JPS5918183Y2 - Noise prevention wall material for structures - Google Patents

Description

[Detailed Description of the Invention] The present invention is a housing, case, or cover formed of a casting or the like, such as a cylinder block, front cover, intake manifold, exhaust manifold, rocker cover, or transmission case of an internal combustion engine. The present invention relates to a noise prevention wall material that is implemented in a structure that itself vibrates and generates noise when an internal combustion engine operates.

Various types of noise prevention wall materials have been known in the past. For example, ribs or flanges are provided protruding from the wall surface to reduce the planar portion, thereby improving the natural frequency of the wall material. It increases rigidity and prevents noise.

However, the provision of ribs and flanges increases the weight accordingly.

This goes against the idea of reducing the weight of the material.

Generally, it is not possible to simultaneously reduce the weight of a material and improve its rigidity.

On the other hand, various soundproof structures for blocking or absorbing propagated noise are known, and these soundproof structures have irregularities on their surfaces.

However, in the case of a soundproof structure, the rigidity and strength of the structure itself does not matter much.

However, the structure of an internal combustion engine must be made rigid so that the structure itself does not vibrate.

Therefore, the purpose of the present invention is to
To provide a noise prevention wall material for a structure that is rigid, hardly vibrates, and can thereby prevent noise.

The noise prevention wall material for structures according to the present invention is used in the wall structure of a structure such as a cylinder block of an internal combustion engine, and is composed of a plate-like plate as a whole, and has concave portions adjacent to both sides of the plate. The convex portions are arranged alternately, and the concave portions on the other surface are formed on the opposite side of the convex portions on one surface, and the concave portions and the convex portions are integrally connected to each other by a connecting portion.

In this way, since the concave portion is formed on the back side of the convex portion on one side, the overall thickness does not increase.

The individual recesses serve as one shell structure to improve the strength, and the connecting parts serve as ribs to improve the bending strength of the entire plate.

Therefore, vibrations generated on the wall surface of the structure during operation of the internal combustion engine can be reduced as much as possible, thereby reducing noise generation.

In addition, since it is entirely composed of a plate-like plate without any protrusions such as ribs, it does not take up space, and the combination of concave parts, convex parts, and connecting parts provides high rigidity.
As a result, the plate thickness can be reduced.

Embodiments of the present invention will be described below with reference to the drawings.

In the embodiment shown in FIGS. 1 and 2, the wall material designated by the symbol A as a whole is composed of a plate-like plate, and convex portions 1 and concave portions 2 are arranged alternately in a plane. A connecting portion 3 is provided which surrounds the convex portion 1 or the concave portion 2 and extends in a direction perpendicular to the surface of the wall material A.

Therefore, when viewed from the top surface, a concave notch 4 is formed, and when viewed from the back side, a concave notch 5 is formed.

In the illustrated embodiment, the convex portion 1 and the concave portion 2 are formed in a square shape, but they may be rectangular or the dimensions and shapes of the convex portion and the concave portion may be changed depending on the state of use of the wall material A.

In the embodiment shown in FIGS. 3 and 4, the recess 4a seen from the top and the recess 5a seen from the back are circular, and therefore, as shown in FIG. The connecting portions 3a are circularly recessed or protruded, and the connecting portions 3a are inclined between adjacent convex portions.

In this example as well, for example, oval recessed portions 4a and 5a may be formed.

Next, the embodiment shown in FIGS. 5 and 6 is an example in which the entire wall material A is formed by corrugations in the vertical and horizontal directions.

Therefore, the convex portions 1b and the concave portions 2b are arranged alternately.

In this case, the connecting portion 3b is entirely inclined.

In this embodiment, it is also possible to make the pitches of the waves in the transverse and longitudinal directions different.

As described above, according to the present invention, since the convex portion and the concave portion are formed adjacent to each other, there is rigidity, and since the neutral axis is located at the center in contact with bending, the strength is substantially uniform in any direction. It has a certain quality.

Therefore, it is easy to design various wall materials and can sufficiently prevent noise.

Furthermore, the overall structure can be made thinner and lighter.

Therefore, it is extremely suitable as a structure for an internal combustion engine, which itself is a source of vibration. For example, when it was applied to the front cover of a diesel engine, it was able to reduce noise by several decibels.

In addition, it is possible to simultaneously satisfy the two requirements of rigidity and weight reduction, which conventionally could not be satisfied at the same time.

When implementing the present invention, the natural frequency of the wall material is approximately inversely proportional to the area of the convex portion or the concave portion, so by reducing the area, the natural frequency can be made sufficiently high (for example, 2.5 kHz or more).

In addition, since the plate body has high rigidity, it is generally difficult to resonate at low frequencies.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing one embodiment of the present invention, and Fig. 2 is a plan view showing an embodiment of the present invention.
3 is a plan view showing another embodiment of the present invention, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, and FIG. 5 is a sectional view of the present invention. FIG. 6 is a sectional view taken along line VIVI in FIG. 5. FIG.

Claims (1)

[Scope of utility model registration request] In the wall structure of a structure such as a cylinder block of an internal combustion engine, the entire structure is composed of a plate-like plate, and concave portions and convex portions are alternately arranged adjacent to each other on both sides of the plate, and one side is A noise prevention wall material for a structure, characterized in that a concave portion is formed on the other side of the convex portion, and the concave portion and the convex portion are integrally connected to each other by a connecting portion.