JPH0543977B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a device for attaching a detector to an engine for detecting vibrations in an engine of an automobile, etc., and more specifically, for measuring the rotational speed of an engine of an automobile, etc. This invention relates to a detector mounting device for detecting engine vibration.

Prior Art It has been proposed to detect engine vibrations, generate pulse signals related to the vibrations, and count engine revolutions by subjecting the pulses to predetermined processing. The technique is disclosed, for example, in Japanese Patent Application Laid-Open No. 62-35911. When measuring engine speed in this way, engine vibration is detected, but in order to accurately measure engine speed in this case, it is necessary to accurately detect engine vibration. .

Detecting engine vibration itself has been proposed in the past, but in this case, vibrations are 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.

Purpose 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 Furthermore, another object of the present invention is to provide an engine vibration detector mounting device that makes it possible to accurately measure engine rotation speed through engine vibration detection.

Configuration According to the principle of the present invention, the present invention includes a storage part that stores a detector for detecting engine vibration, and a closed cavity part provided adjacent to the storage part,
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 made of an elastic material. As such an elastic body,
Can be made of neoprene rubber or
It is desirable that the hardness is HS70°±5°.

Embodiments 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, an engine 2 is mounted on the front part of an automobile 1, and vibrations of the engine 2 are detected by a known vibration detector (not shown) housed in a mounting device 4 constructed according to the present invention. The detected vibrations are displayed by the oscilloscope 3. 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 4 of the present invention is shown in FIGS. 2 to 5. In the illustrated embodiment, the attachment device 4
has a generally cylindrical shape as a whole and is constructed by combining three parts. That is, the illustrated attachment device 4 has a case 6 having a generally cylindrical shape.
and a disc-shaped end plate 7 that abuts one end of the cylindrical case 6 to close the end thereof.
and a cap 8 that is connected to the case 6 at the end where the end plate 7 abuts. In addition, the cylindrical case 6 and the end plate 7
This forms 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 formed as a sealed space in the illustrated example. In the illustrated example, the cap 8 is formed into a generally cylindrical shape with one end closed, and the open end has a stepped portion formed inside, and the end plate 7 is inserted into the stepped portion. The mounting device 4 is integrally formed by inserting one end of the cylindrical case 6. If necessary, use adhesive or the like to attach the case 6 and the end plate 7.
It is better to integrate it with cap 8.

As shown in FIG. 2, the vibration detector 5 is attached to the case 6.
When the detector 5 is housed inside the detector 5, the detection surface 5a of the detector 5 is in contact with the end plate 7. If necessary, the detection surface 5a can be configured to be pressed against the end plate 7 with an appropriate pressure. On the other hand, the bottom surface of the end of the cap 8 forms a contact surface 8a, and this contact surface 8a is brought into contact with the engine when the mounting device 4 is attached to the engine whose vibration is to be measured. 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 end plate 1.
Detector 5 via detection surface 5a that is in contact with
detected by. Therefore, in this device, vibrations from the engine are not directly detected by the vibration detector 5, but rather indirectly detected through the cavity 10. 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 illustrated in FIG.
Although the cavity 10 is formed as a sealed space filled with air, it is also possible to fill the cavity 10 with a gas other than air, a mixed gas, or other desired medium such as a liquid. Yes, also hollow part 1
The pressure within 0 can also be set to any desired level depending on the application conditions.

Furthermore, in the embodiment shown in FIG. 2, the detector 5 is formed with a protruding connector connecting portion 9 at 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 an inner stepped portion 6b that protrudes radially inward at the other end. A flange 6a is formed. Figures 4a and 4b
The figure shows a longitudinal section and a right-hand side of the cap 8. The cap 8 has a roughly cylindrical shape with one end closed, and the open end has an inner circumferential portion cut away. An inner step portion 8b is formed. 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. Figures 5a 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 preferably at least end plate 7 and cap 8 are constructed from resilient material.
As such an elastic material, it is preferable to use a material having a hardness of Hs 70°±5°, such as neoprene rubber having such hardness. Further, it is preferable that the material has a thickness of about 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 be too small, while if the cavity 10 is too small, noise will not be sufficiently removed from the vibration detection waveform. It becomes impossible to do so. 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, a vibration detector 5 is attached to an engine 2 mounted on an automobile 1 via an attachment device 4 of the present invention. In this case, the contact surface 8 of the mounting device 4 is brought into contact with the engine 4. 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-cycle engine,
The waveform shown in is sampled. 6B shows a case where the vibration detector 5 is directly connected to the engine 2 without using the mounting device 4 of the present invention, while FIG. 6C shows a case where the mounting device 4 of the present invention is used. This shows the waveform obtained. In this way, as is clear from comparing the waveforms in FIGS. 6B and 6C, it can be seen that noise components are almost completely removed from the vibration waveform by using the mounting device 4 of the present invention. be done. By threshold-holding this vibration waveform, a pulse waveform as shown in Figure 6D is obtained, and by counting the pulses of this pulse waveform, it is possible to measure the engine rotation speed. It is.

FIG. 7 shows a case where the engine 2 is a 6-cylinder 4-stroke engine, and even in this case, noise can be almost completely removed from the detected waveform by using the mounting device 4 of the present invention. It is well understood that this makes it possible. Further, 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 is complicated, and therefore, vibrations generated in each cylinder are transmitted to the mounting device 4 of the present invention. The paths may differ significantly, and as a result, the detected vibration waveform has a complicated shape, as shown in FIG. 8B. When such a waveform is processed into a pulse waveform, two pulses are obtained for each of the first two peak-shaped parts as shown in Figure 8C, but the last peak Only one pulse was obtained for the shaped part. In the case of a V-type 6-cylinder 4-cycle engine, three cylinders are installed vertically on the left and right sides of a V-type, and in order to be rotated by the crankshaft, the cylinder is installed on the opposite side from the installation position where this installation device is installed. A part of the vibration may be sampled, so the pulse may be split into two. That is, the vibrations from the three cylinders on one side should become pulses as shown in Figure 8D, but if the vibrations from the cylinders on the opposite side are picked up, the pulses as shown in Figure 8C.
As shown in Figure 2, a pulse that should originally be a single pulse may be divided 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.

Effects As detailed 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 collected.
Even in the case of cycle engines, etc., it is possible to always accurately detect vibrations and measure the rotational speed.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the usage state of the device of the present invention, FIG. 2 is a schematic vertical cross-sectional view showing the overall configuration of the device of the present invention, and FIGS. 3a and 3b are vertical cross-sectional views of the case 6. The right side view, FIGS. 4a and 4b are a vertical sectional view and right side view of the cap 8, and FIGS. 5a and 5b are a front view and right side view of the end plate 7, and FIGS. 6 to 8. These are explanatory diagrams useful for explaining the operation of the device of the present invention. (Explanation of symbols, 4: Vibration detector mounting device,
5: Vibration detector, 6: Case, 7: End plate, 8: Cap.

Claims (1)

[Scope of Claims] 1. An attachment device for attaching a detector for detecting engine vibrations to an engine, comprising: a housing portion for housing the detector; and a closed cavity portion provided adjacent to the housing portion. The wall defining the closed cavity has a first contact portion that can come into contact with the engine and a second contact portion that comes into contact with the detection surface of the detector when the detector is stored in the storage portion. An engine vibration detector mounting device comprising: 2. The engine vibration according to claim 1, wherein the storage section is formed in a substantially cylindrical shape, and the hollow section is formed adjacent to one end of the cylindrical storage section. Detector mounting device. 3 In claim 1 or 2,
An engine vibration detector mounting device, wherein a wall defining the storage 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. The engine vibration detector mounting device according to claim 4, wherein the elastic body has a hardness of HS70°±5°.