JPH0660723U - Silencer - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a silencer capable of improving the silencing performance without expanding the silencer space or changing the structure by increasing the number of members. [Structure] In a multi-expansion cavity type silencer, the internal partition wall is formed into a truncated cone shape, and the front and rear wedge-shaped cross sections formed by the truncated cone shape partition wall, the communication pipe and the body respectively absorb noise. A muffler made of stretched material.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a silencer used for various pipeline systems such as an intake system of an air conditioning system and an exhaust system of an internal combustion engine.

[0002]

[Prior art]

It is well known that there are a single-type silencer 1 shown in FIG. 5 and a multiple-type silencer 1'shown in FIG. 6 as the expansion cavity type silencers used in the pipeline system. In any expansion cavity type silencer, the sound wave attenuation amount is a periodic function, and the frequency band in which the attenuation is effectively obtained is its shape, that is, the area S _{1 of} the inlet pipe 2, the cross-sectional area of the silencer 1, and the silencer 1. It is determined by the length L, the frequency and the speed of sound, and has the attenuation characteristics shown in FIG. Further, in this expansion cavity type silencer, it is generally practiced to attach a sound absorbing material inside to improve the damping characteristic. However, these expansion cavity type silencers do not have sufficient sound wave attenuation, and when used in the intake system of an air conditioning system, they cannot reduce the induct noise so much. Further, when the exhaust system of the internal combustion engine is used, the sound absorbing effect is insufficient due to the low sound absorption coefficient. For this reason, the muffler space has been expanded or the structure has been changed by increasing the number of members, but the current effect is not as expected. (As a prior art document, there is Japanese Utility Model Laid-Open No. 62-10221.)

[0003]

[Problems to be solved by the device]

 Then, this invention aims at providing the silencer which can improve the silencing performance, without enlarging the silencer space or changing the structure by increasing the number of members.

[0004]

[Means for Solving the Problems]

 The muffler of the present invention for solving the above-mentioned problems is a multi-expansion cavity type muffler in which the internal partition wall is formed into a truncated cone shape, and the truncated cone shape partition wall, a communication pipe and a body are formed. The front and rear wedge-shaped cross sections formed by and are each fitted with sound absorbing material.

[0005]

[Action]

 As described above, in the silencer of the present invention, the internal partition wall is formed into a truncated cone shape, and the silencer space can be expanded and the members can be expanded by simply extending the front and rear wedge-shaped cross sections with sound absorbing material. Without increasing the structure, the sound absorption area increases, the number of sound wave reflections at the partition walls increases, and the sound absorption coefficient increases. Therefore, the muffling performance of the muffler is improved.

[0006]

【Example】

 An embodiment of the silencer of the present invention will be described with reference to the drawings. As shown in FIG. 1, an inlet pipe 6 is provided at the center of one end surface of the multi-expansion cavity silencer 5, an outlet pipe 7 is provided at the center of the other end surface thereof, and a partition wall 8 having a truncated cone shape is provided inside thereof. A communication pipe 9 is provided at the center of the partition wall 8 longer than the length of the partition wall 8. As shown in FIGS. 2 and 3, sound absorbing materials 11 are stretched on the front and rear wedge-shaped cross sections formed by the truncated cone-shaped partition wall 8, the communication pipe 9, and the body 10 of the silencer 5. . In the muffler of the embodiment configured as described above, the sound absorbing area is increased and the number of sound wave reflections at the partition wall 8 is increased without expanding the space and without changing the structure by increasing the members. The sound absorption rate of the sound absorbing material 11 is increased. Therefore, the silencing performance of the silencer is improved.

Next, another embodiment of the silencer of the present invention will be described with reference to FIG. 4. In this embodiment, the silencer is arranged so that the inlet pipe 6, the outlet pipe 7 and the communication pipe 9 are not located on the same straight line. The inlet pipe 6 and the outlet pipe 7 are eccentric on both end faces of No. 5, and the others are the same as in the above-mentioned embodiment. The muffler of the embodiment configured in this way has the same sound absorbing area as that of the previous embodiment without expanding the space and without changing the structure by increasing the number of members, and the acoustic wave is generated by the partition wall 8. The number of reflections increases, the sound absorption rate by the sound absorbing material 11 increases, and the sound wave entering from the inlet pipe 6 does not pass through the communicating pipe 9 straightly, and the sound wave entering from the communicating pipe 9 goes straight to the outlet pipe 7. It does not come out of the room, the sound absorption effect is sufficiently performed, and the sound deadening performance is greatly improved.

A silencer of another embodiment shown in FIGS. 5 (a) and 5 (b) has an inlet pipe 6 and an outlet pipe 7 at both end surfaces thereof for the same purpose as the silencer of FIG. It is arranged in a tangential direction with respect to 10. The outer shell of the silencer of the present invention is effectively a cylindrical shape that is the easiest to process and has the least weight, but is not limited to this, and may be an elliptic cylindrical shape, a rectangular cylindrical shape, or the like. But good. The point is that a wedge-shaped cross section is formed in the front and back by the slanted partition wall, the communication pipe, and the body, and sound absorbing performance is improved if the wedge-shaped cross section is stretched, so any shape of the outer shell may be used. It is a thing.

[0009]

[Effect of device]

 As described above, according to the muffler of the present invention, the sound absorbing area can be obtained only by making the inner partition wall into the shape of a truncated cone without expanding the muffler space or changing the structure by adding members. And the number of sound wave reflections at the bulkhead increase, the sound absorption rate increases, the sound deadening performance improves, and when used in the intake system of the air conditioning system, the induct noise can be reduced and the exhaust gas of the internal combustion engine can be reduced. When used in a system, a sufficient silencing effect is obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of a silencer of the present invention.

FIG. 2 is an enlarged cross-sectional view of part A in FIG.

FIG. 3 is a sectional view taken along the line BB of FIG.

FIG. 4 is a schematic cross-sectional view of another embodiment of the silencer of the present invention.

5A and 5B show still another embodiment of the silencer of the present invention, wherein FIG. 5A is a schematic sectional view and FIG. 5B is a side view.

FIG. 6 is a schematic sectional view of a conventional single-type expansion-cavity silencer.

FIG. 7 is a schematic cross-sectional view of a conventional multiplex expansion cavity type silencer.

FIG. 8 is a graph showing a damping characteristic of the expansion cavity type silencer.

[Explanation of symbols]

 5 Multiple expansion cavity type silencer 6 Inlet pipe 7 Outlet pipe 8 Frustum-conical cylindrical partition wall 9 Communication pipe 10 Body 11 Sound absorbing material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobuyoshi Harada, the creator, No. 1 Kawasaki-cho, Kakamigahara-shi, Gifu, Kawasaki Heavy Industries, Ltd. Inside the Gifu factory (72) Masaaki Sato, No. 1, Kawasaki-machi, Kakamigahara, Gifu Kawasaki Heavy Industries, Gifu In the factory (72) Inventor Minoru Adachi 1 Kawasaki-cho, Kakamigahara City, Gifu Prefecture Kawasaki Heavy Industries Gifu Factory

Claims (1)

[Scope of utility model registration request] 1. In a multi-expansion cavity type silencer, the internal partition wall is formed into a truncated cone shape, and is formed into a front and rear wedge-shaped cross section formed by the truncated cone shape partition wall, a communication pipe and a body. A muffler with sound absorbing material stretched on each side.