JPH02241920A - Engine exhaust device for motor-cycle - Google Patents

Abstract

PURPOSE:To ensure the capacity of a muffler without increasing the temperature of intake-air, by connecting the rear end of an exhaust pipe coupled to an exhaust port of an engine, to the front end of one of right and left mufflers, and by connecting the front parts of these mufflers together through the intermediary of a connecting pipe. CONSTITUTION:An exhaust pipe 3 coupled to an exhaust port of an engine is connected at its rear end to the front end of one of right and left mufflers 5 which are mounted to the rear section of a vehicle body 4. Further, the front parts of the right and left mufflers 5 are connected together through the intermediary of a connecting pipe 6. With this arrangement, these two mufflers 5 may be arranged in a well-balanced condition, and accordingly, the back-pressure is decreased so as to prevent the output power of the engine from being lowered. Further, only one exhaust pipe 3 is sufficient, extending along one side of the vehicle body 4 and being connected to the front end of one of the mufflers 5, and accordingly, it is possible to prevent the temperatures of a carburetor and an air-cleaner from increasing. Further, the connecting pipe 6 is disposed on the rear wheel fender 9 side, and accordingly, it can be suitably disposed extending through a clearance above the front part of a rear wheel 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) This invention relates to an exhaust system for a motorcycle engine (prior art) An engine mounted on a motorcycle has an exhaust pipe connected to an exhaust hole of the engine that extends rearward. The rear end of the exhaust pipe is connected to the front end of a muffler that is long and cylindrical in the longitudinal direction on the rear side of the vehicle body, and the muffler muffles exhaust noise and exhaust gas is released from the rear end of the muffler. There is. A muffler needs to have a volume commensurate with the displacement of the engine, and there is a limit to the size of a muffler that can be installed on one side of the rear of the vehicle body, which may reduce the volume and affect engine output.

For this reason, mufflers are provided on the left and right sides of the rear of the vehicle, and the rear part of the exhaust pipe is divided into two parts and connected to the mufflers on both sides to ensure the volume of the muffler. For example, JP-A-59-939
See Publication No. 18.

(Problem to be Solved by the Invention) In order to bifurcate the rear part of the exhaust pipe connected to the engine exhaust hole, the exhaust pipe on one side must cross the center of the vehicle body and extend to the other side. The shape of the exhaust pipe becomes complicated and bending becomes troublesome. In addition, especially in the area where the car body crosses from one side to the other, a carburetor or air cleaner is installed nearby, so the exhaust pipe becomes hot due to the exhaust heat, raising the ambient temperature in the vicinity and reducing the intake air. There is a problem with the temperature rising.

In view of this, this invention secures capacity by connecting the mufflers installed on the left and right sides of the rear of the vehicle body behind the rear wheel mudguard with a connecting vibrator, and connects the exhaust pipe to the tip of one of the mufflers to provide intake air. To obtain an exhaust system for a motorcycle engine that does not increase the temperature of the engine.

(Means for Solving the Problems) In order to achieve the above object, the exhaust system for a motorcycle engine of the present invention has mufflers attached to the rear left and right sides of the vehicle body, and the rear end of the exhaust pipe connected to the exhaust hole of the engine. It is connected to the front end of one muffler, and the front parts of the left and right mufflers are connected by a connecting pipe.

(Function) The two mufflers can be placed in a well-balanced manner on the left and right sides of the rear of the car body, making the volume commensurate with the engine displacement, reducing back pressure and preventing a drop in engine output. In addition, only one exhaust pipe needs to be connected to the front end of one muffler through one side of the car body, which prevents temperature rises near the carburetor and air cleaner. The connecting pipe that connects the front parts of the left and right mufflers can be conveniently placed behind the rear wheel mudguard through the gap in the front upper part of the rear wheel.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show one embodiment of the present invention. Exhaust pipe 3 whose front end is connected to exhaust hole 2 of engine 1
is bent into a U-shape and directed rearward, passes through the right side of the engine 1, and extends rearward along the right side of the vehicle body 4. Muffler 5
There are left and right cylindrical parts that are long in the front and back direction, and are attached to the rear left and right sides of the vehicle body 4, respectively. At the tip of the right muffler 5,
Connect the exhaust pipe 3. The front parts of the left and right mufflers 5 are connected by a connecting vibro. The connecting vibro is designed so that it can be connected by inserting it midway and tightening it with a band, making it convenient to assemble it to the vehicle body. The muffler 5 has a plurality of silencing chambers 7 inside, and the silencing chambers 7 are connected by a baffle vibe 8. In contrast to the muffler 5 on the right side to which the exhaust pipe 3 is connected, the muffler on the left side uses a slightly thicker baffle vibe 8 to reduce back pressure. The connecting vibro that connects the left and right mufflers 5 is the rear wheel mudguard 9.
The left and right mufflers 5 are connected through a gap between the rear side and the front upper part of the rear wheel 10. The connecting vibro may be an integral type that is welded to the left and right mufflers 5, as shown in FIG. Further, a plurality of connected vibrators may be used. Furthermore, as shown in FIG. 5, a connected vibro may be formed in which the steel plates are aligned in the middle to provide a larger volume.

Exhaust gas from the engine 1 flows from the exhaust hole 2 to the exhaust pipe 3 and enters the l'ii'I end of one muffler 5. and,
It also flows to the other muffler 5 through the connected vibro. Compared to one muffler 5, the other muffler 5 has a lower back pressure, so that approximately the same amount of ω flows to the left and right mufflers 5 separately. The mufflers 5 on both sides can have a volume commensurate with the displacement, and each muffler 5 is small and when attached to the vehicle body 4, the amount of outward protrusion can be reduced.

Further, the connected vibro is located behind the rear wheel mudguard 9, and the exhaust pipe 3 is also passed along the side of the vehicle body 4, so that the intake air temperature does not increase.

(Effects of the Invention) As explained above, the present invention enables the left and right mufflers to have a volume commensurate with the displacement, reduces back pressure,
It is possible to prevent a decrease in engine output.

Each muffler is small and can be mounted on the left and right sides of the rear of the car body with little protrusion outward, resulting in good left-right balance. In addition, the exhaust pipe passes through one side of the car body, and the connecting pipe can pass behind the rear wheel mudguard, so it is kept away from the carburetor and air cleaner intakes, and the temperature of the intake air does not rise. There is no reduction in intake efficiency. Additionally, the exhaust pipe is a single piece with few bends, which reduces manufacturing costs.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1 is a side view, FIG. 2 is an enlarged vertical sectional plan view taken along the line A-A in FIG. 1, and FIG. 3 is an overall side view. FIG. 4 is a partial longitudinal sectional plan view showing another embodiment of the invention, and FIG. 5 is a partial lateral sectional view showing still another embodiment of the invention. 1...engine, 2...exhaust hole, 3...exhaust pipe,
4...Vehicle body, 5...Muffler, 6...Connecting pipe.

Claims (1)

[Claims] Mufflers were installed on each side of the rear left and right sides of the car body, the rear end of the exhaust pipe connected to the engine exhaust hole was connected to the front of one muffler, and the front parts of the left and right mufflers were connected with a connecting pipe. Characteristic motorcycle engine exhaust system.