JPS5838629B2 - Internal combustion engine rotation speed detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotation speed detection device for an internal combustion engine, and more particularly to a device for maintaining the peak value of an AC ignition signal generator for an internal combustion engine having a non-contact ignition device.

By the way, the amplitude of the AC signal generated by a conventional AC ignition signal generator always fluctuates over time, so when controlling the future based on the current amplitude, the amplitude of the ignition signal is rectified and smoothed to obtain a constant level. Conventionally, control was performed using voltage levels of multiple cycles, such as methods using voltage levels after the voltage level has changed.

However, when performing control after detecting multiple pulses as described above, when the engine starts or suddenly accelerates or decelerates, even the peak value after one cycle will fluctuate widely, and it is difficult to predict the next cycle based on the current peak value. It was impossible to perform control before the cycle occurred.

That is, at the time of starting and sudden changes, it is impossible to perform future control from the current power distributor signal.

This invention was made to improve the above-mentioned problems of the conventional device, and the peak value of the distributor AC signal immediately after the engine is ignited is always detected by the distributor signal provided in the engine. This is stored and held until the start of the next cycle, and immediately after the start of the next cycle, the held peak value is reset and new peak value detection is immediately started.

That is, when starting and accelerating the internal combustion engine,
Immediately after the ignition signal is applied, the air-fuel mixture of the internal combustion engine is ignited and acceleration begins, so by setting and resetting the peak value in synchronization with the ignition signal, predictive control for the next cycle is performed. Moreover, even during deceleration, predictive control is possible with sufficient accuracy for practical use.

In addition, the peak value of the signal generated by the AC ignition signal generator occurs instantaneously, so when controlling by predicting the future, maintaining the necessary time width and peak value is a necessary means for practical equipment configuration. It is.

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows a peak value detection circuit according to the present invention, where 1 is a battery, 2 is a switch, 3 is an AC signal generator installed in an internal combustion engine equipped with a non-contact ignition device, 4, 5.6 are resistors, and 7 is a diode, 8 is a transistor, 9 is a resistor, 10 is a capacitor, 11 is an operational amplifier, 12.13 is a resistor,
14 is a diode, 15 is a transistor, 17 is a capacitor 18.19 is a resistor, 20 is a transistor, 21
2 is a resistor, 22 is a capacitor, 23 is an output terminal, and 24 is an ignition device output terminal.Next, the operation thereof will be explained with reference to FIGS. 1 and 2.

Now, when the switch 2 is closed, current flows from the battery 1 to the circuit, and as the engine rotates, the AC signal generator 3 generates a signal as shown in FIG. 2a.

The signal generated by the AC signal generator 3 triggers the non-contact ignition device through the ignition device output terminal 24 as shown in FIG.
turns on.

As a result, the transistor 20, which is normally ON, is turned OFF via the capacitor 17 for a time constant period formed by the differentiating circuit composed of the capacitor 17 and the resistor 19, and a positive pulse is generated at the collector of the transistor 20 as shown in FIG. 2C.

This positive pulse passes through the resistor 13 and is applied to the base of the transistor 8, turning it on.

Due to this conduction of the transistor 8, the output of the AC signal generator 3, which has been charged in the capacitor 10, passes through the resistor 5, the diode 1, and the resistor 9, and is transferred to the resistor 5 and the resistor 6.
The divided peak holding minister is reset.

By the way, the time required for resetting is short enough,
Immediately starts the next peak value detection operation.

This situation is shown in FIG. 2d.

The peak value voltage held in the capacitor 10 is input to an operational amplifier 11 having a high input impedance, and is outputted to an output terminal 23 as a non-inverted output.

As described above, the device of the present invention holds the peak value after each ignition signal and performs a reset operation even when the output of the AC signal generator changes due to any rotational fluctuations such as when starting, accelerating, or decelerating the engine. In order to do this, it is possible to accurately predict the next generation of ignition pulses by following the instantaneous rotation of the engine, and to perform control with good transient response.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing operation waveforms of each part of FIG. 1. In the figure, 1 is a battery, 3 is an AC signal generator, 7 is a backflow prevention diode, 8 is a reset transistor,
10 is a peak holding capacitor 11 is an operational amplifier, 1
5 and 20 are reset pulse generating transistors. Note that the same reference numerals in each figure indicate the same parts.

Claims (1)

[Claims] 1. In an internal combustion engine having a non-contact ignition device, a peak value holding circuit is connected to an alternating current signal generating device that generates an alternating current signal corresponding to a crank angle, and has a capacitor that charges and discharges the peak value of the alternating current signal; A reset means is connected to the signal generator and the peak value holding circuit, and discharges the peak value charged in the capacitor via a switching means that operates at the beginning of a cycle of the alternating current signal. Internal combustion engine rotation speed detection device.