JPS5866032A - Knocking detecting apparatus for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the detection accuracy of knocking in a multicylindered engine by providing a pressure detecting means which has larger sensitivity for the downstream side in the flow of engine cooling water. CONSTITUTION:A flanged part 21a' is fixed to a cylinder block 9 in a manner that the pressure receiving surface formed of a vibrator 22 pulsated in accordance with pressure pulsation of cooling water is disposed to face the downstream side of the flow of cooling water. With this, the pressure pulsation of cooling water due to knocking that is generated from a cylinder 7 locating in the downstream side in the flow of cooling water, can be detected with higher sensitivity. Thus, it becomes possible to average detection accuracy of knocking for each cylinder of multicylinders.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention focuses on the use of a knocking detector Wi for use in an ignition timing control device for an internal combustion engine that detects knocking that occurs in an internal combustion engine and controls the ignition timing at m intervals. The present invention relates to a knocking detection device that detects knocking from pressure pulsations of cooling water.

The knocking detector, which detects knocking from pressure pulsations in the cooling water, is installed in the cylinder block so that the vibrating body of the detector is exposed in the cooling water in the water jacket 6 of the internal combustion engine, as shown by reference numeral 2 in Fig. 2. It is screwed into place, and as shown in the block diagram of the knock feedback ignition system shown in FIG. The ignition timing control device 4 advances or retards the ignition timing in accordance with the output of the detection circuit 8 to control it to the optimum position, and sends a signal to the engine 1 via the output signal of this ignition timing control device number. The air-fuel mixture is ignited by the attached spark plug.

By the way, the water-cooled cooling system for an internal combustion engine is shown in FIG. 8 as a schematic vertical cross-sectional view, and a water jacket 6 is provided on the cylinder head 8 and cylinder block 9, and the water jacket 6 and the radiator IO are connected by a hose. 1. Cooling water is forcibly circulated as shown by the arrow by a water pump 11 to cool the cylinder 7+cylinder head 8 inside the water jacket, and the warmed cooling water is led to a radiator and cooled by outside air. Note that a thermostat 11 is provided between the water jacket 6 and the radiator 10 to maintain the temperature of the cooling water at an appropriate temperature.

The flow of cooling water in the water jacket 6 of the cylinder block 9 of a multi-cylinder, for example, 6-cylinder internal combustion engine, flows half way from the front of the engine to the rear, as shown by the arrow in the cross-sectional diagram v4 of the cylinder plotter in Fig. 4. It will be done.

When detecting the 7-stroke of a multi-cylinder internal combustion engine with a single detector, the Kifi is generally installed at the center of the multi-cylinder, as shown by reference numeral 2 in Figure 184.

The construction of one embodiment of the mounting of the knocking detector used in this case on the engine block is shown as a cross-sectional view in FIG. 21 is a gold k integrally formed with the threaded part 21 &
A cylindrical housing of I4Ijll, a disk-shaped vibrating body made of a ggki conductor, whose entire circumference is fixed to the housing 21, and forms a pressure receiving surface.

28 is a piezoelectric body fixed to the surface of the vibrating body 22, 24 is a lead wire, gs is an output terminal, ga is a connector made of an insulator integrally molded with the output terminal 2b, 87 is an O-ring for sealing, and 28 is a mounting gasket. It is.

To explain the operation of the knocking detector shown in FIG. 5, the cylinder? When a vibration occurs in the cylinder 7, the cylinder 7 vibrates and is transmitted to the cooling water of the water jacket 6 as pressure wax, which is transmitted to the vibrating body 22 of the detector 8 attached to the cylinder block 9.

When the vibrating body 22 responds in response to the cooling water pressure mall, an alternating current voltage is generated in the piezoelectric body 8s, and a voltage signal is output to the output terminal 26.

As shown in Figures 1 and 2 above, the knocking detector 8 is installed in the center of the six cylinders in such a way that the vibrating body is approximately flush with the wall surface of the cylinder block 9, and The results of measuring all the pressure pulsations generated by 7-pulling are as shown in Figure 6.
6 indicates each cylinder number sequentially from the front to the rear of the engine,
8 takes the peak value of the engine cooling water pressure pulsation caused by combustion under certain knocking conditions for each cylinder, calculates its distribution, and calculates 6% from one of the large peak values Ii'.
N is the value obtained by calculating the distribution of the peak value of the pressure pulsation coming from that cylinder and taking 8th from the largest one for each cylinder. ,87N
Regarding the knocking detection sensitivity of each cylinder, as shown in FIG. 6, it was found that the knocking detection sensitivity of the downstream part of the cooling water flow was inferior to that of the upstream cylinder.

In view of the above point, the present invention improves the knocking detection sensitivity of each cylinder when detecting knocking of each cylinder from the pressure pulsation of engine cooling water generated by knocking of each cylinder in a multi-cylinder internal combustion engine. It is an object of the present invention to provide a knocking detection device that improves knocking detection accuracy by averaging.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention shown in the drawings will be described. 7th
The first knocking detection device for an internal combustion engine according to the present invention
In the cross-sectional view showing the configuration of the embodiment, 7 is a cylinder block, a 9Fi cylinder block, and a 6Fi water jacket. 8 is a knocking detector, 21 is a housing, and the other 4 are the curved tubular holders 21b and 7 of the housing 81 so as to hold the pressure-receiving surface made of a disc-shaped vibrating body 82 in one direction.
The 7 langes f% 21&' are fixed to the cylinder block with screws 29 so that the pressure receiving surface faces below the flow of cooling water.

2B is a piezoelectric body fixed to the vibrating body n1, and other configurations Fi
This is the same as the 111iI configuration of the seven-track detector shown in the figure.

To explain the operation of the knocking detection device of the present invention having the above configuration, the pressure receiving surface made of a vibrating body that pulsates in accordance with the pressure pulsations of the cooling water is directed downstream of the flow of the cooling water. The pressure pulsations in the cooling water caused by knocking generated from downstream cylinders can be detected with higher sensitivity, and therefore the knocking detection sensitivities of the multiple cylinders can be averaged.

In the embodiment shown in FIG. 7, the disc-shaped vibrating body g84cIF serving as the pressure receiving surface and the W body 28 were simply fixed together, but the cross section 11 is shown in FIG. ! As shown, it may be configured such that the piezoelectric body 88 fixed to the vibrating body 22 is pressed against the insulator 210, or it may be configured to generate a voltage signal in response to pressure pulsations of the cooling water. Then,
Any electromagnetic configuration or any piezoelectric configuration can be used for the device KJIII of the present invention.

FIG. 9 is a cross-sectional view showing the structure of an eighth embodiment of the knocking detection device according to the present invention. In the figure, 81b' is a tubular holder having open ends with different diameters on the left and right sides, and one end is attached to the 7 flange part 91 of the housing 21 at the center opening.
The other end of a tubular support glb' fixed to / is fixed, and disk-shaped IM exciters ggm and ggb are fixed to the large diameter and small diameter opening ends of the tubular holder 21b', respectively. The entire circumference of the moving body 22a is fixed by welding to form a pressure receiving body 22a.

Piezoelectric bodies saa and gab are fixed to ggb, respectively.
Pressure 1111. Body 2B&, 28bJfi each lead 11g
4&.

24b to the output terminal 26. and,
The vibrating body gga at the large-diameter open end of the holding body shb' has a small-diameter open end facing downstream of the flow of cooling water.
7 lunge MS of Heusing 21 with 2b facing upstream
Attach g 1 &' to the cylinder block with screw 29. The rest of the structure is the same as that of the first embodiment shown in FIG.

In the embodiment shown in FIG. 10, the pressure receiving surface made of the IM moving body is located upstream of the flow of cooling water. Because it faces in the direction, the pressure receiving ylJ made of the vibrating body facing downstream has a larger diameter and increases the pressure receiving sensitivity without reducing the detection sensitivity of the cooling water pressure pulsation caused by knocking in the upstream cylinder. By increasing the number of cylinders, the small pressure pulsations of the cooling water generated by pumping the downstream cylinders can be detected more sensitively than in the case shown in Figure 6. The cooling water pressure pulsations due to knocking generated in each cylinder can be averaged and detected with higher sensitivity, and the knocking detection accuracy can be improved as a whole.

As mentioned above, the knocking detection device for the W5 engine according to the present invention is provided with a pressure detection means that is highly sensitive to the lower part of the engine cooling water flow, so It is possible to detect with high sensitivity the pressure pulsations due to knocking generated by a cylinder in a multi-cylinder system, and it is possible to average the detection sensitivity of the pressure pulsations of cooling water generated by knocking from each cylinder in a multi-cylinder system. The present invention has the effect of improving performance, and is useful as a knocking detection W device for a multi-cylinder internal combustion engine.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the knock feedback ignition system.
Fig. 2 is a diagram of the installation state of the knocking detector, Fig. 8 is a schematic vertical cross-sectional view of a permanent cooling system for an internal combustion engine, Fig. 4 is a schematic diagram of the &A # side of a cylinder block of a 6-cylinder internal combustion engine, This figure shows a model of how a knocking detector is attached to an engine block to explain the present invention.
FIG. 7 is a cross-sectional view showing the configuration of the first embodiment of the knocking transverse tumor for internal combustion engines according to the present invention; FIG. The figure shows #II of another embodiment of the main part of the first embodiment shown in FIG.
9 is a cross-sectional view showing the configuration of the ih2 embodiment of the device of the present invention, and FIG. 10 is a cross-sectional view showing the configuration of the knocking detector wL of the second embodiment shown in FIG. FIG. 3 is a characteristic diagram of midsummer knocking detection. 2... Knocking detector, 6... Water jacket, 7... Cylinder, 8... Cylinder head, 9...
... Cylinder block *22 + gga, ggb ... Vibrating body with pressure receiving surface t # 2812 a a l g f9
b--Piezoelectric body. 21 &'-75 inch part, 11 l b, 2
lb′--Holder, 21b'--Support,
81...Heusing. 21a'...7 lange part, 89...screw. Representative patent attorney 14 Iku - 1st illustration 2PS! l Flute 3 Figure rod 4 M Figure 5 Rod 7 Figure 2 Rod 8 Figure and b Figure 9 Figure 10

Claims (1)

[Claims] (1) A knocking detection device 1lIl that detects knocking of a multi-cylinder internal combustion engine by pressure pulsations of engine cooling water.
A knocking detection device for an internal combustion engine, characterized in that a pressure detection means having high sensitivity to the lower ftw of engine cooling water is provided. (2) As the pressure detection means, a pressure detector having a pressure-receiving surface in one lateral direction is provided, and the pressure detector is mounted so that the pressure-receiving surface faces downstream i1 of the engine cooling water. A knocking detection device for an internal combustion engine according to item 1 of the patent application. (8) As the pressure detection means, a detector is provided which has one pressure receiving surface in each symmetrical direction of the lateral direction, and one of the pressure receiving surfaces has a high sensitivity, and the one receiving surface with the high sensitivity of the detector is the engine cooling water. A knocking detection device for an internal combustion engine according to claim 1, characterized in that the knocking detection device for an internal combustion engine is provided with means for mounting the device so as to face the downstream side of the knocking detection device.