JP2016113927A - Muffling device for saddle-riding type vehicle - Google Patents

Abstract

A silencer for a straddle-type vehicle capable of preventing a reduction in design freedom is provided. A silencer for a saddle-ride type vehicle is a silencer for a saddle-ride type vehicle provided in an exhaust passage that guides exhaust gas from an engine unit, and constitutes a part of the exhaust passage. A bulging portion bulging in a direction perpendicular to the flow direction of the exhaust gas, having an internal space for introducing exhaust gas from the upstream opening and exhausting the exhaust gas from the downstream opening; A cross-sectional area perpendicular to the flow direction of the exhaust gas is small, an inlet portion for guiding the exhaust gas guided from the upstream side to the internal space, and a cross-sectional area perpendicular to the flow direction of the exhaust gas is smaller than the internal space. And an outlet portion for guiding the exhaust gas guided to the internal space to the downstream side, an inlet catalyst unit welded to the inlet portion, and an outlet catalyst unit welded to the outlet portion. [Selection] Figure 2

Description

  The present invention relates to a silencer for use in a saddle riding type vehicle.

  As a muffler for a motorcycle or the like, there is one equipped with a plurality of catalyst units arranged in the flow direction inside (for example, Patent Document 1).

JP-A-5-86843

  By the way, in the muffler provided with a plurality of catalyst units inside, in order to improve the exhaust gas purification rate, it is desired to reduce the leakage of exhaust gas and pass the catalyst units. However, when arranging the catalyst unit in the internal space of the silencer, if the cross section of the internal space of the silencer and the cross section of the catalyst unit are made the same size, the exhaust leakage can be reduced and the catalyst unit can be passed. The degree of freedom in designing the silencer is reduced. In addition, when the cross section of the catalyst unit is smaller than the cross section of the internal space of the silencer, it is necessary to provide a partition that fills the gap between the inner wall of the silencer and the outer periphery of the catalyst unit, and the degree of freedom in design is reduced The 1st location which welds a partition and a catalyst unit, and the 2nd location which welds a partition and the inner wall of a silencer are required, and a welding location will increase.

  Therefore, an object of the present invention is to provide a silencer for a saddle-ride type vehicle that can prevent a reduction in design freedom.

  In order to solve the above-described problem, a silencer for a saddle-ride type vehicle according to an aspect of the present invention is a silencer for a saddle-ride type vehicle provided in an exhaust passage that guides exhaust gas from an engine unit. Swelled in a direction perpendicular to the flow direction of the exhaust gas, which constitutes a part of the exhaust passage and has an internal space for introducing exhaust gas from the upstream opening and exhausting exhaust gas from the downstream opening A bulging portion, a cross-sectional area perpendicular to the flow direction of the exhaust gas smaller than that of the internal space, an inlet portion for guiding the exhaust gas guided from the upstream side to the internal space, and the exhaust gas than the internal space A cross-sectional area perpendicular to the gas flow direction is small, an outlet portion for guiding the exhaust gas guided to the internal space to the downstream side, an inlet catalyst unit welded to the inlet portion, and a weld to the outlet portion An outlet catalyst unit.

  According to the said structure, the exhaust gas which passed through the inlet catalyst unit and was primarily purified is muffled by the bulging part. The silenced exhaust gas passes through the outlet catalyst unit, undergoes secondary purification, and is discharged outside the silencer. By welding the catalyst unit to the inlet and the outlet, respectively, welding of the two catalyst units to the bulging portion can be avoided, and the bulging portion can be formed regardless of the outer shape of the catalyst unit. In addition, a partition wall that closes the gap between the bulging portion and the catalyst unit can be eliminated. As a result, the restriction on the design of the bulging portion caused by the catalyst unit can be reduced. For example, by reducing the design restrictions of the bulging part, it becomes easy to form the bulging part having a high silencing effect.

  In the above configuration, the inlet portion and the outlet portion are each formed with an opening portion that opens into the internal space of the bulge portion, and the upstream end portion of the inlet catalyst unit is welded to the opening portion of the inlet portion. The downstream end portion of the outlet catalyst unit may be welded to the opening portion of the outlet portion. According to this structure, it becomes easy to accommodate each catalyst unit in the internal space of the bulging portion.

  The silencer for the saddle-ride type vehicle projects from the upstream opening or the downstream opening toward the outside of the bulging portion, and forms an outer pipe body that forms the inlet portion or the outlet portion. The outer pipe body, the corresponding opening of the upstream opening and the downstream opening, and the corresponding unit of the inlet catalyst unit and the outlet catalyst unit are welded at a common portion. May be. According to this structure, compared with the case where welding between an outer pipe body and a catalyst unit and welding between an outer pipe body and a bulging part are performed separately, a welding location can be reduced.

  The silencing device for a saddle-ride type vehicle projects from the upstream side opening or the downstream side opening toward the inside of the bulging part, and forms an inlet part or the outlet part. And the inner pipe body and the inner pipe body on the inner side of the bulging part than the position where the corresponding opening part of the upstream opening part and the downstream opening part is welded. A corresponding unit among the inlet catalyst unit and the outlet catalyst unit may be welded. According to this structure, a catalyst unit can be arrange | positioned in a preferable position with the length and shape of an inner pipe body, and the freedom degree of design can be improved.

  In the above configuration, the saddle riding type vehicle may be a motorcycle, and the silencer may be disposed behind the engine unit of the motorcycle and ahead of the rear wheel of the motorcycle. Good. According to this configuration, the bulging portion is easily formed in a three-dimensional shape in order to enhance the noise reduction effect while preventing interference with other mounted devices. In the present invention, the degree of freedom in design can be improved, and it is easy to form in a space as large as possible.

  The said structure WHEREIN: The said inlet catalyst unit and the said outlet catalyst unit may mutually be arrange | positioned by shifting | deviating to an up-down direction. According to this configuration, it is possible to prevent the muffler from becoming large in the front-rear direction.

  In the above configuration, the axis of the inlet catalyst unit may extend in the front-rear direction, and the axis of the outlet catalyst unit may extend in the vehicle width direction. According to this configuration, the silencing effect can be improved by changing the direction.

  The said structure WHEREIN: The cover body which block | closes the hole penetrated from the exterior to the inside may be provided in the said bulging part. According to this configuration, since the hole is provided in advance in the bulging portion, foreign matter such as spatter can be discharged from the hole after welding the inlet side and the outlet catalyst unit with the inlet portion and the outlet portion, respectively. . Moreover, it is possible to prevent the exhaust gas from leaking from the hole by closing the hole with the lid thereafter.

  ADVANTAGE OF THE INVENTION According to this invention, the silencer for saddle riding type vehicles which can prevent the fall of a design freedom can be provided.

It is an expansion right side view of a saddle riding type vehicle provided with a silencer concerning a 1st embodiment. It is a perspective view of the silencer concerning a 1st embodiment. It is a right view of the silencer shown in FIG. FIG. 3 is a top view of the silencer shown in FIG. 2. FIG. 3 is a vertical cross-sectional view along the axis of the inlet portion of the silencer shown in FIG. 2. It is a horizontal sectional view in alignment with the axis line of the exit part of the silencer shown in FIG. FIG. 2 is an enlarged bottom view of the saddle riding type vehicle shown in FIG. 1. It is the schematic diagram which showed the structure of the silencer shown in FIG. It is the schematic diagram which showed the structure of the silencer which concerns on 2nd Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. Each direction described below is based on a direction viewed from the rider of the saddle riding type vehicle. Further, in the following description, “upstream side” and “downstream side” refer to the upstream side and the downstream side in the flow direction of the gas discharged from the engine unit of the saddle riding type vehicle, respectively.

(First embodiment)
FIG. 1 is an enlarged right side view of a saddle riding type vehicle 1 provided with a silencer according to the first embodiment. In this embodiment, the saddle riding type vehicle 1 is only an example, but is a motorcycle. As shown in FIG. 1, in the saddle-ride type vehicle 1, a front end portion of a swing arm 3 extending substantially in the front-rear direction is supported on a body frame 2 by a pivot shaft 4, and a rear end portion of the swing arm 3. The rear wheel 5 is rotatably supported. The vehicle body frame 2 is equipped with an engine unit 6 having an engine 12 that generates travel driving force and a transmission 13 connected thereto, and the rotational power output from the output shaft of the transmission 13 is endless power. It is transmitted to the rear wheel 5 via a transmission loop (not shown). An oil pan 14 for storing lubricating oil is disposed at the lower part of the engine unit 6.

  The engine 12 is, for example, a multi-cylinder engine, and a plurality of exhaust ports 12 a of the engine 12 lead a plurality of exhaust gases from the engine 12 (hereinafter simply referred to as “exhaust gas”) from the front to the bottom of the engine 12. The exhaust pipe 8 is connected. The plurality of exhaust pipes 8 are collected in a collecting pipe 9 below the engine 12, and an exhaust chamber 10 serving as a first silencer is connected to a downstream end portion of the collecting pipe 9. Further, an exhaust muffler 11 as a second silencer is connected to the downstream end of the exhaust chamber 10. In this embodiment, only the exhaust chamber 10 as the first silencer will be described, and description of the exhaust muffler 11 will be omitted. However, the exhaust muffler 11 may also have the same characteristics as the exhaust chamber 10.

  FIG. 8 is a schematic diagram showing a simplified configuration of the exhaust chamber 10. As shown in FIG. 8, the exhaust chamber 10 includes a bulging portion 20 having an internal space S that constitutes a part of an exhaust gas exhaust passage, and an inlet portion that guides exhaust gas guided from the upstream side to the internal space S. 50 and an outlet 60 for guiding the exhaust gas guided to the internal space S to the downstream side. Further, the exhaust chamber 10 has an inlet catalyst unit 80 welded to the inlet portion 50 and an outlet catalyst unit 90 welded to the outlet portion 60.

  The bulging portion 20 has an upstream opening 21 for introducing exhaust gas into the internal space S via the inlet portion 50 and a downstream opening for discharging exhaust gas from the internal space S via the outlet portion 60. Part 22. The inner wall of the bulging portion 20 forming the internal space S bulges in a direction perpendicular to the flow direction of the exhaust gas. That is, the bulging portion 20 is formed so that the cross-sectional area of the internal space S in the exhaust gas flow direction is larger than that of the upstream opening 21 and the downstream opening 22.

  The inlet portion 50 includes a first outer pipe body 51 having a portion protruding from the upstream opening 21 of the bulging portion 20 toward the outside of the bulging portion 20, and forms a part of the exhaust gas exhaust passage. To do. The 1st outer pipe body 51 has the 1st connection part 52 for connecting with the downstream end part of the collecting pipe 9 shown in FIG. An opening 53 that opens into the internal space S of the bulging portion 20 is formed at the downstream end of the first outer pipe body 51.

  The outlet portion 60 includes a second outer pipe body 61 having a portion protruding from the downstream opening 22 of the bulging portion 20 toward the outside of the bulging portion 20, and a downstream opening of the bulging portion 20. And an inner pipe body 64 projecting inward from the bulging portion 20 to form a part of the exhaust gas exhaust passage. The 2nd outer pipe body 61 has the 2nd connection part 63 for connecting with the upstream edge part of the exhaust muffler 11 shown in FIG. 1 in the downstream edge part. An opening 65 that opens into the internal space S of the bulging portion 20 is formed at the upstream end of the inner pipe body 64. The cross-sectional areas of the exhaust passages of the inlet portion 50 and the outlet portion 60 (cross-sectional areas perpendicular to the exhaust gas flow direction) are both smaller than the cross-sectional area of the internal space S of the bulging portion 20 in the exhaust gas flow direction. .

  The inlet catalyst unit 80 is a tandem type catalyst unit, and includes a cylindrical casing 81 that forms a part of the exhaust passage, and two carriers 82 having a honeycomb structure that are accommodated in the casing 81 and carry a catalyst for exhaust purification. , 83. The carrier 82 of the inlet catalyst unit 80 is disposed upstream of the carrier 83 in the exhaust passage formed by the casing 81, and a gap is provided between the upstream carrier 82 and the downstream carrier 83. The carrier 82 of the inlet catalyst unit 80 is disposed slightly downstream of the upstream end 81 a of the casing 81 in order to secure a welded portion of the casing 81.

  Further, the outlet catalyst unit 90 includes a cylindrical casing 91 that forms a part of the exhaust passage, and a single carrier 92 that is housed in the casing and carries a catalyst for purifying exhaust gas. The carrier 92 of the outlet catalyst unit 90 is disposed slightly upstream from the downstream end 91 b of the casing 91 in order to secure a welded portion of the casing 81. The two carriers 82 and 83 of the inlet catalyst unit 80 and the carrier 92 of the outlet catalyst unit 90 are not limited, but all have the same size and type.

  The bulging portion 20, the inlet catalyst unit 80, and the first outer pipe body 51 are welded at a common portion (first welding location 41). More specifically, the upstream opening 21 of the bulging portion 20, the upstream end 81 a of the inlet catalyst unit 80, and the outer peripheral surface near the opening 53 of the first outer pipe body 51 are welded. Since the upstream end 81 a of the inlet catalyst unit 80 is welded to the opening 53 of the first outer pipe body 51, the inlet catalyst unit 80 can be easily accommodated in the internal space S of the bulging portion 20. Further, by accommodating the inlet catalyst unit 80 in the internal space S of the bulging portion 20, the exhaust chamber 10 can be reduced in size.

  Moreover, the bulging part 20, the inner pipe body 64, and the 2nd outer pipe body 61 are welded by the common part (2nd welding location 42). More specifically, the downstream opening 22 of the bulging portion 20, the opening 66 on the downstream side of the inner pipe body 64, and the outer peripheral surface in the vicinity of the opening 62 of the second outer pipe body 61 are welded. Furthermore, the downstream end 91b of the outlet catalyst unit 90 and the opening 65 on the upstream side of the inner pipe body 64 are welded (third weld location 43). For this reason, it becomes easy to accommodate the outlet catalyst unit 90 in the internal space S of the bulging portion 20. Further, by accommodating the outlet catalyst unit 90 in the internal space S of the bulging portion 20, the exhaust chamber 10 can be downsized.

  A partition wall 23 that divides the internal space S into a first expansion chamber S1 and a second expansion chamber S2 is provided inside the bulging portion 20. The partition wall 23 is welded and fixed to the inner wall of the bulging portion 20. Further, the peripheral portion 23 b of the partition wall 23 is in contact with the outer peripheral surface of the outlet catalyst unit 90 and supports the outlet catalyst unit 90. The partition wall 23 is provided with a communication passage 23a that communicates the first expansion chamber S1 and the second expansion chamber S2. However, the internal space S is not limited to the expansion chamber. For example, the internal space S may be a resonance chamber.

  As will be described later, the bulging portion 20 forming the first expansion chamber S1 is provided with a lid 25 that closes the hole 24 penetrating from the outside to the inside.

  Hereinafter, the structure of the exhaust chamber 10 will be described in more detail with reference to FIGS. Each direction shown in FIG. 2 coincides with the direction seen from the passenger of the saddle riding type vehicle 1 when the exhaust chamber 10 is attached to the saddle riding type vehicle 1. As shown in FIG. 2, the exhaust chamber 10 introduces the exhaust gas fed from the front through the inlet 50 into the internal space S of the bulging portion 20, and the internal space S through the outlet 60. The exhaust gas is discharged to the upper right rear.

  The bulging portion 20 has a three-dimensional shape that bulges in the vehicle width direction and the vertical direction in the exhaust system extending from the front to the rear of the saddle riding type vehicle 1. As shown in FIGS. 2 to 4, the bulging portion 20 includes a first bulging body 31 disposed on the right side and a first bulging body disposed on the left side with the exhaust chamber 10 attached to the saddle riding type vehicle 1. 2 bulging bodies 32 and a closing body 33 that closes a portion that opens forward when the first bulging body 31 and the second bulging body 32 are combined, and they are integrated by being welded together. Has been. A downstream opening 22 of the bulging portion 20 is formed in a circular shape at the upper right rear of the first bulging body 31. An upstream opening 21 of the bulging portion 20 is formed in a circular shape on the right side of the closing body 33. The second bulging body 32 is provided with the above-described partition wall 23 so as to divide the internal space S into left and right sides. Inside the bulging portion 20, a first expansion chamber S1 is formed on the right side. A second expansion chamber S2 is formed on the left side.

  The first outer pipe body 51 protrudes from the upstream opening 21 of the bulging portion 20 toward the front of the bulging portion 20, that is, the upstream side of the exhaust gas flow. The first outer pipe body 51 is connected to the downstream end portion of the collecting pipe 9 at a first connection portion 52 provided at the upstream end portion thereof. The first outer pipe body 51 is substantially cylindrical and extends so that the axial direction coincides with the collecting pipe 9 extending in the front-rear direction. Further, the inlet catalyst unit 80 extends in the front-rear direction so that the axial direction coincides with the collecting pipe 9 and the first outer pipe body 51 from the upstream opening 21 of the bulging portion 20 toward the inside of the bulging portion 20. Extend to. The downstream end 81b of the inlet catalyst unit 80 opens to the first expansion chamber S1.

  The casing 81 of the inlet catalyst unit 80 is cylindrical, and at least its upstream end 81 a is substantially the same as the upstream opening 21 of the bulging portion 20 and the downstream opening 53 of the first outer pipe body 51. They are the same size and size. More specifically, as shown in FIG. 5, which is an enlarged cross-sectional view taken along arrow VV shown in FIG. 4, the upstream end 81 a of the inlet catalyst unit 80 is slightly more than the upstream opening 21 of the bulging portion 20. The upstream end 81a of the inlet catalyst unit 80 has a small diameter and can be inserted through the upstream opening 21 of the bulging portion 20 with almost no gap. Further, the upstream end 81a of the inlet catalyst unit 80 has a slightly larger diameter than the downstream opening 53 of the first outer pipe body 51, and the downstream opening 53 of the first outer pipe body 51 is The upstream end portion 81a of the inlet catalyst unit 80 can be inserted with almost no gap.

  And as shown in FIG. 5, the outer peripheral surface of the opening part 53 vicinity of the 1st outer pipe body 51, the upstream edge part 81a of the inlet catalyst unit 80, and the upstream opening part 21 of the bulging part 20 are as follows. In a state where they are arranged in a stepped manner so as to overlap in this order in the radial direction, they are joined to each other by one-round welding (first welding spot 41). Here, "the opening 53 of the first outer pipe body 51, the upstream end 81a of the inlet catalyst unit 80, and the upstream opening 21 of the bulging portion 20 overlap in the radial direction" The upstream opening 21 of the outlet 20, the upstream end 81 a of the inlet catalyst unit 80, and the first outer pipe body 51 are all arranged so as to fall within a bead width (for example, 5 mm). Say. In this way, the inlet catalyst unit 80 is fixed to the inlet portion 50 while being accommodated in the internal space S of the bulging portion 20.

  Thus, since the first outer pipe body 51, the inlet catalyst unit 80, and the bulging portion 20 are welded together at one place, welding between the first outer pipe body 51 and the inlet catalyst unit 80, Compared with the case where welding between the 1st outer pipe body 51 and the bulging part 20 is performed separately, a welding location can be reduced. Further, since the first outer pipe body 51, the inlet catalyst unit 80, and the bulging portion 20 are all-around welded, all the exhaust gas passing through the exhaust passage of the first outer pipe body 51 is exhausted without leakage, The carriers 82 and 83 of the inlet catalyst unit 80 can be passed through and introduced into the internal space S of the bulging portion 20.

  As shown in FIGS. 4 and 5, a gap is provided between the outer peripheral surface of the inlet catalyst unit 80 and the inner wall of the bulging portion 20. For this reason, the temperature rise of the bulging part 20 by the inlet catalyst unit 80 can be reduced.

  The second outer pipe body 61 protrudes from the downstream opening 22 of the bulging portion 20 toward the upper right rear of the bulging portion 20, that is, toward the downstream side of the exhaust gas flow. The second outer pipe body 61 is connected to the upstream end portion of the exhaust muffler 11 by a second connection portion 63 provided at the downstream end portion thereof. The second outer pipe body 61 is substantially cylindrical.

  The inner pipe body 64 protrudes inward of the bulging portion 20 from the downstream opening 22 of the bulging portion 20, and has a cylindrical shape with a circular cross section that is curved toward the second expansion chamber S2. The opening 65 on the upstream side of the inner pipe body 64 is located in the first expansion chamber S1. Further, the outlet catalyst unit 90 extends from the upstream opening 65 of the inner pipe body 64 toward the second expansion chamber S2 so that the axial direction of the opening 65 of the inner pipe body 64 coincides. An upstream end 91a of the outlet catalyst unit 90 opens to the second expansion chamber S2.

  The opening 66 on the downstream side of the inner pipe body 64 is at least approximately the same shape and size as the downstream opening 22 of the bulging portion 20 and the opening 62 on the upstream side of the second outer pipe body 61. More specifically, as shown in FIG. 6, the opening 66 on the downstream side of the inner pipe body 64 is slightly smaller in diameter than the downstream opening 22 of the bulging portion 20, and the opening on the downstream side of the inner pipe body 64. The portion 66 can be inserted through the downstream opening 22 of the bulging portion 20 with almost no gap. Further, the opening 66 on the downstream side of the inner pipe body 64 is slightly larger in diameter than the opening 62 on the upstream side of the second outer pipe body 61, and the opening 62 on the upstream side of the second outer pipe body 61 is The opening 66 on the downstream side of the inner pipe body 64 can be inserted with almost no gap.

  Then, the outer peripheral surface in the vicinity of the opening 62 on the upstream side of the second outer pipe body 61, the opening 66 on the downstream side of the inner pipe body 64, and the downstream opening 22 on the bulging portion 20 in this order. In a state where they are arranged stepwise so as to overlap in the direction, they are joined to each other by one-round welding (second welding point 42). Here, “the opening 62 on the upstream side of the second outer pipe body 61, the opening 66 on the downstream side of the inner pipe body 64, and the downstream opening 22 of the bulging portion 20 overlap in the radial direction”. Means that the downstream opening 22 of the bulging portion 20, the downstream opening 66 of the inner pipe body 64, and the second outer pipe body 61 are all within a bead width (for example, 5 mm). The state of being placed.

  The casing 91 of the outlet catalyst unit 90 is cylindrical, and at least the downstream end 91b thereof is substantially the same shape and size as the upstream opening 65 of the inner pipe body 64. More specifically, the downstream end 91b of the outlet catalyst unit 90 has a slightly smaller diameter than the upstream opening 65 of the inner pipe body 64, and the downstream end 91b of the outlet catalyst unit 90 is the inner pipe body 64. The upstream opening 65 can be inserted with almost no gap.

  Then, in the state where the opening 65 on the upstream side of the inner pipe body 64 and the outer peripheral surface in the vicinity of the downstream end 91b of the outlet catalyst unit 90 are arranged stepwise so as to overlap in the radial direction, the entire circumference welding is performed. (Third welding point 43). Here, "the upstream opening 65 of the inner pipe body 64 and the downstream end 91b of the outlet catalyst unit 90 overlap in the radial direction" means that the upstream opening 65 of the inner pipe body 64 In this state, the outlet catalyst units 90 are all disposed so as to be within a bead width (for example, 5 mm). Thus, the outlet catalyst unit 90 is fixed to the bulging portion 20 while being accommodated in the internal space S of the bulging portion 20.

  Thus, since the bulging portion 20, the inner pipe body 64, and the second outer pipe body 61 are welded together in one place, welding between the second outer pipe body 61 and the inner pipe body 64, Compared with the case where welding between the 2nd outer pipe body 61 and the bulging part 20 is performed separately, a welding location can be reduced. Further, the bulging portion 20, the inner pipe body 64, and the second outer pipe body 61 are all-around welded, and the upstream opening 65 of the inner pipe body 64 and the outlet catalyst unit 90 are all-around welded. Therefore, all the exhaust gas that passes through the exhaust passage of the second outer pipe body 61 and is led to the downstream side can be made the gas that has passed through the carrier 92 of the outlet catalyst unit 90 without exhaust leakage.

  Furthermore, the inner pipe body 64 and the outlet catalyst unit 90 are welded on the inner side of the bulging portion 20 rather than the location where the inner pipe body 64 and the downstream opening 22 of the bulging portion 20 are welded. Therefore, the outlet catalyst unit 90 can be arranged at a preferred position depending on the length and shape of the inner pipe body 64, and the degree of freedom in design can be improved. For example, in this embodiment, the second expansion chamber S2, which is downstream from the first expansion chamber S1, is disposed on the left side, but is curved from the upper right rear to the left front to the second expansion chamber S2. By providing the extending inner pipe body 64, the downstream opening 22 of the bulging portion 20 can be provided at the upper right rear.

  As shown in FIG. 5, the partition wall 23 has a peripheral portion 23 c welded to the inner wall of the second bulging body 32 and fixed to the bulging portion 20. 23b is formed to support the lower part of the outlet catalyst unit 90. Thus, since the partition wall 23 for partitioning the internal space S is also used as a support member for the outlet catalyst unit 90, it is not necessary to provide another support member, and the number of parts can be reduced.

  As shown in FIG. 5, a gap is provided between the outer peripheral surface of the outlet catalyst unit 90 and the inner wall of the bulging portion 20. For this reason, the temperature rise of the bulging part 20 by the outlet catalyst unit 90 can be reduced. In addition, since the partition wall 23 is not provided in the clearance gap between the upper part of the exit catalyst unit 90, and the expansion part 20, exhaust gas is not only from the communication path 23a but from this clearance gap from 1st expansion chamber S1. It flows into the second expansion chamber S2.

  As shown in FIG. 7, the straddle-type vehicle 1 according to this embodiment is a motorcycle, and the exhaust chamber 10 is disposed behind the engine unit 6 and in front of the rear wheel 5. Specifically, the oil pan 14 at the bottom of the engine unit 6 is formed of a right shallow portion 14a and a left deep portion 14b. The collecting tube 9 extends in the front-rear direction below the shallow bottom portion 14a and on the left side of the deep bottom portion 14b, and the collecting tube 9 overlaps the deep bottom portion 14b of the oil pan 14 in a side view (see FIG. 1). The exhaust chamber 10 connected to the downstream end portion of the collecting pipe 9 is disposed so that at least the bulging portion 20 does not overlap the engine unit 6 and the rear wheel 5 in a side view. Thereby, the bulging part 20 can be formed in a three-dimensional shape with a high silencing effect while preventing interference with other devices mounted on the motorcycle.

  Although the space between the engine unit 6 and the rear wheel 5 is limited, in the exhaust chamber 10 according to this embodiment, as shown in FIGS. 2 to 4, the inlet catalyst unit 80 and the outlet catalyst unit 90 are They are arranged so as to be shifted in the vertical direction. More specifically, the inlet catalyst unit 80 is disposed in a lower space in the internal space S of the bulging portion 20, and the outlet catalyst unit 90 is disposed in an upper space in the internal space S of the bulging portion 20. Yes. For this reason, the exhaust chamber can be arranged in the space between the engine unit 6 and the rear wheel 5 by designing the exhaust chamber 10 so that the longitudinal dimension thereof is shortened.

  A first connection portion 52 is provided at the upstream end portion of the inlet portion 50, and a second connection portion 63 is provided at the downstream end portion of the outlet portion 60. Therefore, the exhaust chamber 10 is configured to be detachable with respect to another exhaust device (in this embodiment, the collecting pipe 9 and the exhaust muffler 11) adjacent to the exhaust chamber 10, and the other exhaust device is changed. The exhaust chamber 10 corresponding to the required purification performance can be attached without any problem.

  Further, the inlet catalyst unit 80 and the outlet catalyst unit 90 are arranged so that their axes intersect each other in plan view. More specifically, the axis of the inlet catalyst unit 80 is disposed so as to extend in the front-rear direction, and the axis of the outlet catalyst unit 90 is disposed so as to extend in the vehicle width direction. Thus, the silencing effect can be improved by changing the directions of the inlet catalyst unit 80 and the outlet catalyst unit 90.

  As shown in FIGS. 7 and 8, the bulging portion 20 is provided with a lid 25 that closes the hole 24 penetrating from the outside to the inside. In the exhaust chamber 10 according to this embodiment, an inlet catalyst unit 80 is welded to an inlet portion 50 that is an inlet of the bulging portion 20, and an outlet catalyst unit 90 is welded to an outlet portion 60 that is an outlet of the bulging portion 20. Yes. For this reason, in the manufacturing process, when foreign matter such as spatter is present in the bulging portion 20 after the catalyst units 80 and 90 are welded to the bulging portion 20, such foreign matter is different from the bulging portion unlike the gas. 20 cannot be discharged to the outside. However, in this embodiment, since the holes 24 are provided in the bulging portion 20 in advance, even after the inlet catalyst unit 80 and the outlet catalyst unit 90 are welded to the inlet portion 50 and the outlet portion 60, respectively, sputtering is performed. Such foreign matter can be discharged from the hole 24. Further, by closing the hole 24 with the lid 25 thereafter, it is possible to prevent the exhaust gas from leaking from the hole 24.

  The hole 24 preferably has a diameter of 10 mm or more so that foreign matter such as spatter can be reliably discharged. Moreover, it is preferable that the hole 24 is formed so that it may open to 1st expansion chamber S1 which is the space containing the part to which the 1st bulging body 31 and the 2nd bulging body 32 are welded. The lid body 25 is, for example, a metal plate made of the same material as the bulging portion 20. The lid body 25 is fixed to the bulging portion 20 by welding, for example.

  As described above, the exhaust gas discharged from the engine unit 6 passes through the inlet catalyst unit 80 welded to the inlet 50 after passing through the exhaust passage of the inlet 50 and is primarily purified. The primarily purified exhaust gas is introduced into the first expansion chamber S1 of the bulging portion 20, and the exhaust noise is reduced. When the exhaust gas is introduced from the first expansion chamber S1 to the second expansion chamber S2, the exhaust noise is further reduced. The exhaust gas in the second expansion chamber S2 passes through the outlet catalyst unit 90 and is secondarily purified, and then discharged to the outside of the exhaust chamber 10 through the outlet portion 60 welded to the outlet catalyst unit 90. .

  Since the inlet portion 50 and the inlet catalyst unit 80 are welded and the outlet portion 60 and the outlet catalyst unit 90 are welded, the exhaust gas introduced into the exhaust chamber 10 always passes through the catalyst units 80 and 90. Then, it is discharged to the outside of the exhaust chamber 10. For this reason, in order to improve the exhaust gas purification rate, each catalyst unit 80, 90 has the same size and shape as the cross section of the internal space S of the bulging portion 20 and the cross section of the catalyst unit, or the inner wall of the bulging portion 20 There is no need to provide a partition wall that closes the gap between the catalyst unit and the catalyst unit. Therefore, the design restriction of the bulging portion 20 due to the catalyst unit can be reduced, and for example, the bulging portion 20 having a high silencing effect can be easily formed.

(Second Embodiment)
FIG. 9 is a schematic diagram showing the configuration of the exhaust chamber 110 according to the second embodiment. In addition, about the structure which is common in 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 9, in this embodiment, the internal space S of the bulging portion 120 is partitioned in the front-rear direction by a partition wall 23. The outlet portion 160 is a single outlet pipe body 161 having a portion projecting outward from the downstream opening 122 of the bulging portion 120 and a portion projecting inward. Is formed. The outlet pipe body 161 has its upstream opening 162 and the downstream end 91b of the outlet catalyst unit 90 welded together, and a part of its outer peripheral surface and the downstream opening 122 of the bulging portion 120 Is welded. Also in this embodiment, since the inlet 50 and the inlet catalyst unit 80 are welded, and the outlet 160 and the outlet catalyst unit 90 are welded, the bulging caused by the catalyst unit is the same as in the first embodiment. The design restriction of the portion 120 can be reduced, and the bulging portion 120 having a high silencing effect can be easily formed.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, the shape, size, arrangement, and the like of the exhaust chamber can be changed as appropriate in the above embodiment. Further, the number of partition walls and the partition direction in the internal space of the bulging part are not limited to the above embodiment.

  The inlet catalyst unit is not necessarily a tandem type catalyst unit, and the outlet catalyst unit may be a tandem type catalyst unit. However, it is preferable that the purification performance of the inlet catalyst unit is set higher than that of the outlet catalyst unit.

  Further, the inlet portion and the outlet portion only need to have a smaller cross-sectional area perpendicular to the exhaust gas flow direction than the internal space of the bulging portion, and are not limited to the configuration of the above-described embodiment, and can preferably have a preferable configuration. . The inlet portion and the outlet portion may not be separate members to be welded to the bulging portion. For example, the bulging portion, the inlet portion, and the outlet portion may be formed from one member. In addition, for example, the inlet portion may be composed of an inner pipe body and an outer pipe body, and has one part having a part projecting outward and a part projecting inward. You may be comprised with the pipe body. Further, the outlet portion may be configured only by the outer pipe body. The entrance portion and the exit portion may have the same configuration.

1 For straddle type vehicle 6 Engine unit 10 Exhaust chamber
20 bulging portion 21 upstream opening portion 22 downstream opening portion 24 hole 25 lid body 50 inlet portion 51 first outer pipe body 60 outlet portion 61 second outer pipe body 64 inner pipe body 80 inlet catalyst unit 90 outlet catalyst unit S Interior space

Claims (8)

A silencer for a saddle-ride type vehicle provided in an exhaust passage for guiding exhaust gas from an engine unit,
It forms a part of the exhaust passage and has an internal space for introducing the exhaust gas from the upstream opening and exhausting the exhaust gas from the downstream opening, and swells in a direction perpendicular to the flow direction of the exhaust gas The bulging part,
A cross-sectional area perpendicular to the flow direction of the exhaust gas is smaller than the internal space, and an inlet portion that guides the exhaust gas guided from the upstream side to the internal space;
A cross-sectional area perpendicular to the flow direction of the exhaust gas smaller than the internal space, and an outlet for guiding the exhaust gas guided to the internal space to the downstream side;
An inlet catalyst unit welded to the inlet portion;
A silencer for a saddle-ride type vehicle, comprising: an outlet catalyst unit welded to the outlet portion. The inlet portion and the outlet portion are each formed with an opening portion that opens into the internal space of the bulge portion,
The soot according to claim 1, wherein an upstream end portion of the inlet catalyst unit is welded to an opening portion of the inlet portion, and a downstream end portion of the outlet catalyst unit is welded to an opening portion of the outlet portion. Silencer for riding type vehicles. Projecting outward from the bulging portion from the upstream opening or the downstream opening, and comprising an outer pipe body forming the inlet portion or the outlet portion,
The outer pipe body, a corresponding opening among the upstream opening and the downstream opening, and a corresponding unit among the inlet catalyst unit and the outlet catalyst unit are welded at a common portion. Item 3. A silencer for saddle riding type vehicle according to item 1 or 2. Projecting inward of the bulging portion from the upstream opening or the downstream opening, and comprising an inner pipe body forming the inlet portion or the outlet portion,
The inner pipe body and the inlet catalyst unit are located on the inner side of the bulging portion from the portion where the corresponding opening portion of the inner pipe body and the upstream opening portion and the downstream opening portion is welded. The silencer for saddle riding type vehicles according to any one of claims 1 to 3, wherein a corresponding unit among the outlet catalyst units is welded.   The straddle-type vehicle is a motorcycle, and the silencer is disposed behind the engine unit of the motorcycle and ahead of the rear wheel of the motorcycle. 5. A silencer for a saddle-ride type vehicle according to any one of 4 above.   The silencer for a straddle-type vehicle according to claim 5, wherein the inlet catalyst unit and the outlet catalyst unit are arranged so as to be shifted in the vertical direction.   The silencer for a saddle-ride type vehicle according to claim 5 or 6, wherein an axis of the inlet catalyst unit extends in the front-rear direction and an axis of the outlet catalyst unit extends in the vehicle width direction.   The silencer for a saddle-ride type vehicle according to any one of claims 1 to 7, wherein the bulging portion is provided with a lid that closes a hole penetrating from the outside to the inside.

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