JPS62255514A - Exhaust device for motorcycle - Google Patents

Abstract

PURPOSE:To simplify an exhaust system, by providing an exhaust cover adapted to cover the side of a rear end portion of an exhaust pipe and pass the side of a connecting portion between the exhaust pipe and a chamber to continue to a front end of a muffler. CONSTITUTION:Exhaust covers 24 and 25 are provided to cover a rear end portion of exhaust pipes 13 and 14 and pass the side of a connecting portion between the exhaust pipes 13 and 14 and an exhaust chamber 16 to continue to a front end portion of mufflers 18 and 19. The exhaust covers 24 and 25 extend toward the mufflers 18 and 19 regardless of the direction of bending of the exhaust pipes 13 and 14. With this arrangement, it is possible to provide the appearance as if the exhaust pipes were connected to the mufflers and simplify an exhaust system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exhaust system for a motorcycle equipped with a four-stroke engine.

[Prior art]

For example, in a motorcycle equipped with a V-type 4-cycle engine, in order to increase engine output and noise reduction, the exhaust pipes leading out from the front and rear cylinders are connected to a common exhaust chamber, and this exhaust chamber is shaped like a cylinder. Two mufflers are connected, and the exhaust from each cylinder is once introduced into an exhaust chamber and then distributed to both mufflers.

Recently, due to external design requirements, two silencers have been placed one on top of the other on one side of the car body, and after the exhaust pipe of the rear cylinder is guided to the side of the engine, the exhaust pipe from the front cylinder is There is a desire to emphasize the line leading rearward with the exhaust pipe and flowing from the exhaust pipe to the muffler as one of the exterior elements.

[Problem that the invention seeks to solve]

However, in the exhaust system equipped with the above-mentioned exhaust chamber,
Because this exhaust chamber is located deep inside the vehicle body, the rear end of the exhaust pipe that connects to the exhaust chamber has to be bent inward toward the vehicle body forward of the muffler.

Therefore, the arrangement of the exhaust pipe has become complicated, and it has become difficult to create a continuous design for the exhaust pipe and the muffler.

[Means for solving problems]

Therefore, in the present invention, a plurality of exhaust pipes led out from the engine are guided to one side of the vehicle body and arranged vertically in parallel, and the rear ends of these exhaust pipes are bent toward the inside of the vehicle body to form a common exhaust pipe. When connecting a plurality of cylindrical silencers stacked one above the other at the rear of the exhaust pipe to the exhaust outlet of the exhaust chamber, an exhaust pipe is connected to the outer periphery of each of the exhaust pipes. An exhaust cover is provided in the shape of an exhaust pipe that covers at least the rear end of the pipe from the side, passes through the side of the connection between the exhaust pipe and the exhaust chamber, and is continuous with the front end of the muffler. It is characterized by:

[Effect]

According to this configuration, the exhaust cover that covers the rear end of the exhaust pipe extends toward the muffler at the rear, regardless of the bending direction of the rear end of the exhaust pipe, so that the exhaust pipe looks like a muffler. This creates the appearance that the exhaust pipe is directly connected to the muffler, and the line from the exhaust pipe to the muffler can be incorporated as one of the exterior elements.

In addition, since the connection between the exhaust pipe and the exhaust chamber is also covered by the exhaust cover, the complex exhaust system is neatly organized and the appearance is improved.

[Embodiments of the invention]

The present invention will be explained below based on an embodiment shown in the drawings.

Reference numeral l in FIG. 8 denotes a frame constituting the vehicle body, and a main member 3 having a box-shaped cross section is connected to a steering head vibe 2 at the front end of the frame. A four-stroke V-type two-cylinder engine 4 is suspended below the main member 3. This engine 4 has a front cylinder 6 and a rear cylinder 7 arranged in a substantially V-shape in side view on a crankcase 5.
A vaporizer 8 is arranged between them.

In Fig. 8, reference numeral 9 indicates a front fork, IO indicates a frame cover shaped like a fuel tank, and 11 indicates a seat.

Incidentally, in the engine 4, the front cylinder B has a front exhaust, and the rear cylinder 7 has a rear exhaust, and an exhaust pipe 13.1 is connected from the exhaust port 12 of each cylinder 6.7.
4 has been derived. The exhaust pipe 13 of the front cylinder B is
It is guided downward through the front of the crankcase 5, and its lower end portion is guided rearward substantially horizontally through the lower right side of the crankcase 5. Further, the exhaust pipe 14 of the rear cylinder 7 is led out to the right side immediately after the exhaust port 12, and then
It is guided obliquely downward and forward approximately parallel to the axis of the rear cylinder 7, and is led out to the right side of the rear end of the crankcase 5.

After this exhaust pipe 14 is bent rearward into a substantially U-shape on the right side of the crankcase 5,
As shown in the figure, the upper part of the exhaust pipe 13 from the front cylinder 6 is guided rearward, and the rear ends of these re-exhaust pipes 1, 3, 14 are bent toward the left side of the vehicle body at the rear of the crankcase 5. It is being

A large-capacity exhaust chamber 18 in the shape of a flat tank is arranged in the part where the rear end of the exhaust pipe 13.14 faces, that is, in the space between the crankcase 5 and the rear wheel 15. The rear end of the exhaust pipe 13.14 is welded to the exhaust introduction port 17 provided on the upper surface of the exhaust chamber 16.

Further, a pair of cylindrical silencers 18.19 are arranged behind the exhaust pipes 13.14. These silencers 18,
19 are parallel to each other and extend in the front-rear direction,
They are arranged one above the other, and their front ends are closed by a front plate 20. Silencer 18.1
The front end of the exhaust chamber 9 is located on the right side of the exhaust chamber 10, and an exhaust inlet 21, 21 is formed on the inner surface of the front end. The exhaust inlet 21.21 and the exhaust outlet 22 provided on the upper surface of the exhaust chamber IB are connected via a communication pipe 23, so that the stray air from each cylinder 6.7 is transferred to the exhaust pipe. Once introduced via 13.14 into the exhaust chamber 16, it is distributed from there to both silencers 18.19.

The outer diameter of the muffler 18.19 is equal to the exhaust pipe 13°1.
It is formed larger than the outer diameter of No. 4.

By the way, the exhaust pipe 13 led out from each cylinder 6.7
．． Exhaust covers 24 and 25 made of sheet metal are attached to the outer periphery of the exhaust cover 14, respectively. The exhaust cover 24 of the front exhaust pipe 13 covers the exhaust pipe 13 as shown in FIGS. 4 and 6.
It is formed to have an approximately semicircular cross section so as to cover approximately half the circumference of the rear end from the outside, and after passing through the side of the exhaust chamber 16 from the rear end of the exhaust pipe 13, the front end of the lower muffler 18 is formed. It extends in a smooth curve towards the end. Furthermore, the curvature R of the exhaust cover 24 gradually widens as it advances toward the rear muffler 18 side, to the same extent as the outer diameter of its front end. It is shaped like an exhaust pipe.

Such an exhaust cover 24 is constructed by press-fitting the exhaust pipe 13 into the ring 2B welded to the inner periphery of the front end, and by butt welding the end member 27 welded to the inner periphery of the rear end to the front plate 20. It is integrated with the exhaust pipe 13 and the muffler 18, and these exhaust pipe ■3 and the muffler 1
It covers the space between 8 and 8 from the side.

On the other hand, the exhaust cover 25 of the exhaust pipe 14 on the rear side
The exhaust pipe 14 is provided over the entire length of the exhaust pipe 14 and has a substantially semicircular cross section so as to cover the portion of the exhaust pipe 14 that extends to the right side of the vehicle body from the side. The rear end of this exhaust cover 25 is
It extends above the exhaust cover 24 in a smooth curve toward the front end of the upper muffler 19,
The curvature R of this rear end portion gradually widens as it moves toward the muffler 19 at the rear, similarly to the one exhaust cover 24 described above. The exhaust pipe 14 is inserted into the retaining rings 29 and 30 welded to the inner periphery of the front end and the intermediate part of the exhaust cover 25, and the intermediate retaining ring 30 and the exhaust pipe 14 are welded together. The end member 31 welded to the inner periphery of the rear end of the exhaust cover 25 is butt-welded to the front plate 20 of the muffler 19, so that it is integrated with the exhaust pipe 14 and the muffler 19.
and the silencer 19 from the side.

According to such a configuration, the exhaust cover 24.25 attached to the outer periphery of the exhaust pipe 13.14 can be directly connected to the rear muffler 18 regardless of the bending direction of the rear end of the exhaust pipe 13.14.
．． Since the exhaust chamber 16 is located between the exhaust pipes 13, 14 and the silencer 18, 19, the two exhaust pipes 1
3.14 appears as if it were directly connected to the silencer 18.19. Therefore, the exhaust pipe 13.
The line from 14 to the silencers 18 and 19 can be emphasized as one of the external appearance elements, which is convenient in terms of design.

In addition, the existence of the exhaust covers 24, 25 also covers the connecting portion between the exhaust pipes 13, 14 and the exhaust chamber 16, so that the complex exhaust system can be neatly integrated, which has the advantage of improving the appearance and commercial value.

Note that the engine according to the present invention is not limited to a ■ type two-cylinder engine, but also a parallel two-cylinder engine, a four-cylinder engine, or a four-cylinder engine.
A single cylinder engine may be used as long as two exhaust pipes are led out from one cylinder, such as a valve engine.

〔Effect of the invention〕

According to the present invention described in detail above, it is possible to obtain an appearance as if the exhaust pipe is directly connected to the muffler, and the line from the exhaust pipe to the muffler can be emphasized and incorporated as one of the external appearance elements. Can be done.

Another advantage is that the complex exhaust system is streamlined and the appearance and product value are improved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a side view of the entire exhaust system, FIG. 2 is a plan view thereof, and FIG. 3 is a side view showing the positional relationship between the exhaust pipe, exhaust cover, and muffler. Figure 4 is a plan view of the exhaust cover, Figure 5 is v- in Figure 3.
6 is a sectional view along line Vl-Vl in Figure 4, Figure 7 is a sectional view along line ■-■ in Figure 2, and Figure 8 is a side view of the motorcycle. It is. 1... Vehicle body (frame), 4... Engine, 13.
14... Exhaust pipe, 16... Exhaust chamber, 18.
19...Silencer, 24.25...Exhaust cover.

Claims (1)

[Scope of Claims] A plurality of exhaust pipes led out from the engine are guided to one side of the vehicle body and arranged vertically in parallel, and the rear ends of these exhaust pipes are bent toward the inside of the vehicle body to form a common exhaust chamber. and a plurality of cylindrical silencers arranged one above the other at the rear of the exhaust pipe are connected to the exhaust outlet of the exhaust chamber, the exhaust device comprising: , an exhaust cover in the shape of an exhaust pipe that covers at least the rear end of the exhaust pipe from the side, passes through the side of the connection between the exhaust pipe and the exhaust chamber, and continues to the front end of the muffler; An exhaust system for a motorcycle, characterized by being provided with.