JPS5920846B2 - Muffler connection structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a muffler connection structure that includes a communication pipe that communicates between two mufflers.

Some motorcycles equipped with a two- or four-cylinder engine are provided with mufflers on both sides of the vehicle body.

By the way, as a method of effectively utilizing the expansion chambers of the mufflers provided on both sides of the vehicle body, it is known to connect the mufflers with each other through a communication pipe. In this way, the use of other mufflers and the communication pipe itself as a noise-reducing expansion chamber has become widely practiced in recent years because it increases the noise-reducing effect, makes the muffler smaller, and makes effective use of the space inside the vehicle. I'm getting old. However, in the conventional connection structure of this type of muffler, the work of joining the communication pipe to the muffler is relatively complicated, and from the viewpoint of noise prevention due to the increase in engine displacement, manufacturing has been slowed down. There has been a demand for a muffler that is easy to use and has a higher muffling effect.

The present invention has been made in response to such demands, and has an extremely simple structure in which a shell-shaped sub-expansion chamber is provided on the side of the muffler, which makes it easy to connect the communicating pipe to the muffler, and which also has a high erasing effect. This provides a connected structure.

Hereinafter, its configuration and the like will be explained in detail with reference to embodiments shown in the drawings. Fig. 1 is a plan view showing an exhaust system when the present invention is applied to a four-cylinder engine, Fig. 2 is a side view thereof, Fig. 3 is a cross-sectional view, and Fig. 4 is a cross-sectional plan view. . In these figures, reference numerals 1 and 2 indicate exhaust pipes whose tips are connected to the exhaust port of an engine (not shown), and 3 indicates a single muffler 4, which will be described later, between these two exhaust pipes 1 and 2. It is a collecting pipe to guide the In the embodiment shown in the figure, the muffler 4 includes a muffler outer pipe 4a, a diffuser pipe 4b installed in the muffler outer pipe 4a, a muffler outer pipe 4c connected to the muffler outer pipe 4a, and the muffler outer pipe 4c. It is composed of a diffuser pipe 4d provided inside. Reference numeral 5 denotes a communicating pipe, and the muffler side end 5a of the communicating pipe 5 is an exhaust hole bored inside near the tip of the muffler outer pipe 4a and the diffuser pipe 4b, that is, on the side facing the other paired muffler. It is provided so as to face the opening 6 and T without being joined to it.

Reference numeral 8 denotes a connecting member for connecting this communication pipe 5 to a communication pipe 5 provided in another muffler, and 9 a shell-like member that holds the communication pipe 5 and forms the sub-expansion chamber 10.

The sub-expansion chamber 10 is formed by joining a pair of members from above and below, each having a dust pan-like shape and integrally having a joining flange 9a on the entire periphery. That is, the outer end 9b is welded to the muffler outer pipes 4a, 4c, the inner end 9c welds and holds the communication pipe 5, and the other flange part is connected to the paired shell member. There is. Note that the opening indicated by reference numeral 14 is the sub-expansion chamber 1.
0 and the inside of the muffler outer pipe 4c. 10 and 11 are connection fittings, 12 is a cover, and 13 is a bracket for attaching this exhaust system to the vehicle body.

Since the muffler of the present invention is configured in this way, a part of the pressure wave due to the exhaust gas discharged to the diffuser vibe 4b is discharged into the communication pipe 5, and a part of the pressure wave is discharged into the communication pipe 5.
It is also discharged into the sub-expansion chamber 10 through the gap g between the air outlet a and the exhaust port 6.

Further, a part of the pressure wave emitted from the diffuser vibe 4d and reflected within the muffler enters the sub-expansion chamber 10 through the z opening 14 and is subjected to an expansion action. In the embodiment shown in the figure, a wide gap g is provided between the muffler side end 5a of the communication pipe 5 and the exhaust port 6 of the muffler outer pipe 4a, and this is used as an exhaust passage. It is also possible to provide a structure in which a cut groove is provided in the pipe 5 or the opening width of the discharge port 6 is made wider on the sub-expansion chamber 10 side. In addition, in the embodiment shown in the figure, the muffler outer pipe 4a and the diffuser vibe 4b
Although the structure is such that both discharge ports 6 and 7 are provided and the communication pipe 5 is placed in opposition thereto, the present invention is not limited to such a structure, and the communication pipe is connected only to the diffuser vibe or the muffler outer pipe. Needless to say, it can also be applied to structures. As explained above, according to the present invention, since the sub-expansion chamber is formed by the connecting member for connecting the communication pipe to the muffler, the expansion chamber can be formed without increasing the number of parts, and the muffler It is possible to enhance the sound deadening effect without increasing the size of the device.

Further, since this sub-expansion chamber is provided within a dead space in the vehicle body, there is no need to sacrifice mounting space for other components. Furthermore, according to the present invention, the muffler side end of the communication pipe is simply opposed to the outlet provided on the muffler side without being joined, and the holding is performed at the inner end. There is also the practical effect that high-precision processing is not required in the drilling or bending of the communicating pipe.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an exhaust system implementing the connection structure according to the present invention, Fig. 2 is a side view thereof, Fig. 3 is a sectional view taken along the line ■-■ of the main part, and Fig. 4 is a cross-sectional plan view. . 4...Muffler, 5...Communication pipe, 10.
...Sub-expansion chamber.

Claims (1)

[Claims] 1 A shell-shaped sub-expansion chamber is provided on each opposing side of the two mufflers arranged in parallel, and the inner end of the sub-expansion chamber holds a communication pipe connecting the two mufflers, and this A muffler connection structure characterized in that a muffler side end of a communicating pipe is opposed to an exhaust port bored in a side of the muffler without being joined to the exhaust port.