.

As is well known, in order to operate an internal combustion engine satisfactorily, it is necessary to control the ignition position of the engine in accordance with the rotational speed of the engine. When a non-contact ignition device is used, the ignition position is controlled by controlling the generation phase of a signal that determines the ignition position using an electronic circuit. A characteristic is required to advance the ignition position as the rotational speed increases. Recently, there has been a demand for accurate control of the ignition position in order to save fuel and purify exhaust gas, but all of the devices that have been proposed so far have only been able to control the rotational speed in order to achieve accurate control. Since it requires a detection circuit and has a complicated circuit configuration, it has the disadvantage that the assembly and adjustment of the device are complicated and it is expensive.

An object of the present invention is to provide non-contact ignition for an internal combustion engine that uses two signal generation circuits, two triangular wave generation circuits, and one monostable multivibrator to accurately control the ignition position with a simple configuration. An object of the present invention is to provide an ignition signal generator for a device.

In order to solve the above-mentioned problems, the present invention provides an ignition signal generator for a non-contact ignition device for an internal combustion engine, which generates a first signal at a position corresponding to the maximum advance position of the internal combustion engine. signal generating means for generating a second signal at a position corresponding to the angular position; and generating a first triangular wave that rises at a predetermined gradient from the position where the first signal is generated to the position where the second signal is generated. a monostable multivibrator that is triggered by the second signal and outputs a rectangular wave signal with a constant time width; a second triangular wave generating circuit that generates a second triangular wave that rises at a predetermined slope to a position where the second signal is generated and maintains a maximum value until the position where the second signal is generated; Second
and an ignition signal generation circuit that compares the levels of the triangular waves and outputs an ignition signal that determines the ignition position of the internal combustion engine when the levels match.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ignition signal generator of the present invention will be explained in detail below with reference to the illustrated embodiments.

FIG. 1 shows the overall configuration of an embodiment of the present invention. In the figure, 1 and 2 are first and second signal coils that generate signals in synchronization with the rotation of the internal combustion engine, respectively. be. The first and second signal coils 1 and 2 are installed in a signal generator attached to the engine, and the first signal coil 1 corresponds to the maximum advance position where the phase is sufficiently advanced from the top dead center of the engine. A signal is generated at a first position θ ₁ and a second signal coil 2 generates a signal at a second position θ ₂ corresponding to a minimum advance position close to top dead center of the engine. The outputs of the first signal coil 1 and the second signal coil 2 are input to the first and second waveform shaping circuits 3 and 4, respectively, to produce first and second signals e ₁ and e ₂ with pulse-like waveforms. will be exchanged. The first signal coil 1 and the first
The waveform shaping circuit 3 outputs the first signal at the first position.
A first signal generation circuit 5 that generates e ₁ is configured,
The second signal coil 2 and the second waveform shaping circuit 4 constitute a second signal generating circuit 6 that generates a second signal e ₂ at a second position. These first and second signal generating circuits 5 and 6 constitute a signal generating means. The first signal _e1 and the second signal _e2 are respectively supplied to the set terminal S and the reset terminal R of the RS flip-flop circuit 7, and the output terminal of the flip-flop circuit 7 is connected to the first signal e2.
The output terminal Q is connected to the control terminal 8a of the first integrator 8 as a triangular wave generating circuit, and the output terminal Q is connected to the first control terminal 9 of the second integrator 9 as the second triangular wave generating circuit.
It is input in a. The second signal e ₂ is also input to the trigger terminal of the monostable multivibrator 10, and the output of the monostable multivibrator 10 is
is input to the second control terminal 9b of the integrator 9. The first integrator 8 is a capacitor during the period when the output terminal of the flip-flop circuit 7 is in the "0" state (from the time when the first signal _e1 is generated until the second signal _e2 is generated). Charge C ₁ with a constant current i ₁ and perform an integral operation. The second integrator 9 activates the monostable multivibrator 1 during the period when the output terminal Q of the flip-flop circuit 7 is in the "0" state.
When the output of 0 changes from "1" to "0", the capacitor
Starts the integral operation of charging C ₂ with constant current i ₂ , and
When the flip-flop circuit 7 is set by the signal _e1 and the output terminal Q becomes "1", the integration operation is stopped. This second integrator 9 has a memory function and is designed to hold the integral value at the time when the first signal _e1 is generated and the integration operation is stopped until it is reset next time. . The second integrator 9 is connected to the monostable multivibrator 1 by means of the second signal e ₂
It is reset when the output of 0 becomes "1",
Next, when the output of this monostable multivibrator falls to "0", the integration operation is started again.

The first and second triangular waves Vc 1 and Vc ₂ obtained at the output terminals of the first and second integrators 8 and ₉ are input to the comparator circuit 11 and compared, and when the levels of both triangular waves match, the comparator circuit When the signal Vh is output from the pulse generator 11, the pulse generator 12 outputs the ignition signal Vs for determining the ignition position. The comparison circuit 11 and the pulse generator 12 constitute an ignition signal generation circuit that generates an ignition signal when the outputs of the first and second integrators match.

The signal waveforms of the respective parts indicated by symbols A to I in the embodiment shown in FIG. 1 are shown as shown in FIG. 2 A to I, respectively, with respect to the rotation angle .theta. of the crankshaft of the engine. That is, the first and second signal generating circuits 5 and 6 are connected to the first signal generating circuit 5 and 6, respectively, as shown in FIGS.
The flip-flop circuit 7 generates the first signal e ₁ and the second signal e 2 at the position θ ₁ and the second position θ ₂ , and the flip-flop circuit 7 generates the first signal _{e 1 as} shown in FIG. 2C. A signal in the state of "1" is output to the output terminal Q during the period from when the signal e ₂ is generated until the second signal e 2 is generated (period of |θ ₁ −θ ₂ |). Flip-flop circuit 7
A signal obtained by negating the signal at output terminal Q is obtained at the output terminal of . Furthermore, the monostable multivibrator 10 is triggered by the second signal e ₂ and the monostable multivibrator 10 is
As shown in the figure, a rectangular wave signal with a constant time interval τ is output. The time interval τ of this signal is constant regardless of the rotation speed, and therefore the falling position θ ₃ of the rectangular wave signal changes depending on the rotation speed.

The first integrator 8 performs an integration operation while the flip-flop circuit 7 outputs a signal of "0" to the output terminal, and when the potential of the output terminal reaches "1", the first integrator 8 stops the integration operation and connects the integrating capacitor to a certain level. Discharge with a time constant. Therefore, as shown in FIG. 2E, the output terminal of the first integrator 8 rises at a constant slope from angle θ ₁ to θ ₂ , starts discharging at angle θ ₂ , and reaches a predetermined level. A triangular wave that descends with a slope is obtained. On the other hand, the second integrator 9 starts an integrating operation as shown in FIG. 2F when the output of the monostable multivibrator 10 changes from "1" to "0" at an angle θ ₃ . The integration operation of this second integrator is performed by the flip-flop circuit 7 at an angle θ ₁ .
stops when the potential of the output terminal Q rises to "1",
The integral value is held until reset. This second integrator is reset when the second signal _e2 is generated and the potential at the output terminal Q of the flip-flop circuit 7 falls to "0". Therefore, the output terminal of the second integrator has an angle θ ₃ as shown in FIG.
A second triangular wave is obtained which rises linearly from to angle θ ₁ and maintains its maximum value between angles θ ₁ and θ ₂ . The first triangular wave Vc ₁ obtained from the first integrator and the second Vc ₂ obtained from the second integrator
are compared by _the comparator _circuit 11 as shown in _{FIG .} A rectangular waveform signal Vh as shown in Figure H is output. At the rising edge of this signal Vh, the pulse generator 12 generates an ignition signal Vs, and this ignition signal Vs causes a non-contact ignition device (not shown) to perform an ignition operation.

The configuration of the non-contact ignition device to which the above-mentioned signal generation device is connected is arbitrary, and may include a capacitor discharge type ignition device that performs ignition operation by discharging the charge of a capacitor through a thyristor to the primary coil of the ignition coil, or A current interrupt type ignition device that connects an exciter coil and a semiconductor switch such as a transistor in parallel with the primary coil of the coil, and performs the ignition operation by switching the semiconductor switch from a conductive state to a cutoff state, and ignition by an ignition signal. Any type of igniter with a defined position can be used.

In Fig. 2, the angle θ ₀ is the top dead center, and the angle from this angle θ ₀ to the first signal e ₁ is α°,
Let the angle up to the second signal e ₂ be β°, and the times during rotation through angles α° and β° are tα and t, respectively.
Let it be β. Further, if the angle from angle θ ₁ to angle θ _i (ignition position) where the outputs of the first and second integrators match is γ°, and the time during which the angle γ° is rotated is tγ, then the ignition position θ The terminal voltage Vc ₁ of the capacitor C ₁ of the first integrator 8 at _i is Vc ₁ = (i ₁ /C ₁ )tγ ...(1), and the capacitor of the second integrator at the ignition position θ _i The terminal voltage Vc ₂ of C ₂ is as follows, where the rotational speed of the engine is N (rpm), Vc ₂ = (i ₂ /C ₂ ) {(60/N)−tα+tβ −τ} (2). Since Vc ₁ = Vc ₂ at the ignition position θ _i , the timing during rotation from angle θ ₁ to θ _i at the rotational speed N (rpm) is tγ = (C ₁ i ₂ /i ₁ C ₂ ) { (60/N)-tα +tβ-τ} ...(3). Converting this into an angle γ°, γ = (C ₁ i ₂ / i ₁ C ₂ ) (360° − α + β −6Nτ) ...(4), and the angle from top dead center θ ₀ to ignition position θ _i (advanced angle) is δ=α−γ=α−(C ₁ i ₂ /i ₁ C ₂ )(360°−α+β−6Nτ)=α{1+(C ₁ i ₂ /i ₁ C ₂ ) } −(C ₁ i ₂ / i ₁ C ₂ ) (360° + β) + 6Nτ (C ₁ i ₂ / i ₁ C ₂ ) ...(5) Here, if we set δ≡K ₁ +K ₂ N, then K ₁ = α {1 + (C ₁ i ₂ /i ₁ C ₂ )} − (C ₁ i ₂ /i ₁ C ₂ ) (360° + β) ...(6) K ₂ = 6τ (C ₁ i ₂ /i ₁ C ₂ ) ...(7). That is, the ignition position θ _i advances as the rotational speed increases, and by changing the constant K ₂ it is possible to control the ignition position with respect to the rotational speed.
Also, the width τ of the output signal of the monostable multivibrator
Various advance angle characteristics can be obtained by changing .

In the above explanation, the integral value of the second integrator is expressed as the angle θ
₁ to θ ₂ , but the integration operation of the second integrator is performed up to the angle θ ₂ , and the triangular wave of the output of the first integrator and the triangular wave of the output of the second integrator are generated. The ignition position can also be advanced relative to the rotational speed by comparing.

In the embodiment shown in FIG. 1, the first
If the output voltage of the second integrator is set higher than the output voltage of the integrator, the outputs of the first and second integrators will always match at an angle θ ₂ , ₂ until the capacitor of the first integrator finishes discharging (resetting), the output voltage of the first integrator is higher than the output voltage of the second integrator, so the comparator circuit From 11, the angle θ ₂
A rectangular wave signal Vh is obtained that lasts from 1 to 1 until the discharge of the capacitor of the first integrator is completed. That is, at low speeds, θ _i =θ ₂ , and ignition is performed at an angle θ ₂ . As the rotational speed increases, the output voltage of the second integrator (the voltage held between angles θ ₁ - _{θ 2} ) decreases and the ignition position advances along the slope of the first integrator. When the ignition position advances and θ _i =θ ₁ , it becomes impossible to compare the output voltages of the first and second integrators, but in this case, the first signal e ₁ is supplied to the ignition device as an ignition signal. If it is set, ignition can be performed at an angle _θ1 . Therefore, the advance angle characteristic in this case is as shown in FIG.

FIG _. 4 _is a connection diagram showing an embodiment embodying the configuration shown _in FIG _.
It is made up of. When a voltage is generated in the first signal coil 1 with the ground side shown being positive, the resistance
The current flowing to the base of the transistor TR ₁ through R ₁ now flows to the first signal coil 1 side, so that the transistor TR ₁ is cut off and the first signal e ₁ as shown in A is obtained. The waveform shaping circuit 4 includes a transistor TR ₂ , a diode D ₂ and a resistor.
The configuration of R ₃ and R ₄ is exactly the same as that of the waveform shaping circuit 3 described above. The flip-flop circuit 7 is a known circuit constructed by combining two NOR circuits _NOR1 and _NOR2 . The first integrator 8 includes a field effect transistor FET ₁ and a resistor that constitute a constant current circuit.
_R5 , an integrating capacitor _C1 , a transistor _TR3 and a resistor _R6 forming a reset circuit for discharging the charge of the capacitor _C1 , and the output terminal of the flip-flop circuit 7 is in the "0" state _θ1 For a period of ~θ ₂ , the transistor TR ₃ is kept in a cut-off state and the capacitor C ₁ is charged with a constant current i ₁ . When the output terminal Q of the flip-flop circuit 7 becomes a "1" state at an angle θ ₂ , the transistor TR ₃ becomes conductive, so the integration operation stops and the capacitor
C ₁ discharges with a constant time constant. Therefore, the output voltage of the first integrator obtained across the capacitor _C1 becomes a triangular wave as shown in FIG. 2E.

The second integrator 9 includes a transistor TR ₄ which becomes conductive when the potential of the output terminal Q of the flip-flop circuit 7 is in a "0" state, a field effect transistor FET ₂ and a resistor R ₇ forming a constant current circuit; It is composed of an integrating capacitor _C2 and a reset transistor _TR5 , and when the transistor _TR4 is turned on while the transistor _TR5 is in a cut-off state, an integral operation is started to charge the capacitor _C2 with a constant current _i2 . It's getting old. The monostable multivibrator 10 also includes transistors TR ₆ and TR ₇ , a capacitor C ₃ , a Zener diode ZD ₁ , and resistors R ₈ and R _9.
The base of transistor TR 6 is connected to the collector of transistor TR 2, and the base of transistor TR ₆ is connected to the collector of transistor TR ₂ .
The collectors of TR ₇ are respectively connected to the bases of transistors TR ₅ . In this monostable multivibrator, the capacitor _C3 is initially charged to the polarity shown through the resistor _R8 by a DC power source (not shown), and the transistor _TR7 is made conductive by being supplied with a base current through the Zener diode _ZD1 . In this state, when the second signal e ₂ is applied to the base of the transistor TR ₆ at an angle θ ₂ , the transistor TR ₆ becomes conductive and instantly discharges the charge in the capacitor C ₃ . When capacitor _C3 discharges, all the current supplied from the DC power supply through resistor _R8 flows to capacitor _C3 , so transistor _TR7
base current is no longer supplied to the transistor
TR ₇ becomes blocked and the potential at its collector increases. When the second signal e ₂ disappears, the transistor TR ₆ returns to the cut-off state, and the capacitor C ₃ is charged with a constant time constant. At an angle θ ₃ , the terminal voltage of the capacitor C ₃ becomes the Zener diode ZD ₁
When the Zener voltage is exceeded, the transistor TR ₇ becomes conductive and the potential at its collector decreases. Therefore, the potential of the collector of the transistor TR ₇ (the output terminal of the monostable multivibrator 10) becomes "1" during the angle θ ₂ to θ ₃ , as shown in FIG. 2D, and during this period the second integral Transistor TR ₅ of device 9
is maintained in a conductive state to maintain the second integrator 9 in a reset state. When the output of the monostable multivibrator 10 becomes "0" at the angle θ ₃ , the transistor TR ₅ is cut off. At this time, the potential of the output terminal Q of the flip-flop circuit 7 is "0" and the transistor _TR4 is in a conductive state, so
Charging of the capacitor C ₂ of the second integrator 9 is started, and the terminal voltage of the capacitor C ₂ increases as shown in FIG. 2F. When the potential of the output terminal Q of the flip-flop circuit 7 becomes "1" at the angle θ ₁ , the transistor TR ₄ is cut off and the integration operation is stopped. Between the angles θ ₁ and _{θ 2} , the output of the monostable multivibrator 10 is “0” and the transistor TR ₅ is kept in the cut-off state, so the terminal voltage (integral value) of the capacitor C ₂ remains unchanged. Retained.

Comparison circuit 11 consists of operational amplifier OP and resistors R ₁₀ and R ₁₁
As shown in FIG. 2F, this comparator circuit is composed of
A rectangular wave signal that connects while exceeding the integral value of
Output Vh. The pulse generator 12 is an AND circuit
It consists of an AND circuit and an OR circuit OR, and the signal Vh is supplied to one input terminal of the AND circuit AND and one input terminal of the OR circuit OR. and circuit
The other input terminal of AND is supplied with the first signal e ₁ , and the output terminal of AND circuit AND is supplied with OR circuit OR.
is connected to the other input terminal of When obtaining the advance angle characteristic shown in FIG. 3, the ignition signal Vs in the range N≦n ₂ is given from the comparison circuit 11 through the OR circuit OR. In addition, in the range of N>n ₂ , the AND circuit AND is established at the maximum advance angle position θ ₁ , and the ignition signal Vs is passed through the AND circuit and the OR circuit OR.
is given. In FIG. 4, the terminal with the symbol "+" attached to the white circle is connected to the positive terminal of the DC power supply.

In the above embodiment, two triangular waves are generated using an integrator that charges the capacitor with a constant current, but in the present invention, a predetermined triangular wave is generated between the maximum advance angle position θ ₁ and the minimum advance angle position θ ₂ . a first triangular wave generation circuit that generates a first triangular wave that rises with a slope;
The output of the monostable multivibrator triggered at the minimum advance angle rises at a predetermined gradient from the fall position θ ₃ to at least the maximum advance angle position θ ₁ , and maintains its maximum value until the minimum advance angle position θ ₂ . A second triangular wave generating circuit that generates a second triangular wave may be provided to compare the first and second triangular waves, and the triangular wave generating circuit is limited to the integrator shown in the above embodiment. It's not something you can do. As described above, the second triangular wave generating circuit may generate a triangular wave that continuously rises from angle θ ₃ to θ ₂ .

As described above, according to the present invention, there is an advantage that the ignition position can be accurately controlled with respect to the rotational speed with a simple circuit configuration without detecting the rotational speed. In particular, according to the present invention, from the falling position of the output signal of the monostable multivibrator that outputs a rectangular wave signal with a constant time width triggered by the second signal generated at a position corresponding to the minimum advance angle position of the engine. A second triangular wave is generated. Therefore, even if the engine rotation speed changes, the time width of the output signal of the monostable multivibrator remains constant, so the falling position of the monostable multivibrator's rectangular wave signal changes depending on the change in engine rotation speed. That is, since the generation position of the second triangular wave changes, the ignition timing can be changed in accordance with changes in the rotational speed of the engine with a simple configuration. Additionally, by simply selecting the time width of the rectangular wave signal output from the monostable multivibrator, the generation position of the second triangular wave can be changed, making it possible to obtain various advance angle characteristics with a simple configuration. It has the advantage of being possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention, FIGS. 2A to I are signal waveform diagrams of various parts explaining the operation of the embodiment of FIG. 1, and FIG. A diagram showing an example of the obtained advance angle characteristic, and FIG. 4 is a connection diagram showing an embodiment embodying the configuration of FIG. 1. DESCRIPTION OF SYMBOLS 1...First signal coil, 2...Second signal coil, 3...First waveform shaping circuit, 4...Second waveform shaping circuit, 5...First signal generation circuit, 6...
... second signal generation circuit, 7 ... flip-flop circuit, 8 ... first integrator, 9 ... second integrator, 10 ... monostable multivibrator, 11 ...
...Comparison circuit, 12...Ignition signal generation circuit.

Claims (1)

[Scope of Claims] 1. Signal generating means for generating a first signal at a position corresponding to the maximum advance position of the internal combustion engine and generating a second signal at a position corresponding to the minimum advance position of the engine; , the first signal rises at a predetermined gradient from the position where the first signal is generated to the position where the second signal is generated.
a first triangular wave generating circuit that generates a triangular wave; a monostable multivibrator that is triggered by the second signal and outputs a rectangular wave signal with a constant time width; a second triangular wave generating circuit that generates a second triangular wave that rises at a predetermined gradient to at least a position where the first signal is generated and holds a maximum value until a position where the second signal is generated; an ignition signal generation circuit for comparing the levels of the first and second triangular waves and outputting an ignition signal that determines the ignition position of the internal combustion engine when the levels match; an ignition signal for an internal combustion engine non-contact ignition device; Generator. 2 The second triangular wave rises at a constant slope from the falling position of the output of the monostable multivibrator to the position where the first signal is generated, and the second triangular wave rises from the position where the first signal is generated to the second signal. The ignition signal generating device for an internal combustion engine non-contact ignition device according to claim 1, wherein the ignition signal generating device has a waveform that maintains a maximum value up to a position where . 3 The second triangular wave rises at a constant slope from the falling position of the output of the monostable multivibrator to the position where the second signal is generated, and reaches a maximum at the position where the second signal is generated. The ignition signal generating device for an internal combustion engine non-contact ignition device according to claim 1, which has a waveform.