JPH11280467A - Exhauster of saddle-seat type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To elongate an exhaust pipe as long as possible on condition that a necessary capacity as a muffler is secured and improve an engine performance by connecting a downstream edge of the exhaust pipe to the intermediate part of the muffler in the longitudinal direction, concerning a vehicle in which the muffler, connected to a downstream edge of the exhaust pipe, is arranged in the longitudinal direction. SOLUTION: In a saddle-seat type motorcycle, an engine for running is suspended on the front of a body frame and an exhaust system Ex is connected to an exhaust port P opened on the head front of the engine E directly under a fuel tank. An exhaust pipe Pe, which is a main part of the exhaust system Ex, is composed of an upstream exhaust pipe 1 and a downstream exhaust pipe 2. In this case, the downstream exhaust pipe 2 is inserted into the intermediate part of a muffler M directly under a seat S and a downstream edge of the exhaust pipe 2 is opened in an upstream expansion chamber of the muffler M. Also, the muffler M is elongated in the longitudinal direction directly under the seat S, and its intermediate part is suspended on a body frame F through a hanger H to be supported thereby. Consequently, elongation of the exhaust pipe Pe can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a straddle-type vehicle, and more particularly to an exhaust system for a straddle-type motorcycle.

[0002]

2. Description of the Related Art In general, an exhaust system of a straddle-type motorcycle is constructed by connecting a silencer to a downstream end of an exhaust pipe connected to an exhaust port of an engine, and the silencer is disposed along a longitudinal direction of a body frame. However, in such an exhaust system, there is a tendency that the capacity of the silencer is increased in order to enhance the effect of reducing the exhaust noise. In such a case, since the total length of the exhaust system is naturally limited, conventionally, it is necessary to increase the total length of the exhaust pipe while securing the capacity of the muffler. The exhaust pipe is detoured back and forth in front of the silencer in a back and forth manner.

[0003] An expansion chamber for accommodating the exhaust manifold is provided in series between the exhaust pipe and the muffler (Japanese Patent Publication No. 6-50005).
No. 2).

In general, the technical means described above has been adopted.

[0005]

However, if the above technical means are employed, there is a problem that the exhaust resistance is inevitably increased, which not only causes a decrease in engine efficiency but also impairs the appearance of the entire motorcycle. Further, if the above technical means are adopted, the length of the exhaust pipe is restricted by the silencer, and the substantial silencing capacity cannot be sufficiently secured even if the silencer has a large external shape. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made to solve the above-mentioned problem by making the overall length of the exhaust pipe as long as possible while securing the necessary capacity as a silencer. It is a main object of the present invention to provide an exhaust device for a straddle-type vehicle.

[0007]

According to the first aspect of the present invention, a muffler is connected to an exhaust port of an engine mounted on a vehicle body frame and connected to a downstream end of an exhaust pipe. An exhaust system for a saddle-ride type vehicle, which is provided along one side of the frame in the front-rear direction of the vehicle body frame, wherein a downstream end of the exhaust pipe is connected to a front-rear intermediate portion of the muffler. According to this feature, the required capacity of the silencer can be secured while setting the entire length of the exhaust pipe to a predetermined length in consideration of the engine performance, and the engine performance and the silencer performance are improved. In addition, the exhaust device does not impair the appearance and appearance of the entire vehicle.

According to the second aspect of the present invention, in the first aspect, the muffler case of the muffler includes a first half connected to a downstream end of the exhaust pipe, and a first half connected to the first half. A rear half portion connected to a rear end, wherein the front half portion is formed of a metal plate material and formed by coupling an outer plate half, and the rear half portion is formed by a cylindrical body; An upstream expansion chamber into which exhaust gas from the exhaust pipe flows directly is formed, and a downstream expansion chamber into which exhaust gas from the upstream expansion chamber flows is formed in the first half. According to this feature, in order to achieve the above-described effect of the first aspect of the present invention, the upstream expansion chamber into which the exhaust gas from the exhaust pipe directly flows is made cylindrical to secure sufficient rigidity and achieve a noise reduction effect. While further raising the downstream expansion chamber , By forming a bond of the outer plate halves, muffler overall design is easily on the processing of the silencer is facilitated.

According to a third aspect of the present invention, in the second aspect, the upstream expansion chamber is provided with the first expansion chamber.
The downstream expansion chamber is a second or third expansion chamber, and the exhaust gas flowing through the exhaust pipe is discharged from the first expansion chamber to the atmosphere through the second and third expansion chambers. According to this feature, in addition to achieving the same effect as the invention of the second aspect, the design of the second and third expansion chambers is facilitated by the improvement of the workability of the downstream expansion chamber. ,
The noise reduction effect can be further enhanced, and it is easy to set a desired design.

According to a fourth aspect of the present invention, in the second aspect, the connecting portion between the downstream end of the exhaust pipe and the muffler is located below the seating position of the seat on the vehicle body frame. The front half of the silencer case is formed in a flat shape in which the lateral width is narrower than the vertical width with respect to the body frame, and the legs of the occupant sitting at the seating position are the front half of the silencer. It is characterized by being located on the outside of the portion, according to such features, in order to achieve the same effect as the invention of claim 2, around the legs of the occupant sitting on the seat, The lateral width of the vehicle can be reduced, and the feet of the occupant can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

This embodiment is an embodiment in which the present invention is applied to a straddle-type motorcycle.
Left and right and up and down refer to the traveling direction of the motorcycle.

FIG. 1 is a side view of a motorcycle provided with the exhaust device of the present invention, FIG. 2 is a plan view taken along line 2 of FIG. 1, and FIG.
4 is a sectional view taken along line 4-4 in FIG. 3, FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG. 4, and FIG. Enlarged sectional view along line -6, FIG.
4 is an enlarged sectional view taken along line 7-7 in FIG. 4, FIG. 8 is an enlarged sectional view taken along line 8-8 in FIG. 4, and FIG. 9 is an enlarged sectional view taken along line 9-9 in FIG. 10 is an enlarged sectional view along line 10-10 in FIG.

1 and 2, a traveling engine E is suspended at the front of a body frame F of a straddle-type motorcycle, and a fuel tank T and a seat S are arranged in tandem around an upper surface of the body frame. It is installed. Immediately below the fuel tank T, an exhaust port P
The exhaust port P is connected to an exhaust system Ex.

When the engine E is a multi-cylinder engine, an exhaust system is connected to an exhaust port via an exhaust manifold.

An exhaust pipe Pe, which is a main part of the exhaust system Ex, comprises an upstream exhaust pipe 1 and a downstream exhaust pipe 2, and is integrally provided at an upstream end of the upstream exhaust pipe 1. connection flange 1 _1, an exhaust port P of the engine E
Connected to. The upstream exhaust pipe 1 extends from the front of the engine E to the rear of the vehicle body frame F through one side (right side) of the engine E, and its rear end faces above the rear wheel of the motorcycle. The upstream exhaust pipe 1
The front end of the downstream exhaust pipe 2 is integrally connected to the rear end thereof, and the downstream exhaust pipe 2 extends to the rear of the vehicle body frame F. is inserted into the middle portion of elaborating muffler M, the downstream end thereof is opened to the upstream side expansion chamber or first expansion chamber C ₁ of the muffler M.

Next, the structure of the silencer M is shown in FIGS.
This will be described with reference to FIGS.

The silencer M extends in the front-rear direction just below the seat S, and its middle portion is suspended and supported by a body frame F via a hanger H, and its front end extends to below the fuel tank T. Has been reached. The silencer case 3 of the silencer M is
It is formed in a hollow cylindrical shape that is long in the front-rear direction, and secures high rigidity at the rear end of the front half portion 3F, which is mostly formed flat in the left-right direction of the vehicle body frame F, in order to reduce the horizontal width. The rear end 3R formed of a cylindrical body is formed by integrally fitting and connecting the front ends thereof. The hanger H for suspension to the vehicle body frame F is integrally formed on the upper surface of the connection portion. ing.

The front half portion 3F is formed by fitting and connecting the inner plate half 4 and the outer plate half 5 formed by metal working of a metal plate by welding or the like. , 4 and FIGS. 7 and 8, the inner end edges of the inner plate half 4 having a flat cross section and the outer plate half 5 having an arcuate cross section on the side moving away therefrom. Are fitted together and joined together to form a Monaca-shaped cross section. As shown in FIG. 3, the flattening ratio in the left-right direction gradually decreases from the front end to the rear end. The width gradually increases as the shape seen from the front goes to the rear. The rear half portion 3R is formed of a cylindrical body having the same diameter over its entire length. An inner member 7 made of a punched metal is also provided on the inner surface of an outer member 6 made of a cylindrical metal plate with a glass wool 8 interposed therebetween. A tail plate 10 is integrally connected to the rear end of the opening of the body portion 9 composed of a laminated double tube.

Inside the silencing case 3, a first partition wall 12 for partitioning the front half portion 3F, which is flat in the left-right direction, and a second partition wall for partitioning the boundary between the front half portion 3F and the cylindrical rear half portion 3R. The partition 13 and the third partition 14 partitioning the rear part in the rear half portion 3R back and forth partition the second, third and first expansion chambers C ₂ , C ₃ and C ₁ from the front end to the rear end. Have been. The first expansion chamber C ₁ is constituted the upstream expansion chamber exhaust from the exhaust pipe Pe flows directly located at the rear of the muffler M, the second half of the cylindrical shape as shown in FIGS. 4-6 In the portion 3R, the trunk portion 9;
The second and third partitions 13 and 14 define the partition. As shown in FIG. 5, the vicinity of the first partition wall 12 in the first expansion chamber C _1, and the porous plate 15 across the first expansion chamber C ₁ is fixed, the first expansion chamber C ₁ Exhaust gas flowing through the perforated plate 15 is diffused. Also, as described later, the first expansion chamber C ₁
The downstream end of the downstream side exhaust pipe 2 communicates. A third partition 14 is provided between the third partition 14 and the tail plate 10.
A reinforcing plate 19 to be joined to the base plate is interposed.

The second and third expansion chambers constitute a downstream expansion chamber into which exhaust gas from the first expansion chamber C ₁ as an upstream expansion chamber sequentially flows, and the second expansion chamber C _2. Is located at the front of the sound deadening case 3 and is defined by outer plate halves 4 and 5 and the first partition 12, forming a front half 3F thereof. is be formed in a flat shape in the lateral direction, the lateral inner surface of the second expansion chamber C _2, inner plate 17 made of punched plates sandwiching the glass wool 16 are joined together. Further, the third expansion chamber C ₃ is located in the middle part in the front-rear direction of the sound deadening case 3, and forms the front half part 3 </ b> F. are defined, as shown in FIG. 7, the cross-section is formed in a wide flat in the lateral direction than the second expansion chamber C _2.

A first expansion chamber C _{1 at} the rear of the silencing case 3,
The second expansion chamber C _{2 at} the front portion is defined by the first and second partition walls 1.
2, 13 and the perforated plate 15, are communicated with each other by a straight first communication pipe 21.
And the expansion chamber C _2, and the third expansion chamber C ₃ of the rear, the second communicating pipe 22 supported by the first partition wall 12 communicate with each other, the further third expansion chamber C ₃ second partition wall 13, It is communicated with the atmosphere by an atmosphere discharge pipe 24 supported by the reinforcing plate 19 and the tail plate 10. As shown in FIG. 9, a sound absorbing tube 26 in which glass wool 25 is laminated on the inner surface is attached to the rear part of the air release pipe 24, and a large number of small a hole 24 ₁ is bored, noise of the exhaust gas flowing through the air discharge pipe 24 is adapted to be sound reduction flows through the sound absorbing cylinder 26.

As clearly shown in FIG. 4, the silencer case 3
The lower surface of the front portion of the insertion slot 2 that communicates with the second expansion chamber C ₂
8 is opened downward, and the exhaust pipe 2 on the downstream side of the exhaust pipe Pe is inserted into the muffler M through the insertion port 28, and the intermediate portion of the exhaust pipe 2 on the downstream side is inserted into the insertion port 2.
8 supported. Most of the downstream exhaust pipe 2 is inserted into the muffler M, extends in the muffler M in the longitudinal direction, and is supported by the first and second partition walls 12 and 13. And that the downstream end thereof is open to the muffler M first expansion chamber C ₁ of the rear. In the third the expansion chamber C _3, a portion of the outer periphery of the downstream exhaust pipe 2 are sound absorbing tube 30 is wound that Matoigi glass wool 29 in the inner surface, a downstream side exhaust pipe facing to the glass wool 29 A number of small holes 31 are formed in the exhaust pipe 2, and the exhaust noise of the exhaust gas flowing through the downstream exhaust pipe 2 can be absorbed and reduced by the sound absorbing cylinder 30.

As shown in FIGS. 4 and 10, a bracket 33 for attachment to the vehicle body frame F is provided integrally with the downstream exhaust pipe 2 in the vicinity of the connection with the upstream exhaust pipe 1. 33 is attached to the rear part of the body frame F.

As shown in FIGS. 1 and 2, the outer surface of the silencer M is covered with a protector 35 having an arc-shaped cross section, and front and rear portions of the protector 35 are provided with mounting members 36 and 37 such as mounting bolts. To the body frame F.

As described above, since most of the downstream exhaust pipe 2 is inserted into the silencer M, the capacity of the silencer M is reduced even if the entire length of the exhaust pipe Pe is increased. Nothing.

Next, the operation of this embodiment will be described.

[0028] Now the engine E is operated, the exhaust gas discharged therefrom through the upstream exhaust pipe 1 and the downstream exhaust pipe 2 of the exhaust pipe Pe, the rear portion of the first expansion chamber C ₁ of the muffler M Inflow. The exhaust gas that has entered the silencer M is supplied to the first expansion chamber C.
_{From 1} , the gas passes through the first communication pipe 21 and flows into the second expansion chamber C ₂ , and further flows therefrom through the second communication pipe 22 into the third expansion chamber C ₃ , during which the exhaust gas expands. The sound is effectively reduced by repeating the contraction. The third enters the expansion chamber C _3, exhaust gas is sound reduction are discharged to the atmosphere through the air discharge pipe 24.

The downstream exhaust pipe 2 is inserted into the silencer M from the middle part in the longitudinal direction of the silencer M and extends in the silencer M in the longitudinal direction, so that the entire length of the exhaust pipe Pe can be reduced. The exhaust pipe can be made as long as required for the performance of the engine, because it is possible to secure a sufficient capacity without shortening the overall length of the muffler. Moreover, the length of the exhaust pipe does not reduce the silencing capacity of the silencer.

In the silencer M, the latter half 3R is formed of a cylindrical body capable of ensuring sufficient rigidity, and the exhaust gas with high exhaust noise from the exhaust pipe Pe directly flows into the latter half 3R. Here, the exhaust noise can be effectively reduced, and the first half portion 3F made of a metal plate material and formed by connecting the inner and outer plate halves 4 and 5 is a second half made of a rigid rigid cylinder. The exhaust which is primarily reduced by the portion 3R can be efficiently reduced secondarily, and the first half 3F is formed by coupling the inner and outer plate halves 4 and 5, whereby Although it is not as rigid as the first half 3F,
The workability can be improved, and the design of the muffler as a whole becomes easier.

A downstream end of the exhaust pipe Pe and a muffler M
Is located below the seating position of the seat S on the body frame F, and the front half portion 3F of the sound deadening case 3 is formed in a flat shape in which the left-right width is narrower than the up-down width with respect to the body frame F. Then, the legs of the occupant sitting at the seating position of the seat S are located outside the front half portion 3F of the muffler M, and the lateral width of the vehicle around the occupant's legs can be reduced. Therefore, it is possible to improve the occupant's feet.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various embodiments are possible within the scope of the present invention. For example, in the above-described embodiment, a case has been described in which the present invention is applied to the exhaust system of a saddle-ride type motorcycle. However, the present invention can be applied to the exhaust system of another saddle-ride type vehicle, for example, a saddle-ride type motorcycle. Of course, in the above-described embodiment, the first half of the muffler has the first expansion chamber as the upstream expansion chamber, and the second half has the second and third expansion chambers as the downstream expansion chamber. However, two or more upstream expansion chambers may be formed in the second half, and one or three or more downstream expansion chambers may be formed in the first half.

[0033]

According to the first aspect of the present invention, a muffler is connected to an exhaust port of an engine mounted on a body frame and connected to a downstream end of an exhaust pipe, and the muffler is connected to one side of the body frame. In the exhaust system for a saddle-ride type vehicle, which is provided along the front-rear direction of the body frame, the downstream end of the exhaust pipe is connected to the middle part in the front-rear direction of the muffler, so that the entire length of the exhaust pipe The required capacity of the silencer can be secured while setting the length to a predetermined length in consideration of the engine performance, and the engine performance and the silencer performance can be improved. The appearance and appearance are not impaired.

According to the second aspect of the present invention, in the first aspect, the muffling case of the muffler includes a first half to which a downstream end of the exhaust pipe is connected, and a first half of the muffler. A rear half portion connected to a rear end, wherein the front half portion is formed of a metal plate material and formed by coupling an outer plate half, and the rear half portion is formed by a cylindrical body; An upstream expansion chamber into which exhaust gas from an exhaust pipe flows directly is formed, and a downstream expansion chamber into which exhaust gas from the upstream expansion chamber flows is formed in the first half. In order to achieve the above-described effects of the invention described in the above, the upstream expansion chamber into which exhaust gas from the exhaust pipe directly flows is made into a cylindrical body to secure sufficient rigidity to further enhance the noise reduction effect, and to increase the downstream expansion chamber inside. , Formed by joining outer skin halves More, facilitates the machining of the muffler,
Further, the overall design of the silencer becomes easier.

According to the third aspect of the present invention, in the second aspect, the upstream expansion chamber is the first expansion chamber.
The downstream expansion chamber is a second or third expansion chamber, and the exhaust gas flowing through the exhaust pipe is discharged from the first expansion chamber to the atmosphere through the second and third expansion chambers. So
In order to achieve the same effect as the invention of claim 2,
The design of the downstream-side expansion chamber is facilitated by the improvement of the workability of the downstream-side expansion chamber, the noise reduction effect can be further enhanced, and it is easy to set a desired design.

According to a fourth aspect of the present invention, in the second aspect, the connection between the downstream end of the exhaust pipe and the muffler is located below the seating position of the seat on the body frame. The front half of the silencer case is formed in a flat shape in which the lateral width is narrower than the vertical width with respect to the body frame, and the legs of the occupant sitting at the seating position are the front half of the silencer. Since it is located on the outer side of the portion, in addition to achieving the same effect as the invention of the second aspect, the lateral width of the vehicle around the legs of the occupant sitting on the seat can be narrowed. Therefore, the occupant's feet can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle provided with the exhaust device of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a partially broken plan view of the exhaust device.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is an enlarged sectional view taken along line 6-6 in FIG. 4;

FIG. 7 is an enlarged sectional view taken along line 7-7 in FIG. 4;

FIG. 8 is an enlarged sectional view taken along line 8-8 in FIG. 4;

FIG. 9 is an enlarged sectional view taken along line 9-9 in FIG. 4;

FIG. 10 is an enlarged sectional view taken along line 10-10 in FIG. 4;

[Explanation of symbols]

3 Silent case 3F First half 3R Second half 4 Inner plate half 5 ··· Outer plate half C ₁ ······ Upstream expansion chamber (first expansion chamber) C ₂ ····· Downstream expansion chamber (second expansion chamber) C ₃ ··· ····· Downstream side expansion chamber (third expansion chamber) E ····· Engine F ····· Body frame M ········ Silencer Pe ··· ····Exhaust pipe

Claims (4)

[Claims] An exhaust pipe (Pe) connected to an exhaust port (P) of an engine (E) mounted on a vehicle body frame (F).
A silencer (M) is connected to the downstream end of the vehicle body, and the silencer (M) is provided along one side of the body frame (F) in the front-rear direction of the body frame (F). An exhaust system for a straddle-type vehicle, wherein a downstream end of the exhaust pipe (Pe) is connected to an intermediate portion of the muffler (M) in a front-rear direction. 2. A silencing case (3) for said silencer (M).
Comprises a first half (3F) to which the downstream end of the exhaust pipe (Pe) is connected, and a second half (3R) connected to the rear end of the first half (3F), and the first half (3F)
Is formed by joining inner and outer plate halves (4, 5) made of a metal plate material, and the latter half (3R) is formed by a cylindrical body, and the latter half (3R) is provided with an exhaust pipe (3R). upstream expansion chamber exhaust from Pe) flows directly (C ₁₎ is formed, also on the front half portion (3F), downstream expansion chamber exhaust from said upstream expansion chamber (C ₁₎ flows ( _2. The exhaust device for a saddle-ride type vehicle according to claim 1, wherein C ₂ , C ₃ ) are formed. 3. The upstream expansion chamber (C ₁ ) is a first expansion chamber, and the downstream expansion chamber (C ₂ , C ₃ ) is a _second expansion chamber.
The exhaust gas flowing through the exhaust pipe (Pe) is the third expansion chamber, and the exhaust gas flows from the first expansion chamber (C ₁ ) to the second and third expansion chambers (C ₂ , C ₃ ).
Characterized in that it is released to the atmosphere through
The exhaust device for a straddle-type vehicle according to claim 2. 4. A connection portion between a downstream end of the exhaust pipe (Pe) and a muffler (M) is located below a seating position of a seat (S) on a vehicle body frame (F). The first half (3F) of (3) is formed in a flat shape in which the lateral width is narrower than the vertical width with respect to the body frame (F), and the leg of the occupant sitting at the seating position is provided with a silencer. The exhaust device for a saddle-ride type vehicle according to claim 2, wherein the exhaust device is located outside a front half portion (3F) of the case.