JPH062525A - Muffler - Google Patents

Abstract

PURPOSE:To prevent glass wool of a sound absorbing material from flying away. CONSTITUTION:Stainless steel plates 6 which are 0.3 to 0.5mm in thickness are wound in multiple layers around the circumference of an inner pipe 1 in which multiple small holes 2 are bored. In the stainless steel plate 6, the small holes 6a around which projections 6b are provided are arranged on the whole surface of the stainless steel plate 6 at a pitch different from the pitch of the small holes 2. The stainless steel plate 6 is wound while placing its projections 6b inside. A caption number 5 is an outer pipe. Air layers communicated with each other by the small holes 6a are thus formed across multiple layers so as to obtain sound absorbing effect and noise eliminating effect respectively. And also, it is possible to prevent its flying-away since no glass wool is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system silencer used in an internal combustion engine of an automobile or the like.

[0002]

2. Description of the Related Art In a conventional silencer, as shown in FIG. 2, a wire wool 3 made of thin stainless fiber is provided around an inner tube 1 having many small holes 2 and a space between the wire wool 3 and an outer tube 5 is provided. Was filled with glass wool 4 as a sound absorbing material.

The wire wool 3 prevents the glass wool 4, which is a sound absorbing material, from scattering due to high temperature and pulsation of exhaust gas, and in order to utilize the function of the wire wool itself as a sound absorbing material, the glass wool 4 and the inner tube 3 It was set up between and.

[0004]

SUMMARY OF THE INVENTION In the above conventional technique,
Since the wire wool has a thin fibrous shape, it is oxidized by the high temperature of the exhaust gas and the glass wool 4 is scattered.

Therefore, an object of the present invention is to provide a muffler that can solve such a problem.

[0006]

In order to achieve the above object, the muffler of the present invention has a pitch of the small holes (2) on the outer circumference of an inner pipe (1) having a large number of small holes (2). A plate (6) having small holes (6a) having protrusions (6b) at different pitches was wound in multiple layers so that the protrusions (6b) were on the inside, and an outer tube (5) was provided on the outside.

[0007]

[Operation] A small hole (6) is formed around the inner pipe (1) of the main exhaust passage.
The air layers communicated in a) are formed in multiple layers to produce a sound absorbing effect and a sound deadening effect by expansion.

Further, since it is not a thin fiber like the conventional wire wool, it is not easily oxidized at a high temperature, and the surface of the plate (6) is only slightly oxidized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in FIGS. 1 (a), 1 (b) and 1 (c), 1 is an inner pipe provided with a large number of small holes 2 at an appropriate pitch.
Is an outer tube whose both ends are welded to the inner tube 1, and 6 is a thickness of 0.3-0.
Small holes 6a formed on the outer periphery of a projection 6b projecting to one side of the plate 6 with a stainless steel plate of about 5 mm are provided on the entire surface of the plate 6 at a pitch different from the pitch of the small holes 2.

The plate 6 is wound around the outer circumference of the inner tube 1 in multiple layers so that the projections 6b are on the inner side, and the large diameter portion of the outer tube 5 is provided on the outer side of the plate 6 in close contact therewith. The arrow A in FIG. 1C indicates the direction in which the plate 6 is wound.

[0011]

Since the muffler of the present invention is constructed as described above, since the plate (6) has a certain level of thickness unlike wire wool or glass wool made of thin fibers as in the prior art, It is hard to oxidize at high temperature, and because it oxidizes only on the surface, the sound absorbing and silencing effects do not deteriorate over time. Also, since glass wool and wire wool are not used, the scattering problem can be solved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention,
(B) is a cross-sectional view taken along line BB of (a) of the same figure, (c) is a plate (6).
Part of a developed cross-sectional view of FIG.

FIG. 2 is a vertical sectional view of a conventional technique.

[Explanation of symbols]

 1 inner tube 2 small hole 5 outer tube 6 plate 6a small hole 6b protrusion

Claims (1)

[Claims] 1. A small hole (6a) having protrusions (6b) is arranged on the entire surface of an inner pipe (1) having a large number of small holes (2) formed therein, at a pitch different from the pitch of the small holes (2). Board (6)
A silencer in which the protrusion (6b) is wound in a multi-layered manner and the outer tube (5) is provided on the outer side.