ES2299117T3 - EXHAUST SYSTEM FOR MOTORS OF MULTIPLE CYLINDERS FOR MOTORCYCLE. - Google Patents

Abstract

A motorcycle that has an exhaust system for a multi-cylinder engine, including: a plurality of exhaust pipes (22, 23) whose ends located upwards are connected to an engine body (18) of a multi-cylinder engine ( AND); a confluence exhaust pipe (24) including a plurality of individual tube portions (24a, 24b) for connecting the downstream ends of the exhaust pipes (22, 23) independently and a confluence tube portion (24c) to combine the downward ends of the individual tube portions (24a, 24b); and an exhaust silencer (26) connected to the downward end of the confluence tube portion (24c), the downward end of a throttle tube (41) attached to the downward end of at least one of the exhaust pipes (22, 23) in at least one of the individual tube portions (24a, 24b), where the throttle tube (41) is fixed as a separate piece to the downward end of at least one exhaust pipe ( 22).

Description

Exhaust system for cylinder engines Multiple for motorcycle.

The present invention relates to a system of exhaust for multi-cylinder motorcycle engines, which includes: a plurality of exhaust pipes whose ends located up are connected to the motor body of a motor multiple cylinders; a confluence exhaust pipe including a plurality of individual tube portions to connect the end portions located down the exhaust pipes independently and a portion of confluence tube for combine the end portions located down the individual tube portions; and a connected exhaust silencer to the end located down the tube portion of confluence, and the downward end of a tube choke connected to the end portion located down of at least one of the exhaust pipes is inserted into at least one of the individual tube portions.

An exhaust system for cylinder engines Multiple for motorcycle that improves the characteristics of power in the low to medium speed ranges of an engine connecting a plurality of exhaust pipes that extend from a multi-cylinder engine to a confluence exhaust pipe e inserting a choke tube connected to the end towards down one of the exhaust pipes to the exhaust pipe of confluence is known for JP-A-62099628, for example.

In the prior art exhaust system, the choke tube that integrates with one of the exhaust pipes processing an exhaust pipe in order to narrow its portion of end located down and inserted into the exhaust pipe of confluence, it is welded to the confluence exhaust pipe.

The length of the choke tube has a severe influence on engine power characteristics. Be Accurate high dimensional accuracy for tube length choke and a high degree of design freedom is required to the choke tube to easily change its design according to The movement characteristics of a motorcycle.

Since the choke tube is integrated with the exhaust pipe in the technical exhaust system above, it is difficult to improve dimensional accuracy with the tube choke alone.

When the tube design needs to be changed choke, you have to redesign all the exhaust pipes and, for Therefore, the degree of design freedom is not high.

An object of the present invention realized in view of that situation is to provide an exhaust system to multi-cylinder motorcycle engines, which allows to improve the dimensional accuracy of a choke tube regardless of an exhaust pipe and changing the design of the choke tube only in order to increase the degree of freedom of design.

To achieve the object, the invention set forth in claim 1 is a motorcycle having a system of exhaust for a multi-cylinder engine, including: a plurality of exhaust pipes whose ends are facing up are connected to the engine body of a cylinder engine multiple; a confluence exhaust pipe including a plurality of individual tube portions to connect the downstream ends of the exhaust pipes independently and a portion of confluence tube for combine the ends located down the tube portions individual; and an exhaust silencer connected to the end located down the confluence tube portion, the end located down a choke tube attached to the end located down at least one of the exhaust pipes is Insert in at least one of the individual tube portions, where

The choke tube is fixed as a piece separated at the end located down from at least one tube of escape.

In addition to the configuration of this invention according to claim 1, the invention set forth in the claim 2 is a motorcycle, where soundproofing means are attached to the confluence exhaust pipe near the end located down the choke tube.

In addition to the configuration of this invention according to claim 1 or 2, the invention set forth in claim 3 is a motorcycle, wherein the end located upward of the choke tube is fixed to the portion of downward end of the shortest exhaust pipe of the plurality of exhaust pipes that differ from each other in length and whose ends up are connected to the body of the motor that has a pair of benches forming a V shape, and the downward end of the choke tube is inserted in the shortest individual tube portion of the plurality of individual tube portions and located behind the end located down the exhaust pipe other than the exhaust pipe more Short in the front and rear direction of the motorcycle.

In addition to the configuration of this invention according to claim 3, the invention set forth in the Claim 4 is a motorcycle, where the ends located down the exhaust pipes whose ends facing above are connected to exhaust holes formed on the faces sides on opposite sides of the benches arranged in the Motorcycle front and rear steering are interposed between the exhaust holes of the benches under the body of the engine, the confluence exhaust pipe is connected to the downstream ends of the exhaust pipes below the engine body, and a catalyst is located in a step of exhaust on the down side of the exhaust pipe of confluence.

According to the invention set forth in the claim. 1, since the choke tube is separated from the plurality of exhaust pipes and attached to the end located at least down one of the exhaust pipes, the dimensional accuracy of the pipe choke can be improved regardless of the tubes escape and you can change the design of the choke tube alone, making it possible to increase the degree of freedom of design.

According to the invention set forth in the claim. 2, since the degree of freedom of shape of the choke tube is high, the soundproofing means can be attached to the exhaust pipe of confluence near the downward end of the choke tube and an excellent soundproofing effect of the media can be obtained soundproofing properly determining the final position towards down the choke tube.

According to the invention set forth in the claim. 3, although the shapes and lengths of the exhaust pipes in particular are limited by the installation space and the multi-cylinder engine configuration which is an engine of multiple cylinders of the V type mounted on the motorcycle, the power characteristics in the medium to low speed ranges of the motor can be improved by fixing the choke tube to the end  located down the shortest exhaust pipe, doing so possible to easily change the power characteristics of the engine.

According to the invention set forth in the claim. 4, catalyst purification performance on the side located down the confluence exhaust pipe can be stabilize by making the exhaust pipe lengths of the pair from banks to the confluence exhaust pipe as small as possible possible and reducing the temperature difference between gases of Exhaust that join in the confluence exhaust pipe. Besides, the exhaust gas temperature in contact with the catalyst is can make uniform ensuring the distance of the exhaust pipes to the catalyst, and a reduction in the efficiency of catalyst purification.

Figure 1 is a side view of a motorcycle.

Figure 2 is a front view of an engine and an exhaust system as seen from the represented direction by an arrow 2 in figure 1.

Figure 3 is a view as seen from the direction represented by an arrow 3 in figure 2.

Figure 4 is a plan view of part of the exhaust system without representing the engine, as seen from the direction represented by an arrow 4 in figure 3.

Figure 5 is an enlarged view of a part represented by an arrow 5 in figure 3 of the system of escape.

Figure 6 is an enlarged sectional view. cut on line 6-6 in figure 5.

Figure 7 is a sectional view cut in line 7-7 in figure 6.

Figure 8 is a sectional view cut in line 8-8 in figure 6.

Figure 9 is an enlarged sectional view. cut on line 9-9 in figure 5.

Figure 10 is a sectional view cut in line 10-10 in figure 5.

Figure 11 is a diagram representing the engine power characteristics.

A preferred embodiment of the present invention later with reference to the drawings companions

Figures 1 to 11 show an embodiment of The present invention. Figure 1 is a side view of a motorcycle, figure 2 is a front view of an engine and a exhaust system as seen from the direction represented with an arrow 2 in figure 1, figure 3 is a view as seen from the direction represented by an arrow 3 in figure 2, the Figure 4 is a partial plan view of the exhaust system without represent the engine as seen from the direction represented by an arrow 4 in figure 3, figure 5 is an enlarged view of a portion represented by an arrow 5 in figure 3 of the system Exhaust, Figure 6 is an enlarged sectional view cut in line 6-6 in figure 5, figure 7 is a section view cut on line 7-7 in the Figure 6, Figure 8 is a sectional view cut in the line 8-8 in figure 6, figure 9 is a view enlarged section cut on line 9-9 in the Figure 5, Figure 10 is a sectional view cut in the line 10-10 in Figure 5, and Figure 11 is a diagram of the engine power characteristics.

In figure 1, front forks 16 for articulate the front wheel WF the front end is supported of the body frame 15 of this motorcycle in such a way that can be directed, and the front portion of a swing arm 17 to articulate the rear wheel WR in the rear is supported in the intermediate portion of the body frame 15 of such so that it can swing in the vertical direction. The body of engine 18 of a V-type multi-cylinder engine E is interposed between the front wheel WF and the rear wheel WR and placed in body frame 15, and engine power of multiple cylinders E is transmitted to the rear wheel WR by a drive gear of drive shaft type (no represented) partially stored in the swing arm 17.

In figure 2 and figure 3, the body of the Engine 18 is a two-cylinder V-type engine including a pair of first and second BA and BB banks in the front direction and rear of the motorcycle, and an exhaust system 21 is connected to exhaust holes 20A and 20B formed on the side faces in the opposite sides of cylinder heads 19A and 19B of the BA and BB banks.

The exhaust system 21 includes a pair of pipes first and second exhaust 22 and 23 whose ends toward above are connected to the exhaust holes 20A and 20B of the cylinder heads 19A and 19B of the engine body 18, a tube of confluence exhaust 24 consisting of a pair of two portions of individual tube 24a and 24b to connect the end portions located down the first and second exhaust pipes 22 and 23 and a portion of confluence tube 24c to combine the downward ends of the individual tube portions 24a and 24b, a catalyst converter 25 connected to the end located down the confluence tube portion 24c of the confluence exhaust pipe 24, and an exhaust silencer 26 connected to the downward end of the catalyst converter 25.

Also with reference to figure 4, the first exhaust pipe 22 whose end up is connected to the exhaust hole 20A on the front side face of the cylinder head of cylinder 19A of the first bank BA on the front side of the BA and BB banks of the motor body 18 extends down the exhaust hole 20A at the front of the engine body 18 and later back on the right side and below the engine body 18 as you look forward in the direction front and rear motorcycle.

The second exhaust pipe 23 whose end located up is connected to the exhaust hole 20B in the rear side face of cylinder head 19B of second bank BB on the rear side of the BA and BB banks of the motor body 18, is curved to the right side of the motor body 18 from the exhaust hole 20B and extends down on the side right of the engine body 18 and then back below of the motor body 18 as you look forward in the direction front and rear motorcycle.

Thus, the ends located below the first and second exhaust pipes 22 and 23 are interposed between the exhaust holes 20A and 20B of the BA and BB banks below the motor body 18. That is, as depicted in Figure 3, the downstream ends of the exhaust pipes first and second 22 and 23 are interposed between the vertical lines LA and LB hanging from the centers of the hole ends of the Exhaust holes 20A and 20B in side view.

The confluence exhaust pipe 24 is connected to the downstream ends of the exhaust pipes  first and second 22 and 23 under the motor body 18. In addition, the length of the first exhaust pipe 22 is less than the length of the second exhaust pipe 23.

In Figure 5 and Figure 6, the exhaust pipe of confluence 24 is composed of a pair of means elements 27 and 28 interconnected to each other and a couple of training elements of side wall 29 and 30 interposed between the means elements 27 and 28. Includes the first and second 24th individual tube portions and 24b having the side wall forming elements 29 and 30 as the inner side walls and the tube portion of confluence 24c to interconnect the ends located down of the first and second individual tube portions 24a and 24b and it is formed substantially in the form of the letter Y. In addition, the length of the first portion of individual tube 24a is less than the length of the second portion of individual tube 24b, pieces of first and second mouths 31 and 32 that are cylindrical and have a pair of grooves 33 and 34 to allow expansion are fixed to the upward ends of the tube portions individual first and second 24a and 24b, and step portions annulars 31a and 32a that look aside in front of the exhaust pipe of confluence 24 are formed in the interior walls of the first and second mouth pieces 31 and 32, respectively.

Ring caps 35 and 36 are fixed on the outer walls near the ends located down from the first and second exhaust pipes 22 and 23, respectively, the end portion located down the first exhaust pipe 22 mounted with an annular seal 37 is mounted on the first mouth piece 31 together with the stop 35 and the seal 37 while the seal 37 is sandwiched between the portion of step 31a and the stop 35, and the end located below the first exhaust pipe 22 is connected to the first portion of individual pipe 24a of confluence exhaust pipe 24 holding the first mouth piece 31 with a clamping band 39 rolled up around. The end portion located down from the second exhaust pipe 23 whose outer wall is mounted with a gasket ring seal 38, is mounted on the second mouthpiece 32 together with the stop 36 and the seal 38 while the seal 38 is sandwiched between the step portion 32a and the stop 36, and the downward end of the second tube of exhaust 23 is connected to the second portion of individual tube 24b of the confluence exhaust pipe 24 holding the second piece of mouth 32 with a clamping band 40 wrapped around it.

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The upward end of a tube choke 41 that is separated from the first exhaust pipe 22, it is fixed to the end portion located downwards of at least one of the first and second exhaust pipes 22 and 23, that is, the end portion located down the first exhaust pipe 22 which is the shortest pipe of the first and second exhaust pipes 22 and 23 in this embodiment. The end located down the choke tube 41 protruding from the downward end of the first exhaust pipe 22 is inserted in at least one of the first and second individual tube portions 24a and 24b of the tube confluence exhaust 24. In this embodiment, the end located down the throttle tube 41 is inserted in the first portion of individual tube 24a that is shorter than the second portion of individual tube 24b.

The choke tube 41 has a portion of expanded diameter 41a at the end positioned upward so that is cylindrical with a step, and the diameter portion expanded 41a inserted from the downward end of the first exhaust pipe 22 to the first exhaust pipe 22 is fixed in the inner wall near the end located down the first exhaust pipe 22 by welding or the like. In addition, the tube choke 41 is fixed on the first exhaust pipe 22 of such so that part of it protrudes from the downward end of the first exhaust pipe 22.

A cylindrical ring 42 so that the tube protrudes choke 41 is fixed to the inner wall at the end located down the first exhaust pipe 22 by welding or analogues such that part of it protrudes from the first tube exhaust 22, and the outer wall of the choke tube 41 is fixed to the inner wall of the ring 42 by welding or the like.

Thus, the part that protrudes from the located end down the first exhaust pipe 22 of the choke tube 41 it is inserted into the first portion of individual tube 24a. In addition, the downward end of the choke tube 41 is located behind the downward end of the second exhaust pipe 23 connected to the second portion of individual tube 24b.

With reference to Figure 7 and Figure 8, first soundproofing means 44 are attached to the exhaust pipe of confluence 24 near the end located down the tube choke 41. The first soundproofing means 44 is they build loading, for example, a soundproofing material of steel stainless 45 that allows the circulation of exhaust gases from the individual tube portions 24a and 24b in the space between the first and second individual tube portions 24a and 24b.

That is, the wall formation elements lateral 29 and 30 that form the inner side walls of the first and second individual tube portions 24a and 24b are they consist of a porous plate that has a large number of pores 46 and 47, and the soundproofing material 45 is charged a soundproofing chamber 48 formed between the means elements 27 and 28 outside of these lateral wall formation elements 29 and 30 and between side wall elements 29 and 30.

In figure 9, second soundproofing means 49 are attached to the intermediate portion of the tube portion of confluence 24c of the confluence exhaust pipe 24. The seconds soundproofing means 49 are formed by loading a material 54 stainless steel soundproofing in a soundproofing chamber ring 53 formed between a swollen portion 50 outward in the radial direction and formed in the confluence tube portion 24c and a cylindrical element 51 that is fixed to the inner wall of the confluence tube portion 24c, cylindrical and composed of a porous plate that has a large number of pores 52.

In Figure 10, a sensor junction tube 55 to install an oxygen sensor, not shown, is fixed on the upper portion of the confluence tube portion 24c in the downward side of the second soundproofing means, and third soundproofing means 56 are attached to the tube portion of confluence 24c under the sensor junction tube 55. The third soundproofing means 56 are formed by introducing a 61 stainless steel soundproofing material in one chamber soundproofing 60 formed between a lower swollen portion 57 which it bulges out in the radial direction and is formed below of the confluence tube portion 24c and a curved element 58 fixed to the inner wall of the confluence tube portion 24c and composed of a porous plate that has a large number of pores 59 with arched section.

Going back to figure 9, the converter catalyst 25 has a box 63 connected to the end located towards below the confluence pipe portion 24c of the exhaust pipe of confluence 24, and a catalyst 64 is located in a passage of exhaust 65 formed in the case 63 through the tube portion of confluence 24c.

The function of this is described below. realization. The choke tube 41, which is separated from the first exhaust pipe 22, is fixed to the end portion located towards below the first exhaust pipe 22 of the first exhaust pipes and second 22 and 23 such that part of it protrudes from the end located down the first exhaust pipe 22, and the part that protrudes from the downward end of the first exhaust pipe 22 is inserted into the first portion of shorter individual tube 24a of the first and second individual tube portions 24a and 24b which differ from each other in length and are arranged in the tube of confluence exhaust 24a.

That is, as the choke tube 41 is separated from the first exhaust pipe 22 and fixed to the portion of downward end of the first exhaust pipe 22, the dimensional accuracy of the choke tube 41 can be improved regardless of the first exhaust pipe 22 and the tube design choke 41 can only be changed, making it possible Improve the degree of design freedom.

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Since the first soundproofing means 44 are attached to the confluence exhaust pipe 24 near the end located down the choke tube 41 and the degree of freedom shape of the choke tube 41 is high, the first means Soundproofing 44 may be attached to the exhaust pipe of confluence 24 near the end located down the tube choke 41 and you can get an excellent effect soundproofing of the first soundproofing means 44 determining properly the bottom down position of the choke tube 41.

In addition, the ends located upwards of the first and second exhaust pipes 22 and 23 that differ one from other in length, they are connected to the motor body 18 which has a pair of BA and BB banks that form a V-shape, the end located upstream of the choke tube 41 is fixed to the end located down the first exhaust pipe 22 which is the shorter pipe of both exhaust pipes 22 and 23, and the end located down the choke tube 41 is located behind from the downward end of the second exhaust pipe 23 in the front and rear direction of the motorcycle. Therefore, the shapes and lengths of the first and second exhaust pipes 22 and 23 in particular are limited by the installation space and the configuration of the multi-cylinder engine E which is an engine of V-type multiple cylinders mounted on the motorcycle. Without However, the choke tube 41 is fixed to the end located down the first shorter exhaust pipe 22 in order to improve power characteristics in speed ranges medium to low engine, making it possible to easily change The power characteristics of the engine.

That is, the torque and power in the ranges of medium to low engine speed of a motorcycle in which the choke tube 41 is attached to the downward end of the first exhaust pipe 22, can be increased as they represent continuous line curves in figure 11 compared to those of a motorcycle in which the choke tube is not fixed to the end located down the first exhaust pipe 22 as represent dashed lines in figure 11.

In addition, in the motor body 18, the ends located down the first and second exhaust pipes 22 and 23 whose ends up are connected to the exhaust holes 20A and 20B formed on the side faces in opposite sides of the BA and BB banks arranged in the direction front-rear motorcycle, are interposed between the exhaust holes 20A and 20B of the benches BA and BB under engine body 18, the exhaust pipe of confluence 24 is connected to the ends located down of the first and second exhaust pipes 22 and 23 under the body of the engine 18, and the catalyst 64 is located in the exhaust passage 65 on the downward side of the confluence exhaust pipe 24.

In this configuration, the benefits of purification of catalyst 64 on the downward side of the confluence exhaust pipe 24 can be stabilized by making lengths of the exhaust pipes 22 and 23 from the pair of banks BA and BB to the confluence exhaust pipe 24 as small as possible possible and reducing the temperature difference between gases of exhaust that join in the confluence exhaust pipe 24. Also, the temperature of the exhaust gases in contact with the catalyst 64 can be made uniform ensuring the distance of the pipes first and second escape 22 and 23 to catalyst 64, and you can avoid a reduction in the purification efficiency of the catalyst 64.

Although the realization of the present invention, it is to be understood that the present invention does not it is limited to the realization and you can make several changes and modifications in the invention without departing from its spirit and scope.

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Description of reference numbers

18:

motor body

20A, 20B:

exhaust hole

22, 23:

exhaust pipe

24:

confluence exhaust pipe

24a, 24b:

single tube portion

24c:

confluence tube portion

26:

exhaust silencer

41:

choke tube

44:

soundproofing media

64:

catalyst

65:

escape step

BA, BB:

Bank

AND:

multi cylinder engine.

Claims (4)

1. A motorcycle that has a system of exhaust for a multi-cylinder engine, including: a plurality of exhaust pipes (22, 23) whose ends are located upwards they are connected to an engine body (18) of a multi-cylinder engine (E); a confluence exhaust pipe (24) including a plurality of individual tube portions (24a, 24b) to connect the ends located below the exhaust pipes (22, 23) independently and a tube portion of confluence (24c) to combine the ends located towards below the individual tube portions (24a, 24b); and a exhaust silencer (26) connected to the end located down of the confluence tube portion (24c), introducing the downward end of a choke tube (41) attached to the downward end of at least one of the exhaust pipes (22, 23) in at least one of the individual tube portions (24a, 24b), where the choke tube (41) is fixed as a separate piece to the end located at the bottom of at least one tube exhaust (22). 2. The motorcycle according to claim 1, where soundproofing means (44) are attached to the exhaust pipe of confluence (24) near the downward end of the tube choke (41). 3. The motorcycle according to any of the preceding claims, wherein the upward end of the choke tube (41) is fixed to the end portion located down the shortest exhaust pipe (22) of the plurality of exhaust pipes (22, 23) that differ from one another in length and whose ends facing up are connected to the motor body (18) that has a pair of benches (BA, BB) forming a V shape, and the downward end of the tube choke (41) is inserted into the single tube portion more short (24a) of the plurality of individual tube portions (24a, 24b) and is located behind the downward end of the tube exhaust (23) other than the shortest exhaust pipe (22) in the front and rear direction of the motorcycle. 4. The motorcycle according to claim 3, where the downstream ends of the exhaust pipes (22, 23) whose ends located up are connected to Exhaust holes (20A, 20B) formed on the side faces in the opposite sides of the banks (BA, BB) arranged in the direction front and rear of the motorcycle, are interposed between Exhaust holes (20A, 20B) of the banks (BA, BB) under the engine body (18), the confluence exhaust pipe (24) is connected to the ends located down the tubes of exhaust (22, 23) under the engine body (18), and a catalyst (64) is located in an escape passage (65) on the side located down the confluence exhaust pipe (24).