JP2000199426A - Muffler device for v-type motorcycle engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve engine characteristics by fitting exhaust pipes with almost equal length for both front and rear cylinders of a V type engine and enhance mounting strength of the exhaust pipes. SOLUTION: A rear cylinder 18r of a V type engine 16 has an exhaust port 20r at its rear wall. A first exhaust pipe 22r connected to the exhaust port 20r passes through a rear side of the engine 16 and then the beneath of an engine case 16a. The exhaust pipe 22r is concavely curved facing its concave to the front and connected to one end 26a of a U-shaped tube member 26 located beneath of the engine case 16a. The exhaust pipe is then extended rearwardly from the other end 26b of the U-shaped tube member 26 to communicate to a muffler after combining with a second exhaust pipe 22f at a collecting member 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a muffler device for a V-type engine mounted on a motorcycle.

[0002]

2. Description of the Related Art Conventionally, in a V-type engine for a motorcycle, a muffler device is constructed by connecting exhaust pipes from exhaust manifolds of front and rear cylinders (cylinders) to mufflers at the rear of a vehicle body. In order to properly bring out the engine performance, it is preferable to make the front and rear exhaust pipe lengths equal.

[0003]

However, the above-mentioned V
It was difficult to make the length of the exhaust pipe of the type engine, especially the exhaust port of the rear cylinder, equal (especially in the engine with the exhaust port of the rear cylinder facing backward, it is difficult to keep the distance to the muffler. Was not possible). Further, it is desired to connect the front and rear exhaust pipes to improve the output. However, it is necessary to make the length of the exhaust pipe from the connection portion to each of the front and rear cylinders equal.

In Japanese Patent Application Laid-Open No. Sho 62-60914, V
With respect to a motorcycle equipped with a type engine, the exhaust pipe of the rear cylinder is meandering so that the U-turn portion is located below the engine case. Also, Japanese Patent Application Laid-Open No. 5-35
0321 and JP-A-5-10122 also disclose V
The meandering U-turn portion of the exhaust pipe is located on the lower surface of the case of the type engine. However, none of the publications discloses the attachment of the exhaust pipe to the vehicle body, including the connection portion of the exhaust pipe, and the exhaust pipe is supported at the muffler attachment point integrally with the exhaust port and the muffler. The strength of the exhaust pipe was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has been made to improve engine characteristics by making the length of a pipe to a connecting portion of an exhaust pipe of a V-type engine substantially the same in front and rear cylinders. It is an object of the present invention to provide a muffler device for a V-type engine for a motorcycle, which can increase the mounting strength of an exhaust pipe.

[0006]

The present invention has the following configuration to achieve the above object. The present invention is a muffler device that extends an exhaust pipe from each exhaust port of a front side and a rear side cylinder of a V-type engine and communicates with a muffler, wherein the rear cylinder of the engine has an exhaust port at a rear side. The first exhaust pipe connected to the rear side exhaust port communicates with one end of an arcuate pipe located from the rear side of the engine to the engine lower side and extends rearward from the other end of the arcuate pipe to form a muffler. A second exhaust pipe connected to a front cylinder is connected to the first exhaust pipe by a communication pipe near the arcuate pipe portion, and the second exhaust pipe is connected to the first exhaust pipe at a position below the vehicle body of the first exhaust pipe and the arc shape is formed. Attachment to the vehicle body is provided at or near the pipe portion, and at least a portion connected to the communication pipe of the arc-shaped pipe portion, the communication pipe, and the second exhaust pipe is integrally formed. A muffler device of the V-type engine for a motorcycle in front cylinders characterized by. In the present invention, it is possible to have a detachable connection structure in the middle of the second exhaust pipe connected to the front cylinder and at a position in front of the vehicle body mounting portion of the first exhaust pipe. Further, in the present invention, the first exhaust pipe connected to the rear cylinder is assembled to the second exhaust pipe at a position rearward of the communication pipe, and the collected exhaust pipe is connected to the muffler, and the first exhaust pipe is connected to the first exhaust pipe. The pipe can be integrally formed with the connecting pipe, the collecting portion, and the exhaust muffler. The arc-shaped tube portion includes a curved tube portion in which a part or the whole of a U-shaped tube portion, a C-shaped tube portion, or the like is formed in an arc shape.

According to the present invention, the rear cylinder of the engine has the first exhaust pipe connected to the exhaust port on the rear side of the engine. Since it is structured to extend rearward from the other end of the arcuate tube portion and to be connected to the muffler, the length of the exhaust passage of the first exhaust pipe can be increased, and the exhaust pipes of the front and rear cylinders can be made equal. Therefore, the output characteristics of the engine can be improved. Further, since the mounting portion to the vehicle body is provided at the position below the vehicle body of the first exhaust pipe and at or near the arcuate tube portion, the exhaust pipe and the muffler are attached and fixed to the vehicle body to fix the exhaust pipe and the muffler to the vehicle body. Compared to fixing at multiple points, the span between the muffler mounting part and the exhaust pipe mounting part can be made longer, that is, the mounting pitch can be made longer, so that it is fixed to the vehicle body over a wide range. And is advantageous in strength. Further, since at least a portion connected to the communication pipe of the arc-shaped pipe portion, the communication pipe, and the second exhaust pipe is integrally formed, the rigidity near the arc-shaped pipe portion having the mounting portion is increased, and the mounting is performed at a high rigidity. It becomes more advantageous.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 is an overall side view of a motorcycle equipped with a muffler device according to an embodiment, FIG. 2 is an explanatory view of a state of attachment of the muffler device to an engine of the motorcycle, FIG. 3 is a plan view of the muffler device, and FIG. FIG. 5 is a sectional view taken along line VV in FIG. 2.

As shown in FIG. 1, the motorcycle includes a front wheel 1
A vehicle body frame 14 is provided so as to connect between the zero steering device 10a and the suspension device 12a for the rear wheel 12. The vehicle body frame 14 has a truss-like front portion (frame front) 14f to which a head pipe is fixed at a front end, extends obliquely downward and rearward, and a central portion (frame center) 1.
4c extends downward and has a substantially L-shape together with the front part,
Further, a frame rear 14r extending rearward and rising rearward is fixed at the center, and a V-type engine 16 is suspended (suspended) on the body frame 14 by bolting. Fixed.

As shown partially in FIG. 1 and as a whole in FIG. 2, the V-type engine 16 has front and rear cylinders 18f.
And 18r are two-cylinders erected from the upper part of the engine case 16a by tilting forward and backward at a wide angle of 90 ° or more. As an intake system for each of the cylinders 18f and 18r, a fuel carburetor 18a connected to the intake port of each cylinder is located between the cylinders, and an air cleaner 18b is provided at a position overlapping the cylinders 18f and 18r in a top view. A radiator 18c is provided adjacent to the front cylinder 18f above the cylinder head and connected to the engine water jacket.

In the muffler device of the engine 16, a second exhaust pipe 22f and a first exhaust pipe 22r extend from the exhaust ports 20f and 20r to the front and rear cylinders 18f and 18r, respectively. And communicates with a single cylindrical muffler 24 located on the right side of the vehicle body.

A rear cylinder 18r of the V-type engine 16 has an exhaust port 20r on the rear side, and the rear side exhaust port 20r
The first exhaust pipe 22r connected to the engine 1
6 (in this case, the rear cylinder 18r and the engine case 16
a) Dive into the lower part of the engine case 16a from the rear side to form a generally open-ended front opening.
6a U-shaped pipe portion located on the lower side (an example of an arc-shaped pipe portion) 2
6 and extends rearward from the other end 26b of the U-shaped tube portion 26 to join the second exhaust pipe 22f and the later-described collecting portion 36 to form a muffler 24.
And a structure that communicates with

As shown in FIGS. 3 and 4, the front cylinder 18f
The second exhaust pipe 22f is connected to the second exhaust pipe 22f, extends slightly forward and downward from the exhaust port 20f, and then wraps around the cylinder 16f below the engine 16 (engine case 16a) and further along the bottom of the engine case 16a. Extend to. Then, the second exhaust pipe 22
The end extending to the rear of f is connected to the first exhaust pipe 22r near the U-shaped pipe portion 26 by a communication pipe 28 so as to communicate therewith. Also, the first exhaust pipe 22r
At the lower position of the vehicle body and at or near the U-shaped tube portion 26, the attachment portion 30
And at least the U-shaped tube portion 26 and the communication tube 28
And a portion connected to the communication pipe 28 of the second exhaust pipe 22f is integrated.

As shown in detail in FIG. 5, at the connecting portion of the communication pipe 28, a cutout opening 28a is opened in the first exhaust pipe 22r and the second exhaust pipe 22f to communicate with the communication pipe 28. The U-shaped portion 26 is formed by welding a plate material formed with a U-shaped depression into the middle structure, and has a flow path that is slightly inclined toward the inside of the vehicle body with respect to the vertical direction. The upper part of the U-shaped part 26 and the second part
The exhaust pipe 22f is wrapped in a side view of the vehicle body, but the U-shaped portion 26 is located slightly higher than the second exhaust pipe 22f, and the communication pipe 28 is substantially in the horizontal direction or the outside of the vehicle body. It is oblique so that it is slightly higher.

A point 32 in the middle of the second exhaust pipe 22f connected to the front cylinder 18f and in front of the vehicle body mounting portion 30 of the first exhaust pipe 22r.
In a detachable connection structure. In this case, a portion extending from the exhaust port 22f of the second exhaust pipe 22f to the lower portion of the engine case 16a is inserted into the location 32, and the location 32 is fastened and fixed by the band 32a.

The first exhaust pipe 22r connected to the rear cylinder 18f is connected to the second exhaust pipe 22r at a position rearward of the communication pipe 28.
Of the exhaust pipes 22f in a Y-shape (a portion to be assembled is referred to as an assembly portion 36), and the assembled exhaust pipes 22c are connected to the muffler 24. The first exhaust pipe 22r is connected to the communication pipe 22r. 28, the collecting portion 36 and the exhaust muffler 24. Note that the first exhaust pipe 22r
Has a connection structure 38 that is detachable near the rear cylinder 18r. This connection structure may be either a connection structure in which the exhaust port 20r side is inserted into the remaining portion and fastened and fixed with a band 38a, as in the connection structure portion 32 of the second exhaust pipe 22f, or any other connection structure. Good.

According to the muffler device of the present embodiment, the rear cylinder 18r of the V-type engine 16 is provided with the exhaust port 20r at the rear side.
The first exhaust pipe 22r connected to the engine 1
6 is connected to one end of the U-shaped pipe portion 26 and extends downward from the other end of the U-shaped pipe portion 26 to be connected to the muffler 24. 1
The exhaust passage length of the exhaust pipe 22r can be increased. Therefore, in this muffler device, as shown in FIG. 4, the distances R and F to the respective collecting portions 36 of the first exhaust pipe 22r connected to the rear cylinder 18r and the second exhaust pipe 22f of the front cylinder 18f are set. It can be of equal length. Therefore, the exhaust characteristics of the front and rear cylinders are uniform, and the output characteristics of the engine can be improved.

Further, since the attachment portion 30 to the vehicle body is provided at the position below the first exhaust pipe 22r and at or near the U-shaped pipe portion 26, the exhaust pipes 22r and 22f and the muffler 24 are connected to the vehicle body. The exhaust pipes 22r, 22
As compared with fixing the m or the muffler 24 at a plurality of points, the span between the mounting portion 24a and the mounting portion 30 of the muffler 24 can be made longer, that is, the mounting pitch can be made longer. It can be fixed to the vehicle body, which is advantageous in strength. Further, at least the U-shaped pipe section 26, the communication pipe 28, and the second exhaust pipe 22
Since the portion connected to the communication pipe of f is formed integrally, the rigidity in the vicinity of the U-shaped pipe portion 26 having the mounting portion 30 is increased, and the mounting is performed at a location having high rigidity, which is advantageous in strength.

Although the preferred embodiment of the present invention has been described in the above embodiment, it is needless to say that the present invention is not limited to this. That is, a V-type engine having a plurality of cylinders disposed in front and rear, respectively, is also within the scope of the present invention.

[0020]

As described above, according to the present invention, V
The pipe length up to the connecting portion of the exhaust pipe of the type engine is made substantially the same in the front and rear cylinders, thereby improving the engine characteristics and increasing the mounting strength of the exhaust pipe.

[Brief description of the drawings]

FIG. 1 is an overall side view of a motorcycle equipped with a muffler device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a state in which a muffler device is attached to an engine of a motorcycle.

FIG. 3 is a plan view of the muffler device.

FIG. 4 is a side view of the muffler device.

FIG. 5 is a cross-sectional view of the inside of the U-shaped portion along the line VV in FIG. 2;

[Explanation of symbols]

Reference Signs List 16 engine 18f, 18r front and rear cylinders 22f, 22r second exhaust pipe, first exhaust pipe 24 muffler 26 U-shaped pipe part 28 communication pipe 32 connection point 36 collecting part

Claims (3)

[Claims] 1. A muffler device in which exhaust pipes extend from respective exhaust ports of front and rear cylinders of a V-type engine and communicate with a muffler, wherein a rear cylinder of the engine has an exhaust port on a rear side. A first exhaust pipe connected to the rear side exhaust port communicates with one end of an arcuate tube located below the engine from the rear of the engine and extends rearward from the other end of the arcuate tube to form a muffler. A second exhaust pipe connected to the front cylinder is connected to the first exhaust pipe near the arc-shaped pipe by a communication pipe, and the second exhaust pipe is connected to the first exhaust pipe at a position below the vehicle body of the first exhaust pipe. An attachment portion to the vehicle body is provided at or near the arcuate tube portion, and at least a portion connected to the communication tube of the arcuate tube portion, the communication pipe, and the second exhaust pipe is integrated. Muffler device of the V-type engine for a motorcycle in front cylinders, characterized in that the. 2. The connecting structure according to claim 1, wherein a connecting structure is provided in the middle of the second exhaust pipe connected to the front cylinder and at a position in front of the vehicle body mounting portion of the first exhaust pipe. Muffler device for V-type engine for motorcycles. 3. A first exhaust pipe connected to the rear cylinder is assembled to a second exhaust pipe at a position rearward of the communication pipe, and the collected exhaust pipe is connected to a muffler, and the first exhaust pipe is connected to the first exhaust pipe. The muffler device for a V-type engine for a motorcycle according to claim 1 or 2, wherein the muffler is formed integrally with the connecting pipe, the collecting portion, and the exhaust muffler.