JPS58154624A - Detecting method of knocking - Google Patents

Abstract

PURPOSE:To detect surely vibration acceleration of knocking vibration, by detecting the knocking vibration acceleration in a parallel direction to a cylinder arranging direction of a series multicylinder engine. CONSTITUTION:A convex part 1a is provided at nearly the central part of the side face of a series multicylinder engine block 1 vertically to a cylinder arranging direction and a knocking detector 2 is attached so as to detect knocking vibration in an arrow mark B direction parallel to the cylinder arranging direction. A vibration level signal having wide amplitude is obtained from the detector 2 and the knocking is controlled stably using even one knocking detector because the knocking vibration of the cylinder separated from the detecting position is detected with wide decision width of the presence of the knocking vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting knocking in knocking vibration of an in-line multi-cylinder engine.

Knocking vibration is a phenomenon in which the pressure inside the cylinder rises rapidly due to the rapid combustion of the end gas in the cylinder.The free vibration of the gas, which is determined by the shape of the combustion chamber, creates a standing wave, and the standing wave vibration, or knocking vibration, causes the cylinder wall to It is subjected to forced vibration. In automobile gasoline engines, it has been found that knocking vibration can be reduced by adjusting the ignition timing. Therefore,
In order to prevent the occurrence of serious knocking that would adversely affect the engine, a knock detector attached to the engine detects slight knocking as an electrical signal, and uses this signal to control the ignition timing.

Conventionally, there are resonant type and non-resonant type knocking detection devices, but in both cases, vibration acceleration has directionality in one direction. Gagaruno.

Conventionally, the king detection device is installed on the side surface of the central part of the engine block 1 so that the vibration sensing direction is perpendicular to the direction in which the engine cylinders are arranged as shown by arrow A. It is being

In the knocking detection method having the above configuration, a vibration level signal as shown in FIG. 2 is outputted from the non-king detector 2 while the engine 1 is operating.

On the other hand, a knocking condition occurs independently in each cylinder. Therefore, it is best to provide a knocking detector for each cylinder, but to avoid high costs, a single knocking test is used for all cylinders. Therefore, it is desirable that this single non-king detector has a knocking state detection sensitivity that is equal and sufficiently high for each cylinder.

Further, according to experiments conducted by the present inventor, it has been found that the vibration component in the cylinder arrangement direction has a sufficiently larger vibration level than the vibration component in the direction perpendicular to the cylinder arrangement direction.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a knocking detection method that reliably detects the vibration acceleration of knocking vibration of a multi-cylinder engine.

In the knocking detection method according to the present invention, knocking vibration acceleration in a direction parallel to the cylinder arrangement direction of an in-line multi-cylinder engine is detected.

Hereinafter, a third embodiment of the knocking detection method according to the present invention will be described.
This will be explained with reference to FIG.

In the knocking detection method according to the present invention, a convex portion 1a is provided at approximately the center of the side surface of the in-line multi-cylinder engine block 1 perpendicularly to the cylinder arrangement direction.

Further, a non-king detector 2 is attached to the convex portion 1a so as to detect knocking vibration in the direction of arrow B parallel to the cylinder arrangement direction.

In the knocking detection method having the above configuration, a vibration level signal having a larger amplitude than the detection vibration level signal according to the conventional method is obtained from the engine block 1 as shown in FIG. 4 during engine operation from the knocking detector 2.

In this way, in the knocking detection method according to the present invention, the knocking detector can detect knocking vibrations in cylinders that are far from the detection position with a wide range of judgment for the presence or absence of knocking vibrations, so even if one knocking detector is used, stable knocking can be achieved. It can be controlled.

[Brief explanation of the drawing]

Fig. 1 is a layout diagram showing the installation of a knocking detector on the engine body showing a conventional knocking detection method, Fig. 2 is a knocking detector output characteristic diagram in a conventional knocking detection method, and Fig. 3 is a diagram according to the present invention. FIG. 4 is a layout diagram showing the installation of a knocking detector to an engine body showing an embodiment of the knocking detection method, and FIG. 4 is a knocking detector output characteristic diagram in the knocking detection method of the present invention. Explanation of symbols of main parts 1...Engine body lα, Yamanaka, convex portion 2...Knocking detector Applicant Japan Electronics Co., Ltd. Agent Patent attorney Fuji Hiko Muramoto Exhibition/Picture 37 O 4 Zugin Soku

Claims (1)

[Claims] A knocking detection method for detecting vibration acceleration in an in-line multi-cylinder engine of an internal combustion engine, the method comprising detecting vibration acceleration in a direction parallel to the cylinder arrangement direction of the in-line multi-cylinder engine.