JP2013160193A - Exhaust muffler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust muffler by which sufficient muffling effects can be obtained and whose manufacturing cost is not increased unnecessarily.SOLUTION: An exhaust muffler includes: a tubular muffler body 1 in which an expansion space 1C is formed; a partitioning member 4 which is shorter than a length direction of the muffler body 1 and in which a cross-sectional area of a recessed portion is smaller than the cross-sectional area of a tubular space within the muffler body; an inflow pipe 2 into which exhaust gas flows through an outer wall of the muffler body; and an exhaust pipe 3 which exhausts internal exhaust gas through the outer wall. While forming a gap 8 between an outer circumferential surface of the partitioning member 4 and an inner peripheral surface of the muffler body 1, the partitioning member 4 is disposed as a partition in the internal space of the muffler body, and a first chamber 10 and a second chamber 11 which are defined by the partitioning member 4 and formed at both sides thereof are communicated via a communicating path formed from the gap 8.

Description

  The present invention relates to an exhaust muffler suitable for a leisure vehicle or the like.

  Leisure vehicles (referred to as motor vehicles including motorcycles, boats such as planing boats (PWC), and rough terrain vehicles (ATV)), such as motorcycles, exhaust (combustion gas) from an engine combustion chamber through an exhaust port. ) To the outside is extended. An exhaust muffler is provided at the end of the exhaust passage for the purpose of silencing and the like.

The exhaust muffler has a muffler body having a cylindrical appearance with both ends closed. The inside of the muffler body is divided into a plurality of chambers by partition walls. Then, exhaust gas discharged from the engine side is sequentially introduced into each chamber inside the exhaust muffler, thereby reducing the exhaust noise to a predetermined level and discharging it to the outside air side.
Specifically, the muffler main body has a cylindrical muffler main body closed at both ends by attaching end plates (end plates) by welding or the like to both ends of a thin steel plate bent into a cylindrical shape. It is formed. Then, before welding at least one end plate of the end plates to one end, a partition wall having a shape corresponding to the cross-sectional shape of the cylindrical body is inserted into the inside of the muffler body, and around the partition wall. The partition wall is fixed in the muffler body by plug welding the formed flange portion for mounting and the inner peripheral surface of the side peripheral wall of the muffler body. Thus, the interior space is partitioned into a plurality of chambers by dividing the inside of the exhaust muffler with one or a plurality of partitions (see Patent Document 1).

  For example, the interior of the exhaust muffler is partitioned into three chambers including a first chamber, a third chamber, and a second chamber from the front to the rear by two partition walls. Exhaust gas from the engine first flows into the first chamber through the inflow pipe through the exhaust pipe, and then from the first chamber to the second chamber, the first communication pipe (communication). (Also referred to as a common pipe), and then flows from the second chamber to the third chamber via the second communication pipe, and finally from the third chamber to the outside of the exhaust muffler. What is comprised so that it exhausts through a pipe (discharge pipe) is known (refer to patent documents 2).

Japanese Utility Model Publication No. 1-111416. JP-A-8-326521.

  However, in the case of the conventional exhaust muffler, the mounting flange portion formed around the partition wall and the side peripheral wall of the muffler body are fixed only at predetermined intervals by plug welding. For this reason, in the part which is not plug-welded, the small clearance gap has arisen among these. In addition, the cause of the gap is that the partition wall and the side peripheral wall of the muffler body are manufactured by press working, and the processing accuracy is lower than that of machining.

  For this reason, the entire amount of exhaust gas does not flow in accordance with the flow of exhaust gas described above, but a part of the exhaust gas does not pass through the second chamber and passes through the gap from the first chamber to the third chamber. As a result, the exhaust gas directly flows into the tank. That is, in the exhaust muffler, there is a problem that a part of the exhaust gas bypasses from a predetermined flow path and a desired silencing effect cannot be obtained.

  As a countermeasure, it may be possible to continuously weld the contact portion between the flange portion of the partition wall and the inner peripheral surface of the muffler body over the entire circumference. In such a case, the muffler body and the partition wall are formed of a thin plate. Therefore, the whole is deformed due to thermal distortion, or the manufacturing cost is greatly increased. In addition, there is a problem that the welding torch cannot be inserted into the muffler body and it is difficult to weld all around.

  The present invention has been made in view of such a situation, and an object thereof is to provide an exhaust muffler that can obtain a sufficient silencing effect and does not unnecessarily increase the manufacturing cost.

An exhaust muffler for a leisure vehicle according to the present invention includes a cylindrical muffler body in which an expansion space for silencing is formed and both ends are closed,
An inflow pipe that allows exhaust to flow through the outer wall of the muffler body;
At least one partition member that partitions the expansion space in the muffler body into a plurality of chambers;
A communication path that is partitioned by the partition member and communicates between the chambers located on both sides of the partition member;
An exhaust pipe that passes through the outer wall of the muffler body and exhausts the exhaust inside to the outside;
With
The at least one partition member is
A cylindrical peripheral wall and a bottom wall that closes one end of the muffler main body that are accommodated in the muffler main body and have a shorter cross-sectional dimension than the longitudinal dimension of the muffler main body and a cross-sectional dimension smaller than the cross-sectional dimension of the inner space of the muffler main body Comprising a concave form surrounded by the peripheral wall and the bottom wall,
The communication path is
It is formed by the clearance gap formed between the surrounding wall of the said partition member, and the inner surface of a muffler main body.

According to the exhaust muffler according to the present invention configured as described above, each chamber formed on both sides of the partition wall member includes the peripheral wall and the bottom wall, and is a concave partition wall member surrounded by the peripheral wall and the bottom wall. If the partition wall member is formed by pressing the plate member (steel plate or the like) with a single plate material (such as a steel plate) to form the peripheral wall and the bottom wall, a space portion in a concave shape surrounded by the peripheral wall and the bottom wall The exhaust does not flow in by bypassing the first chamber or the second chamber, and a sufficient silencing effect can be obtained.
That is, if there is a first chamber located on the upstream side, for example, the exhaust gas flows into the second chamber on the downstream side from the first chamber via the communication path consisting of the gap, and thereafter From the second chamber, it flows into the concave space part surrounded by the peripheral wall and the bottom wall from the opening part on the side opposite to the bottom wall of the partition member.
Therefore, when the space portion formed inside the concave shape of the partition wall member is made an independent chamber by narrowing the opening portion of the partition wall member, for example, an opening on the side opposite to the bottom wall as described below is used. When the exhaust muffler is configured such that the third chamber is formed by closing with a closing member and the second chamber and the third chamber are connected with a communication pipe, the first muffler from the most upstream side is used. There is no bypass of exhaust to the third chamber.
In addition, as in the present invention, when the communication path that communicates each chamber (for example, the first chamber and the second chamber) is formed by the gap, the partition wall is an essential structure in the related art. A communication pipe for communicating between the chambers on both sides of the member can be omitted. For this reason, the effect of “two birds with one stone” can be obtained that the number of parts can be reduced and the man-hours and processing (welding) for attaching the pipe can also be reduced.
For this reason, it is possible to further reduce the cost of the exhaust muffler, which is currently rationalized as it approaches the limit.

Further, in the exhaust muffler, when the length of the peripheral wall of the partition member is 1/10 to 1/2 of the length of the muffler main body, the space formed inside the concave shape of the partition member Is sufficiently large as an expansion space, and the length of the communication path formed by the gap is sufficient, so that a necessary silencing effect can be obtained. Further, even if a minute gap is generated between the outer peripheral surface of the peripheral wall of the partition member and the inner peripheral surface of the muffler main body other than the welded portion, due to the pressure loss due to the length of the partition member, The exhaust gas can be prevented from bypassing.
Moreover, in the case of the said structure, it becomes a preferable structure to open the upstream end of the said discharge pipe to the concave internal space of this partition member.

  The exhaust muffler further includes a closing member that closes an opening on the side opposite to the bottom wall of the peripheral wall of the partition member, a communication pipe that passes through the closing member, and an opening portion of the partition member that is formed by the closing member. And a third chamber formed in the partition wall member so that exhaust can flow through the third chamber and the first chamber or the second chamber through the communication pipe. If comprised, the preferable exhaust muffler which has three expansion chambers by simple structure is realizable.

  Further, the both end portions of the muffler body are respectively closed by end plates, and the inflow pipe penetrates the end plate closing one end so that exhaust can flow into the inside, and the other end is closed. The exhaust pipe penetrates through the end plate so that the internal exhaust can be discharged to the outside, the upstream end of the exhaust pipe is opened in the third chamber, and the bottom surface of the partition member is the bottom of the inflow pipe The first chamber is formed so as to face the opening at the downstream end, and is formed between the bottom surface of the partition wall member and the end plate closing the one end, and the first chamber is formed from the downstream end of the inflow pipe. The exhaust gas is allowed to flow into the first chamber, the exhaust gas is allowed to flow into the second chamber through the communication path including the gap, and the second chamber passes through the communication pipe. Allowed to flow into the exhaust to the third chamber, the from the chamber of the third through the discharge pipe configured to discharge the exhaust to the outside of the muffler body, it is possible to realize an exhaust muffler of the preferred configuration.

  Further, in the exhaust muffler, if the bottom surface of the partition member has a pointed shape, the exhaust muffler can smooth the flow of exhaust and does not unnecessarily increase the back pressure of the exhaust passage.

  Further, in the exhaust muffler, if the bottom surface of the partition member is configured as an uneven surface, the exhaust collides with the uneven portion and a part of the exhaust energy is consumed, resulting in an exhaust muffler with a high noise reduction effect. .

  Further, in the exhaust muffler, when the gap is formed at a plurality of different locations on the outer periphery of the partition wall member, a bypass type exhaust muffler can be realized without using a communication pipe. .

In addition, the partition member includes a first partition member and a second partition member that are disposed in the muffler body so as to be spaced apart from each other in the longitudinal direction, and the first partition member and the muffler body A first chamber is provided between one end on the upstream side, and a second chamber is provided between the second partition member and one end on the downstream side of the muffler body,
Further, a third chamber between the first partition member and the second partition member, a communication pipe that circulates exhaust gas from the first chamber to the second chamber, and the first chamber A first communication path that communicates the third chamber with a gap formed between a peripheral wall of the first partition member and an inner surface of the muffler body; the second chamber; and the third chamber. When the chamber is configured to include a second communication path that allows the chamber to communicate with a gap formed between the peripheral wall of the second partition member and the inner surface of the muffler body, simple configuration and simple assembly An exhaust muffler in the form of a bypass type can be realized by processing.

  According to the exhaust muffler configured as described above, it is possible to provide an exhaust muffler that can obtain a sufficient silencing effect and does not unnecessarily increase the manufacturing cost.

It is sectional drawing cut | disconnected in the center site | part along the longitudinal direction which shows the schematic structure of the exhaust muffler concerning Example 1 of this invention. FIG. 2 is a transverse cross-sectional view taken along the line II-II in FIG. 1 illustrating the internal configuration of the exhaust muffler according to the first embodiment. It is sectional drawing cut | disconnected by the center site | part along the longitudinal direction which shows the schematic structure of the exhaust muffler concerning Example 2. FIG. FIG. 4 is a transverse cross-sectional view taken along the line IV-IV in FIG. 3 illustrating the internal configuration of the exhaust muffler according to the second embodiment. It is sectional drawing cut | disconnected by the center site | part along the longitudinal direction which shows the schematic structure of the exhaust muffler concerning Example 3. FIG. FIG. 6 is a cross-sectional view taken along arrow VI-VI in FIG. 5 illustrating the internal configuration of the exhaust muffler according to the third embodiment. It is sectional drawing cut | disconnected by the center site | part along the longitudinal direction which shows the schematic structure of the exhaust muffler concerning Example 4. FIG. FIG. 8 is a cross-sectional view taken along arrow VIII-VIII in FIG. 7 illustrating the internal configuration of the exhaust muffler according to the fourth embodiment.

   Hereinafter, an exhaust muffler for a leisure vehicle according to an embodiment of the present invention will be specifically described with reference to the drawings.

Example 1
1 and 2, A is an exhaust muffler. The exhaust muffler A includes a muffler main body 1 having a cylindrical shape with both ends closed, and an inflow pipe 2 that allows exhaust to flow into the exhaust muffler A. , A discharge pipe 3 that discharges the internal exhaust to the outside of the exhaust muffler A, and a partition member 4 that is disposed in the muffler main body 1 as a partition partitioning an expansion space in the muffler main body 1 into a plurality of chambers. The exhaust muffler A shown in FIGS. 1 and 2 is a so-called “DC exhaust muffler”.

  In the case of this embodiment, the muffler body 1 is formed by bending a flat plate-like member 1a at seven locations and continuously welding the two free ends as shown in FIG. 1D is formed, and as shown in FIG. 1, one end (upstream end) in the longitudinal direction of the side peripheral wall 1D is closed with an end plate (a part of the outer wall) 1A. The other end (downstream end) is closed with an end plate (a part of the outer wall) 1B to form a cylindrical body. An expansion space 1 </ b> C is formed inside the muffler body 1.

The end plate (a kind of outer wall) 1A is provided with the inflow pipe 2 penetrating from an exhaust port of a combustion chamber of an engine (not shown) (four-cycle engine in this embodiment) through an exhaust pipe. Exhaust gas is configured to flow into the muffler body 1 through the inflow pipe 2. Moreover, in the connection part of the said inflow pipe 2 and the end plate 1A, the outer peripheral surface of this inflow pipe 2 is continuously welded to the edge part of the through-hole of the end plate 1A, and the airtightness in a connection part is ensured. Yes.
Similarly, the exhaust pipe 3 is disposed through the end plate (a kind of outer wall) 1B so as to exhaust the exhaust silenced in the exhaust muffler A to a predetermined level. Moreover, in the connection part of the said discharge pipe 3 and the end plate 1B, the outer peripheral surface of the said discharge pipe 3 is continuously welded to the edge part of the through-hole of the end plate 1B, and the airtightness in a connection part is ensured. Yes.

As shown in FIG. 1, the partition member 4 has a “pail can” -like shape in which the peripheral wall is straight (no constriction) in side view in this embodiment. Further, the length of the partition member 4 is shorter than the length of the muffler main body 1, and in this embodiment 1, the length is about 1/3 of the entire length of the muffler main body 1. The length of the partition member 4 is, for example, approximately 1/10 to approximately 1/2 of the entire length of the muffler body 1.
Further, as shown in FIG. 2, the cross-sectional dimension of the partition wall member 4 is smaller than the cross-sectional dimension of the muffler body 1, that is, a dimension that allows the partition wall member 4 to be accommodated inside the muffler body 1. Thus, in the first embodiment, as shown in FIG. 2, the overall cross-sectional dimension is small enough to be accommodated in a state of being in close contact with the inside except for the lower end portion. In the lower end portion of the muffler body 1, a gap 8 is formed between the inner peripheral surface (the inner peripheral surface of the side peripheral wall 1 </ b> D) and the outer peripheral surface of the partition wall member 4. ing. The cross-sectional area of the gap 8 shown in FIG. 2 is configured to be approximately 1/12 to 1/8 of the cross-sectional area of the muffler main body 1 in the case of the first embodiment. It is appropriately determined in view of the desired noise reduction effect and exhaust efficiency. Therefore, the specific values are merely examples and do not limit the present invention. The length of the communication path formed by the gap 8 is the same as the length of the partition wall member 4.
Further, the position of the gap 8 is formed at the lower end portion of the muffler body 1 in the first embodiment, but may be any position, for example, the upper end portion or the side end portion. .
However, as described above, when configured to be small enough to be accommodated in a state of being in close contact with the inside except for the lower end portion of the muffler body 1, the partition wall member 4 is in close contact with the shape of the muffler. Since it is locked in the main body 1 without floating, a large load to be peeled does not act on a welded portion such as a plug welded portion for fixing the partition wall member 4.

In the case of this embodiment, the partition wall member 4 is formed by pressing (drawing) a single plate material to form the cylindrical peripheral wall 4c as described above and the bottom wall 4d closing one end thereof, Therefore, there is no gap through which the exhaust gas bypasses the concave wall portion formed by the peripheral wall 4c and the bottom wall 4d.
As shown in FIG. 1, the opening on the opposite bottom wall side (left side in FIG. 1) of the partition member 4 is in contact with a blocking member 4B having a shape substantially equal to the shape of the opening. Therefore, it is blocked by plug welding or all-around welding. As a result, the third chamber 12 is formed inside the partition member 4 surrounded by the concave portion and the closing member 4B. Of course, the closing member 4B and the opening of the partition wall member 4 are attached (clamped) by a mechanical joining structure such as “caulking” or “shell joint” like the connecting portion of the lid portion of the can. ) The attachment structure of the closing member 4B to the opening of the partition member 4 can be in various forms other than those described above.
Further, the outer surface 4b of the bottom wall 4d of the partition member 4 may have a pointed shape instead of a flat surface as shown by a two-dot chain line (virtual line) in FIG. 1, or two points in FIG. As described with a chain line (virtual line), the surface of the outer surface 104b of the bottom wall of the partition wall member 104 may be uneven.

  Further, in the first embodiment, the upstream end of the partition member 4 is located at approximately half of the entire length from the upstream side of the muffler body 1, and the downstream end of the partition member 4 and the end plate 1B The partition member 4 is disposed in the muffler main body 1 so that the size of the muffler main body 1 is about 1/6 of the entire length of the muffler main body 1. As a result, a space (first chamber 10) having a length of about ½ of the entire length of the muffler main body is formed on the upstream end side of the partition wall member 4, and on the downstream end side of the partition wall member 4. A space (second chamber 11) having a length of about 1/6 of the entire length of the muffler body 1 is formed. Further, in the first embodiment, the partition member 4 is disposed in a state where the partition member 4 is laid sideways so that the opening side (the anti-bottom wall 4d side or the closing member 4B side) of the partition member 4 faces the downstream end. The peripheral wall 4c of the member 4 and the side peripheral wall 1D of the muffler body 1 are welded (fixed) using plug welding or the like. Instead of such plug welding, it may be fixed by ordinary welding, or may be fixed by bonding with a heat-resistant adhesive.

  As described above, in the muffler body 1 in which the partition member 4 is disposed, two chambers, that is, the first chamber 10 and the second chamber 11 are provided on both sides of the partition member 4 in the front-rear direction. Is formed. Then, exhaust gas flows from the first chamber 10 to the second chamber 11 through the communication path formed by the gap 8.

  In addition, a through hole is formed in the closing member 4B, and the communicating pipe 9 is disposed so as to pass through the through hole, so that the exhaust flows from the second chamber 11 to the third chamber 12. It is configured.

  Further, a through hole different from the through hole is formed at another position of the closing member 4B, and the discharge pipe 3 passes through the through hole, and its upstream end is in the third chamber 12. It is open at. For this reason, the exhaust gas can be discharged from the third chamber 12 to the outside of the main exhaust muffler A through the discharge pipe 3.

  By the way, the opening end 2a on the downstream side of the inflow pipe 2 passes through the substantially central portion of the end plate 1A and is disposed so as to generally face the bottom surface 4b of the partition wall member 4.

The exhaust muffler A configured as described above silences the exhaust as follows. That means
According to the exhaust muffler A having the above configuration, the exhaust gas flowing into the muffler body 1 from the inflow pipe 2 is expanded in the first chamber 10 and silenced to a predetermined level. The fluid flows into the second chamber 11 through the communication path including the gap 8, expands in the second chamber 10 and is further silenced to a predetermined level. Then, the fluid flows from the second chamber 11 through the communication pipe 9 into the third chamber 12 and expands in the third chamber 12 to be further silenced. Further, the exhaust gas is exhausted from the third chamber 12 through the exhaust pipe 3 to the outside air side from the exhaust muffler A in a state where the sound is silenced to a predetermined level.

  In the case of the exhaust muffler A according to the present embodiment, as described above, the partition member 4 divides the space in the muffler main body 1 into two chambers (a first chamber 10 and a second chamber 11). Therefore, even if a slight gap occurs due to plug welding or sheet metal processing at the attachment (welding) location between the peripheral wall 4c of the partition wall member 4 and the side peripheral wall 1D of the muffler body 1, Exhaust gas does not bypass the first chamber 10 to the third chamber 12, and a sufficient silencing effect can be obtained.

  Further, as described above, since the gap 8 is used as a communication path between the first chamber 10 and the second chamber 11, it is necessary for the conventional exhaust muffler to communicate between these two chambers. The existing pipe for communication can be omitted. For this reason, the structure can be simplified. Furthermore, since the number of assembling steps and the assembling process can be reduced, the manufacturing cost can be reduced.

(Example 2)
As an embodiment (embodiment 2) different from the embodiment 1, as shown in FIGS. 3 and 4, the outer peripheral surface of the partition member 104 and the inner peripheral surface of the muffler main body 101 (the inner peripheral surface of the side peripheral wall 101D). ) May be formed at two places including the gaps 108A and 108B. That is, the gaps 108 </ b> A and 108 </ b> B constituting the communication path are formed at a plurality of different locations on the outer peripheral side of the partition wall member 104. For example, in the case of the second embodiment, as shown in FIGS. 3 and 4, the gap 108 </ b> A and the gap 108 </ b> B are formed at the upper end and the lower end of the muffler main body 101. As described above, when the gaps 108A and 108B are formed at a plurality of locations on the upper end and the lower end of the muffler main body 101, the two flows are transferred from the first chamber 110 to the second chamber 111 through the gaps 108A and 108B. Then, the exhaust gas flows in, and the flow of the two exhaust gases merges in the second chamber 111 to be in a vortex state. Such merging reduces the energy of the exhaust and can provide a higher noise reduction effect. Further, in the second embodiment, two communication pipes necessary for the conventional exhaust muffler can be reduced.
The other configuration of the exhaust muffler 100A according to the second embodiment is basically the same as the configuration described in the first embodiment, and the main components corresponding to the components of the first embodiment are described in the embodiment. The reference numerals used for each component of 1 are added with the reference numerals added with “100”, and the overlapping description is omitted.

(Example 3)
As an example (Example 3) different from Examples 1 and 2, as shown in FIGS. 5 and 6, the outer peripheral surface of the partition wall member 204 and the inner peripheral surface of the muffler main body 201 (inside the side peripheral wall 201D). A plurality of gaps 208 may be formed between the peripheral surface and the entire circumference except for the attachment portion, and these may be used as communication paths. For example, the partition member 204 is fixed in the muffler main body 201 at a plurality of positions on the entire periphery via mounting members 216, and the outer peripheral surface of the partition member 204 and the inner peripheral surface of the side peripheral wall 201D of the muffler main body 201 A communication path including a gap 208 formed over the entire circumference may be formed between the two.

With this configuration, the exhaust gas flows from the first chamber 210 to the second chamber 211 through the gap 208 formed in the entire periphery of the partition wall member 204, and in the second chamber 211, Remarkably swirl and merge. Due to such merging, the energy of the exhaust gas is reduced, and a higher noise reduction effect can be obtained.
The other configuration of the exhaust muffler 200A according to the third embodiment is basically the same as the configuration described in the first embodiment, and the main components corresponding to the components of the first embodiment are described in the embodiment. The referential mark which added "200" to the referential mark used for the component of 1 is attached | subjected, and the overlapping description is abbreviate | omitted.

Example 4
As a different embodiment from the first to third embodiments (embodiment 4), as shown in FIGS. 7 and 8, a so-called “bypass type exhaust muffler” according to the present invention is realized with a simple configuration. Can do. That is, as shown in FIG. 7 and FIG. 8, the first partition member 304A and the second partition member 304B are used as the partition members so as to move back and forth in the longitudinal direction in the muffler body 301 and each partition member 304A, It arrange | positions so that the opening part 304e of 304B may oppose.
Further, at the place where the partition member 304A is disposed, a communication path including a first gap 308A is formed between the partition member 304A and the side peripheral wall 301D at the lower end portion of the muffler body 301, and the partition member In a place where 304B is disposed, a communication path including a second gap 308B is formed between the inner peripheral surface (the inner peripheral surface of the side peripheral wall 301D) and the partition wall member 304B at the upper end portion of the muffler main body 301. To do.
In the fourth embodiment, the third chamber 312 is formed between the concave space portion of the first partition member 304A and the concave space portion of the second partition member 304B. Yes.
Then, a communication pipe 309 is disposed so as to penetrate the first partition member 304A and the second partition member 304B, and between the first partition member 304A and the end plate 301A of the muffler body 301. A part of the exhaust gas can be allowed to flow from the first chamber 310 formed in the second chamber 311 formed between the second partition member 304B and the end plate 301B of the muffler body 301. It is configured as follows.
Further, a discharge pipe 303 is disposed so as to penetrate the bottom wall of the second partition wall member 304B and the end plate 301B and to open the upstream end of the third chamber 312. The exhaust gas is discharged from the chamber 312 to the outside of the exhaust muffler 300A.
In the fourth embodiment, the cross-sectional shape of the muffler main body 301 is elliptical as shown in FIG. 8, and the first partition member 304A and the second partition member 304B correspond to this. The cross-sectional shape is such that a part thereof (the lower end or the upper end in the fourth embodiment) is cut off. Thus, the cross-sectional shape of the muffler main body can be in various forms.

  When the exhaust muffler 300A is configured as described above, the two partition members 304A and 304B may be simply fixed to the side peripheral wall 301D of the muffler body 301 by plug welding or the like in order to form an internal partition. That is, it becomes a very rational configuration in that it is not necessary to weld the closing member around the opening of the partition wall member as in the first to third embodiments.

In the exhaust muffler 300A according to the above configuration, the exhaust gas flows from the inflow pipe 302 into the first chamber 310 in the muffler main body 301, and then a part of the exhaust gas passes through the communication pipe 309. In addition, the exhaust gas flows into the second chamber 311 and other part (the remaining) exhaust gas flows into the third chamber 312 through the communication path formed by the first gap 308A.
Further, the exhaust gas flowing into the second chamber 311 flows into the third chamber 312 through the second gap 308B. Then, in the third chamber 312, the exhaust gas that has flowed through the two flow paths joins in a vortex state. By such merging, the energy of the exhaust gas is reduced, and a higher noise reduction effect can be obtained.
Then, the air is discharged from the third chamber 312 to the outside air through the discharge pipe 303.

In the case of the exhaust muffler 300A according to the fourth embodiment, the first partition member 304A and the second partition member 304B are sub-assembled in advance via the communication pipe 309, and further the exhaust pipe If these members including 303 are sub-assembled, before the end plate 301B of the muffler main body 301 and one end plate of the end plate 301A are disposed, the inner periphery of the muffler main body 301 is inserted into the muffler main body 301. If it is fixed to the surface by plug welding or the like, it is excellent in that it can be manufactured easily despite having a relatively complicated flow path.
The other configuration of the exhaust muffler 300A according to the fourth embodiment is basically the same as the configuration described in the first embodiment, and the main components corresponding to the components of the first embodiment are described in the embodiment. The referential mark which added "300" to the referential mark used with the component of 1 is attached | subjected, and the overlapping description is abbreviate | omitted.

  In FIGS. 1, 3, 5, and 7 showing the respective embodiments, a curve with an arrow at the tip indicates the flow of exhaust.

  As described above, the present invention can be applied to a serial exhaust muffler as in the first to third embodiments as well as a bypass exhaust muffler as in the fourth embodiment. Effects can be obtained.

  Moreover, although it does not mention in terms of material about each structure in the said Example, generally a sheet steel plate is used. However, each configuration is not particularly limited to the material, and ceramics, heat resistant resin, or the like can be used as necessary.

  Moreover, in the said Examples 1-3, although both the cross-sectional shape of the partition member and the Marahu main body was made into the polygon, the combination of cross-sectional shape is not restricted to this, For example, let the cross-sectional shape of a muffler main body be a polygon. 2, the cross-sectional shape of the partition member 400 may be circular as indicated by a two-dot chain line, the cross-sectional shape of the muffler body may be circular, and the cross-sectional shape of the partition member may be polygonal.

  Further, the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be implemented in various forms within the scope based on the technical idea of the present invention.

  The exhaust muffler according to the present invention can be used as an exhaust muffler for an internal combustion engine such as a leisure vehicle.

A ... Exhaust muffler
1 ... Muffler body
1C ... Expansion space
2 ... Inflow pipe
3 ... discharge pipe
4 ... Bulkhead member
8 ... Gap
10 ... first chamber
11 ... second chamber

Claims (8)

A cylindrical muffler body in which an expansion space for silencing is formed and both ends are closed,
An inflow pipe that allows exhaust to flow through the outer wall of the muffler body;
At least one partition member that partitions the expansion space in the muffler body into a plurality of chambers;
A communication path that is partitioned by the partition member and communicates between the chambers located on both sides of the partition member;
An exhaust pipe that passes through the outer wall of the muffler body and exhausts the exhaust inside to the outside;
With
The at least one partition member is
A cylindrical peripheral wall and a bottom wall that closes one end of the muffler main body that are accommodated in the muffler main body and have a shorter cross-sectional dimension than the longitudinal dimension of the muffler main body and a cross-sectional dimension smaller than the cross-sectional dimension of the inner space of the muffler main body Comprising a concave form surrounded by the peripheral wall and the bottom wall,
The communication path is
An exhaust muffler for a leisure vehicle, wherein the exhaust muffler is formed by a gap formed between a peripheral wall of the partition member and an inner surface of the muffler body.   The exhaust muffler according to claim 1, wherein the length of the peripheral wall of the partition member is 1/10 to 1/2 of the length of the muffler body. The exhaust muffler further includes
A closing member for closing the opening on the side opposite to the bottom wall of the peripheral wall of the partition member;
A communication pipe penetrating the blocking member;
A third chamber formed in the partition member by closing the opening of the partition member with the closure member;
2. The exhaust muffler according to claim 1, wherein exhaust gas can be circulated between the third chamber and the first chamber or the second chamber through the communication pipe. The both ends of the muffler body are respectively closed by end plates, the end plate closing one end is configured to allow the inflow pipe to pass through the end plate and exhaust to flow inside, and the other end closing the end The exhaust pipe penetrates the plate, and the internal exhaust can be discharged to the outside.
Opening the upstream end of the discharge pipe in the third chamber;
The bottom surface of the partition member is disposed so as to face the opening at the downstream end of the inflow pipe, and the first chamber is formed between the bottom surface of the partition member and the end plate closing the one end,
Exhaust gas flows into the first chamber from the downstream end of the inflow pipe, and exhaust gas flows into the second chamber from the first chamber through the communication path including the gap, and the second chamber The exhaust gas is allowed to flow from the third chamber through the communication pipe to the third chamber, and the exhaust gas is discharged from the third chamber to the outside of the muffler body through the discharge pipe. The exhaust muffler according to claim 3.   The exhaust muffler according to any one of claims 1 to 4, wherein an outer surface of a bottom wall of the partition member has a pointed shape.   The exhaust muffler according to any one of claims 1 to 4, wherein an outer surface of a bottom wall of the partition wall member is configured by an uneven surface.   The exhaust muffler according to any one of claims 1 to 6, wherein the gaps are formed at a plurality of different locations on the outer periphery of the partition wall member. The partition member includes a first partition member and a second partition member, which are disposed in the muffler main body and spaced apart from each other in the longitudinal direction,
A first chamber is provided between the first partition member and one end on the upstream side of the muffler body,
A second chamber is provided between the second partition member and one end on the downstream side of the muffler body,
further,
A third chamber between the first partition member and the second partition member;
A communication pipe for circulating exhaust gas from the first chamber to the second chamber;
A first communication path that connects the first chamber and the third chamber by a gap formed between a peripheral wall of the first partition member and an inner surface of the muffler body;
A second communication path that connects the second chamber and the third chamber by a gap formed between a peripheral wall of the second partition wall member and an inner surface of the muffler body;
An exhaust muffler according to claim 1.

Images