JPH0329985B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to an improvement in a silencer for an internal combustion engine, particularly a relief silencer for a supercharger, etc., and is used in automobiles, etc. .

(Prior art) As a prior art related to the present invention, for example,
-There is one described in Publication No. 17414.

This is a silencer for internal combustion engines that has a sound absorption chamber equipped with a sound absorber on the air intake side and an expansion chamber that communicates with the sound absorption chamber on the exhaust port side. Welding or caulking is performed to form sound absorption chambers and expansion chambers.

(Problems to be Solved by the Invention) However, in this prior art, since the number of outer shell members is large, welding and caulking take time. Alternatively, air leakage may occur due to defective welding or caulking. Furthermore, since a metal plate is used, there are many problems such as heavy weight and easy rusting.

The technical object of the present invention is to solve the above-mentioned problems and provide a muffler that is easy to manufacture and free from defects.

[Structure of the invention]

(Means for solving the problem) The technical means taken to achieve the above technical problem is to have a sound absorption chamber provided with a sound absorber on the air supply port side, and a sound absorption chamber provided with a sound absorption body on the exhaust port side. In a silencer for an internal combustion engine having a communicating expansion chamber, an outer shell member forming the sound absorption chamber and the expansion chamber is blow-formed from a resin material, and the expansion chamber is composed of a first expansion chamber and a second expansion chamber. The sound absorption chamber, the first expansion chamber, and the second expansion chamber are arranged in a substantially U-shape, and the outer shell member has a constriction portion between the sound absorption chamber and the expansion chamber; One end of the porous pipe constituting the sound absorber is supported by the constriction part, and the other end of the porous pipe is supported by a cover member that is fitted into the outer shell member to form the sound absorption chamber, and the outer periphery of the porous pipe is This is because a stopper was installed in the section.

(Function) By the above means, the outer shell member can be integrally molded even if it has a complicated shape.

(Example) Hereinafter, the present invention will be explained based on examples.

The muffler 11 has a sound absorption chamber 12, a first expansion chamber 13, and a second expansion chamber 14, and the sound absorption chamber 12, the first expansion chamber 13, and the second expansion chamber 14 are approximately U as shown in FIG. arranged in a letter shape. The sound absorption chamber 12 includes an outer shell 15, a cover member 17 for the air supply port 16, a porous pipe 18, and a sound absorption material 19. One end of the porous pipe 18 is fitted into and supported by a constriction part 20 provided in the outer shell 15 between the sound absorption chamber 12 and the expansion chamber 13, and the other end is a cover member fitted into the opening of the outer shell 15. 1
7 and is supported. The porous pipe 18 includes
A stopper 22 is attached to prevent the porous pipe 18 from coming off toward the axial sound absorption chamber 13. A sound absorbing material 19 is arranged in an annular manner between the porous pipe 18 and the outer shell 15. The porous pipe 18 and the sound absorbing material 19 constitute a sound absorbing body. A constriction section 23 is provided between the 20 expansion chambers 13 and 14, and an exhaust port 24 at the end of the expansion chamber 14 is also constricted. Throttle parts 20, 23, exhaust port 2
4. The outer shell member consisting of the outer shell 15 is molded as a single member. In this molding method, a tube raw material made of resin with good fluidity, such as polyethylene or polypropylene, is inserted into the outer mold of the outer shell member, and high-pressure air is blown into the tube raw material to form the tube. As a result, the tube raw material swells, the tube raw material is pressed almost uniformly along the inner surface of the outer hollow mold, and the desired outer shell member is obtained by further hardening the tube raw material.

〔Effect of the invention〕

As described above, by blow molding the outer shell member from a resin material, it is possible to obtain an outer shell member that is easy to manufacture and lightweight. In addition, due to blow molding, it is possible to manufacture products with complex shapes that cannot be obtained with metal plates, and the radius of the corners can be improved.
Since it is easy to form, it is effective in reducing wind noise during use. In addition, since one sound absorption chamber and two expansion chambers are arranged in a substantially U-shape, the silencer itself is compactly constructed, making it particularly suitable for automobile silencers that require a reduction in tower installation space. It is.

Furthermore, both ends of the porous pipe placed in the sound absorption chamber are securely fixed by the constriction part of the outer shell member and the cover, and a stopper placed on the outer periphery of the porous pipe prevents it from slipping out into the expansion chamber. This ensures reliable operation as a silencer.

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the present invention, and FIG. is a view taken along the arrow in FIG. DESCRIPTION OF SYMBOLS 11... Silencer, 12... Sound absorption chamber, 13, 14... Expansion chamber, 15... Outer shell, 18... Porous pipe, 19... Sound absorbing material.

Claims (1)

[Scope of Claims] 1. A silencer for an internal combustion engine having a sound absorbing chamber provided with a sound absorbing body on the air supply port side and an expansion chamber communicating with the sound absorption chamber on the exhaust port side, comprising: the sound absorption chamber and the expansion chamber; The outer shell member forming the is blow molded from a resin material, and the expansion chamber is composed of a first expansion chamber and a second expansion chamber, and the sound absorption chamber, the first expansion chamber, and the second expansion chamber are approximately The outer shell member is arranged in a U-shape, and has a constriction section between the sound absorption chamber and the expansion chamber, supports one end of the porous pipe constituting the sound absorber with the constriction section, and supports the constriction section. A silencer for an internal combustion engine, wherein the other end of the porous pipe is supported by a cover member that is fitted into the outer shell member to form the sound absorption chamber, and a stopper is provided on the outer periphery of the porous pipe.