DE602006000343T2 - Motorcycle exhaust system for a multi-cylinder engine - Google Patents

Description

The present invention relates to an exhaust system for motorcycle multi-cylinder engines, which includes: several exhaust pipes whose upstream Ends with a motor body a multi-cylinder engine are connected; a confluence exhaust pipe comprising a plurality of individual pipe parts to the downstream To connect end portions of the exhaust pipes individually, and a Einmündungsrohrteil, around the downstream to summarize lying end portions of the individual pipe parts; and a silencer, the one with the downstream lying end of the Einmündungsrohrteils connected, wherein the downstream end of a throttle tube, the one on the downstream lying end part of at least one exhaust pipe is fixed in at least one of the individual pipe parts is introduced.

An exhaust system for multi-cylinder motorcycle engines which provides the output characteristic in low to medium engine speed ranges by connecting a plurality of exhaust pipes extending from a multi-cylinder engine to a muzzle exhaust pipe and inserting a throttle pipe connected to the downstream end of one of the exhaust pipes into a muzzle exhaust pipe improved, for example, is through JP-A-62099628 known.

at the exhaust system according to the prior art is the throttle tube, that with one of the exhaust pipes by machining an exhaust pipe to constriction his downstream lying end portion is summarized and in the confluence tailpipe introduced is with the muzzle exhaust pipe welded.

The Length of the Throttle pipe has a strong influence on the output characteristics of the motor. High dimensional accuracy is for the length of the throttle tube required and a high degree of freedom of design for the Throttle pipe is required to change its shape according to the movement characteristic a motorcycle easily.

There the throttle pipe with the exhaust pipe in the exhaust system after the Prior art is summarized, it is difficult to dimensional accuracy to improve with throttle throttle alone. If the shape of the throttle tube to change It is necessary to redesign all the exhaust pipes and consequently, the design freedom is not high.

It is an object of the present invention, given the situation was made, an exhaust system for motorcycle multi-cylinder engines to provide an improvement in the dimensional accuracy of a throttle tube regardless of an exhaust pipe and the change in the shape of the throttle tube alone allows so as to increase the freedom of design.

Around To achieve the object is the invention set forth in claim 1 a motorcycle with an exhaust system for a multi-cylinder engine, comprising: a plurality of exhaust pipes whose upstream ends are connected to the motor body a multi-cylinder engine are connected; comprising a confluence exhaust pipe several individual pipe parts to the downstream ends of the exhaust pipes to connect individually, and a junction pipe part to the downstream To summarize ends of the individual pipe parts; and a silencer that with the downstream lying end of the Einmündungsrohrteils connected, wherein the downstream end of a throttle tube, the one on the downstream lying end of at least one exhaust pipe is attached, in at least one of the individual pipe parts is introduced, wherein the throttle tube as a separate part at the downstream end at least an exhaust pipe is attached.

In addition to The arrangement of the present invention according to claim 1 is that in claim 2 set forth invention a motorcycle, wherein a sound absorber at the confluence exhaust pipe near the downstream lying end of the throttle tube is mounted.

In addition to the arrangement of the present invention according to claim 1 or 2 is the in claim 3 invention a motorcycle, wherein the upstream End of the throttle tube at the downstream end portion of the shortest Exhaust pipe of the several exhaust pipes is attached to each other in length distinguish and their upstream ends with the motor body connected to a pair of benches having a V-shape and the downstream End of the throttle tube in the shortest single Pipe part of the several individual pipe parts is inserted and behind the downstream end of the exhaust pipe, unlike the shortest exhaust pipe in the front and return direction of the motorcycle.

In addition to the arrangement of the present invention according to claim 3, the invention set forth in claim 4 is a motorcycle in which the downstream ends of the exhaust pipes, the upstream ends of which are connected to the exhaust ports, in the side surfaces on the opposite sides of the in front and rear direction of the motorcycle arranged benches are formed, are inserted between the outlet openings of the banks below the engine body, the confluence exhaust pipe is connected to the downstream ends of the exhaust pipes below the engine body, and a catalyst is mounted in the exhaust passage on the downstream side of the confluence exhaust pipe.

According to the in Claim 1 set forth, since the throttle tube of the several exhaust pipes is separated and at the downstream End of at least one exhaust pipe is attached, the dimensional accuracy the throttle tube regardless of the exhaust pipes are improved and the shape of the throttle tube alone can be changed, which makes it possible to increase the degree of freedom of design.

According to the in Claim 2 set forth, since the degree of freedom of the throttle tube is high, the sound absorbent at the confluence tailpipe near the downstream lying end of the throttle tube are attached and an excellent Sound absorption effect of the sound absorber can by suitably determining the downstream end position of the Throttle tube can be achieved.

According to the in Claim 3 may, although the shapes and lengths of the Exhaust pipes in particular by the installation space and the design of the multi-cylinder engine, which is a multi-cylinder V-engine mounted on the motorcycle, limited are, the output characteristics in medium to low speed ranges the engine can be improved by the throttle pipe at the downstream End of the shortest exhaust pipe is attached, which makes it possible is to easily change the output characteristics of the motor.

According to the in Claim 4 set forth invention, the cleaning performance of Catalyst on the downstream lying side of the confluence exhaust pipe be stabilized by the lengths the exhaust pipes from the pair of benches to the confluence exhaust pipe made as small as possible and a temperature difference between them in the confluence exhaust pipe mixing exhaust gases is reduced. In addition, the temperature the exhaust gases in contact with the catalyst are made uniform be ensured by the distance of the exhaust pipes to the catalyst is and a reduction in the cleaning efficiency of the catalyst repressed can be.

1 is a side view of the motorcycle.

2 is a front view of an engine and an exhaust when it comes out through an arrow 2 in 1 seen direction is seen.

3 is a view when viewed from the arrow 3 in 2 seen direction is seen.

4 is a plan view of a part of the exhaust system, without showing the engine when it comes out of the arrow 4 in 3 seen direction is seen.

5 is an enlarged view of a part indicated by an arrow 5 in 3 the exhaust system is shown.

6 FIG. 10 is an enlarged sectional view taken along line 6-6 in FIG 5 ,

7 is a sectional view taken along the line 7-7 in 6 ,

8th is a sectional view taken along the line 8-8 in FIG 6 ,

9 is an enlarged sectional view taken along the line 9-9 in 5 ,

10 is a sectional view taken along the line 10-10 in 5 ,

11 is a diagram illustrating the output characteristic of the motor.

A preferred embodiment will be described below with reference to the accompanying drawings.

The 1 to 11 represent an embodiment of the present invention. 1 is a side view of a motorcycle, 2 is a front view of an engine and an exhaust when it comes out through an arrow 2 in 1 seen direction, 3 is a view when viewed from the arrow 3 in 2 seen direction, 4 is a partial top view of the exhaust system without showing the engine when it comes out of the box by an arrow 4 in 3 seen direction, 5 is an enlarged view of a part indicated by an arrow 5 in 3 the exhaust system is shown 6 FIG. 10 is an enlarged sectional view taken along line 6-6 in FIG 5 . 7 is a sectional view taken along the line 7-7 in 6 . 8th is a sectional view taken along the line 8-8 in FIG 6 . 9 is an enlarged sectional view taken along the line 9-9 in 5 . 10 is a sectional view taken along the line 10-10 in 5 and 11 is a diagram of the output characteristic of the motor.

In 1 are front forks 16 to record of the front wheel WF at the front end of the body frame 15 this motorcycle stored in such a way that it can be steered, and the front part of a swing arm 17 for receiving the rear wheel WR at the rear is at the central part of the body frame 15 stored in such a way that it can swing in the vertical direction. The engine body 18 of a multi-cylinder V engine E is interposed between the front wheel WF and the rear wheel WR and on the body frame 15 mounted and the driving force is from the multi-cylinder engine E to the rear wheel WR via a drive shaft-transmission gear (not shown), partially in the swing arm 17 is housed, transferred.

In 2 and 3 is the engine body 18 a two-cylinder V-type engine comprising a pair of first and second banks BA and BB in the front and rear direction of the motorcycle, and an exhaust system 21 is with outlet openings 20A and 20B connected in the side surfaces on the opposite sides of the cylinder heads 19A and 19B Banks BA and BB are formed.

The exhaust system 21 includes a pair of first and second exhaust pipes 22 and 23 whose upstream ends are connected to the outlet openings 20A and 20B the cylinder heads 19A and 19B of the engine body 18 connected, a confluence exhaust pipe 24 that consists of a pair of two single pipe parts 24a and 24b for connecting the downstream end portions of the first and second exhaust pipes 22 and 23 and a confluence raw 24c for summarizing the downstream ends of the individual pipe parts 24a and 24b There is a catalyst 25 connected to the downstream end of the confluence tube portion 24c of the confluence exhaust pipe 24 connected, and a silencer 26 that with the downstream end of the catalyst 25 connected is.

Likewise in 4 extends the first exhaust pipe 22 , whose upstream end with the outlet opening 20A on the front side surface of the cylinder head 19A the first bank BA at the front of the banks BA and BB of the engine body 18 is connected, from the outlet opening 20A in front of the engine body 18 down and then on the right side and below the engine body 18 towards the rear, viewed in the front and rear direction of the motorcycle forward.

The second exhaust pipe 23 , whose upstream end with the outlet opening 20B on the rear side surface of the cylinder head 19B the second bank BB at the rear of the banks BA and BB of the engine body 18 is the direction of the right side of the engine body 18 from the outlet opening 20B curved and extends down to the right side of the engine body 18 and then backwards underneath the engine body 18 , viewed in front and rear direction of the motorcycle forward.

Thus, the downstream ends of the first and second exhaust pipes 22 and 23 between the outlet openings 20A and 20B Banks BA and BB below the engine body 18 inserted. That is, as in 3 is shown, the downstream ends of the first and second exhaust pipes 22 and 23 are between the vertical lines LA and LB, from the centers of the opening ends of the outlet openings 20A and 20B in the side view run down, inserted.

The muzzle exhaust pipe 24 is with the downstream ends of the first and second exhaust pipes 22 and 23 below the engine body 18 connected. In addition, the length of the first exhaust pipe 22 set smaller than the length of the second exhaust pipe 23 ,

In 5 and 6 is the muzzle exhaust pipe 24 from a pair of half-elements 27 and 28 which are connected to each other, and a pair of side wall forming elements 29 and 30 between the half elements 27 and 28 are inserted, composed. It includes the first and second individual pipe parts 24a and 24b , the elements forming the sidewall 29 and 30 as having the inner side walls, and the confluence tube part 24c for connecting the downstream ends of the first and second individual pipe parts 24a and 24b and is essentially formed like a letter Y. In addition, the length of the first single pipe part 24a set smaller than the length of the second single pipe part 24b , first and second mouthpieces 31 and 32 which are cylindrically shaped and a pair of slots 33 and 34 to allow expansion, are at the upstream ends of the first and second individual pipe parts 24a and 24b attached, and annular stepped parts 31a and 32a that one of the confluence exhaust pipe 24 Opposite opposite side are respectively on the inner walls of the first and second mouthpieces 31 and 32 educated.

ring stopper 35 and 36 are respectively on the outer walls near the downstream ends of the first and second exhaust pipes 22 and 23 attached, with an annular seal 37 equipped downstream end portion of the first exhaust pipe 22 is in the first mouthpiece 31 together with the stopper 35 and the seal 37 used while the seal 37 between the step part 31a and the stopper 35 is squeezed, and the downstream end of the first exhaust pipe 22 is with the first single pipe part 24a of the confluence exhaust pipe 24 by attaching the first mouthpiece 31 with a fastening tape wrapped around it 39 connected. The downstream end portion of the second exhaust pipe 23 whose outer wall with an annular seal 38 is in the second mouthpiece 32 together with the stopper 36 and the seal 38 used while the seal 38 between the step part 32a and the stopper 36 is squeezed, and the downstream end of the second exhaust pipe 23 is with the second single pipe part 24b of the confluence exhaust pipe 24 by attaching the second mouthpiece 32 with a fastening tape wrapped around it 40 connected.

The upstream end of a throttle tube 41 that from the first exhaust pipe 22 is separated, is at the downstream end part of at least one of the first and second exhaust pipes 22 and 23 attached, ie the downstream end portion of the first exhaust pipe 22 that is the shorter pipe of the first and second exhaust pipes 22 and 23 in this embodiment. The downstream end of the throttle tube 41 coming from the downstream end of the first exhaust pipe 22 protrudes is at least in one of the first and second individual pipe parts 24a and 24b of the confluence exhaust pipe 24 introduced. In this embodiment, the downstream end of the throttle tube 41 in the first single pipe part 24a introduced, which is shorter than the second single pipe part 24b ,

The throttle tube 41 has a diameter-expanded part 41a at the upstream end so as to be formed cylindrically with a step, and the diameter-expanded part 41a is from the downstream end of the first exhaust pipe 22 in the first exhaust pipe 22 introduced and on the inner wall near the downstream end of the first exhaust pipe 22 fixed by welding or the like. In addition, the throttle tube 41 in the first exhaust pipe 22 attached in such a way that part of it from the downstream end of the first exhaust pipe 22 protrudes.

A cylindrical sleeve 42 to survive the throttle tube 41 is on the inner wall at the downstream end of the first exhaust pipe 22 fixed by welding or the like in such a manner that a part thereof from the first exhaust pipe 22 protrudes, and the outer wall of the throttle tube 41 is on the inner wall of the sleeve 42 fixed by welding or the like.

Thus, a part that is from the downstream end of the first exhaust pipe 22 of the throttle tube 41 protrudes, in the first single pipe part 24a introduced. In addition, the downstream end of the throttle tube 41 behind the downstream end of the second exhaust pipe 23 that with the second single pipe part 24b is connected, arranged.

In 7 and 8th is a first sound absorber 44 at the confluence exhaust pipe 24 near the downstream end of the throttle tube 41 appropriate. The first sound absorbent 44 is made by filling, for example, a stainless steel sound absorbing material 45 created, which is the circulation of an exhaust gas from the individual pipe parts 24a and 24b in the space between the first and second individual pipe parts 24a and 24b allowed.

That is, the side wall forming elements 29 and 30 covering the inner side walls of the first and second individual pipe parts 24a and 24b form, consist of a porous plate with a large number of pores 46 and 47 and the sound absorbing material 45 gets into a sound absorption chamber 48 filled between the half-elements 27 and 28 outside of this side wall forming elements 29 and 30 and between the sidewall elements 29 and 30 is trained.

In 9 is a second sound absorbent 49 at the intermediate part of the confluence tube part 24c of the confluence exhaust pipe 24 appropriate. The second sound absorbent 49 is done by filling a stainless steel sound absorbing material 54 in an annular sound absorption chamber 53 created between an extended part 50 is formed, which is expanded outward in the radial direction and in the mouth pipe part 24c is formed, and a cylindrical element 51 on the inner wall of the junction tube part 24c is fixed, cylindrical and made of a porous plate with a large number of pores 52 consists.

In 10 is a transmitter mounting tube 55 for installing an oxygen meter, not shown, in the upper part of the confluence tube part 24c attached to the downstream side of the second sound absorbing means and a third sound absorbing means 56 is at the junction pipe part 24c below the encoder mounting tube 55 appropriate. The third sound absorbent 56 is done by filling a stainless steel sound absorbing material 61 in a sound absorption chamber 60 created between a lower stretched part 57 is formed, which expands outward in the radial direction and below the confluence raw material 24c is formed, and a curved element 58 on the inner wall of the junction tube part 24c is attached and made of one porous plate with a large number of pores 59 exists to have a bent portion.

Back in 9 indicates the catalyst 25 a housing 63 on that with the downstream end of the confluence tube portion 24c of the confluence exhaust pipe 24 connected, and a catalyst 64 is in an exhaust passage 65 mounted in the housing 63 through the junction pipe part 24c is trained.

A description of the function of this embodiment will be given below. The throttle tube 41 that from the first exhaust pipe 22 is separated, is at the downstream end portion of the first exhaust pipe 22 the first and second exhaust pipes 22 and 23 attached in such a way that a part thereof from the downstream end of the first exhaust pipe 22 protrudes and that from the downstream end of the first exhaust pipe 22 protruding part in the shortest first single pipe part 24a the first and second individual pipe parts 24a and 24b which differ in length and in the confluence exhaust pipe 24 are provided.

That is, because the throttle tube 41 is separated from the first exhaust pipe and at the downstream end portion of the first exhaust pipe 22 attached, the dimensional accuracy of the throttle tube 41 regardless of the first exhaust pipe 22 be improved and the shape of the throttle tube 41 can be changed alone, thereby making it possible to increase the design freedom.

Because the first sound absorbent 44 at the confluence exhaust pipe 24 near the downstream end of the throttle tube 41 is attached and the design freedom of the throttle tube 41 big, may be the first sound absorbent 44 at the confluence exhaust pipe 24 near the downstream end of the throttle tube 41 be attached and an excellent sound absorption effect of the first sound absorbent 44 can by suitably determining the downstream end position of the throttle tube 41 be achieved.

In addition, the upstream ends of the first and second exhaust pipes 22 and 23 , which differ in length with each other, with the engine body 18 having a pair of banks BA and BB, which form a V-shape, the upstream end of the throttle tube 41 at the downstream end of the first exhaust pipe 22 attached, which is the shorter tube of the two exhaust pipes 22 and 23 is, and the downstream end of the throttle tube 41 behind the downstream end of the second exhaust pipe 23 is arranged in the front and rear direction of the motorcycle. As a result, the shapes and lengths of the first and second exhaust pipes 22 and 23 in particular limited by the installation space and the design of the multi-cylinder engine E, which is a mounted on the motorcycle multi-cylinder V-engine. The throttle tube 41 however, is at the downstream end of the shortest first exhaust pipe 22 mounted to improve the output characteristic in a medium to low speed range of the engine, whereby it is possible to easily change the output characteristic of the motor.

That is, the torque and output power can be used in mid to low rpm ranges of the engine of a motorcycle where the throttle tube 41 at the downstream end of the first exhaust pipe 22 is fixed, as indicated by the curves of the solid lines in 11 as compared with those of a motorcycle in which the throttle pipe is not at the downstream end of the first exhaust pipe 22 is attached as indicated by the dashed lines in 11 is shown.

Further, in the engine body 18 the downstream ends of the first and second exhaust pipes 22 and 23 whose upstream ends are connected to the outlet openings 20A and 20B are connected in the side surfaces on the opposite sides of the arranged in the front and rear direction of the motorcycle benches BA and BB, between the outlet openings 20A and 20B Banks BA and BB below the engine body 18 inserted, the muzzle exhaust pipe 24 with the downstream ends of the first and second exhaust pipes 22 and 23 below the engine body 18 connected and the catalyst 64 in the exhaust passage 65 on the downstream side of the confluence exhaust pipe 24 appropriate.

In this arrangement, the cleaning performance of the catalyst 64 on the downstream side of the confluence exhaust pipe 24 be stabilized by the lengths of the exhaust pipes 22 and 23 from the pair of banks BA and BB to the confluence exhaust pipe 24 be kept as small as possible and a temperature difference between them in the confluence exhaust pipe 24 mixing exhaust gases is reduced. In addition, the temperature of the catalyst 64 In contact exhaust gases are made uniform by the distance from the first and second exhaust pipes 22 and 23 to the catalyst 64 is ensured and a reduction in the cleaning efficiency of the catalyst 64 can be suppressed.

While the embodiment of the present invention has been described, it should be understood The present invention is not limited to the embodiment and various changes, and modifications to the invention may be made without departing from the spirit and scope thereof.

18

motor body

20A, 20B

outlet

22 23

exhaust pipe

24

Confluence exhaust pipe

24a, 24b

separate pipe parts

24c

Junction pipe part

26

silencer

41

choke tube

44

Sound absorbent

64

catalyst

65

Exhaust passage

BA, BB

Bank

e

Multi-cylinder engine

Claims (4)

Motorcycle with an exhaust system for a multi-cylinder engine comprising: a plurality of exhaust pipes ( 22 . 23 ) whose upstream ends are connected to an engine body ( 18 ) of a multi-cylinder engine (E); a confluence exhaust pipe ( 24 ) comprising a plurality of individual pipe parts ( 24a . 24b ) to the downstream ends of the exhaust pipes ( 22 . 23 ) and a confluence tube part ( 24c ) to the downstream ends of the individual pipe parts ( 24a . 24b ); and a silencer ( 26 ) connected to the downstream end of the confluence tube portion (FIG. 24c ), wherein the downstream end of a throttle tube ( 41 ) located at the downstream end of at least one exhaust pipe ( 22 . 23 ), in at least one of the individual pipe parts ( 24a . 24b ), wherein the throttle tube ( 41 ) as a separate part at the downstream end of at least one exhaust pipe ( 22 ) is attached. A motorcycle according to claim 1, wherein a sound absorber ( 44 ) at the confluence exhaust pipe ( 24 ) near the downstream end of the throttle tube ( 41 ) is attached. Motorcycle according to one of the preceding claims, wherein the upstream end of the throttle tube ( 41 ) at the downstream end portion of the shortest exhaust pipe ( 22 ) of the several exhaust pipes ( 22 . 23 ), which differ in length and whose upstream ends are connected to the engine body ( 18 ) having a pair of banks (BA, BB) which form a V-shape and the downstream end of the throttle tube (FIG. 41 ) in the shortest individual pipe part ( 24a ) of the several individual pipe parts ( 24a . 24b ) and behind the downstream end of the exhaust pipe ( 23 ), unlike the shortest exhaust pipe ( 22 ) in the front and rear direction of the motorcycle. A motorcycle according to claim 3, wherein the downstream ends of the exhaust pipes ( 22 . 23 ), whose upstream ends with the outlet openings ( 20A . 20B ), which are formed in the side surfaces on the opposite sides of the front and rear direction of the motorcycle arranged banks (BA, BB), between the outlet openings ( 20A . 20B ) of the banks (BA, BB) below the engine body ( 18 ), the confluence exhaust pipe ( 24 ) with the downstream ends of the exhaust pipes ( 22 . 23 ) below the engine body ( 18 ) and a catalyst ( 64 ) in the exhaust passage ( 65 ) on the downstream side of the confluence exhaust pipe ( 24 ) is attached.