JP2005188364A - Muffler for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miniaturizable muffler for a vehicle, having sufficient silencing performance, and providing exhaust pressure resistance according to a traveling condition. <P>SOLUTION: This muffler is provided with a silencer body 3, an exhaust introducing pipe 2 with two or more small holes 11 communicated with the inside of the silencer body 3 formed, a first finisher 4a connected to the downstream end of the exhaust introducing pipe 2 through a first passage and whose downstream end is opened to the atmosphere, an exhaust pressure regulating valve 5 arranged in the first passage and opened/closed based on exhaust gas pressure, at least one of inner pipes 15, 16 externally arranged at predetermined interval from the outer wall of the exhaust introducing pipe 2, a first expansion chamber R1 formed on the downstream side of a small hole 11, throttle passages P2-P4 sectioned between the inner pipes 15, 16 and the silencer body 3, a second expansion chamber R2 formed on the downstream sides of the throttle passages P2-P4, and a second finisher 4b whose upstream end is communicated with the second expansion chamber R2 and downstream end is opened to the atmosphere. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an engine exhaust muffler used in a four-wheeled vehicle or the like.

  As a conventional technique related to a muffler (silencer), Patent Document 1 discloses an operation mechanism including a casing, a gas suction pipe to the casing, a diaphragm, a supporting elastic body, a piston rod, and a pressure connecting portion. A silencer comprising a pressure vessel, a valve closing element attached to the piston rod, and a pressure conduit for transmitting the total gas pressure to the pressure side of the diaphragm, the operation vessel having a plurality of chambers separated by the diaphragm. However, each diaphragm is supported by an elastic body, each chamber has a pressure connection, and another pressure conduit conveys the gas static pressure to the low pressure side of the diaphragm, thereby eliminating the need for an external control device. It is said that a silencer having a variable attenuation characteristic curve can be provided.

Further, in Patent Document 2, the inside of the casing is partitioned into first to fourth chambers by a partition wall from the front end wall to the rear end wall of the casing, and an inlet pipe and exhaust for introducing exhaust gas from the engine into the casing Two outlet pipes for guiding gas from the inside of the casing to the outside are provided, the downstream end of the inlet pipe opens into the fourth chamber, the upstream end of the first outlet pipe opens into the second chamber, and the second outlet pipe The upstream end of the first chamber opens into the first chamber, the first chamber and the fourth chamber communicate with each other through a communication pipe, and a partition hole that separates the second chamber from the third chamber is provided with a communication hole that communicates the two chambers. A large number of small holes are formed in the portion of the inlet pipe and the communication pipe existing in the third chamber, and the exhaust pipe on the first chamber side of the communication pipe opens when the exhaust pressure on the fourth chamber side exceeds a predetermined value. Of muffler with control valve Is disclosed, thereby when the exhaust pressure becomes high, let reduce the exhaust resistance, there is a can so as not to reduce the engine efficiency.
JP-A-9-166010 Japanese Unexamined Patent Publication No. 2002-295225 (paragraph numbers 0003 and 0004, FIG. 6)

  However, what is disclosed in Patent Document 1 is a plurality of pipes 3 through which gas is circulated between the inside and outside of the casing 2 and the three expansion chambers 21, 23, 35, as shown in FIG. .1, 3.2, 3.3, 3.4 are arranged in parallel or vertically. For this reason, there exists a malfunction that the whole apparatus must be enlarged.

  Further, the one disclosed in the above-mentioned Patent Document 2 also includes four pipes in the casing 2, that is, an inlet pipe 6, a communication pipe 7, and first and second outlet pipes 8 as shown in FIG. , 9 are arranged in parallel, the entire apparatus becomes large.

  Therefore, an object of the present invention is to provide a muffler for a vehicle that has a sufficient silencing performance, can obtain an exhaust pressure resistance according to a running state, and is downsized.

  In order to solve the above problems, the present invention provides a muffler for a vehicle provided in an exhaust passage of an engine mounted on a vehicle, wherein a silencer body and an upstream end communicate with the exhaust passage, and the silencer body is disposed around a downstream end. An exhaust introduction pipe in which a plurality of small holes communicating with the interior of the exhaust introduction pipe is formed, a first finisher connected to the downstream end of the exhaust introduction pipe via a first passage, and the downstream end being opened to the atmosphere; A discharge pressure adjusting valve that is disposed in the first passage and opens and closes communication between the exhaust introduction pipe and the first finisher based on the pressure of the exhaust gas; and a predetermined pressure from an outer wall of the exhaust introduction pipe At least one inner pipe provided outside at intervals, a first expansion chamber formed on the downstream side of the small hole, and a throttle defined between the inner pipe and the silencer body A passage, a second expansion chamber formed on the downstream side of the throttle passage, and a second finisher whose upstream end communicates with the second expansion chamber and whose downstream end is open to the atmosphere. (Claim 1).

  The inner pipe includes a first inner pipe provided with a predetermined distance from an outer wall of the exhaust introduction pipe, and an outer pipe provided with a predetermined distance from the outer wall of the first inner pipe. The throttle passage is formed by a second passage formed between an outer wall of the second inner pipe and an inner wall of the silencer body, and the first inner pipe. A third passage formed between an outer wall and the inner wall of the second inner pipe; a fourth passage formed between the outer wall of the exhaust introduction pipe and the inner wall of the first inner pipe; Preferably, the second expansion chamber is formed on the downstream side of the fourth passage (claim 2).

  Further, it is preferable that the first finisher and the second finisher are respectively extended from opposing surfaces of the silencer body.

  According to the vehicle muffler having the above-described configuration, a plurality of inner pipes having different diameters are provided in the silencer body, and a space defined between the inner pipes is used as a throttle passage, thereby achieving an excellent silencing effect. Therefore, the size can be reduced. In addition, an exhaust pressure adjustment valve is provided that opens when the exhaust gas from the engine exceeds a predetermined pressure and short-circuits the exhaust gas path, reducing exhaust resistance when high output is required, and reducing engine output. It can be improved. Further, in the vehicle muffler of the present invention, two finishers are respectively extended from the surface of the silencer body facing the vehicle width direction, so that two side outs which are one of muffler structures preferred by the user are provided. The structure, that is, the muffler structure in which the two finishers are extended from both sides of the rear portion of the vehicle, can be realized more easily than the conventional device (see Patent Document 2).

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  A vehicle muffler 1 shown in FIG. 1 includes an exhaust introduction pipe 2, a silencer body 3, finishers 4a and 4b, an exhaust pressure adjusting valve 5, and the like. The exhaust introduction pipe 2 guides exhaust gas discharged from the engine into the silencer body 3, and extends through the one side cover 10 that constitutes one end of the silencer body 3 to the inside of the silencer body 3. A plurality of small holes 12 are formed in the silencer body 3 in the vicinity of the one-side cover 10. The silencer body 3 is a metal member such as stainless steel formed in a substantially rectangular parallelepiped shape, and is a portion that forms the outermost part of a silencing mechanism that reduces pulsation of exhaust gas introduced by the exhaust introduction pipe 2. Inside, the first inner pipe 15, the second inner pipe 16, the first exhaust outlet 17 constituting the upstream end of the first finisher 4 a, and the upstream end of the second finisher 4 are constituted. The second exhaust outlet 18 and the exhaust pressure adjusting valve 5 are arranged.

  The finishers 4a and 4b are pipe-like members that discharge exhaust gas that has passed through the silencer body 3 into the atmosphere, and extend from the surface of the silencer body 3 that faces the vehicle width direction. The first finisher 4 a is connected to the downstream end portion of the exhaust introduction pipe 2 through the first exhaust lead-out portion 17 and penetrates the other side cover 21 that constitutes the other end portion of the silencer body 3. Open to the atmosphere. The second finisher 4b communicates with a space S2, which will be described later, via the second exhaust lead-out portion 18, and passes through the one-side cover 10 and opens into the atmosphere.

  The first inner pipe 15 is a cylindrical member having a diameter larger than that of the exhaust introduction pipe 2, and is provided outside the outer wall of the exhaust introduction pipe 2 with a predetermined interval. The predetermined part of 15 is crushed and fixed to the exhaust introduction pipe 2 by pressure contact. The second inner pipe 16 is a cylindrical member having a diameter larger than that of the first inner pipe 15, and is provided outside the outer wall of the first inner pipe 15 with a predetermined interval. A predetermined portion of the second inner pipe 16 is crushed and brought into pressure contact with the first inner pipe, and the exhaust 24 is exhausted by a fixture 24 provided at a portion upstream of the small hole 11 of the exhaust introduction pipe 2. It is fixed to the outside of the introduction pipe 2 and the first inner pipe 15.

  The silencer body 3 is partitioned into a first space S1 and a second space S2 by a partition plate 25. One end side of the first inner pipe 15 communicates with the first space S1, and the other end side communicates with the second space S2. One end side and the other end side of the second inner pipe 16 communicate with the inside of the first space S <b> 1 via the fixture 24.

  The first exhaust outlet 17 is disposed in the second space S2, and its upstream end is connected to the downstream end of the exhaust introduction pipe 2, and its downstream end is It is connected to the first finisher 4a. The second exhaust lead-out portion 18 is fixed through the partition plate 25 and the one-side cover 10, and has an upstream end communicating with the second space S2 and a downstream side thereof. Are connected to the second finisher 4b.

  With the above-described configuration, the silencer body 3 includes the first side cover 10 and the silencer body 3 on the downstream side of the first passage P1 defined in the exhaust introduction pipe 2 and the small hole 11 of the exhaust introduction pipe 2. A first passage R2 defined by the inner wall of the silencer body 3 and the first passage R2 defined by the inner wall of the silencer body 3 and the first passage R2. A third passage P3 defined by the outer wall of the inner pipe 15 and the inner wall of the second inner pipe 16, and the outer wall of the exhaust pipe 2 and the inner wall of the first inner pipe 15. A fourth passage P4, a second expansion chamber R2 defined downstream of the fourth passage P4 in the second space 2, and a first exhaust outlet 17; Fifth passage P5, second exhaust A sixth passage P6 defined in the lead-out portion 18 is formed.

  The exhaust pressure adjusting valve 5 opens and closes according to the pressure of the exhaust gas from the engine and changes the flow path of the exhaust gas formed in the silencer body 3, and the downstream end of the exhaust introduction pipe 2 And a fixed member 30, a rod member 31, a valve body 32, a valve seat 33, a spring 34, and a spring receiver 35. The fixing member 30 is fixed to the inner wall surface of the exhaust introduction pipe 2, has a shape through which exhaust gas can pass, and the front end of the rod member 31 is fixed. A spring receiver 35 is fixed to the vicinity of the rear end of the rod member 31. The valve body 32 is a substantially conical member, and is fixed to the middle of the rod member 31 so as to be slidable. The valve seat 33 is formed at the rear end portion of the exhaust introduction pipe 2 and has a shape capable of airtightly contacting the edge portion of the valve body 32. The spring 34 has a front end fixed to the back surface of the valve body 32 and a rear end fixed to the spring receiver 35.

  According to the vehicle muffler 1 configured as described above, when the pressure of the exhaust gas from the engine is smaller than the biasing pressure (and atmospheric pressure) of the spring 34, that is, during normal travel, as shown in FIG. The body 32 is in a closed state. As a result, the exhaust gas passes from the first passage P1 through the small hole 11 and flows into the first expansion chamber R1 as shown by the arrow in the figure, and enters the second passage P2, the third passage. Through the second passage S3 and the fourth passage P4, into the second expansion chamber R2, through the second space S2 and the sixth passage P6, and discharged from the second finisher 4b. . At this time, pulsation (noise) of exhaust gas is sufficiently reduced by passing through a complicated throttle path and expansion chamber.

  On the other hand, when the pressure due to the exhaust gas from the engine is larger than the biasing pressure (and atmospheric pressure) of the spring 34, that is, during high power traveling, the valve body 32 moves to the open position as shown in FIG. To do. As a result, most of the exhaust gas flows directly from the first passage P1 to the fifth passage P5 and is discharged from the first finisher 4a as shown by the arrows in FIG. Thereby, since the exhaust resistance is reduced, the engine output is improved.

  As described above, according to the vehicle muffler 1 according to the present embodiment, the silencer body 2 is provided with the plurality of inner pipes 15 and 16 having different diameters, and the space defined between these members is exhausted. By using it as a throttle passage, an excellent silencing effect and downsizing can be realized. Further, during normal driving where only a low power output is required in the normal range, the exhaust gas passes through a complicated throttle passage and an expansion chamber because the valve body 32 of the exhaust pressure adjusting valve 5 is in the closed position. A sufficient silencing effect can be obtained. On the other hand, during high-power running such as high-speed running or acceleration, the valve element 32 moves to the open position, so that the exhaust gas is short-circuited and is discharged from the finisher 4a that is not used during the normal running. Thereby, exhaust resistance is reduced and engine output can be improved. Further, by extending the two finishers 4a and 4b from the surface of the silencer body 2 facing the vehicle width direction, two side-out structures that are one of the muffler structures preferred by the user, A muffler structure in which the two finishers 4a and 4b are extended from both sides of the rear portion of the vehicle can be easily realized.

  As described above, according to the present invention, a muffler for a vehicle that has sufficient noise reduction performance, can obtain exhaust pressure resistance in accordance with a running state, and is excellent in design is provided while downsizing. can do.

FIG. 1 is a diagram showing a state of the vehicle muffler according to the embodiment of the present invention during normal running. FIG. 2 is a diagram illustrating a state in which the vehicle muffler according to the embodiment of the present invention is traveling at a high output.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle muffler 2 Exhaust introduction pipe 3 Silencer body 4a 1st finisher 4b 2nd finisher 5 Exhaust pressure regulating valve 11 Small hole 15 1st inner pipe 16 2nd inner pipe 17 1st exhaust lead-out part 18 1st 2 exhaust outlet 25 partition plate 30 fixing member 31 rod member 32 valve body 33 valve seat 34 spring 35 spring receiver P1 first passage P2 second passage P3 third passage P4 fourth passage P5 fifth passage P6 6th passage R1 1st expansion chamber R2 2nd expansion chamber S1 1st space S2 2nd space

Claims (3)

In a vehicle muffler provided in an exhaust passage of an engine mounted on a vehicle,
A silencer body,
An exhaust introduction pipe in which an upstream end communicates with the exhaust passage, and a plurality of small holes formed around the downstream end communicate with the interior of the silencer body;
A first finisher connected to the downstream end of the exhaust pipe through a first passage, the downstream end being open to the atmosphere;
An exhaust pressure adjusting valve that is disposed in the first passage and opens and closes communication between the exhaust introduction pipe and the first finisher based on the pressure of exhaust gas;
At least one inner pipe provided outside the outer wall of the exhaust introduction pipe with a predetermined interval;
A first expansion chamber formed downstream of the small hole;
A throttle passage defined between the inner pipe and the silencer body;
A second expansion chamber formed downstream of the throttle passage;
A vehicle muffler comprising: a second finisher having an upstream end communicating with a second expansion chamber and a downstream end opened to the atmosphere. The inner pipe is externally provided with a predetermined distance from the outer wall of the first inner pipe, and a first inner pipe externally provided with a predetermined distance from the outer wall of the exhaust introduction pipe. A second inner pipe,
The throttle passage includes a second passage formed between an outer wall of the second inner pipe and an inner wall of the silencer body, and an outer wall of the first inner pipe and an inner wall of the second inner pipe. A third passage formed between, and a fourth passage formed between the outer wall of the exhaust introduction pipe and the inner wall of the first inner pipe,
The vehicle muffler according to claim 1, wherein the second expansion chamber is formed on the downstream side of the fourth passage.   3. The vehicle muffler according to claim 1, wherein the first finisher and the second finisher are respectively extended from opposing surfaces of the silencer body. 4.

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