JPH07145732A - Exhaust valve device for motorcycles - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an exhaust valve device for a motorcycle that does not interfere with the operation of the motorcycle and can secure a bank angle. An exhaust valve device for a motorcycle, which includes a valve 23 that closes a cross section of the exhaust pipe so that the cross-section can be almost completely closed, and a shaft 22 that is located on a rotation center line of the valve 23 and projects outside the exhaust pipe. The rotation center line of the valve 23 is provided in the vehicle body 20 so that the end of the shaft 22 located outside the vehicle body is located above the end of the shaft 22 located inside the vehicle body with respect to the ground line GL.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is designed to burn fresh air in a combustion chamber by self-compression ignition during low load operation.
The present invention relates to an exhaust valve device for motorcycles applied to a cycle engine.

[0002]

2. Description of the Related Art Conventionally, it has been known to mount an exhaust valve device on a muffler component of a two-cycle engine motorcycle in order to burn fresh air in a combustion chamber by self-compression ignition during low load operation.

[0003]

In the prior art, the arrangement of the exhaust valve device has not been sufficiently taken into consideration, and the existence of the exhaust valve device has a problem in relation to other parts.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to secure a bank angle without interfering with the operation of a motorcycle. An exhaust valve device for a motorcycle is provided.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a valve member which closes the cross section of the exhaust pipe so that the cross section can be almost fully closed, and an exhaust pipe which is located on the rotation center line of the valve member. In an exhaust valve device for a motorcycle, which comprises a drive shaft protruding inward, a rotation of the valve member such that the drive shaft end located outside the vehicle body is located above the drive shaft end located inside the vehicle body. The center line is inclined with respect to the ground line.

[0006]

The function of the exhaust valve device is arranged inside the other parts of the motorcycle, so that it does not hinder the operation of the motorcycle.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a schematic side view of a motorcycle to which an exhaust valve device for a motorcycle according to the present invention is applied, and FIG.
FIG. 2 is an enlarged arrow view of a main part of a cross section taken along the line AA of FIG. 1.

As shown in FIG. 1, in a motorcycle,
A front wheel 2 is supported by a front fork 3 on the lower front side of the vehicle body 1, and an upper portion of the front fork 3 is rotatably supported by a head pipe 4 of the vehicle body 1.

At the upper end of the front fork 3, left and right handle grips 6, 6 are arranged on both ends of a bar-shaped handle 5 on a top bridge, and the front face of the handle 5 is exposed to the front. The lamp 7 and direction indicator lamps located on the left and right sides of the lamp 7 are provided. The upper part of the front wheel 2 is covered with a fender 8.

On the other hand, a vehicle body frame 9 is formed from the front side to the rear side of the vehicle body 1, and a power unit 10 is provided at a substantially central lower portion of the vehicle body frame 9, and the power unit 10 is provided.
Muffler component 11 for muffling and exhausting the exhaust gas
Is mounted on the right side of the vehicle body 1 so as to be parallel to the vehicle body 1. The muffler constituent member 11 is an upstream exhaust pipe 11
a, a downstream exhaust pipe 11b, and a muffler 11c.

Further, as shown in FIG. 2, the vehicle body frame 9
A footrest step 12 is arranged at the lower end of the, and a swing arm 14 supporting a rear wheel 13 is rotatably supported. Further, the vehicle body frame 9 is covered with a power unit cover 15 and a vehicle body cover 16 extending to a rear upper portion of the rear wheel 13, and the like, and a seat 17 is disposed on the vehicle body cover 16. 18 is Anda cowl.

The exhaust valve 20 includes a muffler constituent member 11
Upstream exhaust pipe 11a and downstream exhaust pipe 11 constituting the
It is arranged between b.

As shown in FIG. 2, the exhaust valve 20 includes a pipe 21, a shaft 22 having both ends projecting from the pipe 21 at right angles to the axial direction of the pipe 21, and a valve 23 fixed to the shaft 22 inside the pipe 21. , A drum 24 fitted to a shaft 22 protruding from the pipe 21.
The drum 24 includes a throttle cable 25 that drives the exhaust valve 20 in association with the movement of the throttle grip 6.
Is wrapped around. The exhaust valve 20 is covered with a protector 20a to protect its constituent parts.

Then, as shown in FIG. 1, the exhaust valve 2
Since 0 is provided inside the under cowl 18,
It is possible to prevent stones, muddy water, curbs, and the like from directly hitting the exhaust valve 20 during traveling. Further, as shown in FIG. 2, the installation angle θ1 of the exhaust valve 20 is 0 ° to 45 ° with respect to the ground line GL. Therefore,
Since it is inside the surface formed by the line S connecting the side portion of the front wheel 2 and the end portion of the step 12, the bank angle θ2 can be secured.

Further, as shown in FIG. 1, the exhaust valve 20
Is installed in front of the lowermost portion 11d of the muffler constituent member 11, so that valve malfunction due to oil can be prevented.

[0016]

As described above, according to the present invention, the center line of rotation of the valve member is set to the ground line so that the drive shaft end located outside the vehicle body is located above the drive shaft end located inside the vehicle body. Since it is inclined with respect to, the bank angle can be secured.

[Brief description of drawings]

FIG. 1 is a schematic side view of a motorcycle to which an exhaust valve device for a motorcycle according to the present invention is applied.

FIG. 2 is an enlarged arrow view of a main part of a cross section taken along the line AA of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vehicle body, 11 ... Muffler constituent member, 11a ... Upstream exhaust pipe (exhaust pipe), 11b ... Downstream exhaust pipe (exhaust pipe), 11c ... Muffler, 11d ... Bottom part of muffler constituent member, 12 ... Step, 18 ... Under cowl , 20 ...
Exhaust valve (exhaust valve device), 22 ... Shaft (driving shaft), 23 ... Valve (valve member), GL ... Ground line, θ1 ... Installation angle, θ2 ... Bank angle.

Claims (1)

[Claims] 1. An exhaust gas for a motorcycle, comprising: a valve member that closes a cross section of the exhaust pipe so that the cross section can be substantially fully closed; and a drive shaft that is located on a rotation center line of the valve member and projects outside the exhaust pipe. In the valve device, the rotation center line of the valve member is inclined with respect to the ground line so that the drive shaft end located outside the vehicle body is located above the drive shaft end located inside the vehicle body. Exhaust valve device for motorcycles.