JPS5865973A - Ignition timing controller for internal-combustion engine - Google Patents

Abstract

PURPOSE:To reduce the breakage of an engine by immediately preventing advance of the ignition timing in the fail state and allowing the max. delayed angle is formed after a prescribed time, in the captioned apparatus for correcting the ignition timing by use of the knocking indication signal. CONSTITUTION:A gate 8 is arranged between the first timer 7 in an arithmetic circuit 100 and an ignition timing correction amount calculating circuit 9, and the gate 8 is immediately closed according to a fail response signal 25 when fail is judged in a fail judging circuit 5, and application of an advance timing signal 26 to the correction amount calculating circuit 9 is prevented, and the advance calculation in the circuit 9 is suppressed. In the state where the gate 8 is closed and the signal 26 is suppressed, the fail detection signal 28 which is generated after a prescribed time by the second timer 6 is input into the correction amount calculating circuit 9 and controlled so that the max, delayed angle can be calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ignition timing control device for an internal combustion engine of the type that corrects the ignition timing of the engine using a knocking indication signal outputted from a knocking sensor in an internal combustion engine, and particularly to The present invention relates to a device with improved control when a fail state occurs.

A signal generation period synchronized with the rotation of the internal combustion engine, an ignition device which has an ignition timing control function, and a knocking sensor that detects knocking factors such as engine vibration and sound, and provides basic instructions from the signal generator. According to a conventional ignition timing control device of the type that includes a calculation circuit that calculates a correction amount for correcting the ignition timing and causes the ignition device to ignite at the corrected ignition timing, a knocking display signal output from a knocking sensor is used. (referred to as a knock signal), the correction amount is calculated and output, and the ignition timing is delayed by a certain amount.
In addition, when the knock signal interval becomes longer than a predetermined time (the knocking interval becomes longer than the knocking interval or the knocking state disappears), the ignition timing is advanced by a predetermined amount at fixed intervals, and abnormalities such as wire breaks, short circuits, and breakdowns occur. When a condition occurs, that is, when the knock signal fails, the ignition timing is controlled to be maximum retarded after a predetermined period of time.

Therefore, there is no problem when the knock signal generation detection is performed normally, but depending on the timing of the failure state, advance angle control may be performed even in the knocking state, which may cause damage to the engine. there were.

In order to eliminate this drawback, the present invention provides an ignition timing control device configured so that when a failure occurs, the ignition timing is not immediately advanced, but is retarded to the maximum after a predetermined period of time. As a result, even if knocking occurs in the engine from the time when the fail state occurs until the maximum retardation is reached, damage to the engine can be reduced more than before.

The present invention will be explained below with reference to the drawings.

In FIG. 1 showing a block diagram of an embodiment of the present invention, 1 indicates a knocking sensor that detects knocking factors occurring in the engine cylinder through vibration, pressure, etc. and converts it into an electrical signal, and 100 indicates the basic ignition timing. A calculation circuit that calculates the amount of correction; 2 is a frequency filter that passes only frequency components including knocking components from the sensor signal 21 obtained by the knocking sensor 1; 3 is a frequency filter 2;
A knocking determination circuit that determines whether there is a knocking component in the output signal of the knocking component and outputs a knock signal (used as a retard timing signal) in response to the knocking component;
is connected to a frequency filter and determines whether the signal from the knocking sensor 1 is in an abnormal state such as a disconnection or short circuit, that is, a fail condition 111 or not, and sends a fail response signal.
7 is a first timer that is reset when the knocking determination circuit 3 determines knocking and outputs an advance timing signal at first predetermined time intervals; 6 is a fail determination circuit; When the circuit 5 determines that there is a failure, the second timer 8 outputs a fail detection signal after a second predetermined time period after the first PJ'r predetermined time period. 9 is a date circuit that transmits the input signal to the output side, and 9 is a delay timing signal, an advance timing signal;
An up/down counter calculates the ignition timing correction amount based on the fail detection signal, and 10 represents an /A conversion circuit that converts the digital output signal 9 into an analog ignition timing correction amount. 11 outputs a basic ignition timing display signal 31 output from a signal generator 12 synchronized with the engine, and
This is an ignition device that determines one ignition timing Z by correcting it according to the output signal of the A conversion circuit 10.

The operation will be explained with reference to FIG. 2 which shows a timing chart of the signal waveform of the main part of the configuration in FIG. is selected from noise and becomes the filter output signal 22. The filter output signal 22 is sent to a knocking detection circuit 3, which detects the presence or absence of a knocking component as a knock signal (retard timing signal) 23.
The ignition timing correction amount calculation circuit 9 calculates to retard the ignition timing.

On the other hand, when the knock signal 23 is generated, the first timer 7
The advance timing is counted, and when the knock signal interval is longer than a predetermined time, an advance timing signal 26 is output, and after passing date 8, it is input 27 to the ignition timing correction amount calculation circuit 9 to advance the timing. (See section A in Figure 2.) Here, if the knocking sensor 1 signal fails, conventionally the ignition timing is configured to be retarded to the maximum after a predetermined time. However, the ignition timing advances from the time the failure occurs to the time it reaches the maximum retardation (see the broken line in the second equivalency number 30), so if knocking occurs in the engine during this time, This may cause engine damage. When a fail state or an abnormality of the knock sensor is detected, the timing is not immediately retarded, but is delayed to the maximum by a second predetermined time longer than the first predetermined time. If the knock signal continues to occur in the case where the knock signal returns to normal immediately after being blocked by a wire breakage, etc., the retard angle control is continued, and if neither the knock signal nor the fail response signal 25 is detected, the advance angle control is performed. This is to perform control according to the engine condition.

The present invention provides a date 8 between the first timer 7 and the arithmetic circuit 9, and when the fail determination circuit 5 determines a failure, the date 8 is immediately closed with a fail response signal 25, and an advance timing signal is sent. 26, is prevented from being applied to the ignition timing correction amount calculation circuit 9, thereby prohibiting advance angle calculation of the circuit. Note that if the fail state is instantaneous or temporary and is no longer a fail state and returns to a normal state, the fail response signal also returns and the date circuit 8 is also opened to allow the entire advance timing signal 26 to pass through.

When the date 8 is closed and the advance timing signal is blocked, the fail detection signal 28 generated by the second timer 6 after a predetermined time is input to the ignition timing correction amount calculation circuit 9, and the maximum retardation amount is calculated. It is controlled so that (Refer to the solid line No. 30 in Figure 2) Therefore, according to the present invention, advance angle control is not performed until υ and sensor signal 21 reach the fue angle, so even if knocking occurs in the engine, the engine This has the effect of reducing damage to the body compared to conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a timing chart of the main part IE waveform in FIG. 1: Knocking sensor 2: Frequency filter 3: Knocking judgment circuit 5: Fail judgment circuit 6: Second timer
7: First timer 8: /7A-to 9: Ignition timing correction amount calculation circuit 31: Ignition device 100: Calculation circuit. Agent: Asamura Akira, 4 guests, If troubles, Qt. 8 yen, Day 1) To 8.

Claims (1)

[Scope of Claims] An ignition timing control device that corrects the ignition timing of an ignition device of an internal combustion engine based on a knocking sensor output signal, comprising: a knocking determination means that outputs a knocking signal indicating a knocking state based on the knocking sensor output signal; , a fail determination means that detects whether the knock sensor output signal is in a fail state and outputs a fail response signal; a first timer that outputs an advance timing signal at first predetermined time intervals after receiving the knock signal; 2nd P longer than the 1st predetermined time after receiving the fail response signal
a second timer that outputs a fail detection signal after a 9T fixed time; a calculation means that calculates an ignition timing correction amount in response to the advance timing signal, the fail detection signal, or the knock signal; An ignition timing control device for an internal combustion engine, comprising a date circuit that prohibits input of an advance timing signal.