JPH0542629U - Sub muffler - Google Patents

Abstract

(57) [Summary] [Purpose] The weight is reduced by eliminating the need for two separators that support the inner pipe. [Structure] Elastic portions 9b and 10b having a corrugated cross section are formed around the inner pipe insertion openings 9a and 10a of the front and rear outer plates 9 and 10, and the front end 11a and the rear end of the inner pipe 11 are integrally formed. The ends 11b were inserted and fixed in the inner pipe insertion ports 9a and 10a, respectively.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vehicle sub-muffler for silencing engine exhaust noise.

[0002]

[Prior Art]

 The structure of a conventional sub-muffler is shown in FIGS. 3 and 4. 1 is an elliptic cylindrical outer shell, and 2A is an outer plate. 3, 3 is a separator, 4 is an inner pipe on the inlet side, and the inlet end (left end) is welded and fixed to the outer plate 2.

An inner pipe 5 on the outlet side is welded and fixed at its outlet end (right end) to the outer plate 2A. 6 is a stainless wool wrapped around the inner pipes 4 and 5 and functions as a sound absorbing material. Reference numerals 7, 7 and 7 are silencing chambers (resonance chambers), and 8 is glass wool filled in the silencing chamber 7 and functions as a sound absorbing material.

The inner pipes 4 and 5 are provided with a large number of small holes 4a and 5a. The right end of one inner pipe 4 is slightly reduced in diameter, and the inner pipe 4 has a slide structure in which it is inserted into the left end of the inner pipe 5.

As described above, the inner pipe is divided into two parts indicated by reference numerals 4 and 5, and one end part is fitted into the other end part by the thermal strain of the inner pipe due to the heat of the exhaust gas. Even if (expansion) occurs, the sub-muffler can be prevented from being damaged only by the fact that the fitting portions of both inner pipes slide and the overlapping length increases. In other words, the sliding structure of the fitting part absorbed the thermal strain.

However, since the inner pipe is divided into two parts, in order to prevent the damage due to the vibration force acting on each inner pipe due to the vibration of the vehicle, the inner pipe 4 near the right end and the inner pipe 4 are prevented. The separators 3 and 3 for supporting the vicinity of the center of 5 were required.

Such an inner pipe having a two-piece split structure has a problem of thermal strain when the entire length of the inner pipe, that is, when the distance between the outer plates 2 and 2A is about 250 mm or more. It has been adopted for.

[0008]

[Problems to be solved by the device]

 In the above conventional technology, the inner pipe is divided into two and has a slide structure, so that a total of two inner plates are required to support each inner plate, which not only complicates the structure but also increases the weight. There was a problem.

Therefore, an object of the present invention is to provide a novel structure of a sub-muffler which can solve such a problem.

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, the sub muffler of the present invention has elastic portions (9b) (10b) having a corrugated cross section around the inner pipe insertion openings (9a) (10a) of the front and rear outer plates (9) (10). ) Is formed, the front end (11a) and the rear end (11b) of the integrally formed inner pipe (11) are inserted and fixed in the inner pipe insertion ports (9a) (10a).

Advantageously, the corrugations of the elastic parts (9b) (10b) are recessed inside the muffler at the central part where they join the respective ends (11a) (11b) of the inner pipe.

[0012]

[Action]

 When the inner pipe becomes hot due to the heat of exhaust gas and expands, the front and rear outer plates are deformed to the outside of the muffler by the elastic part of the corrugations, and absorb the thermal strain of the inner pipe.

[0013]

【Example】

 In the embodiment of FIGS. 1 (a) and 1 (b), 1 is an outer shell having an elliptic cylindrical shape, 9 and 10 are front and rear outer plates, respectively, and a cross section is corrugated around the inner pipe insertion ports 9a and 10a at the center thereof. Elastic portions 9b, 10b are formed.

The corrugations of the elastic portions 9b and 10b are recessed inside the muffler at the central portion where they are connected to the respective ends of the inner pipe 11. The details of the shape of this portion are shown in FIG. 2 by enlarging the portion B in FIG.

The inner pipe 11 is formed of a single straight pipe, and its front end 11a and rear end 11b are inserted and fixed to the inner pipe insertion ports 9a and 10a of the front and rear outer plates 9 and 10, respectively. 11 c is a large number of small holes formed in the inner pipe 11, 6 is stainless wool as a sound absorbing material wound around the inner pipe 11, 7 is a resonance chamber as a sound deadening chamber, 8 is a sound absorbing material filled in the resonance chamber 7. It is glass wool.

The outer plate thus formed with the corrugated elastic portion is deformed in the left-right direction of FIG. 1B perpendicular to the plate surface of the corrugated plate, like a diaphragm forming a hollow used in a barometer. Therefore, even if the exhaust gas at about 700 ° C. passes through the inner pipe and the inner pipe thermally expands, the outer plate deforms and absorbs the thermal strain.

[0017]

[Effect of the device]

 Since the sub-muffler of the present invention is constructed as described above, it is not necessary to use two separators for supporting the inner pipe having the slide structure as in the prior art, and the inner pipe may be one straight pipe. Since it is good, the assembly is easy and the weight can be reduced.

[Brief description of drawings]

1A and 1B are views as seen from A in FIG. 1B, and FIG. 1B is a longitudinal sectional view of an embodiment of the present invention.

FIG. 2 is an enlarged view of part B in FIG.

FIG. 3 is a vertical cross-sectional view of a conventional technique.

FIG. 4 is a partially enlarged view of FIG.

[Explanation of symbols]

 9, 10 Outer plate 9a, 10a Inner pipe insertion port 9b, 10b Elastic portion 11 Inner pipe 11a Front end 11b Rear end

Claims (2)

[Scope of utility model registration request] 1. Elastic parts (9b) (10b) having a corrugated cross section are formed around the inner pipe insertion openings (9a) (10a) of the front and rear outer plates (9) (10) and are integrated as one body. The front end (1) of the inner pipe (11) formed on the
A sub-muffler in which 1a) and a rear end (11b) are inserted and fixed in the inner pipe insertion openings (9a) and (10a), respectively. 2. The waveform of the elastic portions (9b) (10b) is
The sub-muffler according to claim 1, wherein the sub-muffler is recessed inside the muffler at a central portion where each end (11a) (11b) of the inner pipe is joined.