JPH038819Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a damping plate that blocks vibration noise or suppresses vibration noise itself.

"Conventional technology" Conventional vibration damping plates include (1)
Disclosed in Publication No. 193946, (2) Utility Model Publication No. 1973-
There are those disclosed in Publication No. 38002, and (3) those described as rear end plates on page 23 of the TOYOTA mark new model car manual (issued September 1979).

That is, the first one covers important parts of the engine rear plate, which is a vibration damping plate, with a high damping material, and the second one covers the vibration damping cover, which is a vibration damping plate, between a plurality of metal plates. A space is formed between the two and fixed to each other in a spot shape.
The engine rear plate, which is a damping plate,
It is constructed by combining two plates of equal thickness.

``Problems that the invention attempts to solve'' However, with such conventional damping plates,
In the first method, the substrate must be covered with a high damping material of a different material, and the high damping material must be shaped to suit the key points.
The second method is complicated and expensive to manufacture, and since a space must be formed between multiple metal plates, the shape and mutual dimensional accuracy of these multiple metal plates must be high. Therefore, the cost is high, there are restrictions on the shape due to the thick structure, and there is a big restriction on the use.Furthermore, each plate vibrates inside the space, so there are doubts about the vibration damping effect. , since it is simply two plates of equal thickness put together, if a vibration that matches the natural frequency of each constituent plate is input, it will resonate and it will not be possible to obtain a sufficient damping effect. The point was hot.

The present invention has been developed by focusing on these conventional problems, and aims to provide a vibration damping plate that is easy to manufacture and provides a sufficient vibration damping effect, thereby solving the above problems. It is said that

"Means for Solving the Problem" The gist of the present invention to achieve this purpose is to provide at least one sheet with a different thickness,
The vibration damping plate is characterized by having a plurality of plates stacked one on top of the other with a thin wall on the side exposed to space, and each constituent plate is solidified to each other at key points.

``Effect'' However, since it is formed by overlapping multiple plates with different thicknesses, even if one plate resonates as a result of their natural frequencies not matching, the other plates suppress this and provide strong vibration damping. The side that is exposed to the space and vibrates to emit sound is a thin plate with a low resonance frequency, so only sound waves that are less likely to cause discomfort to humans are radiated into the air, suppressing the generation of unpleasant sound waves. In addition, since plates of almost the same shape are stacked, simultaneous processing is possible and manufacturing is easy.

“Embodiment” An embodiment of the present invention will be described below based on the drawings.

The figure shows an embodiment of the present invention, and as can be seen in Figs. 4 and 5, the rear plate between the engine 10, which is the vibration source, and the transmission 20, which is the transmission destination, is equipped with a control system to which the present invention is applied. This is a swing plate 30.

As shown in FIGS. 1 to 3, the vibration damping plate 30 has a generally flat plate shape, in which a thick metal plate 30a with a thickness of 1.4 mm and a thin metal plate 30b with a thickness of 0.6 mm are closely overlapped. An inverted T shape with a thick insertion hole 31 for the transmission shaft approximately in the center.
A starter shaft insertion hole 32 is bored next to the insertion hole 31. The damping plate 30 has a thick metal plate 30a on the transmission 20 side and a thin metal plate 3 on the transmission 20 side.
It is assembled with 0b facing the engine 10 side.

The outer periphery of the vibration damping plate 30 shown separated by a dashed line is a portion 33 where the housing 21 of the transmission 20 comes into contact.
The inner side separated by the three-dot chain line is the part 3 where the cylinder block 11 of the engine 10 comes into contact.
4, and the part shown surrounded by the two-dot chain line around the insertion hole 32 is the part 35 with which a starter (not shown) comes into contact.

In FIG. 1, an embossed portion 36 is formed at a portion forming the lower edge of the insertion hole 31. As shown in FIG.

On both sides of the upper part along the part 33, there are insertion holes 33a and 33b for fastening bolts of the cylinder block 11, the housing 21 of the transmission 20, and the damping plate 30.
are drilled, and the same insertion holes 33 are provided on both sides of the middle lower part.
c, 33d are bored, and the housing 21 is provided at the lower end.
and the insertion holes 33e, 3 for fastening bolts between the damping plate 30 and the damping plate 30.
3f is drilled. In addition, a starter mounting bolt insertion hole 35 is provided at a portion 35 with the insertion hole 32 in between.
a, 35b are drilled. That is, the thick metal plate 30a side of the damping plate 30 is covered and connected to the housing 21 of the transmission 20 on its entire outer periphery, and the thin metal plate 30b side is connected to the engine at 3 to 4 locations on the outer periphery. 10, while the lower half and upper right in FIG.
The engine 10 is exposed to space.

The thick metal plate 30a and the thin metal plate 30b are fixed to each other by spot welding at the following points.

That is, two points between the insertion hole 33a and the insertion hole 33b, one point between the insertion hole 31 and the insertion hole 32 at the intermediate part between the insertion hole 33a and the insertion hole 33c,
One point is symmetrical to this point with the insertion hole 31 in between, and one point is between the insertion hole 33c and the insertion hole 33e.
1 point between insertion holes 33e and 33f, insertion hole 3
One point between insertion hole 3f and insertion hole 33d, insertion hole 33b
and the insertion hole 33d, and one point between the insertion hole 32d and the insertion hole 32d.
1 point on the outer periphery, 2 points on the embossed part 36, part 3
3 and two points on both sides of the lower part 37 of the vibration damping plate 30 that is outside the part 34.

As will be explained later, when the thick metal plate 30a and the thin metal plate 30b are layered and press-formed, there are areas where the opening is likely to open due to the squeezing process, etc., and membrane vibration of both plates becomes large. parts,
They are installed in areas where they will rub against each other during large vibrations.

That is, in order to form the damping plate 30, the materials of the thick metal plate 30a and the thin metal plate 30b are stacked,
They are solidified by spot welding at each of the points, and then press-formed by handling them as if they were a single raw material plate. This type of molding is possible because the thick metal plate 30a and the thin metal plate 30b are in close contact with each other.

In the damping plate 30 having the above structure, the thick metal plate 30a and the thin metal plate 30b are in close contact with each other, but are not completely integrated, and are solidified at important points by spot welding. Only.

When a vibration that causes one plate to resonate is applied from the engine 10, the resonance point of the other plate is off, so the resonance of one plate is suppressed by the other plate.

Due to the difference in thickness between the thick metal plate 30a and the thin metal plate 30b, the resonance frequency is distributed in a low range and a high range, and as a result, resonance is suppressed in each region.
Vibration is suppressed in all areas, radiated sound due to curtain vibration of the damping plate 30 is reduced, and noise can be reduced. Transmission of vibration from the engine 10 to the transmission 20 is suppressed, and from the transmission 20 to the vehicle body etc. It is possible to improve the effect of reducing transmitted vibration noise. According to experiments, it has been found that setting the thin metal plate 30b on the engine 10 side and the thick metal plate 30a on the transmission 20 side as described above is highly effective.
This is considered to be because the thin metal plate 30b has a resonant frequency that is different from the 1.6 to 2.5 KHz frequency that humans find more uncomfortable. In other words, damping plate 3
The thick metal plate 30a of No. 0 covers the entire circumference of the housing 21 of the transmission 20 for sound insulation, and the thin metal plate 30b side has a portion that protrudes from the cylinder block 11 of the engine 10 and emits sound waves into the space. However, because the resonant frequency is low, the radiated sound is less likely to be unpleasant to humans.

As can be seen in Figure 6, which shows the average value of the noise level measured in three directions around the engine, a shows a high level when using one plate, and b shows a slight improvement when using two plates of equal thickness. However, the noise level is still high, and c, which is related to this example, shows the best results and has a much lower noise level than a.

In addition, in the above embodiment, a damping plate made of two thick metal plates and a thin metal plate was shown, but a plurality of damping plates may be stacked, with at least one plate having a different thickness. Needless to say, the material can be selected as appropriate. In addition, spot welding is not the only way to consolidate key points between plates.
An adhesive may be used, and it may be in the form of dots, bands, etc., as long as it binds both plates locally rather than over the entire surface. Therefore, in some cases, it may be sufficient to simply fasten with a fastening bolt. The adhesion of each plate is sufficient as long as there are minute gaps due to processing errors.

In addition to interposing it between the vibration source and the transmission destination, in order to suppress its own vibration and prevent noise radiation, for example, it is formed into a cover shape with one side facing the atmosphere, and the thin side facing the atmosphere. It can be implemented as if the

Further, it is effective if the ratio of the thickness of the thin plate to the thick plate is set in the range of 0.1 to 0.9.

"Effects of the invention" The damping plate according to the invention effectively suppresses the transmission of vibrations from the vibration source, and also effectively suppresses the vibration of the damping plate itself, and also suppresses the sound waves that make people feel uncomfortable. Since the damping plate suppresses radiation and is easy to mold, it can be manufactured at low cost and has an excellent damping effect.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention, in which FIG. 1 is a front view of the damping plate, FIG. 2 is a perspective view, and FIG. 3 is a sectional view taken along the line of FIG. Figure 4 is a front view of the engine and transmission with damping plates interposed,
FIG. 5 is an exploded perspective view, and FIG. 6 is a diagram illustrating the effect. 10...Engine, 20...Transmission, 30...
Damping plate, 30a... thick metal plate, 30b... thin metal plate.

Claims (1)

[Scope of utility model registration request] A damping plate characterized in that a plurality of plates are stacked one on top of the other, at least one of which has a different thickness, and the side exposed to space is thinner, and the constituent plates are bonded to each other at key points.