JPS6085255A - Ignition timing control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve the noise resistance by generating a control signal for the maximum/minimum spark advance position through a hysteretic rectangular wave shaping circuit by means of rotating a rotor which has angular information data contrary to each other at intervals corresponding to the spark advance width. CONSTITUTION:The signal of a sensor 2, which comes from the rotation of a magnetic rotor 20 with a protrusion 21 corresponding to the spark advance width, is level-converted at a constant voltage Vr, which is made as a set signal through a comparator 103 and an inverter 104. Through a hysteretic rectangular wave shaping circuit 30, it is shaped into rectangular pulses at intervals of an angular space corresponding to the spark advance width, and further, through an integrating circuit 40, it is converted into operational waves with the prescribed inclination which is reset once per rotation of the rotor. And a point where it intersects the threshold value Vth of a comparator 112 is the ignition point, generating an ignition signal J. In this way, a signal sensor can detect the maximum/minimum spark advance position, and the noise resistance can be considarably improved by the hysteretic action.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition timing control device that is used in a non-contact ignition device for an internal combustion engine and is low cost and has excellent noise resistance.

[Prior art]

Conventionally, this type of ignition device was disclosed in Japanese Patent Application Laid-Open No. 57-131.
As described in Japanese Patent No. 867, the maximum and minimum advance angle positions are detected by a rotor having a narrow protrusion and two sensors arranged at an angular interval corresponding to the advance angle width. Then, a signal that rises at the maximum advance angle position and falls at the minimum advance angle position is created from the two detection signals via an R-S flip-flop, and this signal causes an integral circuit using an operational amplifier to perform an integral operation. The integrated output is compared with a comparator and an ignition signal is generated.

However, the conventional method described above is expensive because it uses two sensors, and is susceptible to noise because it uses an R-S flip-flop as a circuit for generating a control signal from a sensor signal. There's a problem.

[Purpose of the invention]

Therefore, in order to solve the above problem, the present invention has a configuration in which the maximum and minimum advance angle positions are detected with one sensor by using rotors having mutually contradictory angle information at intervals corresponding to the advance angle width, Further, by using a rectangular wave shaping circuit with hysteresis as a circuit for generating a control signal from a sensor signal, the present invention aims to reduce costs and significantly improve noise resistance.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings.

In FIG. 1, 1 is a capacitor charging coil of a magnet generator, and its positive direction output (in the direction of the solid arrow) charges the main capacitor 5 via the diode 4 and the primary coil 6a of the ignition coil 6. One part charges a smoothing capacitor 11 via a resistor 9, a diode 10, and a Zener diode 12, and uses the terminal voltage vrN of this capacitor 11 as a DC power source for the advance angle calculation circuit 15. 3.4 is the diode, 8 is Cyrisk, 5 is the main capacitor,
6 is an ignition coil, 6a and 6b are its primary and secondary coils, and 7 is an ignition plug, which constitute a known capacitor discharge type ignition circuit. Further, 2 is a magnetic sensor.

As shown in FIG. 2, a projection 21 having a mechanical angle width corresponding to the advance angle width is provided on the outer periphery of a magnetic rotor 20 of the magnet generator, and the sensor 2 is attached to the outer periphery of the rotor 20. It is composed of an electromagnetic pink-up having a permanent magnet 22 and a signal coil 23 arranged therein. Then, as shown in FIG. 4(A), the sensor 2 detects the
A set of negative and positive half-wave signal voltages are generated corresponding to the maximum and minimum advance positions, respectively. Therefore, the maximum and minimum advance positions can be detected using the rotor 20 having a protrusion width corresponding to the advance width and one sensor 2.

By the way, in the extremely low speed rotation region, the DC power supply voltage (V x
Since N) is low, the advance angle calculator 17815 does not operate and the ignition signal (J) cannot be obtained. Therefore, the minimum advance angle position signal (K) of the sensor 2 is transmitted via the resistor 13 and the diode 14.
By creating a signal (J) and a signal (K) and connecting the signal (J) and signal (K) to the gate of the thyristor 8 like an OR circuit, the ignition signal in the extremely low speed rotation region is secured. here,
If the starting rotation speed is high, the circuit via the resistor 13 and diode 14 may be omitted.

The lead angle calculation circuit 15 calculates the DC power supply voltage (VIN) and
The signal (A>) from the sensor 2 is input, and an ignition signal (J) that triggers the thyristor 8 is output.

Next, the internal configuration, ie, a block diagram, of the advance angle calculation circuit 15 is shown in FIG. Since the DC power supply voltage (VIN) becomes a ripple current, it is stabilized by the constant voltage circuit 50 to obtain a constant voltage Vr, which is used as a power source for a comparator, an operational amplifier, a theoretical circuit, etc.

The following description will be made based on the block diagram shown in FIG. 3 and the time chart shown in FIG. 4. The signal from the sensor 2 is level-exchanged by a constant voltage Vr and resistors 100, 101, and 102, resulting in a waveform shown in FIG. 4(A'). This waveform (
8') is compared with the threshold value ■1 by the comparator 103, and further inverted by the inverter 104, resulting in the result shown in FIG.
The cent signal shown in C) is obtained. On the other hand, Compare Lake 10
5. The rectangular wave shaping circuit 30 with hysteresis, which is composed of an inverter 106 and an analog switch 116 and has two threshold values of zero and
This is a rectangular wave pulse that falls only by an angular interval corresponding to the advance angle width shown in . This pulse is inverted by inverter 107, resistors 117 and 118, and capacitor 10.
9. Integrating circuit 4 along with analog switches 108 and 110
The signal is input to an operational amplifier 111 that constitutes 0. here,
Since the analog switch 108 is open during the period in which the waveform (D) shown in FIG. On the other hand, in the section where the waveform (D) is at a high level, the analog switch 108 is closed, so the capacitor 109 and the resistor 117,
A constant current is discharged with a time constant determined by 118. Furthermore, the capacitor 109 is connected to the analog switch 110 in FIG.
Since the reset signal shown in FIG. 4(F) is rotated once per rotation of the rotor, the operational waveform shown in FIG. 4(F) is obtained as the output of the operational amplifier 111. This waveform is determined by the comparator 112 at a threshold value vth
The intersection point P becomes the ignition position. Inverter 11
3. Among the intersection points P and P' between the calculated waveform and the threshold value, the NOR circuit 114 makes valid only the intersection point P that is within the advance angle width, and invalidates the intersection point P' that is outside the advance angle width. It is a provision. Further, the OR circuit 115 is provided to add a minimum advance angle position signal. As described above, the ignition signal (J
) is obtained, and the ignition timing characteristics as shown in FIG. 5 are obtained. Note that the analog switch 108 used in the above explanation,
110 and 116 are both closed at high level and open at low level.

In the above embodiment, the output (C) of the inverter 104 controls the opening and closing of the analog switch 110, but the output (J) of the OR circuit 115 controls the opening and closing of the analog switch 110. Figure 4 (F
), capacitor 1 at ignition timing P, as shown by the two-dot chain line.
09 may be discharged.

Further, in the above-described embodiment, the rotor 20 is provided with the protrusion 21 corresponding to the advance angle width, but a recess corresponding to the advance angle width may be provided.

Further, in the above-described embodiment, the magnetic sensor 2 is constituted by an electromagnetic pickup, but by fixing magnets of mutually different polarities, N and S poles, at the maximum advance angle position and the minimum advance angle position, the Hall element A similar effect can be obtained by configuring the magnetic sensor with a magneto-resistance element or the like.

〔Effect of the invention〕

As described above, in the present invention, the direction of change is alternately reversed each time one magnetic sensor detects angle information as the rotor rotates and has angle information that contradicts each other at intervals corresponding to the advance width. An alternating current output is generated, and in response to the alternating current output, a rectangular wave control signal with hysteresis is generated that alternately inverts the maximum advance angle position and the minimum advance angle position, and in response to this control signal, Since the charging and discharging of the capacitor is controlled, the maximum and minimum advance angle positions can be detected with one sensor, which not only greatly reduces costs, but also eliminates the hysteresis effect of the rectangular wave shaping circuit with hysteresis. - It has the excellent effect of being able to be used effectively to significantly improve noise resistance.

[Brief explanation of drawings]

Fig. 1 is an electric circuit diagram showing an embodiment of the ignition device to which the device of the present invention is applied, Fig. 2 is a perspective view showing the structure of the magnetic sensor portion applied to the above embodiment, and Fig. 3 is a diagram showing the structure of the magnetic sensor part applied to the above embodiment. FIG. 4 is a detailed electrical circuit diagram of the main parts, FIG. 4 is a waveform diagram of each part to explain the operation of the above embodiment, and FIG. 5 is an ignition timing characteristic diagram in the above embodiment. 2... Magnetic sensor 20... Rotor, 21... Protrusion constituting angle information, 30... Rectangular wave shaping circuit with hysteresis, 109... Capacitor, 112... Comparator forming a comparison circuit. ^ ^ Ha ha ^ ^ To's cn O- 0 li 9 ν, +J ν ν;

Claims (1)

[Claims] A rotor has angular information that contradicts each other at intervals corresponding to the advance angle width, and as the rotor rotates, the angular information is magnetically detected, and the direction of change is alternately reversed each time this angular information is detected. One magnetic sensor that generates an AC output, and an intelligent type with hysteresis that generates a rectangular wave control signal that alternately inverts between the maximum advance angle position and the minimum advance angle position in response to the AC output generated by this magnetic sensor. A wave shaping circuit and a maximum advance angle position force in response to a control signal from this shaping circuit.
An internal combustion engine comprising: a capacitor that is discharged from the beginning to the minimum advance position and discharged from the minimum advance position to the maximum advance position; and a comparison circuit that generates an ignition signal when the voltage of the capacitor is discharged to a predetermined value. Ignition timing control device for use.