JP2006214323A - Muffler for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a muffler for an internal combustion engine compact and having high degree of freedom of placement position. <P>SOLUTION: A shell member 2 covering a part in a circumferential direction of an outer periphery of an exhaust pipe 1 through which exhaust gas discharged from the internal combustion engine passes is attached to the exhaust pipe and a chamber 10 is formed by the part in the circumferential direction of the outer periphery of the exhaust pipe 1 and the shell member 2. The shell member 2 has a hollow structure formed by joining an upper shell member 4 and a lower shell member 6. An outer diameter of the exhaust pipe 1 is set almost equal to a thickness of the shell member 2. Small holes 12 are formed in a part of the exhaust pipe 12 and the chamber 10 and the inside of the exhaust pipe 1 are connected together though the small holes 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a muffler for an internal combustion engine attached to an exhaust system of an internal combustion engine mounted on an automobile or the like.

  Conventionally, mufflers for internal combustion engines that are attached to an exhaust system of an internal combustion engine mounted on an automobile or the like have been known to have various structures, and suitable structures according to various conditions such as the size of the internal combustion engine. Is adopted. Further, an exhaust system in which two types of mufflers for an internal combustion engine, a sub muffler and a main muffler, are also known.

For example, as disclosed in Patent Document 1, the sub-muffler includes a substantially cylindrical shell member, a through pipe that penetrates the shell member from the upstream side to the downstream side, and a separator that partitions the inside of the shell member. Are known. The through pipe is connected to the upstream exhaust pipe and the downstream exhaust pipe, and a plurality of small holes are formed in the through pipe in the shell member. When the exhaust gas introduced into the sub-muffler passes through the through pipe, noise is reduced due to an expansion effect and an interference effect due to the small holes and the rooms partitioned by the separator.
JP 2000-213328 A

  However, in such a conventional one, the through pipe is covered with a substantially cylindrical shell member, and a ring-shaped chamber is formed between the outer periphery of the through pipe and the inner periphery of the shell member. There was a problem that the external shape of the slab would become large. In particular, since the exhaust system is provided under the floor of the automobile along the bottom surface, there is a problem that if the outer shape of the muffler for the internal combustion engine is large, the arrangement location is restricted.

  An object of the present invention is to provide a muffler for an internal combustion engine that is small in size and has a high degree of freedom in arrangement.

In order to achieve this problem, the present invention has taken the following measures in order to solve the problem. That is,
A shell member that covers a part of the outer circumferential direction of the exhaust pipe through which exhaust gas discharged from the internal combustion engine passes is attached to the exhaust pipe, and a part of the outer circumferential direction of the exhaust pipe and the shell member A muffler for an internal combustion engine is characterized in that a chamber is formed, a small hole is formed in a part of the exhaust pipe, and the room and the exhaust pipe communicate with each other through the small hole. The shell member may be attached to the bent portion of the exhaust pipe. Moreover, it is good also as a structure which attached the said shell member which covers a part of circumferential direction of the outer periphery of both said exhaust pipes to the two said exhaust pipes arrange | positioned in parallel. The outer diameter of the exhaust pipe and the thickness of the shell member may be substantially the same. Alternatively, the shell member may have a middle structure in which the upper shell member and the lower shell member are overlapped.

  In the muffler for an internal combustion engine of the present invention, a shell member that covers a part of the outer circumference of the exhaust pipe is attached to the exhaust pipe, and the chamber is formed by the outer circumference of the exhaust pipe and the shell member. , There is an effect that the degree of freedom of the arrangement location is high.

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
As shown in FIG. 1, reference numeral 1 denotes an exhaust pipe, and an upstream exhaust pipe 1 is connected to an internal combustion engine (not shown), and exhaust gas discharged from the internal combustion engine passes through the exhaust pipe 1 from the downstream side. Released into the atmosphere. A shell member 2 is attached to the exhaust pipe 1, and the shell member 2 includes an upper shell member 4 and a lower shell member 6 as shown in FIGS. 2 and 3.

  The shell member 2 is formed in a flat and substantially rectangular parallelepiped shape, and is formed with a middle structure in which the inside is formed hollow by overlapping the three sides of the upper shell member 4 and the lower shell member 6. . An opening 8 is formed on the other side of the shell member 2, and the opening 8 is formed to be recessed in an arc shape according to the outer shape of the exhaust pipe 1. The thickness of the substantially rectangular parallelepiped shell member 2 is substantially the same as the outer diameter of the exhaust pipe 1.

  The opening 8 of the shell member 2 is pressed against the outer periphery of the exhaust pipe 1, the opening 8 is closed, and the shell member 2 is fixed to the outer periphery of the exhaust pipe 1 by welding or the like. The shell member 2 is attached so as to cover a part of the outer circumferential direction of the exhaust pipe 1 in the present embodiment so as to cover almost half of the circumferential direction of the outer circumference of the exhaust pipe 1. A room 10 surrounded by a part of the shell member 2 and the shell member 2 is formed.

  The exhaust pipe 1 has a plurality of small holes 12 communicating with the room 10. In this embodiment, glass wool is filled in the room 10, but glass wool may be provided as necessary. As shown in FIG. 1, the upper shell member 4 and the lower shell member 6 are formed with a plurality of recesses 14 (only part of which are shown) to improve rigidity.

Next, the operation of the muffler for the internal combustion engine of the present embodiment described above will be described.
When exhaust gas is discharged from the internal combustion engine as the internal combustion engine is operated, the exhaust gas passes through the exhaust pipe 1. Exhaust noise caused by exhaust gas pulsation or the like is caused by expansion effect and interference effect due to the room 10 communicating through the small hole 12 of the exhaust pipe 1 when the exhaust passes through the exhaust pipe 1 along the shell member 2. As a result, exhaust noise is reduced.

  The shell member 2 is attached so as to cover a part in the circumferential direction of the outer periphery of the exhaust pipe 1 and is formed in a flat shape having substantially the same thickness as the outer diameter of the exhaust pipe 1. When the exhaust system is arranged on the bottom surface of the floor, it can be arranged if there is a small space, and the degree of freedom of the arrangement place is high.

Next, another embodiment different from the above-described embodiment will be described with reference to FIGS.
As shown in FIG. 4 (a), the exhaust pipe 1 is bent to form a bent portion 1a, and the shell member covers the circumferential portion of the outer periphery of the exhaust pipe 1 of the bent portion 1a. 21 is attached. The shell member 21 is formed in a substantially triangular shape, two sides attached to the exhaust pipe 1 are opened, and the other side is closed, and the outer periphery of the exhaust pipe 1 of the bent portion 1 a and the shell member 21 form a chamber. Is formed. In this case, since the shell member 21 can be formed by bending a plate material into a U-shape, the shell member 21 can be easily formed, and can be attached to the bent portion 1a of the exhaust pipe 1. Space can be used effectively.

  Further, as shown in FIG. 4B, the exhaust pipe 1 is bent to form two bent portions 1a and 1b, and one exhaust pipe 1 is folded back in the same direction, so that the upstream exhaust pipe is formed. 1 and the downstream exhaust pipe 1 are substantially aligned.

  A shell member 22 is attached so as to cover a part in the circumferential direction of the outer periphery of the exhaust pipe 1 of both bent portions 1a, 1b. The shell member 22 is formed in a substantially trapezoidal shape, and is formed so as to straddle the exhaust pipe 1 that is bent in both the bent portions 1a and 1b and is substantially aligned. The shell member 22 has three sides open and the remaining one side closed, and a chamber is formed by the outer periphery of the exhaust pipe 1 of both the bent portions 1 a and 1 b and the shell member 22. Also in this case, since the shell member 22 can be formed by bending a plate material into a U shape, the shell member 22 can be easily formed, and can be attached to the bent portions 1a and 1b of the exhaust pipe 1. The vacant space under the floor can be used effectively.

  Further, as shown in FIG. 4C, the two exhaust pipes 1 are arranged substantially in parallel, and the shell member 24 is attached so as to straddle the two exhaust pipes 1. The shell member 24 is formed in a substantially rectangular parallelepiped shape, two sides on both exhaust pipes 1 side are opened, and the other two opposite sides are closed, and the outer periphery of the two exhaust pipes 1, the shell member 24, A room is formed. A narrow space where the two exhaust pipes 1 are arranged side by side can be used effectively.

  Further, as shown in FIG. 5 (a), an exhaust pipe 31 that bypasses the exhaust pipe 1 is provided, and the above-described shell member 2 is attached to the exhaust pipe 31. Further, as shown in FIG. 5 (b), an exhaust pipe 32 branched from the exhaust pipe 1 and closed at its tip is provided, and the above-described shell member 2 can be attached to the exhaust pipe 32 in the same manner. is there.

  The present invention is not limited to such embodiments as described above, and can be implemented in various modes without departing from the gist of the present invention.

It is a front view of the muffler for internal combustion engines as one embodiment of the present invention. It is a side view of the muffler for internal combustion engines of this embodiment. It is AA sectional drawing of FIG. It is explanatory drawing of the muffler for internal combustion engines as other embodiment. It is explanatory drawing of the muffler for internal combustion engines as another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 31, 32 ... Exhaust pipe 1a, 1b ... Bending part 2, 21, 22, 24 ... Shell member 4 ... Upper shell member 6 ... Lower shell member 8 ... Opening part 10 ... Chamber 12 ... Small hole 14 ... Recessed part

Claims (5)

A shell member that covers a part of the outer circumferential direction of the exhaust pipe through which exhaust gas discharged from the internal combustion engine passes is attached to the exhaust pipe, and a part of the outer circumferential direction of the exhaust pipe and the shell member A muffler for an internal combustion engine, wherein a chamber is formed, a small hole is formed in a part of the exhaust pipe, and the chamber communicates with the inside of the exhaust pipe through the small hole. The muffler for an internal combustion engine according to claim 1, wherein the shell member is attached to a bent portion of the exhaust pipe. 2. The muffler for an internal combustion engine according to claim 1, wherein the shell member that covers a part of a circumferential direction of the outer periphery of the two exhaust pipes is attached to the two exhaust pipes arranged in parallel. The muffler for an internal combustion engine according to any one of claims 1 to 3, wherein an outer diameter of the exhaust pipe and a thickness of the shell member are substantially the same. 5. The muffler for an internal combustion engine according to claim 1, wherein the shell member has a middle structure in which an upper shell member and a lower shell member are overlapped with each other.

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