JPH0247247Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an engine noise prevention device, and more particularly to a device that prevents noise caused by standing waves generated in recesses around the engine.

Prior Art Various auxiliary machines or parts are installed around the engine, and for this reason, recessed spaces (hereinafter simply referred to as recesses) are created between these auxiliary machines or parts, or between them and the engine body. is formed, and a standing wave is generated within this recess as the engine operates. The noise caused by these standing waves is then emitted to the outside, which is one of the causes of engine noise.

For example, in a conventional engine, as shown in FIG. 1, a cylinder head 2 is attached to the upper end of a cylinder block 1, and a bracket 3 is fixed to the front end of the cylinder head 2. This bracket 3 is for supporting an oil tank 4 on the engine. That is, the tank 4 is filled with hydraulic oil for power steering. The bracket 3 supporting this tank 4 is shown in FIGS. 2 and 3.
As shown in the figure, its cross-sectional shape is U-shaped, and the inside thereof is a recess 5. Therefore, in such a bracket 3, when the engine is operated, a standing wave 6 as shown by the dotted line in FIG. They were in touch.

One way to prevent the noise caused by the standing waves 6 generated in the recess 5 of the bracket 3 is to fill the recess 5 with a sound absorbing material, as shown in Japanese Utility Model Publication No. 57-7779. It is. Since the recess 5 is no longer present by filling with the sound absorbing material, the generation of standing waves 6 is also prevented, and noise can be reduced. However, if the shape of the space in the recess 5 is complicated, it becomes difficult to manufacture the sound absorbing material. That is, for example, in this case, since the pipe 7 connected to the tank 4 passes through the recess 5, there is a problem that the shape of the sound absorbing material becomes complicated due to the pipe 7. Furthermore, when the volume of the space in the recess 5 is large, a large sound absorbing material is inevitably required, which not only makes the installation troublesome but also disadvantageous in terms of cost. Ta.

Purpose of the invention The present invention has been developed in view of the above problems, and is intended to prevent standing waves generated in the recesses around the engine without filling sound-absorbing materials, thereby reducing engine noise. It is an object of the present invention to provide an engine noise prevention device designed to reduce noise.

Composition of the Invention The present invention provides a device for preventing noise caused by standing waves generated in a recessed portion around an engine. The present invention relates to an engine noise prevention device characterized by being configured to be elastically deformable.

Example The present invention will be explained below with reference to an illustrated embodiment.

FIG. 4 and FIG. 5 show an engine noise prevention device according to the present embodiment, in which the present invention is applied to the power steering hydraulic oil tank 11.
The present invention is applied to a device designed to prevent noise caused by standing waves generated in the recess 13 of the bracket 12. Power steering hydraulic oil tank 11
It has a substantially cup-shaped structure, and a cover plate 14 is attached to the top thereof, and the inside is filled with hydraulic oil for operating the power steering. Note that the oil in this tank 11 is supplied through a pipe 15. This tank 11 is fixed via the bracket 12 to, for example, a cylinder head attached to the upper part of a cylinder block constituting an engine. For this fixation, a bolt 16 is inserted through the bracket 12.

Next, a device for preventing the generation of standing waves in the recess 13 of the bracket 12 will be described. A bent portion 17 is formed approximately at the center of the upper part of the bracket 12. An attached portion 18 is formed. An elastic membrane 19 made of, for example, rubber is attached to the attached part 18, and this elastic membrane 19 prevents the generation of standing waves. That is, the upper mounting portion 20 of the elastic membrane 19 is attached to the bracket 1.
The lower end of the elastic membrane 19 is free in contrast to this. Therefore, as shown in FIG. 4, this elastic membrane 19 can be freely deformed from side to side.

Therefore, by this elastic membrane 19, the bracket 12
The inner recess 13 is partitioned into two spaces, and the volumes of these two spaces are changed by deformation of the elastic membrane 19. Therefore, the resonance frequency of the space partitioned by the elastic membrane 19 also changes, and is therefore prevented from becoming a constant resonance frequency. Therefore, the generation of standing waves in a space that does not have a certain resonant frequency is prevented, and noise due to the standing waves is also inevitably prevented.

In the noise prevention device according to this embodiment, an elastic membrane 19 is provided in the center of the bracket 12, thereby dividing the recess 13 into two spaces with variable volumes, and each of these spaces has a constant volume. In this way, noise caused by standing waves is prevented. Therefore, according to this embodiment, noise can be prevented simply by attaching the elastic membrane 19 to the bracket 12 with its lower end left free. That is, there is no need to insert a sound absorbing material to fill the space in the recess 13 of the bracket 12. Therefore, according to such a configuration, there is no need to prepare a complicatedly shaped sound absorbing material that fills the recess 13 while escaping the pipe 15, and there is no need to use a large shaped sound absorbing material, so that noise prevention is improved. This makes it possible to reduce costs.

Although the present invention has been described above with reference to an illustrated embodiment,
The present invention is not limited to the above embodiments, and various modifications can be made based on the technical idea of the present invention. For example, the above embodiment relates to a device for preventing noise by preventing standing waves caused by the recess 13 of the bracket 12 of the power steering hydraulic oil tank 11, but the present invention relates to a device for preventing noise by preventing standing waves caused by the recess 13 of the bracket 12 of the power steering hydraulic oil tank 11. It can be applied to a device for preventing noise caused by standing waves generated in a recess. Further, in the above embodiment, only one elastic membrane 19 is disposed in the recess 13, but two
The recess 13 may be partitioned into three or more spaces by disposing more than one elastic membrane.

Effects of the invention As described above, the present invention provides partitioning means to partition the recess into a plurality of spaces, and
The present invention relates to an engine noise prevention device in which the partitioning means is configured to be elastically deformable. Therefore, according to the present invention, noise caused by standing waves can be effectively and reliably prevented without filling the recess with a sound absorbing material.

[Brief explanation of the drawing]

Figure 1 is a side view showing the main parts of a conventional engine.
Fig. 2 is a front view showing the mounting structure of the power steering hydraulic oil tank provided in this engine, Fig. 3 is a side view of the same, and Fig. 4 is a view of the power steering hydraulic oil tank according to an embodiment of the present invention. FIG. 5 is a front view showing the mounting structure, and FIG. 5 is a side view of the same. In addition, in the symbols used in the drawings, 11...power steering hydraulic oil tank, 12...bracket,
13... recessed part, 18... attached part, 19... elastic membrane,
20...It is an attachment part.

Claims (1)

[Scope of utility model registration request] In a device for preventing noise caused by standing waves generated in a recessed space around an engine, a partitioning means for partitioning the recessed space into a plurality of spaces is provided, and the partitioning means is configured to be elastically deformable. An engine noise prevention device featuring: