JPH06173672A - Exhaust pipe of multicylinder engine for motorcycle - Google Patents

Abstract

PURPOSE:To simplify the keeping of a stress relieving member by making only an outside pipe function as a stress relieving member applied to a connecting part for connecting each of an exhaust pipes to the cylinder of an engine. CONSTITUTION:A parallel four-cylinder engine is provided with the exhaust pipe of an multicylinder engine for a motorcycle. The exhaust pipe 14 is composed of a pipe section 20 formed of four pipes #1 to 4 and a pipe assemby section. A semicircular plate 29 lies between the mouthes 231, 234 of the outside pipes #1, 4 of the pipes #1 to 4 and the exhaustt ports 241, 244 of a cylinder 24, and is lower in rigidity than the exhaust pipe 14 to lighten stress occurring at the mouthes 231, 234. Since the semicircular plate 29 is used for only the outside pipes #1, 4, the preparation of the semicircular plate 29 used for only the outside pipes #1, 4 will do. Thus the stress relieving member can be simply kept, and the cylinder can therefore be quickly connected to the exhaust pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe for a multi-cylinder engine of a motorcycle. More specifically, it relates to a connecting portion of a multi-cylinder engine of a motorcycle with an exhaust pipe cylinder.

[0002]

2. Description of the Related Art An exhaust pipe of a multi-cylinder engine of a motorcycle is formed by connecting an exhaust pipe, which is composed of a plurality of pipes corresponding to the number of cylinders, and a muffler. Then, each pipe of the exhaust pipe is connected to a cylinder of a multi-cylinder engine, and the other part of the exhaust pipe and the muffler are attached to the frame and other parts of the motorcycle by a suitable fixing means such as welding means. Then, the exhaust pipe is attached to the motorcycle.

However, the engine type is a parallel cylinder,
For example, in an exhaust pipe applied to a parallel four-cylinder engine, the connecting portion of each pipe constituting the exhaust pipe with the cylinder is arranged so as to be substantially parallel to the horizontal direction when viewed from the front-rear direction of the motorcycle. Connected. Due to the structure of the motorcycle, the connecting portion of each pipe with the cylinder is located in a narrow portion between the engine and the front fork / front wheel. Therefore, it is difficult to connect each pipe to the cylinder. In addition, the connection of the pipes to the cylinders is made by the operator on the left and right sides of the vehicle body, so the inner pipes (# 2, 3) are connected to the outer pipes (# 1, 4). ) Will be blocked by. Therefore, the visibility of the inner pipe is poor at the time of assembly, and it may be more difficult to assemble it with the cylinder than the outer pipe.

Further, in an exhaust pipe applied to a parallel cylinder type engine, the stress generated in the portion where each pipe of the exhaust pipe is connected to the cylinder is larger in the outer pipe. Regardless, conventional
The connection structure of each pipe with the cylinder was the same in all pipes. That is, when connecting each pipe to the cylinder, the mouth of each pipe is connected to the exhaust port of the cylinder with a tightening tool such as a clamp, but at this time, at the mouth of each pipe, in order to relieve the stress generated at the mouth. The so-called half-moon plate is used.

Therefore, if the meniscus plate is selected on the basis of the inner pipes # 2 and 3 which generate less stress, the life of the meniscus plate used in the outer pipes # 1 and 4 is shortened, and conversely, the outer pipe # 1 is used. If the meniscus plate is selected on the basis of 1 and 4, the meniscus plate used for the inner pipe becomes too strong in terms of strength, which causes the cost of the relevant part to increase.

Therefore, it is conceivable to use the meniscus plate as a meniscus plate having a strength suitable for each of the inner pipe and the outer pipe, but in that case, different kinds of meniscus plates must be prepared. .
Therefore, storage and assembly are troublesome this time.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and the problem to be solved is to provide an exhaust pipe for an exhaust pipe when the exhaust pipe is connected to a cylinder of an engine. It is possible to eliminate the need to arrange various meniscus plates as stress relaxation members for relieving the stress generated at the mouth of each pipe, and therefore, it is possible to simplify the storage of the meniscus plates and to use the cylinder and the exhaust pipe. It is to provide an exhaust pipe of a multi-cylinder engine of a motorcycle that can be connected quickly.

[0008]

An exhaust pipe of a multi-cylinder engine for a motorcycle according to the present invention solves the above problems and is as follows. That is,
The exhaust pipe of the multi-cylinder engine of the motorcycle according to the present invention,
Only the outer pipe has a stress relaxation member used for the connecting portion when connecting each pipe of the exhaust pipe connected to the cylinder of the parallel multi-cylinder engine and the cylinder of the engine.

[0009]

According to the exhaust pipe of the multi-cylinder engine of the motorcycle of the present invention, since the stress relaxation member used when connecting each pipe of the exhaust pipe and the cylinder of the engine is used only for the outer pipe, A stress relaxation member dedicated to the pipe may be prepared. Therefore, it is not necessary to prepare stress relaxation members for all pipes.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An exhaust system for a multi-cylinder engine of a motorcycle according to the present invention will be described in detail below with reference to the accompanying drawings. 1 is an overall side view showing a state in which an exhaust pipe of a multi-cylinder engine of the motorcycle of the present invention is mounted on the motorcycle, FIG. 2 is a plan view of an exhaust pipe of a multi-cylinder engine of the motorcycle of the present invention, and FIG. FIG. 4 is an enlarged cross-sectional view of a main part showing a state in which an outer pipe # 1 (4) of the exhaust pipe is connected to the cylinder of the engine. FIG. 4 shows an inner pipe # 2 (3) of the exhaust pipe connected to the cylinder of the multi-cylinder engine. FIG. 5 is an enlarged cross-sectional view of an essential part showing a state, FIG. 5 is an exploded perspective view of FIG. 3, and FIG. 6 is a front view of the arrangement of each pipe of the exhaust pipe with respect to the engine.

The motorcycle 2 has a frame 4 as a skeleton. The front and rear wheels 6 and 8 are provided on the front and rear of the frame 4, and a parallel four-cylinder engine 10 is provided between the front and rear wheels 6 and 8 by a fixing means (not shown) to form a skeleton of the motorcycle. It is attached to the frame 4.

An exhaust pipe 12 of a multi-cylinder engine for a motorcycle according to the present invention is attached to the parallel four-cylinder engine 10. The exhaust pipe 12 is an exhaust pipe 14
And mufflers 16, 16 and metal clamps 18, 18 for connecting the exhaust pipe 14 and the mufflers 16, 16
Consists of.

The exhaust pipe 14 is composed of a pipe section 20 composed of four pipes # 1 to 4 and a pipe collecting section 22.

Mouth 2 of each of the pipes # 1 to # 4 of the pipe section 20
3 ₁ to 23 ₄ are respectively connected to the exhaust ports 24 _{1 to} 24 ₄ of the cylinder 24 of the four-cylinder engine 10, and the other portion of the exhaust pipe 14 and the mufflers 16 and 16 are the frame 4 of the motorcycle 2 or other portions. Attached to the exhaust pipe 12 by a suitable fixing means such as welding means.
Is attached to the motorcycle 2.

[0015] Closure 23 _{1-23 4} is a connection portion between the cylinder 24 of each pipe # 1-4, the cylinder as parallel substantially horizontal direction as shown in FIG. 6 as viewed from the front and back direction of the motorcycle 2 24 exhaust ports 24 _{1 to} 24 ₄ are connected. At this time, clamps 27 _{1 to} 27 ₄ which are fastening tools are used to connect the pipes 1 to 4 to the cylinder 24. The clamps 27 _{1 to} 27 ₄ have their pipe holes 28.
After passing the respective pipes # 1-4 to _{1-28 4,} the clamp 2
7 _{1 to} 27 ₄ of each flange 27a (in the drawing, the clamp 27
Only _one flange 27a is shown in FIG. ) Is fastened to the cylinder 24 with a bolt (not shown), so that each of the pipes # 1 to 4 and the cylinder 24 are integrated. The clamps 27 ₁ and 27 ₄ and the clamps 27 ₂
27 ₃ and pipe holes 28 ₁ and 28 ₄ and pipe holes 28 ₂ and 28 ₃ have different diameters, respectively. Specifically, the pipe hole 28
The diameter of ₁ , 28 ₄ is smaller than the outer diameter of the flange of the meniscus plate, which will be described later, and larger than the outer diameter of the large-diameter portion of the half-moon plate holder. The diameter of the pipe holes 28 ₂ and 28 ₃ is smaller than the outer diameter of the cylindrical body described later.

Then, between the mouths 23 ₁ and 23 ₄ of the outer pipes # 1 and 4 of the pipes # 1 to ₄ and the exhaust ports 24 ₁ and 24 ₄ of the cylinder 24, the mouths 23 ₁ and to alleviate the stress generated in 23 _4, the exhaust pipe 14
The so-called half-moon plates 29, 29 which are less rigid than
The pipes # ₁ and ₄ are interposed at the mouths 23 ₁ and 23 ₄ via meniscus plate holders 31 and 31 fixed by brazing in the furnace. The half-moon plate 29 is composed of a flange 29a and a hollow half cylinder portion 29b. Then, as shown in FIG. 5, the meniscus plate 29 is formed into a shape that substantially follows the arcuate portion of the meniscus by bending or the like, and covers the outer periphery of the small-diameter portion of the meniscus plate holder 31 described later. To be installed.

The meniscus plate holder 31 has a substantially hollow cylindrical shape consisting of a large diameter portion 31b having a large outer diameter and a small diameter portion 31c having a small outer diameter via a step portion 31a. In addition, the mouths 23 ₂ , 2 of the inner pipes # 2, 3
The meniscus plate 29 is not interposed between 3 ₃ and the exhaust ports 24 ₂ , 24 ₃ of the cylinder 24, and there is no step at the mouths 23 ₂ , 23 ₃ of the inner pipes # ₂ , _3. The tubular body 32 is fixed by brazing in the furnace. However, lips 2 of pipes # 2 and 3
The strength of the portions is increased by selecting the material of the pipes # 2 and 3 so that the pipes # 2 and 3 themselves can withstand the stress generated in 3 ₂ and 23 ₃ . The exhaust ports 24 _{1 to} 24 ₄
A gasket 33 is inserted in the inside.

The connection of the pipes # 1 to 4 of the exhaust system 12 of the multi-cylinder engine for such a motorcycle with the cylinder 24 will be described separately for the outer pipe and the inner pipe. The method of connecting the inner pipes # 2 and 3 to the cylinder 24 will be described with reference to the relationship with one pipe # 2, and the description with respect to the other pipe # 3 will be omitted because they are the same. First, the pipe # 2 is inserted into the pipe insertion hole 28 ₂ of the clamp 27 ₂ . Then, the tubular body 32 is fixed to the mouth 23 ₂ of the pipe # 2 to which the clamp 27 ₂ is attached. At this time, the diameter of the pipe insertion hole 28 ₂ is the cylindrical body 3
Since it is smaller than the outer diameter of ₂ , the clamp 27 ₂ does not come off from the mouth 23 ₂ of the pipe # 2. In this way, pipe # 2 is ready to be attached to cylinder 24.

Next, the mouth 23 ₂ of the pipe # 2 to which the tubular body 32 is attached is inserted into the exhaust port 24 ₂ of the cylinder 24, and then the flange 27a of the clamp 27 ₂ is applied to the cylinder 24. When tightened, the pipe # 2 and the cylinder 24 are integrally connected via the clamp 27 ₂ and the tubular body 32. Similarly, the pipe # 3 is also connected to the cylinder 24.

The way of connecting the outer pipes # 1 and 4 to the cylinder 24 will be described with reference to the relationship with one pipe # 1, and the description with respect to the other pipe # 4 will be omitted because they are the same. First, pipe the half-moon plate holder 31 #
It sticks to the mouth 23 ₁ of ₁ . The pipe # 1 in this state is inserted into the pipe insertion hole 28 ₁ of the clamp 27 ₁ so that the pipe # 1
Attach the clamp 27 ₁ to. Next, the mouth 23 ₁ of the pipe # 1 to which the holder 31 is attached is attached to the cylinder 2
4, the hollow half-cylindrical portion 29b of the half-moon plate 29 is held so that the tip 29c of the half-moon plate 29 abuts the step 31a of the holder 31 before being inserted into the exhaust port 24 _1.
Cover one. This positions the meniscus plate 29 at the mouth 23 ₁ of pipe # 1. In this way
Pipe # 1 is ready to be attached to cylinder 24.

Next, the mouth 23 ₁ of the pipe # 1 to which the holder 31 and the meniscus plate 29 are attached is inserted into the exhaust port 24 ₁ of the cylinder 24, and then the flange 27a of the clamp 27 ₁ is applied to the cylinder 24. If tightened with a bolt (not shown), the pipe # 1 and the cylinder 24 are integrally connected via the meniscus plate 29 and the holder 31. At this time, since the diameter of the pipe insertion hole 28 ₁ of the clamp 27 ₁ is smaller than the outer diameter of the flange 29a of the half-moon plate 29, the flange 29a contacts the flange 27a of the clamp 27 surrounding the pipe insertion hole 28 _1. Contact. Therefore, the pipe # 1 is prevented from coming off the cylinder 24. Similarly, pipe # 4 is cylinder 2
4 is connected.

As described above, the exhaust pipe 14 of the exhaust pipe 12 is attached to the cylinder 24, and the other portions of the exhaust pipe 14 and the mufflers 16, 16 are welded to the frame 4 of the motorcycle 2 or other portions by welding means or the like. By attaching with appropriate fixing means,
The exhaust pipe 12 is attached to the motorcycle 2.

However, according to the exhaust pipe 12 of the multi-cylinder engine of the motorcycle, since the half moon plate 29 is used only for the outer pipes # 1 and 4, the half moon plate used only for the outer pipes # 1 and 4 is used. All you have to do is prepare 29. Therefore, it is not necessary to prepare the half-moon plate 29 for all the pipes. Therefore, it is possible to eliminate the need to arrange various kinds of the half-moon plate 29 for each pipe, and to simplify the storage of the half-moon plate 29. Further, since the pipe requiring the half-moon plate 29 is only the outer pipe, the connection between the cylinder 24 and the exhaust pipe 14 can be speeded up.

[0024]

According to the exhaust pipe of the multi-cylinder engine of the motorcycle of the present invention, since the stress relaxation member is provided only on the outer pipe, it is only necessary to prepare the stress relaxation member used only on the outer pipe. It will be good. Therefore, it is not necessary to prepare stress relaxation members for all pipes. Therefore, it is possible to eliminate the need to arrange various types of stress relaxation members for each pipe and to simplify the storage of the stress relaxation members. Furthermore, since the pipe requiring the stress relaxation member is only the outer pipe, it is possible to speed up the connection between the cylinder and the exhaust pipe.

[Brief description of drawings]

FIG. 1 is an overall side view showing a state in which an exhaust pipe of a multi-cylinder engine of a motorcycle of the present invention is attached to the motorcycle.

FIG. 2 is a plan view of an exhaust pipe of a multi-cylinder engine of the motorcycle of the present invention.

FIG. 3 is an enlarged sectional view of an essential part showing a state in which a pipe # 1 (4) outside an exhaust pipe is connected to a cylinder of a multi-cylinder engine.

FIG. 4 is an enlarged cross-sectional view of an essential part showing a state in which a pipe # 2 (3) inside an exhaust pipe is connected to a cylinder of a multi-cylinder engine.

FIG. 5 is an exploded perspective view of FIG.

FIG. 6 is a front view of the arrangement of each pipe of the exhaust pipe with respect to the engine.

[Explanation of symbols]

 # 1 pipe # 2 pipe # 3 pipe # 4 pipe 10 parallel multi-cylinder engine 12 multi-cylinder engine exhaust pipe for motorcycle 14 exhaust pipe 24 cylinder 28 stress relaxation member

Claims (1)

[Claims] Claim: What is claimed is: 1. A motorcycle having only the outer pipe having a stress relaxation member used at the connecting portion when connecting each pipe of the exhaust pipe connected to the cylinder of the parallel multi-cylinder engine and the cylinder of the engine. Exhaust pipe of a multi-cylinder engine.