JPH01180425A - Fitting device for engine vibration detector - Google Patents

Abstract

PURPOSE:To accurately detect the vibration of an engine and accurately measure its engine speed by said detection by providing a storage part for storing a detector and a closed cavity part which is provided adjacently. CONSTITUTION:The vibration detector 5 is fitted not directly, but through the fitting device. The detection surface 5a of the detector 5 abuts on a discoid end plate 7, the bottom surface of the end part of a cap 8, on the other hand, forms a contact surface 8a, and while the fitting device is fitted to the engine whose vibration is to be measured, the surface 8a contacts the engine. Consequently, the vibration of the engine is transmitted directly to the surface 8a, from which the vibration is transmitted to a plate 7 through the cavity part 10 and detected by the detection part 5 through the detection surface 5a brought into contact with the end plate 10. The cavity part 10 functions as a damper to reduce noise components which are transmitted from the engine, so that only the vibration components of the engine are transmitted to the detector 5.

Description

[Detailed description of the invention] Techniques ahead! The present invention relates to a device for attaching a detector to an engine for detecting vibrations of an engine of an automobile, etc. More specifically, the present invention relates to a device for attaching a detector to an engine for detecting vibrations of an engine of an automobile, etc. This invention relates to a detector mounting device.

It has been proposed to detect engine vibrations, generate pulse signals related to the vibrations, and count the engine revolutions by subjecting the pulses to certain processing. For example, such technology is disclosed in Japanese Patent Application Laid-Open No. 62-35911.
Disclosed in the issue. When measuring engine speed as shown in this example, engine vibrations are detected.
In this case, in order to accurately measure the engine speed, it is necessary to accurately detect engine vibrations.

Detection of engine vibration itself has been proposed in the past, but in this case, the vibration is usually detected by bringing a vibration detector into direct contact with the engine. If the vibration detector is brought into direct contact with the engine in this way, noise may be mixed into the vibration detection signal, which may have an adverse effect on subsequent signal processing, which may impede accurate vibration detection. be.

Furthermore, the present invention has been made in view of the above points, and provides an engine vibration detector mounting device that eliminates the drawbacks of the prior art as described above and makes it possible to accurately detect engine vibrations. The purpose is to provide. Yet another object of the present invention is to provide an engine/vibration detector mounting device that makes it possible to accurately measure engine rotational speed through engine vibration detection.

According to the principle of the present invention, the engine includes a housing section for housing a detector for detecting vibrations of the engine, and a closed cavity section provided adjacent to the housing section.

Engine vibration detection characterized in that the wall defining the cavity has a first contact part that can come into contact with the engine and a second contact part that can come into contact with a detection surface of a vibration detector housed in the storage part. A device mounting device is provided. In a preferred embodiment, the housing is generally cylindrical in shape, and the cavity is provided at one end of the cylindrical housing. Further, it is desirable that the walls defining the storage section and the cavity are at least partially formed of an elastic material. Such an elastic material can be made of neoprene rubber, and the wall that defines the storage section and the cavity section is preferably made of an elastic material.
It is desirable that the hardness is ＠.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 illustrates the use of the present invention to detect engine vibrations. That is, the engine 2 is installed at the front of the automobile 1.
The vibrations of the engine 2 are detected by a known vibration detector (not shown) housed in the mounting device 4 constructed according to the present invention, and the detected vibrations are detected by an oscilloscope. In the present invention, the vibration detector is not brought into direct contact with the engine 2, but is attached to the engine 2 via a mounting device 4 constructed according to the present invention.

A specific embodiment of the engine vibration detector mounting device i4 of the present invention is shown in FIGS. 2 to 5. In the illustrated embodiment, the mounting device 4 has a generally cylindrical shape as a whole. It is constructed by combining three parts. That is, the illustrated mounting device 4 includes a case 6 having a substantially cylindrical shape, a disc-shaped end plate 7 that abuts one end of the cylindrical case 6 to close the end, and the end and a cap 8 connected to the case 6 at the end where the plate 7 comes into contact. still,
The cylindrical case 6 and the end plate 7 form a storage section in which the vibration sensor or vibration detector 5 can be stored. On the other hand, a cavity 10 is formed by the end plate 7 and the cap 8, and the cavity 10 is shown in the illustrated example.

In the illustrated example in which the cap 8 is formed as a sealed space, the cap 8 is formed in a roughly cylindrical shape with one end closed, and the open end has a stepped portion formed inside. An end plate 7 is inserted into the portion, and one end portion of a cylindrical case 6 is further inserted, so that a mounting device 4 is integrally formed. If necessary, the case 6, end plate 7, and cap 8 may be integrated using adhesive or the like.

As shown in FIG. 2, when the vibration detector lt5 is housed in the case 6C, the detection surface 5a of the detector 5 is brought into contact with the end plate 7. If necessary, detecting surface 5
It is possible to configure so that a is brought into a suppressed state by an appropriate pressure on the end plate 7. On the other hand, the bottom surface of the end of the cap 8 forms a contact surface 8a, and when the attachment device 4 is attached to the engine whose vibration is to be measured,
This contact surface 8a is brought into contact with the engine. Vibrations from the engine are therefore transmitted directly to the contact surface 8a and from there via the cavity 10 to the end plate 7 and further to the detection surface 5a which rests against the end plate 10. is detected by the detector 5 via the. Therefore,
In this device, vibrations from the engine are not directly collected by the vibration detector 5, but by the cavity 10.
It is detected indirectly through the . In this case, the cavity 10 functions as a damper, removing noise components transmitted from the engine and transmitting only engine vibration components to the detector 5. In the embodiment shown in FIG. 2, the cavity 10 is formed as a sealed space filled with air. It is also possible to fill the cavity 10 with the desired medium of
The pressure within can also be set to any desired level depending on the conditions for 'a.

Furthermore, in the embodiment shown in FIG.
A connector connecting portion 9 is formed to protrude from the end opposite to the detection surface 5a. Therefore, an inner flange 6a is formed at the corresponding end of the case 6, making it possible to hold the detector 5 within the case 6. A longitudinal sectional view of the case 6 is shown in FIG. 3a, and a right side view of the case 6 is shown in FIG. 3b. The case 6 has a generally cylindrical shape as a whole, and has an outer stepped portion 6b formed by cutting off the outer circumferential portion at one end thereof, and a stepped portion 6b protruding radially inward at the other end thereof. An inner flange 6a is formed. 4a and 4b show a longitudinal section and a right-hand side of the cap 8, respectively. The cap 8 has a generally cylindrical shape with one end closed, and the open end has an inner circular The inner step portion 8b is formed by cutting out the peripheral portion.

This inner step portion 8b is set to a size that allows the outer step portion 6b of the case 6 to be inserted therein. Fifth
Figures a and 5b show an end plate 7 in the form of a disc. This end plate 7 has a diameter that allows it to be inserted into the inner step 8b of the cap 8. As the vibration detector 5, it is possible to use a known valve train type or any other type.

In the preferred embodiment, case 6, end plate 7, and cap 8 are formed from a resilient material, but it is preferred that at least end plate 7 and cap 8 are constructed from resilient material.

For example, such an elastic material has a hardness of Hs70°±
For example, neoprene rubber having such hardness may be used as the material 1 having a hardness of 5°. Furthermore, the thickness of the material is preferably on the order of 3 to 5 mm.

Furthermore, if the size of the cavity 10 is too large, the amplitude of the waveform detected by the detector 5 will become too small;
On the other hand, if the cavity 10 is too small, it will be impossible to sufficiently remove noise from the vibration detection waveform. Therefore, it is important to set the size of the cavity 10 to an optimal size depending on the application conditions and the like.

Next, the operation of detecting engine vibration using the vibration detector mounting device of the present invention having the above-described configuration will be described below.

As shown in FIG. 1, the vibration detector 5 is attached to the engine 2 mounted on the automobile 1 via the attachment device 4 of the present invention 6. In this case, the contact surface 8 of the attachment device 4 is attached to the engine 4 to be in contact. The detector 5 is connected to an external oscilloscope 3 by a cord extending therefrom via a connector connection 9. When the engine 2 is operated in this state, if the engine is a 4-cylinder 4-stroke engine, Figs. 6 (B) and (C) will appear.
The waveform shown in is sampled. Note that FIG. 6(B) shows a case where the vibration detector 5 is brought into direct contact with the engine 2 without using the mounting device 4 of the present invention;
) shows the waveform obtained using the attachment device 4 of the invention. In this way, as is clear from comparing the waveforms in FIGS. 6(B) and (C), noise components are almost completely removed from the vibration waveform by using the mounting device 4 of the present invention. is understood. By performing threshold processing on this vibration waveform, as shown in Fig. 6 (D)
A pulse waveform as shown in is obtained, and by counting the pulses of this pulse waveform, it is possible to measure the engine rotation speed.

FIG. 7 shows a case where the engine 2 is a 6-cylinder 4-stroke engine, and even in this case, by using the mounting device 4 of the present invention, it is possible to almost completely remove noise from the detected waveform. It is well understood that this is the case. Furthermore.

FIG. 8 shows a case where the engine 2 is a V type 6 cylinder 4 cycle engine. Particularly in this case, the positional relationship between the mounting position where the mounting device 4 of the present invention is mounted on the engine and each cylinder becomes complicated, and therefore the path through which vibrations generated in each cylinder is transmitted to the mounting device 4 of the present invention is complicated. As a result, the detected vibration waveform has a complicated shape as shown in FIG. 6(B).

When such a waveform is processed into a pulse waveform, two pulses are obtained for each of the first two yamabushi sections as shown in Figure 6 (C), but two pulses are obtained for each of the last two sections. Only one pulse is obtained for the mountain-shaped part. This is because in the case of a V-type 6-cylinder 4-stroke engine, three cylinders are arranged vertically on the left and right in a V-shape, and are rotated by the crankshaft. Therefore, a portion of the vibration of the cylinder on the opposite side of the mounting position where this mounting device is installed may be sampled, and therefore the pulse may be divided into two.

In other words, the vibrations from the three cylinders on one side should become pulses as shown in Figure 8 (D), but if the vibrations from the cylinders on the opposite side are picked up, the pulses as shown in Figure 8 (C) will occur. In some cases, a pulse that should originally be single is split into two. In such a state, if the number of revolutions of the engine is measured by counting pulses, it is impossible to accurately measure the number of revolutions.

As described in detail above, according to the present invention, it is possible to remove noise components when detecting the vibration waveform of a vibrating body such as an engine, so that subsequent waveform processing can be performed accurately and easily. It is possible to do so. Furthermore, it is possible to prevent undesired vibration components from being sampled, and it is possible to always accurately detect vibrations and measure the rotational speed, even in the case of a V-type 6-cylinder 4-cycle engine, etc. .

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing how the device of the present invention is used. FIG. 2 is a schematic vertical cross-sectional view showing the overall configuration of the device of the present invention, FIGS. 3a and 3b are vertical cross-sectional views and right side views of the case 6, and FIGS. 4a and 4b are vertical cross-sectional views of the cap 8. A top view and a right side view, FIGS. 5a and 5b are a front view and a right side view of the end plate 7. FIGS. 6 to 8 are explanatory diagrams useful for explaining the operation of the apparatus of the present invention. (Explanation of symbols) 4: Vibration detector mounting device 5: Vibration detector 68 Case 7: End plate 8: Cap Patent applicant Honda Motor Co., Ltd. Figure 1 Figure 2 Figure 30 Figure 3b Figure L■ Chapter Figure 40 Figure 4b rg Figure 5q Figure 5b Figure 6 x = 5 Figure 7 x = 3.33

Claims (1)

[Scope of Claims] 1. An attachment device for attaching a detector for detecting engine vibrations to an engine, which comprises: a storage part for storing the detector; and a closed cavity provided adjacent to the storage part. , the wall defining the closed cavity has a first contact portion that can contact the engine, and a second contact portion that contacts the detection surface of the detector when the detector is stored in the storage portion. An engine vibration detector mounting device characterized by having a contact portion. 2. The engine according to claim 1, wherein the storage section is formed approximately in a cylindrical shape, and the hollow section is formed adjacent to one end of the cylindrical storage section. Vibration detector mounting device. 3. The engine vibration detector mounting device according to claim 1 or 2, wherein the wall defining the housing portion and the cavity portion is formed of an elastic body. 4. The engine vibration detector mounting device according to claim 3, wherein the elastic body is at least neoprene rubber. 5. In claim 4, the elastic body is HS
An engine vibration detector mounting device characterized by having a hardness of 70°±5°.