JPS5836808Y2 - motorcycle exhaust system - Google Patents

Description

[Detailed explanation of the idea] When a motorcycle is equipped with a 4-cylinder multi-cylinder engine, performance such as exhaust sound and output is greatly affected by the structure of the exhaust system, but especially when it comes to motorcycles, the space Also, because of the large restrictions on appearance, conventional structures are not necessarily satisfactory from a performance standpoint.

For example, when a conventional horizontal 4-cylinder engine is installed, the exhaust pipes of the two cylinders on the left half are connected to the two mufflers installed on the left side of the car body, and the exhaust pipes of the two cylinders on the right side are connected to the two mufflers on the right side. A structure in which the muffler is connected to the muffler is known, but in that case, the muffler not only occupies a lot of space and becomes difficult to ride, but also requires the entire muffler to be bulky in order to achieve high performance, which is unfavorable in terms of appearance and cost. It's not right.

Also known is a structure in which two exhaust pipes on the left and right are connected to a collective muffler, one on each side.

In that case, it would be advantageous in terms of appearance and cost, but the left and right mufflers would work independently of each other, and there would be restrictions on output performance, such as the location of the gathering point.

Since the present invention adopts a collective muffler and solves the above-mentioned conventional problems, in FIG. 7 is a collecting pipe that collects the two exhaust pipes 6 on the left side into the muffler 8. 71.
Bl is the collecting pipe and muffler on the right side, and 9 is the connecting pipe.

The connecting pipe 9 communicates a position slightly downstream of the gathering point P of the left collecting pipe 7 with a position slightly downstream of the collecting point V of the right collecting pipe 7'.

For example, exhaust gas discharged from the first cylinder 1 passes through an exhaust pipe 6 and a collecting pipe 7, enters a muffler 8, receives a silencing effect there, and then is released into the atmosphere.

Moreover, when the first cylinder 1 is in the exhaust stroke, the other cylinders are in a stroke other than the exhaust stroke, so the exhaust system that is directly connected to the '1st cylinder 1, ie the exhaust pipe 6, the collecting pipe 7
, outside the muffler 8 via the connecting pipe 9 to the right cylinder 3,
4 has been added to the exhaust system, which is essentially the same as installing a large-capacity muffler, reducing back pressure.
The output increases as the silencing effect increases.

Moreover, the connecting pipe 9 is the gathering point p, p' of the collecting pipes 7, 7'.
Since the downstream positions are connected, the effect of exhaust pulsation generated in any cylinder can be applied to other cylinders, and high output can be obtained from this aspect as well.

In the present invention, the collecting pipe γ is constructed separately from the exhaust pipe 6 and the muffler 8, and the structure is such that the three are connected, making it easier to handle and manage the parts, and also facilitate the assembly work. There are advantages.

In Fig. 2, 1 indicates the case where one muffler is attached to each exhaust pipe, ■ indicates the structure in which the connecting pipe 9 is removed from the state shown in Fig. 1, and ■ indicates the structure shown in Fig. 1 is adopted. The case is shown qualitatively.

As explained above, according to the present invention, compared to the case where collective mufflers are used on both the left and right sides, by adopting the connecting pipe 9, it is possible to obtain high output characteristics without bumps over a wide rotation speed range and to reduce the noise level. It has also been confirmed that it is effective.

However, in the present invention, a horizontal four-cylinder engine is provided with one muffler 8, 8' on each side, and instead of collecting the exhaust pipes 6 into one muffler, two mufflers on each side are provided. It is not possible to connect to one muffler 8, 8' on the corresponding side only by gathering at the gathering points p, p', and,
The connecting pipe 9 connects the upstream portions of the left and right mufflers 8, 8' slightly downstream of the gathering points P and P' so as to communicate with each other.

In other words, a horizontal 4-cylinder engine is connected to two left and right mufflers 8,
By discharging air in 8' sections and connecting them for redundant use, the same effect as equipped with a large-capacity muffler can be obtained.

In addition, since the four exhaust pipes 6゜6.6, 6 are not grouped together, there is no need for complicated piping, which saves space and appearance, especially for motorcycles equipped with horizontal 4-cylinder engines. It is very practical from this point of view.

Furthermore, it is a motorcycle equipped with a horizontally mounted 4-cylinder engine 5, and is equipped with one muffler 8, 8' on each left and right side. Due to the structural feature that the connection pipe 9 is used slightly downstream of the assembly point V, the four-cylinder engine 5
You can enjoy the noise level reduction effect in the engine and the high output characteristics without bumps over a wide rotation speed range.

Also, instead of directly connecting the exhaust pipes 6.6, 6, 6 to the mufflers 8, 8', a separate collecting pipe 9 is first connected to the exhaust pipes 6.6, 6, 6. Since the muffler 8, 8' is connected to the collecting pipe 9, each part is compact, making it suitable for disassembly, assembly and repair, and parts management.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of an exhaust system according to the present invention, and FIG. 2 is a graph for comparing characteristics. 1 to 4...1st to 4th cylinders, 8,8'...muffler,
6...Exhaust pipe, 7.7'...Collecting pipe,
P, Ff... Gathering point, 9... Connecting pipe.

Claims (1)

[Scope of utility model registration request] Equipped with a horizontally mounted 4-cylinder engine and one muffler on each side, the exhaust pipes of the two left cylinders go to the left muffler through the left collecting pipe, and the exhaust pipes of the right two cylinders go to the right side through the right collecting pipe. An exhaust system for a motorcycle, characterized in that the left and right collector pipes are connected to the respective mufflers, and the left and right collector pipes are connected to each other through a connecting pipe at a position slightly rearward from the collection point of the left and right collector pipes.