JP2009041562A - Exhaust device for saddle riding type vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust device for a saddle riding type vehicle capable of providing sufficient muffling effect of exhaust gas without enlarging the shape of a muffler. <P>SOLUTION: A muffler 33 is disposed at a rear end part of an exhaust gas passage EP leading out exhaust gas G from an engine E toward a rear of the engine E, a muffling chamber 38 expanding the exhaust gas G is provided at an upstream side of the muffler 33 in the exhaust gas passage EP, and at least a part of the muffling chamber 38 is positioned between the engine E and a rear wheel 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust device that is mounted on a straddle-type vehicle such as a motorcycle and exhausts exhaust gas from an engine by purifying and silencing it.

In general, an exhaust system that is mounted on a motorcycle to purify and muffle exhaust gas from an engine purifies the exhaust gas led to the exhaust passage from a multi-cylinder engine with a catalytic converter provided in the exhaust passage. The muffler at the rear end of the exhaust passage is further silenced and discharged into the atmosphere (see Patent Document 1). The muffler includes a side muffler type provided on the side of the vehicle body and an upper muffler type provided below the passenger seat.
JP 2006-77727 A

  However, in the conventional exhaust system, in both the side muffler type and the upper muffler type, the shape, that is, the volume cannot be increased so much, and the silencing effect of the exhaust gas tends to be insufficient. That is, when the shape of the side muffler type is increased, the width of the vehicle body including the muffler is widened because the muffler is disposed on the side of the vehicle body. In addition, when the muffler is disposed only on one side, it is necessary to consider the weight balance. On the other hand, the upper muffler type has little space for providing a large muffler at the lower portion of the passenger seat.

  An object of the present invention is to provide an exhaust device for a saddle-ride type vehicle that can obtain a sufficient silencing effect of exhaust gas without increasing the shape of the muffler.

  In order to achieve the above object, a straddle-type vehicle exhaust device according to the present invention includes a muffler disposed at a rear end portion of an exhaust passage through which exhaust gas from an engine is led out toward the rear of the engine. A silencing chamber for expanding the exhaust gas is provided upstream of the muffler in the passage, and at least a part of the silencing chamber is located between the engine and the rear wheel.

  According to this configuration, since there is a relatively wide space between the rear portion of the engine and the rear wheel, a silencing chamber can be easily provided in this space, and the exhaust gas is silenced in the silencing chamber. Since the sound is further silenced by the muffler at the rear end portion of the exhaust passage, the exhaust gas is silenced twice by the silencer chamber and the muffler without increasing the shape of the muffler, so that a great silencing effect of the exhaust gas can be obtained. .

  In the present invention, it is preferable that at least a part of the silencer chamber is located below the swing arm. Since there is room in the space below the swing arm, a large volume silencer chamber can be arranged.

  In the present invention, it is preferable that a silencer pipe that penetrates the silencer chamber and forms a part of the exhaust passage is disposed, and the silencer pipe has a plurality of through holes formed in a peripheral wall. As a result, a part of the exhaust gas introduced into the silencer pipe expands and loses energy by entering the silencer chamber through the through hole of the silencer pipe, and a resonator (resonator) effect in the silencer chamber. As a result, exhaust noise is reduced. In addition, most of the exhaust gas introduced into the muffler pipe flows smoothly toward the muffler through the muffler pipe, so that there is an advantage that the output is improved particularly in the high-speed rotation range.

  In the present invention, the silencer pipe may be curved in the silencer chamber. Thereby, for example, even if the inflow direction of the exhaust gas to the inlet of the silencer pipe and the outflow direction of the exhaust gas from the outlet of the silencer pipe are not in a straight line, the inlet and the outlet are smoothly connected by the silencer pipe. In addition, it is possible to suppress an increase in the passage resistance of the exhaust gas, and to improve the output particularly in the high speed rotation range.

  In the present invention, it is preferable that a resonance chamber for resonating the exhaust gas is provided in the silencer chamber. Thereby, the effect of reducing the exhaust noise in the muffler chamber is improved, and the exhaust noise can be further reduced.

  In the present invention, it is preferable to install a sound absorbing material on the inner surface of the muffler chamber. Thus, the exhaust gas that has entered the inside of the sound deadening chamber through the through hole of the sound deadening pipe can be silenced by the sound absorbing material.

  In this invention, it is preferable to attach the rectification | straightening member which rectifies | straightens the said exhaust gas located in the upstream of the said through-hole formation area to the said silencer pipe. As a result, the exhaust gas having a large kinetic energy immediately after being introduced into the silencer pipe is rectified so as to flow along the axial direction of the silencer pipe, so that the exhaust gas flowing into the silencer chamber through the through hole of the silencer pipe. Since the amount of gas can be suppressed and most of the exhaust gas flows smoothly through the inside of the muffler pipe, the passage resistance is reduced. As a result, the output can be further improved particularly in a high-speed rotation range.

  In the present invention, it is preferable that an anti-vibration stay that suppresses vibration of the silencing chamber by connecting the opposing chamber walls is mounted in the silencing chamber. Thereby, the vibration of the silencer chamber due to the vibration energy of the exhaust gas that has entered the silencer chamber through the through hole of the silencer pipe can be effectively suppressed.

  The straddle-type vehicle according to the present invention includes the exhaust device having the above configuration. In this straddle-type vehicle, the muffler is disposed right above the rear wheel, the exhaust passage is bent so as to rise upward at the rear of the engine, and the muffler chamber is provided at the bent portion. It can be configured. Thus, the present invention can be applied to a so-called upper muffler type vehicle.

  According to the exhaust system for a saddle-ride type vehicle according to the present invention, a silencing chamber is easily provided in a relatively wide space existing between the rear portion and the rear wheel of the engine, and the exhaust gas is silenced in the silencing chamber. Since the sound is further silenced by the muffler at the rear end of the exhaust passage, the exhaust gas can be silenced twice by the silencer chamber and the muffler without increasing the shape of the muffler, thereby obtaining a sufficient silencing effect.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view showing a motorcycle equipped with an exhaust device according to a first embodiment of the present invention. In this motorcycle, a front fork 2 is supported by a front end portion of a main frame 1 constituting a front half portion of a vehicle body frame FR so as to be steerable and a front wheel 4 is supported by a lower end portion of the front fork 2. A handle 9 is attached to the upper bracket 8 that supports the upper end of the front fork 2. A swing arm bracket 10 is formed at the lower rear end of the main frame 1, and a front end portion of the swing arm 11 is swingably supported by the swing arm bracket 10 via a pivot shaft 12. A rear wheel 13 is supported at the rear end of the swing arm 11. A seat rail 14 connected to the rear portion of the main frame 1 constitutes the rear half of the vehicle body frame FR. A shock absorber 17 for the rear wheel 13 is attached between the main frame 1 and the swing arm 11. An engine E is supported at the center lower portion of the main frame 1, and the rear wheel 13 is driven by the engine E via a chain 18.

  A rider's seat 19 and a passenger's seat 20 are supported on the seat rail 14. A fuel tank 21 is attached between the handle 9 and the rider seat 19 at the upper part of the main frame 1, that is, at the upper part of the vehicle body. In addition, a resin cowling 22 that covers a portion from the front of the handle 9 to the side of the front portion of the vehicle body is attached to the front portion of the vehicle body.

  The engine E disposed between the front wheel 4 and the rear wheel 13 is a four-cylinder four-cycle parallel multi-cylinder engine in this embodiment, and includes a crankcase 24, a cylinder 27, a cylinder head 28, and a cylinder head cover. An engine main body 23 having 29 and a transmission 31 are provided. The exhaust device 30 includes four individual front exhaust pipes 32 that are connected to the cylinder head 28 at respective front ends to guide the exhaust gas G downward from the front of the engine E, and the rear exhaust pipes 32. A collecting pipe 34 collecting ends, a box-shaped exhaust chamber 35 connected to the downstream portion of the collecting pipe 34, a single rear exhaust pipe 37 connected to the downstream portion, and a rear portion and a rear portion of the engine E A silencer chamber 38 disposed between the ring 13, a silencer pipe 39 penetrating through the silencer chamber 38 and having a front end connected to the rear exhaust pipe 37, and a rear end part of the silencer pipe 39. The muffler 33 is provided. In this embodiment, the muffler 33 is a side muffler type. The silencing chamber 38 is at least partially located in the lower part of the swing arm 11 except for the upper part in this embodiment. The front exhaust pipe 32, the collecting pipe 34, the exhaust chamber 35, the rear exhaust pipe 37, the silencer pipe 39, and the muffler 33 form a series of exhaust passages EP.

  FIG. 2 is a plan view of the upstream portion of the exhaust passage EP of the exhaust device 30. As shown in the figure, the upstream portion 34a of the collecting pipe 34 protrudes upstream (frontward) from the exhaust chamber 35, and the downstream portion 34b enters the exhaust chamber 35. The downstream portion 34b contains exhaust gas. A catalytic converter 43 for purifying the gas G is accommodated. The upstream portion of the rear exhaust pipe 37 is accommodated in the downstream portion in the exhaust chamber 35, and a gap 36 is provided between the upstream edge of the rear exhaust pipe 37 and the catalytic converter 43. Accordingly, the exhaust gas G once enters the exhaust chamber 35 from the catalytic converter 43, expands and is silenced, and then enters the rear exhaust pipe 37.

  3 is a schematic bottom view showing the relative arrangement of the exhaust device 30 and the engine E. FIG. The collecting pipe 34 and the rear exhaust pipe 37 of the exhaust device 30 are arranged on the right side when viewed from the rider with respect to the vehicle body center line C passing through the center of the front wheel 4 and the rear wheel 13 in the left-right direction. The muffler pipe 39 that penetrates through and forms a part of the exhaust passage EP is smoothly curved from the rear end of the rear exhaust pipe 37 toward the muffler 33. The exhaust chamber 35 is disposed below the engine E on the right side of the center line C of the vehicle body, but a part of the exhaust chamber 35 advances to the left side of the center line C as indicated by a two-dot chain line 35A. In some cases. An oil pan 46 for storing lubricating oil is provided on the left side of the bottom of the engine E. Therefore, the exhaust chamber 35 and the oil pan 46 are arranged in the left-right direction at substantially the same height.

  FIG. 4 is a perspective view of the silencing chamber 38 with the silencing pipe 39 attached in a penetrating state as viewed from the front right side of the vehicle body. The sound deadening chamber 38 is made of metal and has a so-called “monar structure” that forms a sound deadening chamber 61 inside. The right half 38A and the left half 38B sandwich the sound deadening pipe 39 between them. Polymerized and fixed by welding. Thereby, the muffler pipe 39 is fixed in a penetrating state in the front-rear direction with respect to the muffler chamber 38. That is, the silencer pipe 39 is supported by the silencer chamber 38 with its upstream portion penetrating the front wall 38a of the silencer chamber 38 and its downstream portion penetrating the rear wall 38b of the silencer chamber 38. Inner inner surface of the right side wall 38c of the muffler chamber 38, that is, the upper side wall of the right side half body 38A, left inner wall 38d of the muffler chamber 38, that is, upper inner surface of the side wall of the left side half body 38B, and rear wall 38b of the muffler chamber 38 Sound absorbing materials 41A, 41B, and 41C are respectively mounted at three locations with the inner surface of the rear wall of the left half 38B that forms the left half. Details of the sound absorbing material 41 will be described later.

  FIG. 5 is a side view as seen from the right side of the vehicle body with the right half 38A of the muffling chamber 38 removed. The silencer pipe 39 is formed with a plurality of through holes 39a on each peripheral surface on the upstream side (right side in the figure) and downstream side (left side in the figure) in the flow direction of the exhaust gas G in the silencer chamber 38. Connection adapter portions 39b and 39c for connecting to the rear exhaust pipe 37 and the muffler 33 are provided. The silencer pipe 39 is provided with a rectifying member 42 that rectifies the flow of the exhaust gas G in the axial direction upstream of the region where the through hole 39a is formed.

  The rectifying member 42 is a honeycomb structure having a number of parallel elongated passages 45 through which the exhaust gas G passes, as shown in FIG. 6 which is a cross-sectional view perpendicular to the flow direction of the exhaust gas G. The rectifying member 42 is disposed so that the axial direction of the cylindrical honeycomb structure, that is, the direction of the eyes coincides with the flow direction of the exhaust gas G in the silencer pipe 39. Since this flow straightening member 42 is relatively heavy, as shown in FIG. 5, a bracket 48 attached by welding in the vicinity of the flow straightening member 42 in the sound deadening pipe 39, the right half 38A of the sound deadening chamber 38 shown in FIG. It is supported on the inner surface of. The rectifying member 42 may be a honeycomb structured catalyst.

  FIG. 7 is a cross-sectional view of the three sound absorbing materials 41 </ b> A to 41 </ b> C of FIG. 4 provided on the inner surface of the sound deadening chamber 38. The three sound absorbing materials 41A to 41C are different in size and shape, and all have the same structure. The sound absorbing material 41 includes glass wool 47 housed inside a holding body 44 in which a punching metal having a number of punching holes 44a formed into a deep cup shape by bending the peripheral edge portion, and the peripheral edge portion of the holding body 44 is silenced. It is attached to the inner wall surface of the chamber 38 by welding.

  As shown in FIG. 4, two chambers inside the silencing chamber 38 are connected between the chamber walls of the right half 38A and the left half 38B facing each other, in this embodiment, between the right side wall 38c and the left side wall 38d. A vibration-proof stay 49 that suppresses the vibration of the muffler chamber 38 is attached. FIG. 8 is a cross-sectional view of a place where the anti-vibration stay 49 is mounted in the silencer chamber 38. Recessed portions 51 and 52 that are recessed inwardly of the sound deadening chamber 38 are provided at opposite positions of the right half 38A and the left half 38B, and the bottom walls of the left and right recesses 51 and 52 facing each other. A rod-shaped anti-vibration stay 49 is inserted therebetween, and the bolt 53 is screwed into the screw hole of the anti-vibration stay 49 through the insertion holes 50 and 50 of the recesses 51 and 52. It is fixed to the silencer chamber 38. The anti-vibration stay 49 functions as a tension rod for the chamber walls 38c and 38d facing each other on the right half 38A and the left half 38B.

  The silencing chamber 38 shown in FIG. 4 is supported in a cantilevered manner on the vehicle body frame FR (FIG. 1) through a mounting bracket 55 fixed to the front portion, which is upstream of the exhaust gas G. A rear portion, which is a downstream portion in the flow direction of G, is supported by the vehicle body frame FR via the muffler pipe 39 and the muffler 33 in FIG.

  Next, the operation of the exhaust device 30 according to the first embodiment will be described. First, exhaust gas G is led out from the four exhaust ports EX of the engine E of FIG. Passes through the muffler chamber 38 and is discharged from the muffler 33 into the atmosphere. As shown in FIG. 2, the exhaust gas G guided from the plurality of front exhaust pipes 32 to the collecting pipe 34 is purified through the catalytic converter 43 housed in the downstream part 34 b of the collecting pipe 34, After entering the exhaust chamber 35 from the gap 36 and expanding and being slightly silenced, it is introduced into the silencer pipe 39 through the rear exhaust pipe 37.

  A part of the exhaust gas G introduced into the muffler pipe 39 shown in FIG. 5 passes through the through hole 39a of the muffler pipe 39 and enters the muffler chamber 61 in the muffler chamber 38, thereby losing energy and exhausting. Noise is reduced. At this time, a resonator effect in which the exhaust gas G resonates in the muffler chamber 61 is also obtained, and exhaust noise is further reduced. On the other hand, most of the exhaust gas G introduced into the muffler pipe 39 flows smoothly toward the muffler 33 through the muffler pipe 39, so that an increase in passage resistance is suppressed, particularly in a high-speed rotation range. There is an advantage that the output is improved.

  The exhaust device 30 is newly provided with a silencing chamber 38 having a silencing pipe 39 in a penetrating state. The silencing chamber 38 is provided between the rear portion of the engine E and the front end portion of the rear wheel 13 in FIG. Since it arrange | positions in the existing comparatively wide space, the volume can be enlarged and the silencing effect can be heightened. Further, the exhaust device 30 is further silenced by the muffler 33 after the exhaust gas G is silenced in the silencer chamber 38, that is, in addition to being silenced twice, in addition to the preliminary exhaustion in the exhaust chamber 35 before entering the silencer chamber 38. Therefore, even if the shape of the muffler 33 is not increased, a sufficient silencing effect of the exhaust gas G can be obtained.

  Further, as shown in FIG. 5, since the silencer pipe 39 is curved in the silencer chamber 38, the flow direction of the exhaust gas G to the inlet 39 e of the silencer pipe 39 and the exhaust from the outlet 39 f of the silencer pipe 39. Even though the outflow direction of the gas G is not in a straight line, the inlet 39e and the outlet 39f are smoothly connected by the silencer pipe 39 to suppress an increase in the passage resistance of the exhaust gas G. The output can be improved in the high-speed rotation range.

  Furthermore, since the exhaust device 30 has the sound absorbing materials 41A to 41C attached to the inner surface of the silencer chamber 38 of FIG. 4, the exhaust device 30 enters the interior of the silencer chamber 38 through the through hole 39a of the silencer pipe 39 of FIG. The exhaust gas G can be effectively silenced by the sound absorbing material 41A (FIG. 4) to 41C. Further, since the rectifying member 42 is attached to the upstream side of the through-hole 39 a of the silencer pipe 39, the exhaust gas G having a large kinetic energy immediately after being introduced into the silencer pipe 39 flows along the axial direction of the silencer pipe 39. Is rectified as follows. Therefore, the amount of exhaust gas flowing out into the sound deadening chamber 61 through the through hole 39a of the sound deadening pipe 39 can be suppressed, and most of the exhaust gas G can flow smoothly through the inside of the sound deadening pipe 39. This further improves the output in the high-speed rotation range.

  Further, in the exhaust device 30, the chamber walls 38 c and 38 d facing each other are connected by the vibration isolating stay 49 mounted in the noise reduction chamber 38, so that the inside of the noise reduction chamber 38 passes through the through hole 39 a of the noise reduction pipe 39. The vibration of the silencing chamber 38 due to the vibration energy of the exhaust gas G that has entered can be effectively suppressed.

  As is clear from FIG. 1, the entire silencing chamber 38 is located between the engine E and the rear wheel 13 in a side view, but as shown by a two-dot chain line 38A in FIG. The part may overlap the front part of the rear wheel 13 in a side view, or a part may overlap the rear part of the engine E in a bottom view as indicated by a two-dot chain line 38B. In short, it is only necessary that at least a part of the muffling chamber 38 is located in a region between the engine E and the rear wheel 13.

  9 and 10 show a perspective view and a horizontal cross-sectional view of a noise reduction chamber in an exhaust device according to a second embodiment of the present invention. In this embodiment, as shown in FIG. 9 which is a perspective view seen from the left front of the vehicle body, the sound is silenced through the through hole 39a of the sound deadening pipe 39 adjacent to the sound deadening chamber 61 in the metal sound deadening chamber 38. A resonance chamber 62 that resonates and silences the exhaust gas G that has entered the chamber 61 is provided. As shown in FIG. 10, the silencing chamber 38 has an overhanging portion 38f that projects toward the left side from a main body portion 38e through which the silencing pipe 39 is disposed. By partitioning the inside of the silencing chamber 38 with a partition plate 58 with a pipe 57, the silencing chamber 61 is partitioned into a silencing chamber 61 that is an internal space of the main body portion 38e and a resonance chamber 62 that is an internal space of the overhang portion 38f.

  In this embodiment, the pipe 57 is attached by welding to the partition plate 58, and the silencer chamber 61 in the main body 38 e of the silencer chamber 38 and the resonance chamber 62 of the overhang part 38 f communicate with each other by the pipe 57. is doing. Specifically, one end of the pipe 57 projects from the partition plate 58 into the silencer chamber 61 by a predetermined length L1, and the other end of the pipe 57 projects from the partition plate 58 into the resonance chamber 62 by a predetermined length L2. The partition plate 58 is formed with an attachment flange 58a that contacts the inner surface of the noise reduction chamber 38 at the periphery thereof, and is attached to the noise reduction chamber 38 by welding a plurality of locations of the attachment flange 58a to the inner surface of the noise reduction chamber 38. It has been.

  1 to 8 show an example of a structure in which the muffling chamber 38 is divided into two “left and right” monaural structures, but in this embodiment, the muffler chamber 38 is divided into two upper and lower divided “mona structure” as shown in FIG. The lower half 38C and the upper half 38D are polymerized with the muffler pipe 39 and the partition plate 58 sandwiched therebetween, and are fixed by welding. Further, the anti-vibration stays 49 are mounted at two locations inside the overhanging portion 38 f in the noise reduction chamber 38. Specifically, the front side wall 38fa and the rear side wall 38fb of the projecting portion 38f are connected by a vibration isolating stay 49 at two places above and below the pipe 57 protruding from the partition plate 58 toward the resonance chamber 62. Each anti-vibration stay 49 has both ends fixed to the silencer chamber 38 by bolts (not shown). Other configurations are substantially the same as those in the embodiment shown in FIGS. 1 to 8, and the description thereof is omitted here.

  In the case of this second embodiment, in the noise reduction chamber 38, a part of the exhaust gas G entering the noise reduction chamber 61 in the noise reduction chamber 38 through the through hole 39a of the noise reduction pipe 39 expands and loses energy. Due to the resonator effect in which the exhaust gas G resonates in the resonance chamber 62 that communicates with the sound deadening chamber 61 via 57, the exhaust noise is more effectively reduced. That is, in the resonance chamber 62, the exhaust noise is reduced by resonating a specific frequency component of the exhaust noise.

  In the example of the second embodiment in which one end of the pipe 57 protrudes from the partition plate 58 into the silencing chamber 61 and the other end of the pipe 57 projects from the partition plate 58 into the resonance chamber 62, the diameter of the pipe 57 and the silencing chamber 61 Experiments have confirmed that noise is reduced by appropriately setting the inward projection length L1 and the projection length L2 into the resonance chamber 62 as compared with the case where no resonance chamber is provided.

  Further, when the pipe 57 is protruded only from the partition plate 58 into the silencing chamber 61 and the pipe 57 is not projected to the resonance chamber 62 side, the diameter of the pipe 57 and the projecting length into the silencing chamber 61 are also provided. Experiments have confirmed that noise can be reduced by appropriately setting L1 as compared to the case where no resonance chamber is provided.

  In addition, by providing the partition plate 58 in the silencer chamber 38, the rigidity of the silencer chamber 38 can be improved. In the configuration of the second embodiment in which the resonance chamber 62 is provided in the noise reduction chamber 38, the exhaust gas flowing into the noise reduction chamber 61 through the through hole 39a of the noise reduction pipe 39 is the same as in the case of the first embodiment. Since the amount of exhaust gas G can be smoothly flown through the inside of the muffler pipe 39 while suppressing the amount, the output in the high speed rotation region is improved.

  FIG. 11 is a side view showing a motorcycle equipped with an exhaust device 60 according to a third embodiment of the present invention. In FIG. 11, the same or corresponding parts as those in FIG. Description is omitted. This embodiment is an exhaust device 60 that employs an upper muffler type in which a muffler 33 is disposed directly below the rear wheel 13, that is, on the center line C of the vehicle body, almost directly below the passenger seat 20. In the exhaust device 60, the exhaust passage EP is bent by approximately 90 ° so as to rise upward at the rear of the engine E, and a sound deadening chamber 68 that forms a sound deadening chamber 61 is provided in the bent portion. Yes. The silencing chamber 68 is disposed between the engine E and the rear wheel 13 and is entirely located below the swing arm 11. The muffler pipe 69 that passes through the muffler chamber 68 has an outlet end that opens upward between the engine E and the rear wheel 13 and is connected to the vehicle body via a long connection pipe 70 that forms part of the exhaust passage EP. It is connected to the rear muffler 35. The long connecting pipe 70 extends upward from the muffler pipe 69 through the space between the engine E and the rear wheel 13, and further bends rearward to continue to the muffler 33.

  FIG. 12 is a side view of the silencing chamber 68 provided with the silencing pipe 69. The silencing chamber 68 has a box shape close to a rectangular parallelepiped, and the silencing pipe 69 is largely curved so as to be bent approximately 90 ° in the silencing chamber 68 in order to connect to the upper muffler 33 (FIG. 11). It is the shape derived toward. That is, the silencer pipe 69 is supported by the silencer chamber 68 with its upstream portion passing through the substantially vertical front wall 68a of the silencer chamber 68 and its downstream portion passing through the substantially horizontal upper wall 68c. The silencing chamber 68 is arranged on the right side of the center line C of the vehicle body, as in the case of the first embodiment shown in FIG. In the silencer chamber 68, in addition to the silencer chamber 61, a resonance chamber similar to the case of the second embodiment may be provided. As shown in FIG. 11, the connection pipe 70 connected to the downstream end of the muffler pipe 69 extends through the pair of left and right arms of the swing arm 11 and is connected to the muffler 33.

  The silencer pipe 69 is not provided with the rectifying member 42 (FIG. 5) provided in the silencer pipe 39 of the first embodiment, and the through hole 69a is formed in the peripheral surface in the vicinity of the upstream end in the silencer chamber 68 of FIG. Is formed. By introducing the exhaust gas G into the silencing chamber 61 in the silencing chamber 68 via the through hole 69a provided on the upstream side, the exhaust gas having a large kinetic energy immediately after being introduced into the silencing vip 69. Since the gas G is silenced, a high silencing effect can be obtained.

  Further, in particular, in the exhaust device 60, since the silencer pipe 69 is greatly curved, the rear exhaust pipe 37 connected to the inlet of the silencer chamber 68 and the connection pipe 70 connected to the outlet are smoothly connected by the silencer pipe 69. The increase in the passage resistance of the exhaust gas G can be suppressed, and thereby the output can be improved particularly in the high speed rotation region.

  The present invention can be applied to straddle-type vehicles such as tricycles and four-wheel vehicles for traveling on rough terrain, in addition to the motorcycles described in the above embodiments. In addition, configurations can be added, deleted, and changed without departing from the spirit of the present invention, and such configurations are also included in the scope of the present invention.

1 is a side view showing a motorcycle equipped with an exhaust device according to a first embodiment of the present invention. It is a top view of the upstream part of the exhaust passage of an exhaust apparatus same as the above. It is a schematic bottom view which shows relative arrangement | positioning of an exhaust apparatus same as the above and an engine. It is the perspective view seen from the right front of the vehicle body of the noise reduction chamber in an exhaust apparatus same as the above. It is the side view seen from the right side of the vehicle body in the state which removed the right side half of the silencing chamber same as the above. It is a cross-sectional view of the rectification member provided in the muffler pipe in the exhaust device same as above. It is a longitudinal cross-sectional view of the sound-absorbing material provided on the inner surface of the silencing chamber. It is sectional drawing which shows the attachment location of the anti-vibration stay in a silencing chamber same as the above. It is the perspective view seen from the left front of the vehicle body of the silencer chamber in the exhaust apparatus which concerns on 2nd Embodiment of this invention. It is a horizontal sectional view of a silencing chamber same as the above. FIG. 6 is a side view showing a motorcycle equipped with an exhaust device according to a third embodiment of the present invention. FIG. 12 is a side view of a muffle chamber in the exhaust device of FIG. 11.

Explanation of symbols

4 Front wheel 11 Swing arm 13 Rear wheel 33 Muffler 38, 68 Silencer chamber 38c, 38d Silencer chamber side walls 39, 69 Silencer pipes 39a, 69a Through hole 41 Sound absorbing material 42 Rectification member 49 Vibration isolation stay 57 Pipe 58 Partition plate 62 Resonant chamber E Engine EP Exhaust passage G Exhaust gas

Claims (10)

A muffler is disposed at the rear end of the exhaust passage for leading exhaust gas from the engine toward the rear of the engine,
A silencer chamber for expanding the exhaust gas is provided on the upstream side of the muffler in the exhaust passage,
An exhaust system for a saddle-ride type vehicle, wherein at least a part of the silencing chamber is located between the engine and a rear wheel.   2. The exhaust system for a saddle riding type vehicle according to claim 1, wherein at least a part of the muffler chamber is located below the swing arm.   The exhaust of a straddle-type vehicle according to claim 1 or 2, wherein a silencer pipe that penetrates the silencer chamber and forms a part of the exhaust passage is disposed, and the silencer pipe has a plurality of through holes formed in a peripheral wall. apparatus.   The exhaust device for a saddle-ride type vehicle according to claim 3, wherein the silencer pipe is curved in the silencer chamber.   5. The exhaust system for a saddle-ride type vehicle according to claim 1, wherein a resonance chamber that resonates the exhaust gas is provided in the muffler chamber. 6.   6. The exhaust system for a saddle-ride type vehicle according to any one of claims 1 to 5, wherein a sound absorbing material is mounted on an inner surface of the muffler chamber.   The exhaust system for a saddle-ride type vehicle according to any one of claims 1 to 6, wherein a rectifying member that rectifies the exhaust gas is attached to the muffler pipe and is located upstream of the through hole forming region.   The exhaust of a saddle-ride type vehicle according to any one of claims 1 to 7, wherein an anti-vibration stay is provided in the silencing chamber to connect the opposing chamber walls to suppress vibration of the silencing chamber. apparatus.   An exhaust device for a saddle-ride type vehicle, comprising the exhaust device according to any one of claims 1 to 8.   10. The muffler according to claim 9, wherein the muffler is disposed right above the rear wheel, the exhaust passage is bent so as to rise upward at the rear of the engine, and the muffler chamber is provided at the bent portion. Exhaust device for riding type vehicles.

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