JPS62186065A - Ignition timing controller - Google Patents

Abstract

PURPOSE:To suppress the deterioration of exhaust gas caused through the function of a throttle value to the minimum by obtaining a voltage corresponding to an engine rotary speed then detecting the deceleration of an engine on the basis of the variation of said voltage and lagging the angle of ignition timing when the deceleration rate has exceeded over a predetermined level. CONSTITUTION:During operation of engine, a signal voltage produced from an ignition signal generator 1 is fed through a shaper circuit 2 to an ignition timing operating circuit 6 so as to operate an ignition timing. An output signal of manifold pressure detected by a pressure sensor 1 is fed through an amplifier circuit 4 to a function voltage circuit 5 so as to produce a voltage corresponding to the pressure only when the pressure is constant. The output from said generator 1 is also fed through such as a F-V circuit 12 to a capacitor 14 so as to charge the capacitor 14 by increasing the engine rotation while to discharge the capacitor 14 through a resistor 16 by decreasing the engine rotation. A transistor 19 is turned on by the output from a comparator 18 which is at L-level during the discharge so as to lag the ignition timing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ignition timing control device that controls ignition timing based on engine rotational speed and manifold negative pressure.

[Conventional technology]

In recent years, ignition devices for motorcycles and the like have become commonly equipped with advance angle devices based on rotational speed using analog calculations, and moreover, ignition timing control devices using intake manifold negative pressure are increasing in order to improve fuel efficiency. Its configuration includes an ignition signal generator 1 for detecting the crank position shown in FIG. 1 (FIG. 1 shows an embodiment of the present invention), a waveform shaping circuit 2 for shaping its output waveform, and an intake manifold. A pressure sensor 3 that outputs a voltage corresponding to negative pressure, an amplifier unit 4 that amplifies the output of the pressure sensor 3, and a function voltage that outputs a voltage that corresponds only to a certain pressure range among the outputs of the amplifier unit 4. The ignition timing is set to 'f1.' by signals from the circuit 5, the ignition signal generator 1, and the pressure sensor 3. It generally comprises an ignition timing calculation circuit 6 that calculates the ignition timing and determines the ignition timing.

Next, the operation of the conventional device having the above configuration will be explained.

The ignition signal generator 1 generates a voltage and signal at a certain crank position in synchronization with the rotation of the engine, and performs noise removal etc. in the waveform shaping circuit 2, or in some cases shapes it into a rectangular wave and sends it to the ignition timing calculation circuit. 6. The pressure sensor 3 outputs a voltage substantially proportional to the pressure of the intake manifold, which is amplified by the amplifier section 4 and then supplied to the ignition timing calculation circuit 6 via the function voltage circuit 5. The ignition timing calculation circuit 6 calculates the ignition timing after detecting the engine rotation speed from the signal voltage interval of the ignition signal generator 1, outputs a signal at the ignition timing according to the rotation speed, and outputs a signal at the ignition timing according to the rotation speed. The engine is ignited by cutting off the intake manifold, and the output of the pressure sensor 3 is configured to advance the ignition timing as the intake manifold negative pressure increases. The function voltage circuit 5 is for maintaining the maximum and minimum values of the ignition timing with respect to the manifold negative pressure determined by the engine, and only a certain width of the output voltage of the amplifier section 4, that is, a certain width of the manifold negative pressure, is maintained as the negative pressure. By outputting a voltage that is approximately proportional to the maximum value setting value and a constant voltage above the minimum value setting value, the advance angle width due to negative pressure is limited.

[Problem that the invention seeks to solve]

In the conventional device described above, the ignition timing changes in response to rotation and engine load, which is useful for improving engine output and fuel efficiency, but the outlet for negative pressure during vehicle deceleration is downstream of the throttle valve. In this case, when the throttle is closed, the negative pressure becomes maximum and the ignition timing becomes the most advanced, which not only reduces the deceleration force, so-called engine grazing force, but also leaves unburned parts in the exhaust gas, which is a fatal flaw. Was.

As a solution to this problem, it would be desirable to have a mechanism that retards the ignition timing during deceleration, as shown in Japanese Patent Laid-Open No. 59-63366.

This invention was made to eliminate the above-mentioned conventional problems, and detects the deceleration of the vehicle or the driver's intention to decelerate and adjusts the ignition timing without adding a sensor to the conventional device. An object of the present invention is to obtain an ignition timing control device that can delay the ignition timing, throttle the output of an engine, and prevent unburned gas from being mixed into exhaust gas.

[Means for solving problems]

The ignition timing control device according to the present invention obtains a signal from a power source that generates voltage in synchronization with the rotation of the engine, such as an ignition signal generator, and supplies the signal to an integrating circuit to generate a voltage according to the rotation speed. This change in voltage is added to a discrimination circuit such as a voltage comparator to detect deceleration of the engine, and when the deceleration or deceleration time exceeds a certain value, the advance angle due to negative pressure is nullified and retarded. Alternatively, this retardation is performed with a constant time constant.

[Effect]

In this invention, since a signal synchronized with the engine is supplied to the integrating circuit, the integrating circuit can output a voltage corresponding to the rotation of the engine. Since this voltage changes with changes in the rotational speed of the engine, deceleration of the engine is sensed by the change in voltage, and the voltage of the function voltage circuit is thereby controlled to retard the engine.

By providing a certain threshold value or setting a time constant to the discrimination circuit that detects engine deceleration or the circuit that controls the voltage of the function voltage circuit, it is possible to detect potential speed changes during normal driving. First, detect when there is a large deceleration when the throttle valve is throttled to avoid malfunction.

[Example J Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
In the figure, 1 is an ignition signal generator that generates a signal voltage at a constant crank position in synchronization with engine rotation, and 2 is a waveform shaping circuit that shapes the waveform of the signal voltage of the ignition signal generator 1 and removes noise. , 3 is a pressure sensor that generates a voltage according to the manifold negative pressure of the engine, 4 is an amplifier circuit that amplifies the output voltage of the pressure sensor 3, and 5 is a set that sets the relationship between the manifold negative pressure and ignition timing required for the engine. A function voltage circuit receives the output of the amplifier circuit 4 and, as shown in FIG. 5, outputs a constant value P of negative pressure to another constant value P of negative pressure.

It is configured to output a voltage corresponding to negative pressure up to 22, and output a constant voltage corresponding to P1 when the negative pressure is 22 or more, and P1 when the negative pressure is equal to P. 6 is the voltage of the ignition signal generator l, 9 Lus and the pressure sensor 3 to the function voltage circuit 5.
An ignition timing calculation circuit 7 receives a voltage through the ignition timing calculation circuit 6, calculates the ignition timing, and outputs a signal at the ignition timing. It is a switching transistor that turns the current on and off, and when off, induces an ignition voltage in the secondary coil 10 to discharge the glove 11 and ignite the engine. 12 is a frequency-voltage conversion circuit (hereinafter referred to as F-V circuit) which receives voltage/cells from the ignition signal generator 1 via a diode 13 and outputs a voltage proportional to the number of pulses per hour; This capacitor forms a charging/discharging circuit together with resistors 15 and 16. It receives the output of the F-V circuit 12 via a diode 17, and the voltage change of the F-V circuit 12 is transferred to both ends of the resistor 16 by the charging/discharging current of the capacitor 14. Detect with.

A voltage comparator 18 receives the voltage across the resistor 16 at its (T) and (→ terminals), and its output turns on and off a transistor 19t.The transistor 19 is connected to a capacitor 21 from a power supply circuit (not shown) via a resistor 20t. The input voltage of the functional voltage circuit 5 is controlled by turning on and off the photocurrent to the capacitor 21.The capacitor 21 is provided between the Huff circuit 4 and the functional voltage circuit 5, and the resistor 22 constitutes a constant time constant circuit, and constitutes another time constant circuit together with the resistor 20.The ignition timing calculation circuit 6 receives the signal from the ignition signal generator l via the waveform shaping circuit 2, and generates the ignition signal. Signal voltage of device l
A signal that turns on the transistor 7 while advancing the ignition timing according to the rotation speed is outputted after a certain angle based on the calculation based on the rotation speed with respect to the position where the ignition occurs. Also give. Also, pressure sensor 3
receives the output of via the amplifier circuit 4 and the function voltage circuit 5,
The ignition timing is configured to be advanced as the manifold negative pressure increases. The ignition timing output from the ignition timing calculation circuit 6 is as shown in FIG. 4, and as mentioned above, the output of the function voltage circuit 5 is limited by the manifold negative pressure PI+P, so P2 is The maximum advance angle is the island, and the minimum advance angle is the island.

In the above configuration, when the ignition signal generator 1 is driven by the engine, the ignition signal generator 1 generates a signal voltage at a fixed position according to the rotation angle of the engine, and this voltage is transmitted through the waveform shaping circuit 2f. In addition to the ignition timing calculation circuit 6, the ignition timing calculation circuit 6 calculates the ignition timing according to the number of times the ignition signal generator l generates a signal per unit time, and at the ignition timing, the transistor 7 is cut off to ignite the engine. on the other hand,
A certain period of time before the transistor 7 is cut off, the transistor 7 is energized to energize the ignition coil 8.

When the engine starts operating, the pressure in the intake manifold fluctuates depending on the throttle opening and the engine load, and also fluctuates during each stroke of the engine, that is, the intake-compression-combustion-exhaust cycle. A voltage is generated at 3. This voltage is amplified by the amplifier circuit 4 and supplied to the functional voltage circuit 5. On the way, a time constant circuit consisting of a capacitor 21 and a resistor 22 smoothes the high frequency component corresponding to the pressure change due to the stroke of the engine. 5 is applied with a voltage that changes depending on the throttle opening and engine load fluctuations. As shown in FIG. 5, the functional voltage circuit 5 changes the output voltage in response to the voltage of the pressure sensor 3 only when a voltage corresponding to pressures P2 to P is inputted among the output voltages of the pressure sensor 3. For pressures below P2, P,
For pressures of 21 or higher, a voltage corresponding to P is output to the ignition timing calculation circuit 6.

When the pressure of the pressure sensor 3 is 21 or more, the ignition timing calculation circuit 6 ignites at a delayed ignition timing when the engine is running at low speeds, as shown in FIG. 4, so that the engine speed is n.

to rlt, the angle advances with the rotation of the engine, and the rotation is n
If it is 1 or more, ignition is performed at a certain advanced position. On the other hand, if the output of the function 'voltage circuit 5 decreases as the negative pressure applied to the pressure sensor 3 increases (decrease in pressure), the ignition timing at a predetermined rotation speed or higher moves to the advance side, and the pressure decreases to P or less. If this happens, the ignition timing will move to the most advanced curve 21 in Figure 4. The area between the Pl diagram and the P diagram in FIG. 4 changes linearly depending on the pressure of the pressure sensor 3.

The output of the ignition signal generator 1 is F through the diode 13.
-V circuit 12, but since F-V circuit 12 outputs a voltage proportional to the number of input signals per unit time,
An output voltage proportional to the rotational speed of the engine is output via a diode 17, and is photoelectrically connected to a capacitor 14t via a resistor 16. When the rotation of the engine increases, the capacitor 14 is discharged, and when the engine rotation decreases, the capacitor 14 is discharged through the resistor 16. Therefore, the voltage at the terminal of the resistor 160 is maintained at the connection point with the capacitor 14 only when the rotation is decreasing. When the output terminal of the comparator 18 becomes low level only when the rotation of the engine is decreasing, the transistor 19 is turned on and a constant voltage is applied from the power supply to the capacitor 21 and thus as an input to the function voltage circuit 5. The input voltage of the functional voltage circuit 5, that is, the voltage of the capacitor 21, increases with a constant time constant due to the capacitor 21 and the resistor 20 when the transistor 19 is turned on, and the ignition timing gradually changes to P in FIG. move towards. By selecting this time constant to be a constant value, for example, 500m5ec or more, even if the rotation decreases due to other conditions while driving, the ignition timing will only fluctuate slightly around P in Figure 4. When decelerating, the ignition timing can be delayed to Pl regardless of the manifold negative pressure.

FIG. 2 shows a second embodiment of the invention, in which the voltage of the capacitor 14 is connected to the ←) terminal of the converter 18 through the resistor 23.
, 24, and when the discharge current of the capacitor 14 exceeds a certain value due to engine deceleration, the output of the condenser 18 turns on the transistor 19, and the engine A threshold has been set to detect deceleration when the deceleration rate exceeds a certain value, and it can be set to retard the throttle when the driver closes the throttle close to fully closed. Detection of long-term deceleration due to midfield pitching, etc. can be avoided. In this case, the time constants of the capacitor 21 and the resistor 200 can be set small, which is more effective in purifying the exhaust gas. The time constant can be set to a value that can alleviate the shock of a reduction in engine output due to the retardation.

FIG. 3 shows a third embodiment of the present invention, and shows the possibility of replacing the integrating circuit for detecting engine deceleration with something other than the F-V circuit.

In the figure, the output of the ignition signal power generation bag fil photoelectrically connects the capacitor 25 via the diode 13, and the capacitor 25
The terminal voltage further charges capacitor 26 via resistor 28 and capacitor 27 via resistor 29. If the charging/discharging time constant of the integrating circuit consisting of the capacitor 26 and resistor 28 is set to be smaller than the charging/discharging time constant of the integrating circuit consisting of the capacitor 27 and resistor 29, the terminal voltage of the capacitor 26 will be smaller than the terminal voltage of the capacitor 27. Since the setting can be made to be high during acceleration and low during deceleration, the transformer 19 can be turned on during deceleration, and the terminal voltage of the capacitor 21 can be charged from the power supply circuit and increased, and the ignition timing can be delayed.

〔Effect of the invention〕

As described above, according to the present invention, there is provided an output for determining when the engine is decelerating, a retard circuit that operates when this output exceeds a certain threshold, or a circuit that retards after a certain period of time. The ignition timing is delayed when the driver throttles down to indicate the intention to decelerate, minimizing the deterioration of exhaust gas caused by throttle throttling.
It is possible to obtain an excellent ignition system ft which can increase the effect of engine braking and does not make the driver feel unnatural due to unexpected retardation.

[Brief explanation of drawings]

1 to 3 are block diagrams of ignition timing control devices according to first to third embodiments of the present invention, and FIGS. 4 and 5 are operational characteristic diagrams of ignition timing control devices according to the present invention, respectively. be. 1... Ignition signal generator, 3... Pressure sensor, 5...
...Function voltage circuit, 6...Ignition timing calculation circuit, 7...
・Ignition transistor, 8...Ignition coil, 12...
・F-V circuit, 14, 21.25-27... Capacitor, 16.20, 23, 24.28-30... Resistor,
18...Voltage comparator, 19...Transostor. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (5)

[Claims] (1) An ignition signal generator that generates a voltage signal in synchronization with the rotation of the engine, a pressure sensor that receives the negative pressure of the engine manifold and generates a voltage according to the pressure, and a pressure sensor that receives the voltage of the pressure sensor and generates a constant pressure. A function voltage circuit that outputs a voltage according to the pressure only during the interval, calculates the ignition timing according to the rotation speed using the voltage pulse of the ignition signal generator, and also calculates the ignition timing according to the manifold negative pressure by receiving the output of the function voltage circuit An ignition timing calculation circuit that determines the ignition timing of the engine; an integrator that receives a signal from a power source that generates voltage in synchronization with the rotation of the engine; and an integrator that changes the voltage according to the rotation speed; It is equipped with a discrimination circuit for discriminating deceleration of the engine, and an auxiliary power supply circuit that operates based on the output of the discrimination circuit when it discriminates deceleration of the engine and shifts the voltage of the function voltage circuit to the voltage on the retard side. 1. An ignition timing control device characterized in that the ignition timing control device is characterized in that the ignition timing control device is configured to have a constant value, or to provide a constant time constant for voltage changes in a function voltage circuit caused by an auxiliary power supply circuit, or to perform both. (2) Using a frequency-voltage conversion circuit that generates a voltage proportional or inversely proportional to the number of signals in the integrator, and supplying the output of this frequency-voltage conversion circuit to a capacitor having a charging/discharging circuit with a constant time constant; 2. The ignition timing control device according to claim 1, wherein acceleration and deceleration of the engine is determined by comparing voltages of charging and discharging resistors. (3) Two integrating circuits with different time constants are used in the integrator, and acceleration/deceleration of the engine is determined by comparing capacitor voltages of the two integrating circuits. The ignition timing control device according to item 1. (4) A voltage comparator circuit is used in the discrimination circuit, and a constant voltage divider is installed in the input circuit that is on the high potential side during deceleration, or a constant bias voltage is applied to the input circuit that is on the low potential side during deceleration. Claim 1 characterized in that the voltage of the function voltage circuit is shifted to the retard side when the deceleration of the engine exceeds a certain value by having a threshold value.
The ignition timing control device described in . (5) Apply the voltage of the auxiliary power supply circuit to the input terminal of the function voltage circuit, so that the output of the auxiliary power supply circuit is supplied through a fixed time constant circuit, and the voltage of the function voltage circuit changes over a fixed period of time. An ignition timing control device according to claim 1, characterized in that: