JP6773636B2 - Muffler with catalytic converter - Google Patents

Description

The present invention relates to a muffler with a catalytic converter.

A muffler equipped with a catalytic converter in the muffler box is known.
The muffler of a general-purpose engine to be combined with various work machines forms a pair of support bosses protruding into the first muffler chamber and the second muffler chamber (corresponding to the expansion chamber) on both sides of the partition wall in the muffler box. A configuration is disclosed in which a catalytic converter is passed through a single partition wall and supported by a support boss (see, for example, Patent Document 1).
Further, the muffler of a motorcycle has a configuration in which a catalytic converter is supported on a plurality of separators in the muffler (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2014-173519 Japanese Unexamined Patent Publication No. 2007-023866

When the catalytic converter is passed through a single partition wall as in Patent Document 1 and supported, the support structure of the catalytic converter becomes complicated. The reason why the support structure becomes complicated is that if the catalytic converter is directly attached to the partition wall, the catalytic converter may be damaged when the catalytic converter becomes hot and thermally expands. Therefore, flanges are attached to both sides of the catalytic converter. This is because structural additions such as are required.
Further, it is necessary to weld and attach the entire circumference of the catalytic converter to each of the support bosses protruding from the partition wall, which requires time and effort for the welding work (also referred to as joining work). Further, since the catalytic converter extends in a direction substantially orthogonal to the separator in the muffler, it is necessary to shorten the length of the catalytic converter in the case of a small muffler short in that direction.

Further, in the case of a configuration in which the catalytic converter is supported on a plurality of separators as in Patent Document 2, the number of welding points of the catalytic converter increases, so that the welding work requires time and effort.
Therefore, an object of the present invention is to make it possible to easily attach the catalytic converter and to suppress the increase in size of the muffler box.

In order to achieve the above object, the present invention relates to a muffler with a catalytic converter, which comprises a muffler box, one or more separators for partitioning the inside of the muffler box, and a tubular catalytic converter for purifying exhaust gas. The catalytic converter is attached to a predetermined separator which is one of the separators, and is arranged in one of a plurality of expansion chambers partitioned by the predetermined separator, and one end thereof is the catalyst. The other end, which is formed in a tubular shape into which the outlet side end of the converter is inserted and is opposite to the release side of the tubular shape, is provided with a spherically formed metal cap that covers the outlet of the catalytic converter. The predetermined separator is provided with an opening that exposes a part of the spherical portion of the cap into the other expansion chamber partitioned by the predetermined separator, and the other of the spherical portions. The region exposed to the expansion chamber of the above is formed in a porous structure having a large number of through holes, and the region exposed to the one expansion chamber in the spherical portion is formed into a structure without holes, and the region of the catalytic converter exposed portions of the cap, characterized in Rukoto held in the predetermined separator by a bracket for holding the catalytic converter while allowing movement of said catalytic converter with said cap to the reference.

According to this configuration, the mounting structure of the catalytic converter is simple, and the number of parts required for mounting can be reduced. Moreover, the exhaust gas cleaned by the catalytic converter flows into the other expansion chamber with a simple and compact configuration in which a cap into which the outlet end of the catalytic converter is inserted and an opening provided in the separator are provided. be able to. As a result, the catalytic converter can be easily attached and the size of the muffler box can be suppressed.

In the above configuration, the catalytic converter is characterized by having an exhaust gas passage along the surface of the predetermined separator. According to this configuration, even with a thin muffler, a catalytic converter with a long exhaust gas passage can be arranged.

Further, in the above configuration, the surface of the predetermined separator is provided with a recess recessed toward the opposite side of the one expansion chamber, and at least a part of the catalyst converter is housed in the recess. It is a feature. According to this configuration, it is possible to suppress the overhang of the catalytic converter into one of the expansion chambers and to efficiently utilize the space in the muffler to arrange the large-diameter catalytic converter.

Further, in the above configuration, the cap and the predetermined separator are joined over the entire circumference of the opening. According to this configuration, the gap between the cap and the separator can be closed, and the cap and the separator can be fixed.

Further, since the portion of the catalytic converter exposed from the cap is held by the bracket holding the catalytic converter while allowing the catalytic converter to move with respect to the cap, the catalytic converter is held . The catalytic converter can be held while allowing thermal expansion.

Further, in the above configuration, the predetermined separator expands the exhaust gas that has flowed into the other expansion chamber from the catalytic converter into a region of the surface exposed to the other expansion chamber that avoids the recess. It is characterized in that an expansion chamber partition member for partitioning another expansion chamber is attached. According to this configuration, another expansion chamber can be provided by using a predetermined separator, and the muffler can be easily miniaturized as compared with the case where another expansion chamber is partitioned by using another separator.

According to the present invention, it is possible to easily attach the catalytic converter and to suppress the increase in size of the muffler box.

It is a figure which shows the appearance of the engine generator provided with the muffler which concerns on embodiment of this invention. It is a figure which shows the internal structure of an engine generator. It is a perspective view of a muffler. It is the figure which removed the muffler box from FIG. FIG. 4 is a view seen from the V direction. It is the figure which showed the exhaust pipe, the separator and the catalytic converter together with the peripheral composition. It is the figure which showed the back side of the separator together with the peripheral structure. It is the figure which showed the front side of a separator together with the peripheral structure.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing the appearance of an engine generator 1 including a muffler 51 according to an embodiment of the present invention.
As shown in FIG. 1, the engine generator 1 (hereinafter referred to as a generator) includes a substantially rectangular housing 10, and the housing 10 includes a front cover 10F covering the front surface of the generator 1 and a generator. A pair of left and right side cover 10S that covers 1 from the left and right, a back cover 10B that covers the back surface of the generator 1, and an undercover 10L that constitutes the lower surface of the generator 1 are provided. The back cover 10B covers the muffler 51 in the housing 10 and is detachable from the side cover 10S and the undercover 10L by using a plurality of fastening members. The back cover 10B is formed with a first opening 10P for exposing the exhaust port 51A of the muffler 51 to the outside and a second opening 10Q for communicating the inside and outside of the housing 10.

FIG. 2 is a diagram showing an internal configuration of the generator 1. Note that FIG. 2 shows the outlines of the covers 10F, 10S, 10B and 10L as alternate long and short dash lines.
As shown in FIGS. 1 and 2, the front cover 10F exposes the control panel 11 (FIG. 2) in which the terminals for power supply and the like are arranged to the outside and covers the periphery thereof. One of the left and right side cover 10S exposes the recoil starter 20 and the operation knob 21 which is a rotary fuel cock operator to the outside.

Further, a handle 25 is integrally provided on the upper surface of the housing 10 (corresponding to the upper surface portion of the pair of left and right side cover 10S), and the fuel cap 26 is exposed to the outside on the front surface side of the handle 25. By removing the fuel cap 26, the fuel tank 30 (FIG. 2) in the generator 1 can be refueled. Further, a plurality of legs 27 that support the housing 10 are attached to the undercover 10L.

Further, the generator 1 has a pair of left and right reinforcing frames 28 extending vertically on the left and right sides of the fuel tank 30. These reinforcing frames 28 extend upward from the undercover 10L constituting the lower surface of the housing 10 with a space between the left and right sides, and form a gate-shaped frame as a whole.
The undercover 10L also serves as a support frame for supporting the engine 31 and the like, which is an internal combustion engine. In this configuration, the fuel tank 30 is arranged in front of and above the engine 31, the engine intake system such as the air cleaner 33 and the fuel supply device 34, and the engine operation system such as the recoil starter 20 and the operation knob 21 are arranged on the left side of the engine 31. Is placed.

On the back side of the engine 31, a muffler 51 to which the exhaust gas from the engine 31 is supplied via the exhaust pipe 41 is arranged. The muffler 51 is located above the undercover 11L and on the back side of the engine 31, so that the muffler 51 is arranged in a space SS vacant between the engine 31 and the back cover 10B.
This space SS is short in the front-rear direction of the generator 1 (in FIG. 2, the front direction is indicated by reference numeral F) and long in the vertical direction of the generator 1 (in FIG. 2, the upward direction is indicated by reference numeral U). It is formed in the space. Therefore, the muffler 51 is formed in a thin box shape in which the length L1 (corresponding to the front-rear length) along the front direction F is shorter than the length L2 (corresponding to the vertical length) along the upward direction.

FIG. 3 is a perspective view of the muffler 51.
As shown in FIG. 3, the muffler 51 includes a muffler box 52 having a hollow box shape, a single separator 53 that partitions the inside of the muffler box 52, and exhaust gas supplied from the exhaust pipe 41 into the muffler box 52. It has a catalytic converter 54 for cleaning and a tail pipe 55 for forming an exhaust port 51A of the muffler 5.
The muffler box 52 is formed in a substantially rectangular parallelepiped box shape having a front-rear length L1 and a vertical length L2 (see FIG. 2), and is formed into a front-rear two-divided structure composed of a pair of front-rear box halves 52B and 52F. There is. Hereinafter, when the box halves 52B and 52F are described separately, they are referred to as the first box halves 52B and the second box halves 52F.

The muffler box 52 is formed so that a box body having a thin substantially rectangular parallelepiped shape in which the front-rear length L1 is shorter than the vertical length L2 can be divided back and forth with a surface diagonally crossing the front-rear direction as a boundary. .. Therefore, the first box main body 52B located on the back side of the generator 1 is formed in a shape that opens forward and becomes longer in the front-rear direction toward the left and right sides (right direction indicated by reference numeral R in FIG. 3). Will be done. Further, the second box main body 52F located on the front side of the generator 1 is opened rearward, and the front-rear length becomes longer toward the left and right other sides (the left side opposite to the direction indicated by the reference numeral R in FIG. 3). Is formed into a shape.
Flange portions 52B1 and 52F1 projecting to the outer peripheral side are integrally formed on the open surfaces of the box bodies 52B and 52F, and the box bodies 52B and 52F are formed by joining the flange portions 52B1 and 52F1 to each other by welding or the like. Connected to each other.

FIG. 4 is a view in which the muffler box 52 is removed from FIG. 3, and shows the internal structure of the muffler 51.
As shown in FIGS. 3 and 4, the separator 53 is a metal plate-shaped member arranged along the boundary between the box halves 52B and 52F, and the inside of the muffler box 52 is first generated by the separator 53. It is divided into a first expansion chamber 61A, which is an internal space of the box half body 52B, and a second expansion chamber 61B, which is an internal space of the second box half body 52F. The entire circumference of the separator 53 is joined to the inner wall of the muffler box 52 by welding or the like.

As shown in FIG. 3, since the separator 53 is arranged obliquely with respect to the front-rear direction of the generator 1, the first expansion chamber 61A goes to one side on the left and right (right direction indicated by reference numeral R in FIG. 3). As the front and rear length becomes longer, the second expansion chamber 61B becomes a space having a longer front and rear length toward the left and right other sides (the left side opposite to the direction indicated by the reference numeral R in FIG. 3).
The first expansion chamber 61A is an expansion chamber (also referred to as a chamber or a muffling chamber) to which the exhaust gas from the exhaust pipe 41 (FIG. 2) is first supplied. Further, the box halves 52B and 52F are provided with reinforcing ribs 52RB extending in the left-right and vertical directions (FIG. 3 shows the reinforcing ribs RB on the side of the first box halves 52B).

As shown in FIG. 4, the catalytic converter 54 is attached to the surface 53A exposed to the first expansion chamber 61A of the separator 53. Hereinafter, for convenience of explanation, the surface 53A exposed to the first expansion chamber 61A of the separator 53 is referred to as "first surface 53A", and the back surface 53B of the first surface 53A (the surface exposed to the second expansion chamber 61B) is referred to as "first surface 53A". Second surface 53B "is written.
A recess 53G recessed toward the second expansion chamber 61B side is formed on the first surface 53A, and the catalyst converter 54 is first moved by the bracket 57 in a state where a part of the catalyst converter 54 is housed in the recess 53G. It is supported by the surface 53A.

Here, the catalytic converter 54 is formed in a cylindrical shape, and the exhaust gas entering from the inlet on one end side (lower side in FIG. 4) of the axial LX is the other end of the axial LX (upper side in FIG. 4). It is a device that purifies exhaust gas by oxidation / reduction reaction by coming into contact with the catalyst while flowing toward the outlet on the side. In this configuration, since the catalyst converter 54 is arranged along the first surface 53A, the exhaust gas passage in the catalyst converter 54 is a passage along the axial LX. Therefore, even with a thin muffler 51 having a short front-rear length L1, a catalytic converter 54 having a long exhaust gas passage can be arranged within a relatively long vertical length L2.

For the catalyst converter 54, for example, a honeycomb tubular body in which a metal flat plate and a metal corrugated plate were laminated to form a laminated plate and then the laminated plate was wound into a roll to form a plurality of layers was used. A known structure such as a structure or a structure using a porous honeycomb structure coated with a catalyst can be widely applied.

A cap 58 is put on the outlet of the catalytic converter 54. The cap 58 integrally has a tubular body 58A into which the end portion of the catalyst converter 54 is inserted and a covering portion 58B covering the opposite side of the open end of the tubular body 58A, and is formed of a metal plate or the like. ..
The tubular body 58A is formed in a cylindrical shape having an inner diameter substantially the same as the outer diameter of the catalytic converter 54, and after being inserted along the outer peripheral surface of the catalytic converter 54, the entire circumference of the open end of the tubular body 58A is a catalyst. It is joined to the outer peripheral surface of the converter 54 by welding or the like. As a result, the cap 58 and the catalytic converter 54 are connected, and the gap between the cap 58 and the catalytic converter 54 is closed.

As shown in FIG. 4, the separator 53 is formed with an opening 53K that exposes a part of the covering portion 58B to the second expansion chamber 61B. The entire circumference of the opening 53K and the cap 58 are joined by welding or the like.
The covering portion 58B is formed in a spherical shape and has a porous structure in which a region exposed from the opening 53K of the separator 53 has a large number of through holes 58H (hereinafter referred to as gas discharge holes). The region of the covering portion 58B that is not exposed from the opening 53K is formed in a structure without holes. Therefore, the exhaust gas discharged from the catalytic converter 54 is smoothly guided to the gas discharge hole 58H along the inner surface of the covering portion 58B, and is discharged to the second expansion chamber 61B through the gas discharge hole 58H. ..
The gas discharge hole 58H of the covering portion 58B can be made by a punching process, a method of using a punched plate material (punching metal), or the like.

The exhaust resistance from the catalytic converter 54 to the second expansion chamber 61B can be adjusted by adjusting the number, diameter, shape, and the like of the gas discharge holes 58H. For example, when a sufficient sound deadening effect or the like can be obtained for the muffler 51 as a whole, the gas discharge hole 58H may have a large diameter or one hole, and when one hole is used, the opening of the separator 53 The hole may have the same shape as 53K.

FIG. 5 is a view of FIG. 4 from the V direction.
As shown in FIG. 5, a covering member 59 having a porous structure is attached to the inlet of the catalytic converter 54. The covering member 59 is made of a punched metal plate material, and the exhaust resistance of the catalytic converter 54 can be appropriately increased as compared with the case where the covering member 59 is not used.
The number, diameter, shape, and the like of the holes formed in the covering member 59 can be appropriately adjusted. Further, if the exhaust resistance of the catalyst converter 54 is appropriate, the covering member 59 may be omitted.

As shown in FIG. 4, the bracket 57 is formed in a U-shaped cross section capable of surrounding the catalyst converter 54 from the outside, covers the catalyst converter 54 from the outside, and both ends thereof are welded to the first surface 53A of the separator 53 or the like. Be joined. As a result, the bracket 57 functions as a holding member that holds the catalytic converter 54 in the separator 53 while allowing the catalytic converter 54 to move in the axial direction LX.
The catalytic converter 54 is bonded to the separator 53 via a cap 58. Therefore, as the temperature of the catalytic converter 54 becomes higher, the catalytic converter 54 thermally expands toward the inlet side with respect to the cap 58. Since the bracket 57 does not interfere with this thermal expansion, it is possible to preferably hold the catalytic converter 54, which tends to become hot due to the influence of the heat of the exhaust gas and the heat of reaction generated during oxidation / reduction.

As shown in FIG. 5, since the catalytic converter 54 is housed in the recess 53G of the first expansion chamber 61A which is offset to the side where the front-rear length is short, the catalytic converter 54 projects to the second expansion chamber side 61B. Is placed. Therefore, the large-diameter catalytic converter 54 can be arranged without being restricted by the size of the first expansion chamber 61A.
As shown in FIGS. 4 and 5, the separator 53 has a through hole 53P through which the tail pipe 55 penetrates on the side of the first expansion chamber 61A having a long front-rear length, and a first expansion chamber from the first surface 53A. An overhanging portion 53Q is provided on the 61A side.

FIG. 6 is a diagram showing an exhaust pipe 41, a separator 53, and a catalytic converter 54 together with their peripheral configurations. In FIG. 6, the arrow indicates the flow of exhaust gas.
As shown in FIG. 6, since the catalytic converter 54 is arranged at a position separated from the exhaust pipe 41, a relatively wide expansion space can be secured between the exhaust pipe 41 and the catalytic converter 54. Further, since the outlet of the exhaust pipe 41 faces the side surface of the catalytic converter 54, the temperature of the catalytic converter 54 can be rapidly raised by the exhaust gas when the engine 31 is started, and the temperature is suitable for the oxidation / reduction reaction. Can be raised in a short time.

FIG. 7 is a diagram showing the back side (second surface 53B side) of the separator 53 together with the peripheral configuration. In FIG. 7, the arrow indicates the flow of exhaust gas from the opening 53K.
As shown in FIG. 7, on the second surface 53B of the separator 53, an expansion chamber partitioning member 71 for partitioning another expansion chamber 61C (hereinafter referred to as a third expansion chamber) is provided in a region avoiding the opening 53K. It is attached.
The expansion chamber partition member 71 is formed of a metal plate or the like, and is joined to the second surface 53B by welding or the like with a space of the third expansion chamber 61C between the expansion chamber partition member 71 and the second surface 53B. A plurality of through holes 71H serving as gas inflow holes are formed in the lower portion of the expansion chamber partition member 71, and the exhaust gas in the second expansion chamber 61B enters the expansion chamber partition member 71 through these through holes 71H. Inflow.

FIG. 8 is a diagram showing the front side (first surface 53A side) of the separator 53 together with the peripheral configuration. In FIG. 8, the arrow indicates the flow of the exhaust gas in the expansion chamber partition member 71.
As shown in FIG. 8, the exhaust gas that has flowed into the expansion chamber partition member 71 flows upward in the expansion chamber partition member 71, flows into the tail pipe 55, and is discharged to the outside through the tail pipe 55. Will be done.
Here, in the region of the separator 53 facing the expansion chamber partition member 71, an overhanging portion 53Q overhanging from the first surface 53A is provided. With this overhanging portion 53Q, the expansion space in the vicinity of the through hole 71H can be increased, and it becomes easy to efficiently obtain a sound deadening effect (corresponding to a pressure reducing effect).
In this way, the exhaust gas from the exhaust pipe 41 is in the order of the first expansion chamber 61A, the catalytic converter 54, the second expansion chamber 61B, the inside of the expansion chamber partition member 71 (third expansion chamber 61C), and the tail pipe 55. It passes through and a sufficient muffling effect is obtained.

As described above, according to the present embodiment, the catalytic converter 54 is attached to one separator 53 (corresponding to a predetermined separator) in the muffler box 52, and is partitioned by the separator 53. Since it is arranged in the first expansion chamber 61A, which is an expansion chamber, it is not necessary to weld the entire circumference of the catalyst converter 54 to the separator 53, the mounting structure of the catalyst converter 54 is simple, and the catalyst converter 54 can be mounted. Fewer parts are required.
Therefore, the catalyst converter 54 can be easily attached as compared with the structure in which the catalyst converter 54 is supported by penetrating one separator or the structure in which the catalyst converter 54 is supported by a plurality of separators.

Moreover, a cap 58 that covers the outlet of the catalytic converter 54 and an opening provided in the separator 53 that exposes at least a part of the cap 58 into the second expansion chamber 61B, which is the other expansion chamber partitioned by the separator 53. The cap 58 has a gas discharge hole 58H in a region exposed from the opening 53K. As a result, the exhaust gas cleaned by the catalytic converter 54 can flow into the second expansion chamber 61B with a simple and compact configuration in which the cap 58 and the opening 53K are provided.
As a result, the catalyst converter 54 can be easily attached, and the muffler box 52 can be suppressed from becoming large in size.

Further, since the catalyst converter 54 has an exhaust gas passage along the first surface 53A of the separator 53, the catalyst converter 54 having a long exhaust gas passage can be arranged even with a thin muffler 51 having a short front-rear length L1.
Further, the first surface 53A of the separator 53 is provided with a recess 53G recessed toward the opposite side of the first expansion chamber 61A, and at least a part of the catalytic converter 54 is accommodated in the recess 53G, so that the first expansion The large-diameter catalyst converter 54 can be arranged by suppressing the protrusion of the catalyst converter 54 into the chamber 61A and efficiently utilizing the space in the muffler 51. As a result, the degree of freedom in the shape of the catalytic converter 54 is high, and the exhaust gas can be sufficiently purified.

Further, since the cap 58 and the separator 53 are joined over the entire circumference of the opening 53K, the gap between the cap 58 and the separator 53 can be closed, and the cap 58 and the separator 53 can be connected. it can.
Moreover, the cap 58 has a spherical covering portion 58B that covers the outlet of the catalyst converter 54, and the covering portion 58B is provided with a gas discharge hole 58H, so that the exhaust gas discharged from the catalyst converter 54 can be smoothly discharged. It can be guided to the gas discharge hole 58H.

Further, since the bracket 57 functions as a holding member for holding the catalytic converter 54 in the separator 53 so as to be movable in the axial LX of the catalytic converter 54, the catalytic converter 54 is allowed to thermally expand in the axial LX. The catalytic converter 54 can be held. Further, with respect to the bracket 57, since it is only necessary to weld both ends of the bracket 57 to the separator 53, the welding operation is simple.
Further, since the separator 53 has an expansion chamber partitioning member 71 for partitioning the third expansion chamber 61C in a region of the second surface 53B exposed to the second expansion chamber 61B, which avoids the recess 53G, the separator 53 is an existing one. Another expansion chamber can be provided by using the sheet separator 53. Therefore, it is advantageous for the muffler 51 to be downsized as compared with the case where the expansion chamber is provided by using another separator.

The above embodiment is merely an embodiment of the present invention, and can be arbitrarily modified and applied without departing from the spirit of the present invention.
For example, in the above embodiment, the case where the present invention is applied to the muffler 51 having one separator 53 has been described, but the present invention may be applied to the muffler having a plurality of separators. When a plurality of separators are provided, the catalytic converter 54 may be attached to one of the separators (corresponding to a predetermined separator). Further, the case where the present invention is applied to the muffler 51 of the generator 1 has been described, but the present invention is not limited to this, and the present invention may be applied to a muffler other than the generator 1.

1 Engine generator 31 Engine 41 Exhaust pipe 51 Muffler 52 Muffler box 53 Separator 53A Separator first surface 53B Separator second surface 53K Opening 53G Recess 54 Catalytic converter 55 Tail pipe 57 Bracket (holding member)
58 Cap 58B Cover 58H Gas discharge hole 61A First expansion chamber 61B Second expansion chamber 61C Third expansion chamber 71 Expansion chamber partition member

Claims (5)

In a muffler with a catalytic converter, which includes a muffler box, one or more separators that partition the inside of the muffler box, and a tubular catalytic converter that purifies exhaust gas.
The catalytic converter is attached to a predetermined separator which is one of the separators, and is arranged in one of a plurality of expansion chambers partitioned by the predetermined separator.
One end is formed in a tubular shape into which the outlet side end of the catalytic converter is inserted, and the other end, which is the opposite side of the release side of the tubular shape, is formed in a spherical shape covering the outlet of the catalytic converter. With a cap made of
The predetermined separator is provided with an opening that exposes a part of the spherical portion of the cap into the other expansion chamber partitioned by the predetermined separator .
The region exposed to the other expansion chamber in the spherical portion is formed in a porous structure having a large number of through holes, and the region exposed to the one expansion chamber in the spherical portion has a structure without holes. Formed,
A catalytic converter in which a portion of the catalytic converter exposed from the cap is held in the predetermined separator by a bracket that holds the catalytic converter while allowing the catalytic converter to move with respect to the cap. With muffler. The muffler with a catalytic converter according to claim 1, wherein the catalytic converter has an exhaust gas passage along the surface of the predetermined separator. Claim 1 is characterized in that the surface of the predetermined separator is provided with a recess recessed toward the opposite side of the one expansion chamber, and at least a part of the catalytic converter is housed in the recess. Or the muffler with a catalytic converter according to 2. The muffler with a catalytic converter according to any one of claims 1 to 3, wherein the cap and the predetermined separator are joined over the entire circumference of the opening. In the predetermined separator, another expansion chamber for expanding the exhaust gas flowing into the other expansion chamber from the catalytic converter is partitioned in a region of the surface exposed to the other expansion chamber so as to avoid the recess. The muffler with a catalytic converter according to any one of claims 1 to 4, wherein an expansion chamber partition member is attached.

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