JP2005220897A - Muffler and manufacturing method of muffler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a muffler in which a sound absorbing material can be easily inserted into a space part, and a manufacturing method of the muffler. <P>SOLUTION: The muffler 1 is formed, such that an inner pipe 3 having a large number of small holes 7 to communicate connection parts 2a, 2b with each other is provided inside an outer shell 2 having the connection parts 2a, 2b for connecting with an exhaust pipe at the both ends, and the sound absorbing material 9 is stored in the space part 6 formed between the outer shell 2 and the inner pipe 3. The inner pipe 3 is constituted by externally fitting a cylindrical variable part 5 comprising a easily deformable and restorable elastic material to one end of a main body part 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a silencer and a method for manufacturing the silencer.

  A muffler is disposed in an exhaust system of an automobile equipped with an internal combustion engine or a fuel cell for the purpose of reducing exhaust noise. As an example of a silencer, insert an inner pipe with a number of small holes into the outer shell having connecting parts for connecting to the exhaust pipe at both ends so that the connecting parts communicate with each other. There is known a silencer in which a fibrous sound absorbing material such as glass wool is accommodated in a space formed between the two.

  In such a silencer, after inserting the inner tube through the connection portion formed at one end of the outer shell, the sound absorbing material is inserted into the space formed between the outer shell and the inner tube, and then the inner tube is connected to the inner tube. It is manufactured by reducing the diameter of the other end of the outer shell so as to fit inside and forming a connection portion. (For example, see Patent Document 1)

  In addition, after fixing the end plate to one end of the outer pipe, the inner pipe previously covered with a sound absorbing material is inserted into the insertion hole formed in the end plate, and then the end plate formed with the insertion hole is connected to the outer pipe. Manufactured by adhering to the end (see, for example, Patent Document 2)

However, in the above-described silencer manufacturing method in which the outer shell is processed after the sound absorbing material is accommodated in the silencer, there is a problem that the material and shape of the outer shell and the processing method are relatively easy to process. .
JP 2001-280128 A JP 2000-356119 A

  An object of this invention is to provide the silencer which can insert a sound-absorbing material in a silencer easily, and the manufacturing method of a silencer.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that a plurality of small holes are provided in the outer shell provided with connecting portions at both ends for connecting to the exhaust pipe so that the connecting portions communicate with each other. And a silencer in which a sound absorbing material is accommodated in a space formed between the outer shell and the inner tube, and an end portion of the inner tube is formed by a variable portion made of an elastic material. It is characterized by being.

  According to the second aspect of the present invention, after forming an outer shell provided with connecting portions at both ends for connecting to the exhaust pipe, an inner tube formed with a variable portion whose end is made of an elastic material is connected to the outer shell. A space portion is formed between the outer shell and the inner tube so as to communicate with each other; then, the variable portion is elastically deformed and a sound absorbing material is inserted into the space portion; It is characterized by restoring.

  According to the present invention, the sound absorbing material can be easily inserted into the space portion by elastically deforming the variable portion. Moreover, since the shape of the variable portion is restored after the sound absorbing material is inserted into the space portion, it is possible to suppress the sound absorbing material from being discharged from the space portion. Therefore, after the sound absorbing material is inserted into the space, it is not necessary to process the outer shell, so that the material, shape, and processing method of the outer shell can be arbitrarily selected.

  The best mode for carrying out the present invention will be described based on the embodiment shown in FIGS.

  Fig.1 (a) is an axial sectional view of the silencer 1 of the first embodiment of the present invention. FIG.1 (b) is the sectional view on the AA line in (a). FIG.1 (c) is the BB sectional view taken on the line in (a). FIG. 2 is a diagram showing a manufacturing process of the silencer 1 of the present invention.

  First, as shown in FIG. 2A, an outer shell 2 in which small diameter cylindrical connecting portions 2a and 2b are formed at both ends is prepared by blow molding a resin material such as polyethylene. The outer shell 2 has a large-diameter, generally cylindrical shape, and is formed so that a part 2c that is lower in the mounted state is close to an inner tube 3 that will be described later. In this way, by making a part of the lower side of the outer shell 2 close to the inner tube 3, the water contained in the exhaust gas can be easily discharged out of the silencer 1.

  The inner tube 3 is formed by externally fitting a cylindrical variable portion 5 made of an elastic material that can be easily deformed and restored to one end 4a of a main portion 4 formed of a resin material similar to that of the outer shell 2 in a cylindrical shape. Has been. Next, as shown in FIG. 2 (b), the inner tube 3 is inserted into the outer shell 2 so as to connect the connecting portions 2 a and 2 b of the outer shell 2, and between the outer shell 2 and the inner tube 3. A space 6 is formed. The other end 4 b of the main body 4 is closely fitted to the connecting portion 2 b at the other end of the outer shell 2. The variable portion 4 is made of rubber such as foamed ethylene propylene rubber, and is disposed so as to be located from the connection portion 2 a at one end of the outer shell 2 to the space portion 6.

  The main body 4 is provided with a large number of small holes 7 in substantially the upper half of the figure facing the space 6 so that noise can communicate with the space 6. Further, a cushioning material 8 for preventing interference between the outer shell 2 and the inner tube 3 is joined to the lower surface side of the main body 4.

  Next, as shown in FIG. 2 (c), the sound absorbing material 9 is inserted into the space portion 6 as indicated by an arrow C from a passage formed by elastically deforming the deformable portion 5 using the insertion jig X. . As an insertion method, for example, an arbitrary method such as ejecting the sound absorbing material 9 from a nozzle (not shown) can be adopted.

  Next, by removing the insertion jig 9, the variable portion 5 is restored to the shape shown in FIG. 2B, and the sound absorbing material 9 is suppressed from being discharged from the space portion 6.

  As shown in FIG. 1, a cylindrical metal liner 11 is inserted into the connection portion 2 a at one end of the outer shell 2 and slidably inserted into the main body portion 4 in the silencer 1. A difference in thermal expansion between the outer shell 2 and the inner tube 3 is provided to be absorbed. Further, the liner 11 is provided with a step portion 11 a and presses an end edge portion of one end of the variable portion 5 to seal the space portion 6.

  By providing the liner 11 in this manner, the variable portion 5 is prevented from being deformed inward (exhaust flow path side) and the sound absorbing material 9 is prevented from being discharged. Further, it is possible to prevent the connecting portion 2a at one end of the outer shell 2 from being deformed when joining to an upstream exhaust pipe (not shown).

  On the other hand, a collar 12 is provided at the connecting portion 2b at the other end of the outer shell 2 to suppress deformation of the connecting portion 2b at the other end of the outer casing 2 when it is joined to a downstream exhaust pipe (not shown). .

FIG. 3A is an axial sectional view of the silencer 21 according to the second embodiment of the present invention. FIG.3 (b) is the DD sectional view taken on the line in (a).
In the silencer 21 of the second embodiment, the inner tube 23 is provided with a notch 24b at a part of one end 24a of the cylindrical main body 24, and the variable portion 25 made of an elastic material is provided with the notch 24b. It is fixed so as to cover it.

  Since the other configuration is the same as that of the silencer 1 of the first embodiment, the same parts as those described above are denoted by the same reference numerals and the description thereof is omitted. Also in the second embodiment, the liner 11 and the collar 12 may be provided as in the first embodiment.

FIG. 4 is an axial sectional view of the silencer 31 of the third embodiment of the present invention. FIG.3 (b) is the DD sectional view taken on the line in (a).
In the silencer 31 according to the third embodiment, the inner tube 33 is formed of an elastic material on one end 34a of the cylindrical main body 34 over the range of about 3/4 of the space portion side in the circumferential direction of the main body 34. A variable portion 35 made of is fixedly formed.

  Since the other configuration is the same as that of the silencer 1 of the first embodiment, the same parts as those described above are denoted by the same reference numerals and the description thereof is omitted. In the third embodiment, the liner 11 and the collar 12 may be provided as in the first embodiment.

  In the above embodiment, the outer shell is formed by blow molding using a resin material. However, the outer shell may be formed into an arbitrary shape by an arbitrary method using an arbitrary material such as metal, ceramic, or glass. The same applies to the main portion of the inner pipe.

  The variable portion can be selected from known materials that can be easily elastically deformed, such as rubber and titanium-nickel alloy. Further, a metal or resin fine wire knitted so as to be easily elastically deformable may be used.

  As the sound absorbing material, an arbitrary sound absorbing material in a fibrous or granular form such as metal, ceramic, or glass can be selected.

(A) The axial direction sectional view of the silencer of the 1st example of the present invention. (B) AA line sectional view in (a). (C) BB sectional drawing in (a). (A)-(c) The figure which shows the manufacturing process of the silencer of this invention. (A) An axial sectional view of a silencer of the 2nd example of the present invention. (B) DD sectional view taken on the line in (a). (A) An axial sectional view of a silencer of the 2nd example of the present invention. (B) EE sectional view taken on the line in (a).

Explanation of symbols

1,21,31 Silencer 2 Outer shell 3,23,33 Inner tube 4,24,34 Main part 5,25,35 Variable part 6 Space part 7 Small hole 9 Sound absorbing material

Claims (2)

  An inner pipe provided with a number of small holes is provided in the outer shell provided with connecting portions at both ends for connecting to the exhaust pipe, and the outer shell and the inner pipe are connected to each other. A silencer in which a sound absorbing material is accommodated in a space formed between the ends of the inner tube, wherein the end portion of the inner tube is formed of a variable portion made of an elastic material.   After forming the outer shell provided with connecting parts for connecting to the exhaust pipe at both ends, an inner pipe formed of a variable part made of an elastic material at the end is provided so that the connecting parts of the outer shell communicate with each other A space portion is formed between the outer shell and the inner tube, and then the variable portion is elastically deformed and a sound absorbing material is inserted into the space portion, and then the variable portion is restored. A method of manufacturing a silencer.

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