JP2020056345A - Muffler - Google Patents

Abstract

To provide a muffler capable of increasing its size while suppressing distortion.SOLUTION: A muffler 10 includes a muffler body 20 in which a plurality of discharge ports 31A, 31B are formed at a space from each other, and a muffler end cover 40 connected to the end of the muffler body 20, the muffler end cover 40 including an outer periphery wall part 42 located adjacent to the end of the muffler body 20 and going around the outer peripheral edge at the end of the muffler body 20, and a partition wall part 60 extending through between the plurality of discharge ports 31A, 31B and connected at both ends to the outer periphery wall part 42 for partitioning a space in the outer periphery wall part 42 into a plurality of spaces where the discharge ports 31A, 31B are arranged.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a muffler for a straddle-type vehicle.

  Patent Literature 1 discloses a muffler in which discharge ports are lined up and down. In Patent Document 1, the rear end of the muffler covers a radially outer region of the discharge port.

JP 2008-14173 A

  Here, since the rear end of the muffler is exposed to the exhaust gas, the temperature change is large. Therefore, when the rear end of the muffler is enlarged, the thermal distortion of the rear end of the muffler increases, and a large stress is generated at the rear end of the muffler.

  Therefore, an object of the present invention is to provide a muffler that can be enlarged while suppressing distortion.

  In order to solve the above problem, the muffler includes a muffler main body in which a plurality of discharge ports are formed at intervals, and a muffler end cover connected to an end of the muffler main body. Adjacent to the end of the muffler main body, an outer peripheral wall portion surrounding the outer peripheral edge of the end of the muffler main body, and extends between the plurality of outlets, and both ends are connected to the outer peripheral wall portion. A partition wall for partitioning a space in the outer peripheral wall into a plurality of spaces in which the outlets are arranged.

  According to this muffler, since the outer peripheral wall portion goes around the outer peripheral edge of the end portion of the muffler main body, the rear end portion can be enlarged when viewed as the whole muffler. In addition, since both ends of the partition wall are connected to the outer peripheral wall, thermal expansion of the muffler end cover can be suppressed even if the muffler end cover becomes large, reducing the stress applied to the muffler end cover mounting part. can do. Furthermore, since the partition wall part passes between the plural outlets, avoiding the plural outlets, it is possible to suppress the partition wall part from becoming a resistance to exhaust gas discharge, and the performance of the muffler is deteriorated. Can be suppressed.

FIG. 1 is a schematic perspective view showing a motorcycle. It is a side view which shows a muffler. It is a rear view showing a muffler. It is a perspective view which shows a muffler. FIG. 5 is a sectional view taken along line VV of FIG. 3.

  The muffler according to the embodiment will be described. Here, an example in which the muffler is applied to a motorcycle will be described. The muffler is applicable to straddle-type vehicles such as motorcycles, buggy vehicles, motorcycles, and ATVs (All Terrain Vehicles). Note that the saddle-ride type vehicle means a vehicle that the driver drives while straddling the seat.

  FIG. 1 is a schematic perspective view showing a motorcycle 100.

  The motorcycle 100 includes a frame 110, a front wheel 120, a rear wheel 130, a handle 140, an engine 150, and a muffler 10. In the following description, when referring to up / down, front / rear, and left / right, each direction is defined as follows. First, the side where the two wheels 120 and 130 of the motorcycle 100 touch the ground is the lower side, and the opposite side is the upper side. The traveling direction when the motorcycle 100 travels is the front, and the opposite side is the rear. Further, the driving posture of the driver straddling the driver seat is defined as left and right with respect to the driver.

  A steering shaft is rotatably inserted into a head pipe formed in the frame 110. A front fork is supported on the steering shaft via a bracket. A front wheel 120 is rotatably supported at the lower end of the front fork 114.

  The handle 140 is fixed to the steering shaft. When the driver performs an angular displacement operation of the steering wheel 140 around the steering shaft, the front wheel 120 rotates together with the front fork 114, and the motorcycle 100 is steered.

  The frame 110 includes a main frame portion for supporting the front and rear wheels. The main frame portion is inclined downward from the head pipe toward the rear. The main frame portion supports the fuel tank 151, the engine 150, and the swing arm 118. The fuel tank 151 is arranged behind the head pipe. The engine 150 is disposed below the fuel tank 151.

  The swing arm 118 extends in the front-rear direction and is supported by the main frame. Specifically, a front portion of the swing arm 118 is supported so as to be angularly displaceable about a pivot axis set on the main frame portion. A rear portion of the swing arm 118 rotatably supports the rear wheel 130. The driving force of the engine 150 is transmitted to the rear wheel 130 via a transmission and a driving force transmission mechanism such as a chain or a belt, so that the rear wheel 130 is rotationally driven. Specifically, the power shifted by the transmission is transmitted to the rear wheels by a chain adjacent to the swing arm. In the present embodiment, the chain is arranged on one side in the vehicle width direction of the vehicle body, specifically, on the left side on which the side stand is arranged.

  A seat frame 110b for supporting the seat 163 is connected to the main frame portion. The seat frame 110b extends rearward and upward from above a rear portion of the main frame portion. The driver seat 163 on which the driver sits is fixed to the seat frame 110b. A support frame 111 for supporting the muffler 10 is connected to the seat frame 110b. The support frame 111 is connected to the seat frame 110b and extends rearward from a connection position with the seat frame 110b.

  The muffler 10 serves to reduce exhaust noise generated when exhaust gas is discharged from the engine 150 into the atmosphere. The muffler 10 is arranged to face the rear wheel 130 with a space in the vehicle width direction. The muffler 10 is provided on one side of the motorcycle 100, here, on a side (right side) opposite to a side on which a power transmission portion adjacent to a swing arm such as a chain is provided. In the present embodiment, the rear end of the muffler 10 is located forward of the rear end of the rear wheel 130, below the upper end of the rear wheel 130, and above the axle of the rear wheel 130. .

  The muffler 10 has a plurality of internal spaces for reducing energy contained in the exhaust gas. The exhaust gas passes through the internal space in the muffler 10 in order, and thus expands in a stepwise manner, and its pressure energy is reduced. Further, the exhaust gas, which has passed through different passages in the internal space inside the muffler 10, collides or interferes with each other, so that its pressure energy is reduced. This reduces exhaust noise. The exhaust gas discharged from the engine 150 is guided to the muffler 10 via the exhaust pipe 152 and the exhaust chamber 154. Before exhaust gas is discharged into the atmosphere, the catalytic device 153 purifies harmful substances such as nitrogen oxides contained in the exhaust gas. In the present embodiment, the catalyst device 153 is interposed in the exhaust pipe 152. The exhaust chamber 154 is disposed upstream of the muffler 10 and reduces the energy of exhaust similarly to the muffler 10. In the present embodiment, the exhaust chamber 154 is disposed between the engine 150 and the rear wheel 130 in the front-rear direction.

  In the present embodiment, the muffler 10 is formed in a long shape having a long axis extending in the front-rear direction. Specifically, the muffler 10 is attached to the vehicle body with its major axis inclined such that it advances upward from the front end to the rear end. Hereinafter, the muffler 10 will be described based on the mounting state in which the long axis is inclined. In the present embodiment, the muffler 10 is supported by the support frame 111 by a supported portion formed at an intermediate position in the front-rear direction in the upper part.

  The muffler 10 has a front opening formed therein for introducing exhaust gas discharged from the engine 150 into the internal space. The muffler 10 has an outlet at the rear for releasing exhaust gas to the atmosphere. The exhaust gas is diffused and discharged radially from the discharge port in the discharge direction. That is, the exhaust gas expands in the radial direction as it goes backward from the outlet. The direction in which the exhaust pipes 30A and 30B extend is the exhaust gas discharge direction P (see FIG. 5).

  In the present embodiment, the muffler 10 is formed in an enlarged shape in which the inner diameter gradually increases from the front end to the rear as it advances from the inlet to the outlet along the long axis. In the present embodiment, the muffler 10 is formed in a shape in which a cross-sectional shape perpendicular to the front-rear direction of the vehicle increases in diameter as it goes rearward. Specifically, in a side view, the upper edge of the muffler 10 is formed in a shape in which the upper edge is separated upward from the lower edge of the muffler as the vehicle advances backward.

  2 is a side view showing the muffler 10, FIG. 3 is a rear view showing the muffler 10, FIG. 4 is a perspective view showing the muffler 10, and FIG. 5 is a sectional view taken along line VV of FIG. . FIG. 3 is a rear view when viewed along the exhaust gas discharge direction P, and FIG. 4 is a perspective view when the muffler 10 is viewed obliquely from the outside in the vehicle width direction.

  The muffler 10 is formed as an outer shape in a cross section perpendicular to the front-rear direction of the vehicle, and has a vertically long dimension whose vertical dimension is larger than the vehicle width direction dimension. For example, as the external shape in the vertical cross section, a lantern shape in which the middle in the vertical direction bulges outward in the width direction from both ends in the vertical direction, a substantially elliptical shape, an oval shape, or a rectangular shape that is long vertically. Specifically, the outer shape in the vertical cross section is chamfered so that a corner portion has a gentle arc shape. More specifically, the cross section is formed in a shape surrounded by an inner surface in the vehicle width direction, an outer surface in the vehicle width direction, an upper surface, and a lower surface. The upper surface and the lower surface connect the upper and lower surfaces of the inner surface in the vehicle width direction and the outer surface in the vehicle width direction, respectively. As a cross-sectional shape, the lower surface extends substantially horizontally. The upper surface is inclined downward as it advances from the inside in the vehicle width direction to the outside in the vehicle width direction. The vehicle width direction inner side surface and the vehicle width direction outer side surface are formed in a curved shape in which a vertical middle portion bulges outward in the width direction from both ends in the vertical direction. In addition, the position which swells most in the width direction among the inner surface in the vehicle width direction and the outer surface in the vehicle width direction is located above the central position in the upward direction.

  In the present embodiment, the vehicle width direction outer side surface of the muffler 10 is formed in an inclined shape that expands outward in the vehicle width direction as it goes upward from the lower end. As a result, it is possible to prevent the muffler from contacting the road surface when the vehicle is tilted, while suppressing a decrease in the volume of the muffler. In addition, a portion of the muffler 10 that protrudes most outward in the vehicle width direction is directed upward toward the rear. In other words, as the protruding portion that is the outermost in the vehicle width direction, a ridge shape that goes upward as it goes backward is formed.

  The muffler 10 includes a muffler main body 20 and a muffler end cover 40. The muffler body 20 is a part that realizes a function of silencing exhaust gas, and has a plurality of internal spaces for silencing as described above. In other words, even when the muffler end cover 40 is detached from the muffler main body 20, the muffling effect can be realized. The muffler body 20 has an inlet 31C and outlets 31A and 31B. The inlet 31C is formed to guide exhaust gas to the internal space. In the present embodiment, an introduction pipe 156 extending from the exhaust chamber 154 is inserted and connected to the introduction port 31C. The outlets 31A and 31B are formed for discharging exhaust gas from the internal space. The muffler body 20 has a closed space except for the inlet 31C and the outlets 31A and 31B. The energy of the exhaust gas is reduced by repeating the expansion until the exhaust gas moves from the inlet 31C to the outlets 31A and 31B.

  In the muffler main body 20, a plurality of discharge ports 31A and 31B are arranged at intervals. Specifically, the muffler main body 20 has two outlets 31A and 31B arranged at an interval in the vertical direction. Further, the muffler main body 20 includes an expansion chamber forming part 22 that forms an expansion chamber, an outer wall forming part 21 that forms an outer wall, and exhaust pipes 30A and 30B that form respective outlets 31A and 31B. The expansion chamber forming part 22 includes an inner cylindrical part 24 formed in a cylindrical shape, and an inner lid part 26 covering both axial ends of the inner cylindrical part 24. Thereby, the internal space in the muffler main body 20 is formed as an expansion chamber. In practice, the internal space is formed with at least one partition and a communication path communicating with the partition, so that the flow path of the exhaust gas is lengthened or the direction of the flow path is changed.

  In the present embodiment, the exhaust gas from the introduction pipe 156 is introduced into the rear expansion chamber 24A, and goes rearward from the outlet of the introduction pipe 156. Thereafter, the exhaust gas changes direction, passes through a hole 28h formed in the internal partition 28 that separates the rear expansion chamber and the front expansion chamber, and heads toward the front expansion chamber 24B. Thereafter, the air is discharged from the front expansion chamber 24B to the atmosphere via the exhaust pipes 30A and 30B.

  The outer wall forming portion 21 is formed by an outer cylindrical portion 23 formed in a tubular shape, and an outer lid portion 25 covering both axial ends of the outer cylindrical portion 23. The outer cylinder 23 covers the inner cylinder 24 in the circumferential direction and covers the inner cylinder 24 from the outside in the radial direction. The outer lid 25 covers the inner lid 26 from the outside in the axial direction. Thus, the muffler main body 20 of the present embodiment is formed in a double structure. A sound deadening material such as steel wool may be interposed in a radial space formed between the outer tube portion 23 and the inner tube portion 24.

  The exhaust pipes 30A, 30B protrude in the exhaust gas discharge direction P with respect to the expansion chambers 24A, 24B formed in the inner cylindrical portion 24. In the present embodiment, the rear ends of the exhaust pipes 30 </ b> A and 30 </ b> B protrude rearward from the rear surface of the inner cylinder 24 and are located rearward of the rear surface of the inner cylinder 24. As a result, the discharge ports 31A and 31B of the muffler main body 20 are set at positions further away from the rear surface of the inner cylindrical portion 24 than the rear surface. Each exhaust pipe 30A, 30B extends in parallel with each other. Each of the exhaust pipes 30A and 30B extends substantially in the direction along the long axis of the muffler main body 20.

  In the present embodiment, the rear end surface of the inner cylindrical portion 24 is formed in a vertically long shape whose vertical dimension is larger than the vehicle width direction dimension. This makes it easier to arrange the exhaust pipes 30A and 30B side by side in the vertical direction with an interval. The upper portion of the inner cylinder portion 24 is formed to have a larger dimension in the vehicle width direction than the lower portion. The upper exhaust pipe 30 </ b> A located above is disposed such that the central axis thereof is shifted outward in the vehicle width direction as compared with the lower exhaust pipe 30 </ b> B located below. Thereby, the unevenness of the exhaust gas guided to each exhaust pipe 30A, 30B can be reduced. In the present embodiment, the lower exhaust pipe 30B has a larger opening area than the upper exhaust pipe 30A.

  Each exhaust pipe 30A, 30B is a tubular member. As shown in FIG. 5, the outer end opening of each of the exhaust pipes 30A and 30B has a shape cut obliquely with respect to the central axis. Specifically, the opening edges of the exhaust pipes 30A and 30B extend rearward from the lower ends upward. The opening edges of the exhaust pipes 30A, 30B extend forward from the inner end in the vehicle width direction to the outer side in the vehicle width direction. The lower exhaust pipe 30B has a larger opening than the upper exhaust pipe 30A. End openings on the outer side in the vehicle width direction of each exhaust pipe 30 extend on the same plane.

  As shown in FIG. 2, the muffler end cover 40 is a member connected to the rear end of the muffler main body 20. By attaching the muffler end cover 40, the exhaust pipes 30A and 30B protruding from the expansion chambers 24A and 24B can be protected. For example, the provision of the muffler end cover 40 can prevent the external obstacles from coming into contact with the exhaust pipes 30A and 30B.

  Further, by providing the muffler end cover 40, dirt around the exhaust pipes 30A and 30b can be made less noticeable. For example, the surroundings of the exhaust pipes 30A and 30B are likely to be contaminated as the exhaust gas is discharged. For example, the surroundings of the exhaust pipes 30A and 30B may be contaminated by soot and the like contained in the exhaust gas from the exhaust pipes 30A and 30B. In addition, dirt may be caused by carbonization of oil components such as engine oil attached to the exhaust pipes 30A and 30B due to exhaust heat. Since the surroundings of the exhaust pipes 30A and 30B are hidden by the muffler end cover 40, dirt around the exhaust pipes 30A and 30B can be made less noticeable. The muffler end cover 40 is colored black so that the exhaust pipes 30A and 30B and the cylindrical portion can be made less noticeable, and the appearance can be easily prevented from deteriorating.

  The muffler end cover 40 may be a molded product, for example, a metal member such as an aluminum die cast. If the muffler end cover 40 is made of an aluminum alloy, a configuration excellent in heat dissipation can be obtained. The muffler end cover 40 is not limited to a metal and may be formed of a heat-resistant resin or the like. In the present embodiment, the muffler end cover 40 is formed in a thin shape, so that the inside is formed in a hollow shape.

  The muffler end cover 40 includes an outer peripheral wall portion 42 and a partition wall portion 60.

  The outer peripheral wall portion 42 is a portion surrounding the periphery of the rear end side of the muffler main body 20. The outer peripheral wall portion 42 is formed in a ring shape adjacent to the rear end of the muffler main body 20 from the rear thereof and surrounding the outer peripheral edge of the end of the muffler main body 20. The partition wall portion is formed in a shape that vertically partitions an opening space formed by the outer peripheral wall portion, and both ends of the partition wall portion are respectively connected to the outer peripheral wall portion. The opening of the outer peripheral wall, that is, the opening of the muffler end cover 40 on the downstream side in the discharge direction P extends rearward from the lower edge upward as shown in FIG. The opening of the outer peripheral wall portion 42 extends forward from the inner edge in the vehicle width direction to the outer side in the vehicle width direction. Thus, the edge of the opening of the muffler end cover 40 on the downstream side in the discharge direction P faces outward in the vehicle width direction. Therefore, the rear opening of the muffler 10 can be made larger than an opening having a central axis parallel to the long axis of the muffler main body. In this manner, the opening shape of the muffler end cover 40 can be enlarged, and heat can be easily dissipated. In addition, since the rear opening of the outer peripheral wall portion 42 is formed to be large, the exhaust gas discharged from the exhaust pipes 30A and 30B can be easily discharged to the outside of the muffler, and a decrease in output can be suppressed.

  The outer peripheral wall 42 covers each of the exhaust pipes 30A and 30B from the outside in the radial direction. Here, covering the respective exhaust pipes 30A and 30B from the respective radially outer sides means that the outer peripheral wall portion 42 has a radially outer side regardless of whether the upper exhaust pipe 30A or the lower exhaust pipe 30B is focused. It means to cover from. That is, when viewed along the discharge direction P, the outer peripheral wall portion 42 covers around the exhaust pipes 30A and 30B. The outer peripheral wall portion 42 extends to a downstream side in the discharge direction P from the exhaust pipes 30A and 30B. Therefore, when viewed from the outside in the vehicle width direction, each of the exhaust pipes 30A and 30B is hidden by the outer peripheral wall portion 42.

  The outer peripheral wall portion 42 has an outer peripheral surface that is radially outward and an inner peripheral surface that is radially inner. The outer peripheral surface of the outer peripheral wall portion 42 is formed in a reduced diameter shape in which the radius of the peripheral surface becomes smaller as it proceeds downstream in the discharge direction. Further, the inner peripheral surface of the outer peripheral wall portion 42 is formed in an enlarged shape in which the radius of the peripheral surface increases toward the downstream side in the discharge direction. Thus, the vertical dimension between the outer peripheral surface and the inner peripheral surface of the outer peripheral wall portion 42 is formed so as to gradually decrease toward the downstream side in the discharge direction P.

  The outer peripheral surface of the outer peripheral wall portion 42 has a shape similar to the outer peripheral edge of the rear opening of the muffler main body 20 and a shape smaller than the outer peripheral edge from the same shape as the outer peripheral edge of the rear opening of the muffler main body 20. Thus, the direction gradually changes toward the downstream side in the discharge direction P. Here, the lower portion of the outer peripheral surface of the outer peripheral wall portion 42 is formed to have a larger angle for reducing the diameter than the upper portion of the outer peripheral surface of the outer peripheral wall portion 42. Thus, the muffler end cover 40 is retracted upward from the axle of the rear wheel 130 disposed below the muffler end cover 40. This prevents the muffler end cover 40 from interfering with the tool when adjusting the rear wheel 130 to the axle.

  The outer portion in the vehicle width direction of the outer peripheral surface of the outer peripheral wall portion 42 extends on the extension of the outer portion in the vehicle width direction of the outer cylindrical portion 23 toward the downstream in the discharge direction P, and then extends in the middle of the outer wall portion 42. It is bent inward and extends. Thus, the opening of the outer peripheral wall portion 42 can be prevented from becoming excessively large, and the protection effect of the muffler end cover 40 can be enhanced. Further, in the present embodiment, since the inner peripheral surface and the outer peripheral surface of the outer peripheral wall are formed to be inclined and merge at the rear end, rigidity in the front-rear direction can be increased, and collision with an obstacle occurs. The deformation at the time can be suppressed. Thus, it is possible to prevent the muffler end cover from obstructing exhaust gas discharge due to the deformation of the muffler end cover.

  As described above, the muffler end cover 40 has the largest width in the upper half region. Since the muffler end cover 40 is positioned below the observer in the upright state, the opening of the muffler end cover 40 can be made more conspicuous, giving an impression that the muffler end cover 40 is largely opened. Can be.

  On the outer peripheral surface of the muffler end cover 40, the upper portion, the lower portion, and the outer portion in the vehicle width direction are inclined more steeply than the inner portion in the vehicle width direction, and are inclined radially inward of the outer peripheral wall portion 42. For this reason, when the muffler end cover 40 is viewed along the discharge direction P, the outer peripheral surface of the outer peripheral wall portion 42 on the downstream side in the discharge direction P is the outer peripheral surface of the outer peripheral wall portion 42 on the upstream side in the discharge direction P. In the vehicle width direction inward of the upstream edge.

  In the outer peripheral surface of the muffler end cover 40, the upper part, the lower part, and the outer part in the vehicle width direction are recessed toward the inner side of the outer peripheral wall part 42 toward the downstream side in the discharge direction P. Particularly, the outer portion in the vehicle width direction is depressed inward in the vehicle width direction. For this reason, it is easy to make the muffler 10 look small as the muffler 10 as a whole. In addition, since the amount of outward protrusion of the rear edge of the muffler 10 can be reduced, an obstacle does not easily come into contact with the muffler 10.

  A fixing portion for fixing to the muffler main body 20 is formed on the muffler end cover 40. In the present embodiment, outer fixing portions 46 and 47 formed on the outer portion in the vehicle width direction are formed as fixing portions. In the present embodiment, a plurality of outer fixing portions 46 are provided, the first outer fixing portion 46 is formed on an upper portion of the outer width direction outer portion of the outer peripheral wall portion 42, and the second outer fixing portion 47 is formed on the outer peripheral wall portion 42. Are formed in the lower part of the outer part in the vehicle width direction.

  Each of the outer fixing portions 46 and 47 forms a recess along the discharging direction P in a part of the outer portion in the vehicle width direction, and a screw as a fixing tool is inserted into a bottom portion of the recess perpendicular to the discharging direction P. It is formed by forming a hole. Then, in a state where the screw S is inserted into the screw insertion hole as an example of the fixing tool, the screw S is screwed and fastened to a screw groove provided on the muffler main body 20 side.

  Each of the outer fixing portions 46 and 47 is formed in a concave shape, and a lower portion of the inner peripheral portion is formed to have a shape that is inclined downward toward the opening. For this reason, it is possible to suppress accumulation of rainwater or the like in the fixing portions 46 and 47. Thereby, when the screw S is formed of iron or the like, it is possible to suppress the occurrence of rust on the screw S.

  The inner peripheral edge of the inner peripheral surface of the outer peripheral wall portion 42 on the downstream side in the discharge direction P is formed to be smaller (one size smaller) than the outer peripheral edge of the outer peripheral surface of the outer peripheral wall portion 42 on the downstream side in the discharge direction P. I have. The inner peripheral edge of the inner peripheral surface of the outer peripheral wall portion 42 on the downstream side in the discharge direction P is similar to the outer peripheral edge of the rear opening of the muffler main body 20 and has a shape smaller than the outer peripheral edge. The inner peripheral surface of the outer peripheral wall portion 42 is inclined toward the inside of the outer peripheral wall portion 42 (on the exhaust pipes 30A and 30B side) toward the upstream side in the discharge direction P. The degree of inclination of the inner peripheral surface of the outer peripheral wall portion 42 with respect to the discharge direction P is substantially the same in the entire circumferential direction of the inner peripheral surface of the outer peripheral wall portion 42. For this reason, assuming that there is no partition wall portion 60, the outer surface of the outer lid portion 25 has a shape similar to the outer peripheral edge of the rear opening of the muffler body 20 and the outer peripheral edge behind the outer peripheral wall portion 42. It is exposed in a smaller shape. The inner peripheral surface of the outer peripheral wall portion 42 expands in the radial direction as it proceeds downstream in the discharge direction P. This prevents the exhaust gas discharged from the exhaust pipes 30A and 30B from colliding with the inner peripheral surface of the outer peripheral wall portion 42, so that the exhaust gas can be smoothly discharged. In addition, since the inner diameter of the inner peripheral surface gradually increases as it advances in the discharge direction, a sudden change in the expansion of the exhaust gas discharged from the exhaust pipes 30A and 30B can be prevented, and a further noise reduction effect by the muffler end cover 40 is expected. can do.

  The partition wall section 60 extends between the first exhaust port 31A, which is the exhaust port of the upper exhaust pipe 30A, and the second exhaust port 31B, which is the exhaust port of the lower exhaust pipe 30B, and both ends of the partition wall section 60 extend to the outer peripheral wall section 42. Be connected. The partition wall section 60 partitions the space inside the outer peripheral wall section 42 into a plurality of spaces in which the outlets 31A and 31B are arranged. Here, the phrase “the partition wall portion extends between the plurality of outlets” means that the partition wall portion is between the plurality of outlets when viewed along the discharge direction P. For this reason, it is not necessary that the actual portion of the partition wall portion exists between the outlets. For example, as in a modified example described later, the rear end edge of the partition wall portion may pass through a portion protruding downstream between the plurality of outlets in the discharge direction.

  More specifically, the partition wall portion 60 is provided between the upper exhaust pipe 30A and the lower exhaust pipe 30B with respect to a direction connecting the central axis A of the upper exhaust pipe 30A and the central axis B of the lower exhaust pipe 30B. It extends in the direction intersecting, here, in the vehicle width direction.

  The partition wall portion 60 includes a wall main body portion 62, an inner connecting portion 64, and an outer connecting portion 68. The wall main body portion 62 is a portion extending in a direction intersecting the direction in which the exhaust pipes are arranged, in the present embodiment, in the vehicle width direction. The inner connecting portion 64 is a portion connecting the wall main body portion 62 and the outer peripheral wall portion 42 on the inner side in the vehicle width direction. The outer connecting portion 68 is a portion connecting the wall main body portion 62 and the outer peripheral wall portion 42 on the outer side in the vehicle width direction.

  The wall main body portion 62 is formed in a substantially U-shaped cross-sectional shape (shape in a cross section orthogonal to the vehicle width direction) that protrudes rearward, and between the two main surfaces (here, upper and lower surfaces) toward the downstream side in the discharge direction P. Are formed in the shape of a rectangular plate having a smaller size. The wall main body portion 62 is formed in a shape in which the same cross-sectional shape is continuous along the extending direction. The wall main body portion 62 is disposed along the vehicle width direction at a position separating the two exhaust pipes 30A and 30B.

  An inner portion in the vehicle width direction of the wall body portion 62 is connected to an inner portion in the vehicle width direction of an inner peripheral surface of the partition wall portion 60 via an inner connecting portion 64. An outer portion in the vehicle width direction of the wall body portion 62 is connected to an outer portion in the vehicle width direction of an inner peripheral surface of the partition wall portion 60 via an outer connecting portion 68. In the partition wall 60, the closest portion that is closest to both the upper exhaust pipe 30 </ b> A and the lower exhaust pipe 30 </ b> B is formed in the wall main body 62. For example, a portion of the wall main body portion 62 through which a line connecting the central axes A and B of the exhaust pipes 30A and 30B passes is the closest portion. The closest part retreats from the same position with respect to the plurality of exhaust pipes 30A, 30B in the discharge direction P to the upstream side in the discharge direction P in the discharge direction P in at least a part of the partition wall 60 adjacent to the plurality of exhaust pipes 30A, 30B. It is an example of a part located between positions.

  The inner connecting portion 64 is formed so that the width in the vertical direction gradually increases from the inner portion in the vehicle width direction of the wall main body portion 62 to the inner portion in the vehicle width direction of the inner peripheral surface of the partition wall portion 60. . Here, the upper surface of the inner connecting portion 64 is formed so as to face upward toward the inside in the vehicle width direction, and the lower surface of the inner connecting portion 64 is formed so as to face downward toward the inside in the vehicle width direction. For this reason, in the parallel direction in which the first discharge port 31A and the second discharge port 31B are arranged, the outer dimension of the inner connecting portion 64 is the portion of the wall main body 62 adjacent to the first discharge port 31A and the second discharge port 31B. Larger than the external dimensions of

  The partition wall portion 60 is at least a portion closest to the upper exhaust pipe 30A and the lower exhaust pipe 30B, and is located upstream of the exhaust pipes 30A and 30B in the outgoing direction P (that is, the inner side of the outer peripheral wall section 42 that is forward). (See FIG. 5). Further, the inner connecting portion 64 is formed in a shape extending to the downstream side in the discharge direction P as compared with the closest portion. For this reason, the partition wall part 60 is connected to the partition wall part 60 via the inner connection part 64 in a large area in the up-down direction.

  Here, the edge 62a of the wall main body portion 62 on the downstream side in the discharge direction P extends so as to be inclined toward the inside in the vehicle width direction toward the downstream side in the discharge direction P. Each of the discharge ports 31A and 31B is also inclined downstream in the discharge direction P toward the inside in the vehicle width direction, but the inclination angle with respect to a plane perpendicular to the discharge direction P is larger than the inclination angle of the edge 62a. The outer portion in the vehicle width direction of the edge 62a of the wall body portion 62 is located downstream of the plane including the outlets 31A and 31B in the discharge direction P. However, due to the difference between the inclination angles, the closest portion of the edge 62a of the wall main body portion 62 is retracted upstream in the discharge direction P from the plane including the respective discharge ports 31A and 31B. In the present embodiment, the entire portion of the edge 62a of the wall main body portion 62 that is present between the two exhaust pipes 30A and 30B is in the discharge direction P more than the first discharge port 31A and the plane including the first discharge port 31A. It has been evacuated upstream.

  The edge 64a on the downstream side in the discharge direction P of the inner connecting portion 64 extends so as to be inclined toward the downstream side in the discharge direction P toward the inside in the vehicle width direction. The inclination angle of the edge 64a with respect to a plane orthogonal to the discharge direction P is larger than the inclination angle of the edge 62a. Therefore, the inner connecting portion 64 extends downstream in the discharge direction P as compared with the closest portion. Here, the portion of the inner connecting portion 64 closer to the inside in the vehicle width direction is located downstream of the first discharge port 31A and the plane including the first discharge port 31A in the discharge direction P. Therefore, the partition wall section 60 is connected to the partition wall section 60 via the inner connecting portion 64 in a large area in the discharge direction P.

  In the present embodiment, unlike the inner connecting portion 64, the outer connecting portion 68 does not extend downstream in the discharging direction P with respect to the wall main body portion 62 in the discharging direction P. Also, the vertical dimension of the outer connecting portion 68 is not larger than that of the wall main body portion 62.

  Returning to FIG. 2 to FIG. 5, the muffler end cover 40 has an inner fixing portion formed as a fixing portion fixed to the muffler main body. The inner fixing portion 50 is formed on the inner side in the vehicle width direction, and is formed on the inner side in the radial direction of the outer peripheral wall portion 42 in the present embodiment. Here, the radial direction of the outer peripheral wall portion 42 refers to a direction connecting the inside surrounded by the outer peripheral wall portion 42 and the outside thereof, regardless of whether or not the outer peripheral wall portion 42 is circular.

  In the present embodiment, the inner fixed part 50 is formed as a part of the partition wall part 60. As the aspect in which the inner fixing portion 50 is formed radially inside the outer peripheral wall portion 42, it is not necessary to form the inner fixing portion 50 as a part of the partition wall portion 60, and the fixing portion is formed on the inner peripheral portion of the outer peripheral wall portion. It may be. Here, the inner fixing portion 50 is formed on the inner connecting portion 64.

  A recessed portion 64g is formed by recessing a middle portion of the inner connecting portion 64 in the vertical direction and inward in the vehicle width direction toward the muffler main body 20 side. The upper side, the lower side, and the outer side in the vehicle width direction of the concave portion 64g are surrounded by the inner connecting portion 64, and the inner side in the vehicle width direction of the concave portion 64g is surrounded by the outer peripheral wall portion 42. Therefore, the concave portion 64g is formed by the outer peripheral wall portion. 42 and a partition wall portion 60.

  A screw insertion hole through which a screw S serving as a fixing tool can be inserted is formed in a deep portion of the recess 64g. With the screw S inserted through the screw insertion hole, the screw S is screwed into a screw groove provided in the muffler main body 20. The screw S is an example of a fixing tool for fixing the inner fixing portion 50 to the muffler main body 20, and a screw head Sa of the screw S is housed in the recess 64g.

  The concave portion 64g has a concave shape gradually narrowing toward the back side, and its lower portion includes an inclined surface 64ga that is inclined downward toward the opening of the concave portion 64g. For this reason, it can suppress that rainwater etc. accumulate in 64 g of recessed parts. Thereby, when the screw S is formed of iron or the like, it is possible to suppress the occurrence of rust on the screw S.

  The muffler end cover 40 is fixed to the muffler main body 20 at three places by the fixing portions 46, 47, and 50. The fixing portions 46 and 47 are provided at a position on the right side of the muffler end cover 40, and the fixing portion 50 is provided at a position on the left side of the muffler end cover 40. The fixing portion 50 is provided between the fixing portions 46 and 47 in the vertical direction. Therefore, the muffler end cover 40 can be fixed to the muffler main body 20 in a well-balanced manner by the three fixing portions 46, 47, and 50. Note that a rivet or the like can be used as the fixing tool in addition to the screw.

  Here, an example has been described in which the entire partition wall portion 60 is retracted upstream of the outer peripheral wall portion 42 in the discharge direction P. However, a part of the partition wall portion 60, for example, a portion connected to the outer peripheral wall portion 42 may be present at the same position in the discharge direction P with respect to the outer peripheral wall portion 42. In the present embodiment, the fixing portions 46, 47, and 50 are disposed on both sides of the exhaust pipes 30A and 30B. In other words, in the direction in which the partition wall 60 extends, the fixing portions 46, 47, 50 are respectively disposed on both sides of the partition wall 60. In the present embodiment, since the partition wall 60 prevents expansion and contraction in the vehicle width direction, the stress generated in the fixing portions 46, 47 and 50 on both sides due to thermal expansion and contraction can be reduced.

  Further, the muffler 10 is provided between the upper exhaust pipe 30A and the outer peripheral wall 42 and the partition wall 60, and between the lower exhaust pipe 30B and the outer peripheral wall 42 and the partition wall 60. And a second cylindrical member 54B. Each of the tubular members 54A and 54B is fixed to the outer surface of the outer lid 25 by welding or the like.

  The first cylindrical member 54A covers the outer periphery of the upper exhaust pipe 30A at an interval from the upper exhaust pipe 30A. The first cylindrical member 54 </ b> A is also arranged at an interval from an annular inner peripheral surface formed by the upper portion of the outer peripheral wall portion 42 and the partition wall portion 60.

  The first cylindrical member 54A is formed in a cylindrical shape corresponding to an annular inner peripheral surface formed by the upper portion of the outer peripheral wall portion 42 and the partition wall portion 60. Here, the annular inner peripheral surface formed by the upper portion of the outer peripheral wall portion 42 and the partition wall portion 60 is obliquely cut off at one end side of the lower base of the trapezoid when viewed along the discharge direction P, Each corner is formed in a rounded shape. The first cylindrical member 54A is formed in a shape similar to the inner peripheral surface shape and smaller than the inner peripheral surface shape. Therefore, between the outer peripheral surface of the first cylindrical member 54A and the annular inner peripheral surface formed by the upper portion of the outer peripheral wall portion 42 and the partition wall portion 60 in the circumferential direction of the first cylindrical member 54A. , A gap having an equal width is formed.

  The second cylindrical member 54B covers the outer periphery of the lower exhaust pipe 30B at an interval from the lower exhaust pipe 30B. The second cylindrical member 54 </ b> B is also spaced from the annular inner peripheral surface formed by the lower portion of the outer peripheral wall 42 and the partition wall 60.

  The second tubular member 54B is formed in a tubular shape corresponding to an annular inner peripheral surface formed by the lower portion of the outer peripheral wall portion 42 and the partition wall portion 60. Here, the annular inner peripheral surface formed by the lower portion of the outer peripheral wall portion 42 and the partition wall portion 60 obliquely cuts off one of the upper corners of the square as viewed along the discharge direction P, Each corner is formed in a rounded shape. The second cylindrical member 54B is formed in a shape similar to the inner peripheral surface shape and smaller than the inner peripheral surface shape. Therefore, between the outer peripheral surface of the second cylindrical member 54B and the annular inner peripheral surface formed by the lower portion of the outer peripheral wall portion 42 and the partition wall portion 60, the circumferential direction of the second cylindrical member 54B is provided. , A gap having a uniform width is formed.

  The openings of the cylindrical members 54A, 54B are located at the same positions as the respective discharge ports 31A, 31B in the discharge direction P. That is, the openings of the tubular members 54A and 54B are located on a plane including the outlets 31A and 31B.

  Since the first cylindrical member 54A is formed in a cylindrical shape corresponding to the annular inner peripheral surface formed by the upper part of the outer peripheral wall part 42 and the partition wall part 60, the outer shape of the upper part of the muffler main body 20 is reduced. It is formed in a shape in which the shape along the shape is reduced. The second cylindrical member 54 </ b> B is formed in a cylindrical shape corresponding to an annular inner peripheral surface formed by the lower portion of the outer peripheral wall portion 42 and the partition wall portion 60. It is formed in a shape in which the shape along the outer shape is reduced. As described above, since the muffler main body 20 has an asymmetric shape with respect to an imaginary plane perpendicular to the vehicle width direction of the vehicle body, the first cylindrical member 54A and the second cylindrical member 54B are also perpendicular to the vehicle width direction of the vehicle body. The shape is asymmetrical with respect to a virtual surface.

  Specifically, the first tubular member 54A and the second tubular member 54B are vertically arranged side by side.

  The first cylindrical member 54A is formed in a shape whose width gradually decreases upward. In accordance with the outer shape of the muffler main body 20, the inclination of the right portion of the first cylindrical member 54A with respect to the vertical direction is greater than the inclination of the left portion. The second cylindrical member 54B is formed in a shape in which the width dimension gradually decreases downward. In accordance with the outer shape of the muffler body 20, the inclination of the right portion of the second tubular member 54B with respect to the vertical direction is greater than the inclination of the left portion. The inclination of the right portion of the first cylinder member 54A with respect to the vertical direction is greater than the inclination of the second cylinder member 54B. The cylindrical members 54A and 54B can give the impression that the exhaust pipes 30A and 30B are largely open.

  Further, the outer surfaces of the outer lid portion 25 on the rear surface of the muffler main body 20 can be made difficult to see by the cylindrical members 54A and 54B. Thereby, the polishing process for improving the beauty of the rear surface of the muffler main body 20 can be omitted or simplified, and the manufacturing cost can be reduced.

  Further, since the rear surface of the muffler main body 20 is hidden by the tubular members 54A and 54B, an impression that the muffler end cover 40, particularly the outer peripheral wall portion 42 is actually greatly opened can be given. Further, discoloration due to aging such as burning of the exhaust pipes 30A and 30B can be hidden.

  According to the muffler 10, since both ends of the partition wall portion 60 are connected to the outer peripheral wall portion 42, even if the opening of the muffler end cover 40 is enlarged, the thermal expansion of the muffler end cover 40 can be suppressed. The stress applied to the mounting portion of the end cover 40 can be reduced. Furthermore, since the partition wall part 60 avoids the plurality of outlets 31A and 31B and passes between them, it is possible to suppress the partition wall part 60 from becoming a resistance to exhaust gas discharge, and the muffler 10 Can be reduced.

  In addition, since the outer peripheral wall portion 42 goes around the outer peripheral edge of the end portion of the muffler main body 20, the opening at the rear end of the muffler 10 can be enlarged when viewed as the whole muffler 10. For example, a plurality of outlets 31A and 31B are provided at the rear of the muffler 10. When the individual outlets 31A, 31B are noticeably observed, it gives an impression that a small outlet is formed. However, since the outer peripheral wall portion 42 extends around the outer peripheral edge of the end portion of the muffler main body 20, it is conspicuously observed that the opening at the rear end of the muffler end cover 40 is greatly opened. For this reason, it is possible to give an impression that the opening to be discharged is large, and it is possible to improve the appearance.

  Further, in the outer peripheral wall portion 42, the partition wall portion 60 is provided, and since the respective exhaust pipes 30A and 30B are present in the spaces partitioned by the partition wall portion 60, the inside of the muffler end cover 40 is not empty. The impression that a substantial structure exists can be given.

  Further, since the outer peripheral wall portion 42 extends further downstream than the plurality of exhaust pipes 30A and 30B in the discharge direction P, the outer peripheral wall portion 42 can protect the exhaust pipes 30A and 30B. Thereby, the exhaust pipes 30A, 30B can be protected, the exhaust pipes 30A, 30B can be prevented from coming into contact with obstacles, and the deformation of the exhaust pipes 30A, 30B can be suppressed. 10 can be suppressed from deteriorating. Further, at least a portion of the partition wall portion 60 adjacent to the plurality of exhaust pipes 30A, 30B is located at a position retreating from the same position with respect to the plurality of exhaust pipes 30A, 30B in the discharge direction P to the upstream side in the discharge direction P. It is formed in a shape including a portion located between them. Thus, it is possible to suppress the partition wall portion 60 from becoming a resistance to exhaust gas discharge, and to suppress a decrease in performance of the muffler 10. In addition, the closest portions of the exhaust pipes 30 </ b> A and 30 </ b> B in the partition wall 60 are retracted upstream of the rear opening of the muffler end cover 40 in the discharge direction P. For this reason, the partition wall portion 60 is hidden by the muffler end cover 40 so that the partition wall portion 60 is less noticeable, and an impression that the opening to be discharged is large can be given, and the appearance can be improved.

  Further, the inner connecting portion 64 of the partition wall portion 60 is formed in a shape extending to the downstream side in the discharge direction P as compared with the closest portion of the partition wall portion 60. For this reason, the connecting region where the partition wall portion 60 continues to the outer peripheral wall portion 42 can be increased in the discharge direction P, and the deformation of the outer peripheral wall portion 42 can be further suppressed.

  Further, in the partition wall 60, in the parallel direction in which the plurality of outlets 31A and 31B are arranged, the outer dimension of the inner connecting portion 64 connected to the outer peripheral wall 42 is the outer dimension of the portion adjacent to the plurality of outlets 31A and 31B. It is formed in a shape larger than that of. For this reason, the connecting area where the partition wall portion 60 continues to the outer peripheral wall portion 42 can be increased in the parallel direction of the plurality of outlets 31A and 31B, and the deformation of the outer peripheral wall portion 42 can be further suppressed. In addition, by reducing the dimension of the partition wall 60 in the side-by-side direction of the outlets 31A and 31B closest to the outlets 31A and 31B, the partition 60 can be easily arranged between the plurality of outlets 31A and 31B. Thereby, the partition wall portion 60 having the function of suppressing the thermal expansion of the muffler end cover 40 can be easily formed.

  Further, since the inner fixing portion 50 is formed radially inside the outer peripheral wall portion 42 of the muffler end cover 40, the inner fixing portion 50 can be protected by the outer peripheral wall portion 42, and the inner fixing portion 50 is prevented from being damaged. be able to. Further, the inner fixing portion 50 can be hidden by the outer peripheral wall portion 42, and the appearance can be improved.

  Further, since the inner fixing portion 50 is formed on the partition wall portion 60, the structure is easily simplified as compared with a case where the inner fixing portion 50 is separately formed. In particular, a configuration in which the inner fixing portion 50 is provided radially inside the partition wall portion 60 can be easily realized.

  Further, the inner fixing portion 50 is formed on the inner connecting portion 64 of the partition wall portion 60, and the inner fixing portion 50 is formed in a shape that is recessed by the recess 64g. The rigidity of the fixing portion 50 can be increased by the peripheral wall structure or the like that forms the concave portion 64g, and an increase in the thickness for increasing the strength can be suppressed. Further, since a part of the fixing tool such as the screw S is accommodated in the recess 64g, the fixing tool can be easily hidden, and the appearance can be improved.

  Further, the plurality of outlets 31A and 31B are arranged vertically, and the opening area of the upper first outlet 31A is smaller than the opening area of the lower second outlet 31B. The noise generated at the first outlet 31A far from the ground can be made smaller than the noise generated at the second outlet 31B close to the ground, and the noise to the surrounding environment can be reduced while suppressing the output reduction. it can. In this embodiment, the lengths of the two exhaust pipes are different. For example, when exhaust gas is discharged, the phase of the compressional wave of the exhaust gas discharged from each exhaust pipe may be shifted. Since the partition wall is prevented from functioning as a partition relating to exhaust gas discharge, the exhaust gas can be promoted and the noise reduction effect can be enhanced by shifting the phase of the exhaust gas from each other. In the present embodiment, the two exhaust pipes have different lengths. However, the phase of the exhaust gas discharged from the exhaust pipe may be shifted depending on other shapes. For example, the relative position of the exhaust pipe introduction port, the distance of the exhaust path of the exhaust gas passing through each exhaust pipe, the passage area inside the exhaust pipe, and the like may be made different.

  The components described in the above embodiment and each modification can be appropriately combined as long as they do not conflict with each other.

  This specification also discloses the following configuration.

  The partition wall portion 60 has both ends connected to the inside of the outer peripheral wall portion 42, and at least a part thereof is recessed inward from the opening edge portion, and the plurality of exhaust pipes 30 </ b> A inside the outer peripheral wall portion 42, Partition 30B into at least two.

  As a result, at least a part of the partition wall portion 60 is recessed inward from the opening edge portion, so that the partition wall portion 60 is inconspicuous. For this reason, despite the existence of the plurality of exhaust pipes 30A and 30B, one opening due to the outer peripheral wall 42 is conspicuously observed at the rear end of the muffler 10, and the opening as large as possible becomes the rear end of the muffler 10. Can be observed. In addition, since the fixing tool such as the screw S fixed to the inner fixing portion 50 is arranged in the outer peripheral wall portion, the fixing tool is hardly noticeable.

  Further, the partition wall portion 60 is formed with a fixing recess 64g that is recessed from the rear portion toward the muffler main body 20 side. The fixture fixes the muffler end cover 40 to the muffler main body 20 with the head of the fixture (the screw S in the embodiment) being disposed in the fixing recess 64g. Accordingly, the head of the fixing tool is disposed in the fixing recess 64g of the partition wall, so that the fixing tool is less noticeable.

  At least a part of the partition wall portion 60 extends rearward from the plurality of exhaust pipes 30A and 30B. Thereby, partition wall part 60 can control contact with a plurality of exhaust pipes 30A and 30B and other parts.

  The plurality of exhaust pipes 30A and 30B include an upper exhaust pipe 30A and a lower exhaust pipe 30B below the upper exhaust pipe 30A, and an opening of the upper exhaust pipe 30A is smaller than an opening of the lower exhaust pipe 30B. By making the opening of the upper exhaust pipe 30A that is easy to be arranged near the human ear smaller than the lower exhaust pipe 30B that is easy to be arranged at a position far from the human ear, the exhaust sound felt by the human can be reduced.

  The opening edge of the muffler end cover 40 opens from the rear so as to face diagonally outward in the vehicle width direction of the saddle-ride type vehicle. As a result, when viewed from the side of the saddle-ride type vehicle, it is observed that the opening edge is largely open.

  The outer portion in the vehicle width direction of the outer peripheral portion of the outer peripheral wall portion 42 is recessed inward in the vehicle width direction. This makes it difficult for the exhaust pipes 30A and 30B to protrude outward, thereby preventing contact with obstacles.

  Furthermore, this specification includes the following aspects.

  The muffler according to the first aspect includes a muffler main body in which a plurality of outlets are formed at intervals, and a muffler end cover connected to an end of the muffler main body. Adjacent to the end of the muffler main body, an outer peripheral wall portion surrounding the outer peripheral edge of the end portion of the muffler main body, extends through between the plurality of outlets, and both ends are connected to the outer peripheral wall portion, A partition wall that divides a space inside the outer peripheral wall into a plurality of spaces in which the outlets are arranged.

  According to this muffler, since the outer peripheral wall portion goes around the outer peripheral edge of the end portion of the muffler main body, the rear end portion can be enlarged when viewed as the whole muffler. In addition, since both ends of the partition wall are connected to the outer peripheral wall, thermal expansion of the muffler end cover can be suppressed even if the muffler end cover becomes large, reducing the stress applied to the muffler end cover mounting part. can do. Furthermore, since the partition wall part passes between the plural outlets, avoiding the plural outlets, it is possible to suppress the partition wall part from becoming a resistance to exhaust gas discharge, and the performance of the muffler is deteriorated. Can be suppressed.

  A second aspect is the muffler according to the first aspect, wherein the muffler main body includes a plurality of exhaust pipes protruding in an exhaust gas discharge direction with respect to an expansion chamber, and the plurality of exhaust pipes is provided by the plurality of exhaust pipes. Are respectively formed, and the outer peripheral wall portion covers the plurality of exhaust pipes from the respective radial outer sides, extends to the discharge direction downstream side from the plurality of exhaust pipes, and includes the partition wall portion. At least a portion adjacent to the plurality of exhaust pipes is formed in a shape including a portion located between the same position with respect to the plurality of exhaust pipes in the discharging direction and a position retracted upstream in the discharging direction. Is what it is.

  By extending the outer peripheral wall to the downstream side in the discharge direction from the plurality of exhaust pipes, the exhaust pipe can be protected, and the exhaust pipe can be protected from overturning, collision, and contact with other parts caused by obstacles. Deformation can be prevented, and a decrease in muffler performance can be suppressed. Further, the partition wall portion is formed at a position adjacent to at least the plurality of exhaust pipes at the same position with respect to the plurality of exhaust pipes or in a shape retracted upstream in the discharge direction, so that the partition wall portion is Resistance to exhaust gas discharge can be suppressed, and a decrease in muffler performance can be suppressed.

  A third aspect is the muffler according to the first or second aspect, wherein the partition wall portion has a connecting portion continuous with the outer peripheral wall portion, as compared with a portion adjacent to the plurality of outlets. It is formed in a shape extending downstream in the discharge direction.

  Thereby, the connecting region where the partition wall portion is continuous with the outer peripheral wall portion can be increased in the discharge direction, and the deformation of the outer peripheral wall portion can be further suppressed.

  A fourth aspect is the muffler according to any one of the first to third aspects, wherein the partition wall has an outer shape of a connecting portion connected to the outer peripheral wall in a parallel direction in which a plurality of outlets are arranged. The size is formed to be larger than the external dimensions of the portion adjacent to the plurality of outlets.

  Thereby, the connecting region where the partition wall portion is continuous with the outer peripheral wall portion can be increased in the parallel direction of the plurality of outlets, and the deformation of the outer peripheral wall portion can be further suppressed. In addition, by reducing the dimension in the parallel direction of the portion adjacent to the discharge port in the partition wall portion, the partition wall portion can be easily arranged between the plurality of discharge ports, and a function of suppressing thermal expansion of the muffler end cover. It is possible to easily form a partition wall portion to have.

  A fifth aspect is the muffler according to any one of the first to fourth aspects, wherein the muffler end cover is formed radially inward of the outer peripheral wall portion and is fixed to the muffler main body. Is further included.

  Thereby, the fixing portion can be protected by the outer peripheral wall portion, and breakage of the fixing portion can be suppressed. In addition, since the fixing portion is arranged inside the outer peripheral wall portion, the fixing portion can be easily hidden, and the appearance can be improved.

  A sixth aspect is the muffler according to the fifth aspect, wherein the fixing part is formed as a part of the partition wall part.

  This makes it easier to simplify the structure as compared to a case where the fixing portion is separately formed.

  A seventh aspect is the muffler according to the sixth aspect, wherein the fixing portion is formed at a connecting portion of the partition wall portion that is continuous with the outer peripheral wall portion, and the outer peripheral wall portion and the partition wall portion A concave portion is formed which is recessed toward the muffler main body and accommodates a part of a fixing tool for fixing the fixing portion to the muffler main body.

  Thereby, since the fixing portion is formed in a shape depressed by the concave portion, the rigidity of the fixing portion can be increased, and an increase in the thickness for increasing the strength can be suppressed. In addition, since a part of the fixing tool is accommodated in the recess, the fixing part can be easily hidden, and the appearance can be improved.

  An eighth aspect is the muffler according to any one of the first to seventh aspects, wherein the plurality of outlets are arranged vertically, and an upper outlet of the plurality of outlets is disposed. The opening area is smaller than the opening area of the lower outlet.

  This makes it possible to reduce noise to the surrounding environment while suppressing a decrease in output.

  A ninth aspect is a muffler according to the first, third to eighth (excluding those cited in the second aspect), wherein the muffler main body projects in a discharge direction with respect to the expansion chamber. An exhaust port is formed by each of the exhaust pipes, and the outer peripheral wall portion and the partition wall portion cover each exhaust pipe from the radial outside and extend to a downstream side in the exhaust gas discharge direction from each exhaust pipe, and the partition wall is formed. The part is located at the same position with respect to the exhaust pipe with respect to the discharge direction at least around the exhaust pipe, or is disposed upstream in the discharge direction.

  By forming the outer peripheral wall portion and the partition wall portion in this manner, the exhaust pipe can be protected, and the exhaust pipe can be prevented from being deformed from overturning, collision, contact with an obstacle, and the like, thereby suppressing performance degradation. be able to.

  As described above, the present invention has been described in detail. However, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that innumerable modifications that are not illustrated can be assumed without departing from the scope of the present invention.

  For example, in the present embodiment, the muffler is arranged on one side in the vehicle width direction of the rear wheel, but may be arranged on both sides of the rear wheel in the vehicle width direction. The internal structure of the muffler is one example, and a silencing structure including a known silencing structure, such as using a resonance structure, can be applied. In addition, any structure may be used as long as the outer peripheral wall portion and the partition wall portion of the muffler end cover are configured, and the outer shape of the muffler is not limited to the shape of the present embodiment. For example, it may be formed in a substantially triangular shape in which the up-down width increases from the front end to the rear in a side view. Also, the cross-sectional shape perpendicular to the front-rear direction may be formed in a vertically long shape in the direction in which the two exhaust pipes are arranged, and may be formed in an elliptical shape or an oval shape. The present invention includes a case where three or more exhaust pipes are provided. Even in this case, any structure may be used as long as a partition wall located between at least two exhaust pipes is provided.

  The present embodiment is also an example of the structure of the motorcycle other than the muffler, and various structures including a known structure can be applied as the present invention. For example, an existing engine can be used. For example, the number of cylinders may be one cylinder, two cylinders or more. In addition to the in-line engine, a V-type or horizontally opposed engine may be used. When there are a plurality of cylinders, various structures can be applied to a method of assembling the exhaust pipes from the exhaust port to the muffler. In this embodiment, the exhaust chamber is provided. However, the present invention includes a case where the exhaust chamber is not provided. Similarly, various structures including known structures can be applied to the structure of the frame.

  The rear end edge of the partition wall may be formed in a shape including a portion adjacent to each exhaust pipe and located at the same position with respect to each exhaust pipe in the discharge direction. Further, the rear end edge of the partition wall portion 60 may be located at a portion adjacent to each exhaust pipe and located downstream in the discharge direction with respect to each exhaust pipe in the discharge direction. If the outer peripheral wall and the partition wall are located at the same position as the openings of the respective exhaust pipes or extend downstream in the discharge direction, the respective exhaust pipes can be protected and come into contact with obstacles. For example, the deformation of the exhaust pipe can be suppressed due to the above factors, and a decrease in performance as a muffler can be suppressed.

  A drain hole may be formed in the lower region of the outer peripheral wall described in the embodiment so that rainwater that has entered the outer peripheral wall can escape. A drain hole may be formed at the lower portion of the cylindrical member described in the embodiment to allow rainwater that has entered the cylindrical member to escape to the outside. Further, the tubular member may be omitted.

  Similarly to the inner connecting portion, the outer connecting portion of the partition wall portion may extend downstream in the discharging direction relative to the wall main body portion in the discharging direction. Also, the vertical dimension of the outer connecting portion may be larger than that of the wall main body. Like the outer connecting portion, the inner connecting portion of the partition wall portion does not need to extend in the discharging direction to the downstream side in the discharging direction with respect to the wall main body portion in the discharging direction. In addition, the vertical dimension of the inner connecting portion may not be larger than the wall main body portion.

  As an aspect in which the inner fixed portion is formed radially inside the outer peripheral wall portion, the inner fixed portion does not need to be formed on a part of the partition wall portion, and may be formed on the inner peripheral portion of the outer peripheral wall portion. Good. As an aspect in which the inner fixed portion is formed as a part of the partition wall portion, the fixed portion may be formed at a middle portion in the extending direction of the partition wall portion. Further, in the embodiment, the inner fixing portion is formed only on one connecting portion, but may be formed on both connecting portions.

Reference Signs List 10 muffler 20 muffler main body 24A first expansion chamber 24B second expansion chamber 30A upper exhaust pipe 30B lower exhaust pipe 31A first exhaust port 31B second exhaust port 40 muffler end cover 42 outer peripheral wall section 50 fixing section 60 partition wall section 64 inside Connecting part 64g recess S screw

Claims (8)

A muffler body in which a plurality of outlets are formed at intervals,
A muffler end cover connected to an end of the muffler body,
With
The muffler end cover
An outer peripheral wall portion surrounding the outer peripheral edge of the end portion of the muffler main body, adjacent to an end of the muffler main body;
A partition wall portion extending through the plurality of outlets, both ends continuous with the outer peripheral wall portion, and partitioning a space in the outer peripheral wall portion into a plurality of spaces where the outlets are arranged;
A muffler with The muffler according to claim 1,
The muffler body includes a plurality of exhaust pipes protruding in the exhaust gas discharge direction with respect to the expansion chamber,
The plurality of outlets are respectively formed by the plurality of exhaust pipes,
The outer peripheral wall portion covers the plurality of exhaust pipes from a radially outer side thereof and extends to the downstream side in the discharge direction from the plurality of exhaust pipes,
At least a portion of the partition wall adjacent to the plurality of exhaust pipes is located between the same position in the discharge direction and a position retracted upstream from the same position with respect to the plurality of exhaust pipes in the discharge direction. A muffler that is formed in a shape that includes. The muffler according to claim 1 or claim 2,
The muffler, wherein the partition wall portion is formed such that a connecting portion connected to the outer peripheral wall portion extends downstream in the discharge direction as compared with a portion adjacent to the plurality of discharge ports. A muffler according to any one of claims 1 to 3, wherein
In the partition wall portion, in a parallel direction in which a plurality of outlets are arranged, an outer dimension of a connecting portion connected to the outer peripheral wall portion is formed in a shape larger than an outer size of a portion adjacent to the plurality of outlets. Muffler. A muffler according to any one of claims 1 to 4, wherein
The muffler, wherein the muffler end cover further includes a fixing portion formed on a radially inner side of the outer peripheral wall and fixed to the muffler main body. The muffler according to claim 5, wherein
The muffler, wherein the fixing part is formed as a part of the partition wall part. The muffler according to claim 6, wherein
The fixing portion is formed at a connecting portion of the partition wall portion that is continuous with the outer peripheral wall portion,
A muffler, wherein the outer peripheral wall portion and the partition wall portion are formed with a concave portion that is recessed toward the muffler main body and that accommodates a part of a fixture that fixes the fixing portion to the muffler main body. It is a muffler according to any one of claims 1 to 7,
The plurality of outlets are arranged side by side,
A muffler, wherein an opening area of an upper outlet of the plurality of outlets is smaller than an opening area of a lower outlet.

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