JPS6217671B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a non-contact ignition device for an internal combustion engine that controls ignition timing in an analog manner.

(Prior Art) Conventionally, a first angular position and a second angular position are periodically detected in synchronization with the rotation of an internal combustion engine, and a calculation capacitor is connected from the second angular position to the first angular position. A device that gradually charges and gradually discharges the calculation capacitor from the first angular position, and when the voltage of this calculation capacitor is discharged to a set value higher than the charging start voltage, an advance angle pulse is generated according to the rotation speed of the internal combustion engine. (For example, Japanese Patent Publication No. 7681/1983).

(Problem to be Solved by the Invention) However, in the conventional device described above, charging of the calculation capacitor is started only after the charging voltage of the calculation capacitor has finished discharging, or charging of the calculation capacitor is started at the minimum advance angle position. Since it is used to reset the voltage of the calculation capacitor, during sudden acceleration of the internal combustion engine or at medium to high speeds, charging starts again before the calculation capacitor voltage is sufficiently discharged, causing the advance angle pulse to The problem is that the timing of occurrence may be inaccurate.

Therefore, the present invention improves the accuracy of the advance angle pulse generation time even when the internal combustion engine is rapidly accelerating or at medium to high speeds.

(Means for Solving the Problems) Therefore, the present invention provides a position detection circuit that periodically detects a first angular position and a second angular position in synchronization with the rotation of an internal combustion engine, and a calculation capacitor. and,
a discharge circuit that gradually discharges the calculation capacitor from a first angular position according to the output of the position detection circuit; a comparator circuit that generates an advance pulse that advances as the angle increases;
While the advance angle pulse of the comparator circuit and the pulse corresponding to the second angular position of the position detection circuit are generated, the voltage of the calculation capacitor is set to a second set voltage lower than the first set voltage. a charging circuit that gradually charges the calculation capacitor from the second angular position to the first angular position according to the output of the position detection circuit; A non-contact ignition device for an internal combustion engine is provided, which includes an ignition circuit that conducts or disconnects a semiconductor switching element using an advance pulse and generates an ignition spark at an ignition plug.

(Function) As a result, the voltage of the calculation capacitor is rapidly discharged by the advance angle pulse, which advances in accordance with the increase in the rotational speed of the internal combustion engine, until the pulse corresponding to the second angular position finishes being generated. fully discharge the voltage of the calculation capacitor.

(Example) The present invention will be described below with reference to an example shown in the drawings. A case where the present invention is applied to an electronic non-contact ignition device for a single-cylinder four-stroke internal combustion engine using a magnet generator will be described. In Fig. 1, the anti-capacitor charging current of the capacitor charging coil 1 of the magnet generator is:
The current flows through a small resistor (approximately 30Ω) 11 and a diode 3, and at this time, the voltage appearing across the small resistor 11 causes a large capacitance (several hundreds of μ) to flow through the diode 5.
F) capacitor 12 is charged, and the charge of this capacitor 12 is used as a DC power source. As shown in FIG. 7, a wide projection 21 having a mechanical angle equal to the necessary advance width is provided on the outer periphery of the magnetic rotor 20 of the magnet generator. As shown in FIG. 3A, the sensor 2 consists of an electromagnetic pickup having a permanent magnet 23 and a signal coil 24.
The signal voltage of one cycle is shifted by the required advance width and is generated as positive or negative. 4 and 6 are diodes, 7 is a thyristor, 8 is a main capacitor, 9 is an ignition coil,
9a and 9b are the primary coil and secondary coil, 1
0 is an ignition plug, which constitutes a known capacitor discharge type ignition circuit. 13 is an ignition timing control circuit whose internal circuit is shown in FIG. The voltage of the capacitor 12 and the signal voltage of the sensor 2 are input to the ignition timing control circuit 13, and the thyristor 7
It outputs a signal voltage to trigger the ignition signal generation circuit 13a and rotation speed detection circuit 13b. Since the voltage of the capacitor 12 becomes a pulsating current,
This is stabilized by the constant voltage circuit 50, and the constant voltage
Get V ⁺ . This constant voltage V ⁺ is used for comparators, logic circuits,
Used as a power source for constant current circuits, flip-flops, gate circuits, etc. The output of sensor 2 is resistor 10
1, 102, and 103, the comparator 100, which constitutes the position detection circuit,
200 inputs. The other input of comparator 100 is connected to the connection point of resistors 104 and 105, and the other input of comparator 200 is grounded. Then, the output of the comparator 100 is the first
The output of the comparator 200 serves as a reset signal for the first flip-flop 300 and the second flip-flop 350. Here, flip-flop 3
The rising position of the 00 set signal is made to coincide with the high speed fixed advance angle position _θH , and the rising position of the reset signal is made to coincide with the low speed fixed advance angle position _θL . The first calculation capacitor 108 is charged with a constant current IC ₁ by the constant current circuit 400 when both analog switches 600 and 700 are open, and conversely, when the analog switch 600 is closed and the analog switch 700 is open. Then, as shown in Fig. 2, constant current IC ₁ from constant current circuit 400 and constant current id from constant current circuit 600 flow.
Since it is set so that id>ic ₁ , the charge of the first calculation capacitor 108 is a constant current id−ic ₁
It will be discharged. Therefore, the constant current circuit 40
0 forms a charging circuit, and a constant current circuit 500
A discharge circuit is formed by the analog switch 600 and the analog switch 600. Then, the analog switch 600
The switch 700 forming the reset circuit is configured to close when the output of the flip-flop 300 is "1", and the switch 700 forming the reset circuit is configured to close when the output of the OR circuit 910 is "1". The constant voltage V ⁺ is divided by resistors 106 and 107, the voltage across the resistor 107 is set as the first set value, which is the reference voltage V _S , and this reference voltage V _S and the voltage of the first calculation capacitor 108 are compared. Comparator 80 forming a circuit
0 input, and the output of the comparator 800 and the Q output of the first flip-flop 300 are connected to an AND circuit 90.
0, and the output of the AND circuit 900 and the reset signal of the first flip-flop 300 are ORed.
Connected to circuit 910. On the other hand, the second calculation capacitor 109 is charged with a constant current IC ₂ by the constant current circuit 450 when the analog switch 750 is open. Switch 750 is configured to close when the Q output of first flip-flop 300 is "1". The voltage of the second calculation capacitor 109 and the reference voltage V _S are input to a comparator 850, and the output of the comparator 850 is used as a reset signal for the second flip-flop 350.
The Q output of the second flip-flop 350 and the output of the OR circuit 910 are input to an AND circuit 920, and the output of the AND circuit 920 is used as an ignition signal.
Further, when the output of the OR circuit 910 is "1", the analog switch 700 is closed, and the charge in the first calculation capacitor 108 is instantly discharged to 0V, which is the second set voltage.

The operation of the control circuit configured as above is explained in the third section.
This will be explained using the waveform diagram shown in the figure. As shown in FIG. 3A, the sensor 2 generates one cycle of signal voltage for each rotation of the rotor 20. A pulse signal is generated at the output of the comparator 100 as shown in FIG. 3B in synchronization with the positive direction voltage of this signal voltage, and a pulse signal is generated at the output of the comparator 200 in synchronization with the negative direction voltage as shown in FIG. 3C. , a pulse signal is generated. The output of the comparator 100 is used as a set signal for the first flip-flop 300 and the second flip-flop 350, and the output of the comparator 200 is used as a reset signal for the first flip-flop 300. Since the rising position of the set signal coincides with the high-speed fixed advance angle position θ _H and the rising position of the reset signal coincides with the low-speed fixed advance angle position θ _L , the Q of the first flip-flop 300
As shown in FIG. 3D, the output falls to "1" at the high-speed fixed advance angle position _θH . First flip-flop 3
Since the switch 600 is closed when the Q output of 00 is "1", the electric charge of the first calculation capacitor 108, which was charged by the constant current IC ₁ , becomes a constant current from the rising position of the set signal (high-speed fixed advance position). id
-ic starts to discharge at ₁ , first calculation capacitor 1
The voltage at 08 begins to drop. Then, a reference voltage V set by this voltage and resistors 106 and 107
_S is input to the comparator 800, and when [the voltage of the first calculation capacitor 108<the voltage V _S at the voltage dividing point of the resistors 106 and 107], the output of the comparator 800 becomes "1" (the Figure 3G). FIG. 3G shows a state where the rotational speed is lower than the starting rotation speed, and the states during a low speed fixed advance angle, a medium speed advance angle, and a high speed fixed advance angle will be described later. The output of the comparator 800 and the Q output of the first flip-flop 300 are connected to an AND circuit 900.
The output of the AND circuit 900 becomes as shown in FIG. 3H. Then, the output of the AND circuit 900 and the first
What is the reset signal of flip-flop 300?
Through the OR circuit 910, the output of the OR circuit 910 becomes as shown in FIG. 3I.

By the way, the rotation speed detection circuit 13b, which is composed of the constant current circuit 450, the analog switch 750, the second calculation capacitor 109, the comparator 850, and the second flip-flop 350, starts ignition when the rotation speed reaches the set rotation speed. The operation of this starting rotation speed control circuit will be explained below. The second calculation capacitor 109 is charged with a constant current IC ₂ by the constant current circuit 450 when the switch 750 is open. Switch 750 is the first
Since the Q output of the flip-flop 300 (E in FIG. 3 is closed when it is "1", the voltage of the second calculation capacitor 109 is linear from the rising position of the set signal of the first flip-flop 300, as shown in J in FIG. 3). The voltage rises, and the charged charge is instantly discharged at the rising position of the reset signal.Then, this voltage and the reference voltage V _S are input to the comparator 850, and [voltage of the second calculation capacitor 109 > V]
_S ], the output of the comparator 850 becomes "1" (FIG. 3K). Figure 3 J and K represent the state at low rotation speed before reaching the set starting rotation speed N _S ,
The output of comparator 850 is connected to second flip-flop 3.
50, the Q output of the second flip-flop 350 falls to "0" at the rising position of the output of the comparator 850 (FIG. 3L). Since the Q output of the second flip-flop 350 and the output of the OR circuit 910 (I in FIG. 3) become an ignition signal via the AND circuit 920,
As shown, no ignition signal is generated. When the rotation speed increases from this state, the voltage of the second calculation capacitor 109 decreases, and when it exceeds the set number of starting circuits N _S , it becomes lower than the reference voltage V _S as shown in FIG. The output of is always "0". That is, since no reset signal is input to the second flip-flop 350, the Q output of the second flip-flop 350 is always "1" as shown in FIG. 4L. Therefore, OR circuit 910
The output passes through an AND circuit 920 and becomes an ignition signal (M in FIG. 4). As mentioned above, starting rotation speed N _S
is not determined by the output voltage value of the sensor, but is performed by control using the charging and discharging of the calculation capacitor, resulting in extremely high accuracy. Here, the starting rotation speed N _S is set by changing the constant current value IC ₂ of the constant current circuit 450, but it is also possible to set the starting rotation speed N S by changing the capacity of the second calculation capacitor 109 or the reference voltage V _S. You may go.

Since the output of the OR circuit 910 becomes the ignition signal when the starting rotation speed is higher than the set rotation speed, the AND circuit 9
Ignition is performed at a position where the phase is advanced between the rising position of the 00 output and the rising position of the reset signal of the first flip-flop 300 (low speed fixed advance angle position). Further, when the output of the OR circuit 910 becomes "1", the switch 700 is closed, so that the electric charge of the first calculation capacitor 108 is reduced to the OR circuit 910.
Instantly discharges to 0V at the rising position of the output of 10. And analog switches 600 and 7
From the position where both 00 open, that is, the fall position of the output of the OR circuit 910, the first calculation capacitor 108 starts charging again with the constant current _IC1 ,
The voltage of the first calculation capacitor 108 is shown in FIG.
It will be like this.

The voltages of the first calculation capacitor 108 in each state during low-speed fixed advance angle, medium-speed fixed advance angle, and high-speed fixed advance angle are as shown in FIG. 5 as N _L , _NM , and _NH . In other words, at low speed fixed advance angle, the first calculation capacitor 1
Since the charging time of 08 is long, the voltage at the high speed fixed advance angle position θ _H becomes high as shown in N _L in Figure 5, and the position where the voltage drops to the reference voltage V _S lags behind the low speed fixed advance angle position θ _L. However, the OR circuit 910 performs ignition at the low speed fixed advance angle position θ _L. Then, as the rotation increases, the charging time becomes shorter, so the voltage of the first calculation capacitor 108 at θ _H becomes lower, and therefore, the position where it drops to the reference voltage V _S gradually shifts to the advance side. , eventually becomes more advanced than θ _L. In other words, when the rotational speed increases to a certain level, the angle starts to advance from the low speed fixed advance angle position θ _L. This state is N _M in FIG. As the rotation further increases, the ignition timing approaches the high-speed fixed advance angle position _θH , and soon the voltage of the first calculation capacitor 108 reaches the fifth
As shown at N _H in the figure, even θ _H is lower than the reference voltage V _S . In this state, the output of the comparator 800 is always "1", and the ignition timing is set at the position where the Q output of the first flip-flop 300 rises to "1".
In other words, the high-speed fixed advance angle position θ _H is reached. In other words, even if the rotation increases further, the ignition timing will be fixed at _θH . Therefore, the advance angle θ characteristic with respect to the rotational speed N is as shown in FIG.

Note that the charging period of the second calculation capacitor 109 is not limited to from θ _H to θ _L , but also from θ _L to θ _H , from θ _H to the next θ _H , or from θ _L to the next θ _L , Alternatively, the pulse width of θ _H (θ _L ) may be used (however, it is necessary to have a circuit configuration suitable for this). Furthermore, a dedicated signal for starting rotation speed control may be generated.

Furthermore, although the above-described embodiments have been described with respect to a capacitor discharge type non-contact ignition device, it is of course possible to apply the present invention to a current interrupt type ignition device.

In addition, in the embodiment described above, the second calculation capacitor 109 was provided exclusively for controlling the starting rotation speed, but by using the first calculation capacitor 108 also for controlling the starting rotation speed, the analog switch 750, The calculation capacitor 109 and the constant current circuit 450 of No. 2 can be omitted (however, it is necessary to separately apply a reference voltage higher than V _S to the inverting input of the comparator 850).

(Effect of the invention) As described above, in the first invention of the present application, the voltage of the calculation capacitor is rapidly discharged by the advance angle pulse that advances in accordance with the rotation of the internal combustion engine, and the voltage of the calculation capacitor is rapidly discharged. Since the voltage of the calculation capacitor is sufficiently discharged to the second set value by the time the pulse corresponding to the angular position finishes being generated, charging of the calculation capacitor can always be started from the second set voltage. This has the excellent effect of improving the accuracy of the timing at which the advance angle pulse is generated when the internal combustion engine is rapidly accelerating or at medium to high speeds.

Furthermore, according to the second invention of the present application, in addition to the effects of the first invention, since ignition is not performed until the set rotation speed, the compression process is started by a kick starter method or a recoil starter method. If you rev the engine slowly to find it,
There is no ignition, so problems such as reverse rotation or backup fire do not occur, and of course there is an excellent effect that the starting rotation speed is not too high and the engine cannot be started.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing one embodiment of the device of the present invention, FIG. 2 is a detailed electric circuit diagram of the ignition timing control circuit 13 in the device shown in FIG. 1, and FIGS.
The figure is a waveform diagram of each part used to explain the operation of the circuit illustrated in Figure 2. Figure 5 is a waveform diagram of charging and discharging of the first calculation capacitor 108 in the circuit illustrated in Figure 2. Angular characteristic diagram, Figure 7 is the first
FIG. 2 is a schematic perspective view showing the configuration of a sensor portion in the illustrated device. 2... Sensor, 7... Thyristor as a semiconductor switching element, 9... Ignition coil, 10... Spark plug, 13... Ignition timing control circuit, 13a... Ignition signal generation circuit, 13b... Rotation speed detection circuit , 10
0,200...Comparator configuring the position detection circuit,
108... Calculating capacitor, 400... Constant current circuit forming the charging circuit, 500, 600... Constant current circuit and analog switch forming the discharging circuit, 700... Analog switch forming the reset circuit, 800... A comparator that constitutes a comparison circuit.

Claims (1)

[Claims] 1. A position detection circuit that periodically detects a first angular position and a second angular position in synchronization with the rotation of an internal combustion engine, a calculation capacitor, and an output of the position detection circuit. a discharge circuit that gradually discharges the calculation capacitor from a first angular position in response to the increase in rotational speed of the internal combustion engine; and a discharge circuit that gradually discharges the calculation capacitor from a first angular position; A comparator circuit that generates an advance angle pulse, and a voltage of the arithmetic capacitor that changes the voltage of the calculation capacitor to the first angular position while the advance pulse of this comparator circuit and a pulse corresponding to the second angular position of the position detection circuit are generated. a reset circuit that rapidly discharges to a second set voltage lower than the set voltage of the first angular position, and a reset circuit that gradually discharges the calculation capacitor from the second angular position to the first angular position according to the output of the position detection circuit. A non-contact ignition device for an internal combustion engine, comprising a charging circuit for charging, and an ignition circuit for making a semiconductor switching element conductive or disconnected by an advance pulse of the comparison circuit to generate an ignition spark at an ignition plug. 2. The non-contact ignition device for an internal combustion engine according to claim 1, wherein the first angular position is a high speed fixed advance angle position, and the second angular position is a low speed fixed advance angle position. 3 a position detection circuit that periodically detects a first angular position and a second angular position in synchronization with the rotation of the internal combustion engine; a calculation capacitor; a discharge circuit that gradually discharges the calculation capacitor from a position; and a discharge circuit that compares the voltage of the calculation capacitor with a first set voltage to generate an advance angle pulse that advances in accordance with an increase in the rotational speed of the internal combustion engine. A comparator circuit sets the voltage of the arithmetic capacitor to a level lower than the first set voltage while an advance pulse of the comparator circuit and a pulse corresponding to the second angular position of the position detection circuit are generated. a reset circuit that rapidly discharges to a set voltage of No. 2, and a charging circuit that gradually charges the calculation capacitor from the second angular position to the first angular position according to the output of the position detection circuit; An ignition circuit that conducts or interrupts the semiconductor switching element by the advance angle pulse of the comparison circuit and generates an ignition spark at the ignition plug, and an ignition circuit that electronically detects the rotation speed of the internal combustion engine and detects the engine rotation speed at a set value. A non-contact ignition device for an internal combustion engine, comprising: a rotation speed detection circuit for applying the advance angle pulse to the semiconductor switching element from time to time.