JPH06108955A - Knocking control device for multiple cylinder engine - Google Patents

Abstract

PURPOSE:To provide a knocking control device capable of performing the knocking control of a multiple cylinder engine relatively with accuracy while being of simple constitution. CONSTITUTION:A knocking control device for an multiple cylinder engine 1 is provided with a knock sensor provided at the multiple cylinder engine 1; a knock signal processing means 6 for judging the existence of knock from the output of the knock sensor; a cylinder discriminating means for discriminating a knocking cylinder; a storage means 13 previously stored with a coefficient for setting delay quantity corresponding to each cylinder; and a delay control means 14 for setting the delay quantity on the basis of the coefficient according to the cylinder discriminated by the cylinder discriminating means 12 so as to perform the delay control of ignition timing of the engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knocking control device for a multi-cylinder engine.

[0002]

2. Description of the Related Art As a knocking control device for such a multi-cylinder engine, there is, for example, one in which a knock sensor is provided for each cylinder to determine knocking, and the ignition timing is retarded for the cylinder in which knocking is detected.

Further, for example, the fact that the level of the knock signal differs for each cylinder is corrected by providing a knock determination level for each cylinder or for each group depending on the knock signal. There is one that retards all cylinders once.

[0004]

By the way, in the former case,
Since the knock sensor is provided for each cylinder, the structure is complicated and the cost is increased.

In the latter case, in order to set the knock determination level for each cylinder that the level of the knock signal is different for each cylinder or for each group depending on the knock signal, the signal processing is digital. Need to do, A /
Input ports are required on the D converter and the microcomputer side, and similar to the former, the structure is complicated and the cost is increased.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a knocking control device for a multi-cylinder engine, which is a simple device and can relatively accurately control knocking. .

[0007]

In order to solve the above-mentioned problems, a knocking control device for a multi-cylinder engine according to the present invention is provided with a knock sensor provided in the multi-cylinder engine, and the presence or absence of knocking is determined from the output of the knock sensor. Knock signal processing means for performing the above, cylinder discrimination means for discriminating the cylinder to be knocked, storage means for pre-storing a coefficient for setting the retard amount corresponding to each cylinder, and cylinders discriminated by the cylinder discrimination means. According to the above-mentioned coefficient, a retard amount is set based on the above-mentioned coefficient, and a retard control means for performing retard control of the ignition timing of the engine is provided.

[0008]

According to the present invention, the knock signal processing means determines the presence / absence of knock from the output of the knock sensor provided in the multi-cylinder engine, and the storage means preliminarily stores each cylinder in accordance with the cylinder determined by the cylinder determination means. The retard amount is set based on the coefficient set accordingly, and the retard control of the ignition timing of the engine is performed with the set retard amount.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a knocking control system for a multi-cylinder engine according to the present invention will be described below. FIG. 1 is a block diagram of a knocking control device for a multi-cylinder engine.

In FIG. 1, reference numeral 1 is a multi-cylinder engine, and the multi-cylinder engine 1 is provided with a knock sensor 2, a crank angle sensor 3 and a cam position sensor 4. The knock sensor 2 detects knocking of the cylinder, and the output signal of the knock sensor 2 is input to the knock signal processing means 6 via the input interface 5.

This knock signal processing means 6 is composed of a sensor signal processing circuit 7, a judgment level setting circuit 8 and a comparator 9, and judges the presence or absence of knock from the output of the knock sensor 2, and controls this knock present signal. Output to 10.

That is, the sensor signal processing circuit 7 performs signal processing such as noise removal of the output signal of the knock sensor 2. The determination level setting circuit 8 sets the knock determination level, and the knock determination level is set according to the average level of the signal under various conditions such as the engine speed. This sensor signal processing circuit 7
The knock signal from and the signal of the knock determination level from the determination level setting circuit 8 are input to the comparator 9, and when the knock signal exceeds the knock determination level, the presence of knock is determined by the comparator 9. The enable signal is input to the cylinder discriminating means 12 of the control unit 10.

The crank angle sensor 3 is provided corresponding to the crankshaft of the engine, detects the crank angle from the rotation of the crankshaft, and the cam position sensor 4 detects the cam position of the valve operating mechanism. The outputs of the cam position sensor 3 and the cam position sensor 4 are input to the cylinder discriminating means 12 of the controller 10 via the input interface 11, respectively.

The cylinder discriminating means 12 discriminates the cylinder to be knocked from the outputs of the crank angle sensor 3 and the cam position sensor 4. Further, the control unit 10 is provided with a storage means 13, and the storage means 13 stores in advance a coefficient for setting the retardation amount according to each cylinder. Cylinder discrimination means 12
Is output to the retard control unit 14, and when the knock signal is input from the comparator 9 in the retard control unit 14, the storage unit 1 is determined according to the cylinder determined by the cylinder determination unit 12.
The retard amount is set based on the coefficient stored in 3, and the igniter 16 is controlled via the output interface 15 in accordance with the set retard amount to control the ignition timing of the engine.

The parameters that are considered to affect the coefficient value corresponding to each cylinder are, for example, the distance from each cylinder to the knock sensor, or the structure and material of the cylinder, head, etc. of the engine. The coefficient may be set by an analysis method, an actual measurement method, or any other method at the development stage.

Further, the retard control means 14 may be one that controls the ignition timing so that all the cylinders have the same rate, or one that independently controls the ignition timing.

Further, a plurality of knock sensors may be used. In this case, if this is included and a coefficient for setting the retard angle amount is stored, the same as in the case of one knock sensor. is there.

Next, knocking determination of the knocking control device for the multi-cylinder engine will be described with reference to FIGS. FIG. 2 is a diagram showing knocking determination of the first cylinder, and FIG. 3 is a diagram showing knocking determination of the second cylinder.

In FIG. 2, in the first cylinder, the signal output of the knock sensor 2 is averaged by the sensor signal processing circuit 7 to determine the knocking at the level a, and the knock signal is determined by the comparator 9 as the determination level. The determination is made based on the knock determination level A of the setting circuit 8, and when the knock signal exceeds the knock determination level A, knock determination is performed. In this knocking determination, the retard amount is set by multiplying, for example, the coefficient 2 according to the first cylinder, and the retard control of the ignition timing of the engine is performed according to the set retard amount.

Further, in FIG. 3, in the second cylinder, the signal output of the knock sensor 2 is averaged by the sensor signal processing circuit 7, and the knocking is judged at the level b larger than the level a. When the signal exceeds the knock determination level A, knock determination is performed. In this knocking determination, the retard amount is set by multiplying, for example, the coefficient 1 according to the second cylinder, and the ignition timing retard control of the engine is performed according to the set retard amount.

Next, the operation of the knocking control system for this multi-cylinder engine will be described with reference to FIG. FIG. 4 is an operation flowchart of the knocking control device for a multi-cylinder engine. In step a, it is determined whether or not the engine speed is in the knock control region. If it is in the knock control region, it is determined in step b whether or not there is knock. If there is no knock, the process proceeds to step a. To do. If there is a knock, it is judged in step c whether or not it is the first cylinder,
In the case of the first cylinder, the retard amount according to the first cylinder is set in step d, and the retard control of the ignition timing of the engine is performed in step e.

If it is determined in step c that the cylinder is not the first cylinder, the process proceeds to step f to determine whether or not it is the second cylinder. If it is the second cylinder, the second cylinder is selected in step g. The ignition timing is retarded according to the ignition timing of the engine in step e.

Further, if it is determined in step f that the cylinder is not the second cylinder, the process proceeds to step h to determine whether or not the cylinder is the third cylinder. And the ignition timing of the engine is retarded in step e.

After that, similarly, when knocking occurs in all cylinders, the amount of retard angle is set according to the cylinder,
Controls the retard of the engine ignition timing. The ignition timing retard control of the engine may be such that the ignition timing is retarded at a rate of all cylinders, or the ignition timing may be retarded independently for each cylinder. As described above.

[0025]

As described above, according to the present invention, the knock signal processing means determines the presence / absence of knock from the output of the knock sensor provided in the multi-cylinder engine, and according to the cylinder determined by the cylinder determining means, The retard amount is set in the storage means based on the coefficient set in advance for each cylinder, and the ignition timing of the engine is retarded by the set retard amount. The determination can be performed at one determination level, and it is not necessary to provide a knock sensor for each cylinder, so that the device can have a simple structure and can be manufactured at low cost.

Further, since only the presence / absence of knock is determined, the signal processing may be analog, and the A / D converter and the input port on the side of the microcomputer are unnecessary, so that the control unit can be made simple. .

Further, even if the level of the signal input to the knock sensor from each cylinder is large or small, the retard control based on the coefficient according to each cylinder is performed.
Knocking can be controlled relatively accurately.

[Brief description of drawings]

FIG. 1 is a block diagram of a knocking control device for a multi-cylinder engine.

FIG. 2 is a diagram showing knocking determination of a first cylinder.

FIG. 3 is a diagram showing knocking determination of a second cylinder.

FIG. 4 is an operation flowchart of a knocking control device for a multi-cylinder engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-cylinder engine 2 Knock sensor 6 Knock signal processing means 12 Cylinder discrimination means 13 Storage means 14 Delay angle control means

Claims (1)

[Claims] 1. A knock sensor provided in a multi-cylinder engine, a knock signal processing means for judging the presence or absence of knock based on the output of the knock sensor, a cylinder judging means for judging a cylinder to be knocked, and a cylinder signal corresponding to each cylinder. A storage unit that stores in advance a coefficient for setting the retard amount, and a delay unit that sets the retard amount based on the coefficient according to the cylinder discriminated by the cylinder discriminating unit and performs retard control of the ignition timing of the engine. A knocking control device for a multi-cylinder engine, comprising: angle control means.