JPS6319539Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust system for a motorcycle, and more particularly to an exhaust system for a motorcycle equipped with a V-type transverse engine in which a plurality of cylinders are arranged in the longitudinal direction of the vehicle body.

FIGS. 1a and 1b are a conceptual diagram of a main part of a motorcycle 1 showing a conventional exhaust system for a motorcycle, and a plan view thereof, respectively. This motorcycle 1 is equipped with a V-type horizontal 4-cylinder engine 2 (hereinafter simply referred to as the engine), and cylinder heads 2a and 2b located in front of this engine 2, cylinder heads 2c and 2c located in the rear thereof. Exhaust pipes 3, 4, 5, and 6 are connected to 2d, respectively. Further, mufflers 7, 8, 9, and 10 are connected to each of the exhaust pipes 3, 4, 5, and 6, respectively, forming a so-called 4-into-4 type exhaust structure. In FIGS. 1a and 1b, reference numeral 12 is a swing arm, and 13 is a pivot shaft.

By the way, according to the above-mentioned conventional exhaust structure of the V-type horizontally mounted four-cylinder engine 2, a so-called rear exhaust structure is used in which the exhaust gas discharged from the cylinder heads 2c and 2d located at the rear of the vehicle body is discharged from the rear of the vehicle body. Since the exhaust pipes 3 and 4 are connected to the cylinder heads 2a and 2b located at the front of the engine 2, and the cylinder head 2 located at the rear of the engine 2,
c and 2d (the lengths of the exhaust pipes 5 and 6 connected to the cylinder heads 2c and 2d located at the rear of the vehicle body are different from those of the cylinder head 2 located at the front).
(It is shorter than the length of the exhaust pipes 3 and 4 connected to the cylinder heads 2a and 2b, and its volume is smaller.) Therefore, the exhaust efficiency of the exhaust gas discharged from the cylinder heads 2a and 2b located at the front of the vehicle body and the exhaust efficiency of the exhaust gas from the rear of the vehicle body are A difference has arisen in the exhaust efficiency of exhaust gas discharged from the engine 2, which has been a factor in significantly reducing the performance of the engine 2.

In view of the above-mentioned problems with exhaust systems in conventional motorcycles, the present invention has been developed to
The purpose of this system is to provide an exhaust system for motorcycles that can make the exhaust efficiency of a V-type transverse engine as uniform as possible. An exhaust pipe connected to each cylinder head located at the rear of the engine and an exhaust pipe connected to each cylinder head located at the rear of the engine are connected to separate chamber bodies, and a muffler is connected to each of the chamber bodies, Exhaust gas discharged from the cylinder head located at the front of the V-type horizontal engine and exhaust gas discharged from the cylinder head located at the rear of the engine are collected in separate chamber bodies and discharged. This is a configuration of an exhaust system for a motorcycle.

Hereinafter, one embodiment of the motorcycle device according to the present invention will be described in detail.

FIGS. 2a and 2b are conceptual diagrams of main parts of the motorcycle 1 showing an exhaust system for a motorcycle according to the present invention, respectively;
and a plan view thereof, in which the same parts as in FIG. 1 are designated by the same reference numerals.

Exhaust pipes 20 and 21 connected to cylinder heads 2a and 2b located at the front of the V-type horizontal four-cylinder engine 2 in FIGS. The exhaust gas discharged into the exhaust pipes 20 and 21 is once collected in the first chamber body 22. Furthermore, mufflers 25 and 26 are connected to the first chamber body 22 via exhaust pipes 23 and 24, and the exhaust gas collected in the first chamber body 22 is discharged to the atmosphere via the mufflers 25 and 26. be done. On the other hand, exhaust pipes 27 connected to cylinder heads 2c and 2d located at the rear of the engine 2,
A second shaft 28 extends between the rear of the crankcase 2e and the pivot shaft 13 of the swing arm 12, and is located below the swing arm 12.
are connected to the chamber bodies 29 of the exhaust pipes 27, 2, respectively.
The exhaust gas discharged into the chamber 8 is temporarily transferred to the second chamber body 29.
gathered within. Further, mufflers 30 and 31 are connected to the second chamber body 29.
The exhaust gas collected inside is discharged to the atmosphere via mufflers 30 and 31. According to this exhaust system for a motorcycle, exhaust pipes 20 and 21 are connected to cylinder heads 2a and 2b located at the front of a V-type horizontal 4-cylinder engine 2, and are connected to cylinder heads 2c and 2d located at the rear of the engine 2. Exhaust pipe 27,
28 are connected to the first chamber body 22 and the second chamber body 29, respectively, so this first chamber body 22
By appropriately adjusting the volumes of the second chamber body 29 and the cylinder 2 located in front of the engine 2,
The volume of the exhaust pipes 20 and 21 connected to a and 2b,
Cylinders 2c and 2d located at the rear of the engine 2
The volumes of exhaust pipes 27 and 28 connected to the exhaust pipes 27 and 28 are adjusted.

In addition, the V-type horizontal 4-cylinder engine 2 described above is
Cylinder heads 2a, 2b, 2 of the engine 2
The firing order in c and 2d is changed from 2a to 2, respectively.
c → 2b → 2d → 2a, and the crank rotation angle interval between them is 270° between 2a → 2c, 2c →
90° between 2b, 270° between 2b→2d, 2d→
2a, the exhaust pipes with different exhaust timings (exhaust pipe 20 and exhaust pipe 21, and exhaust pipe 27 and exhaust pipe 28) are connected to the first and second chambers, respectively, as described above. By assembling the exhaust gases 22 and 29 together, an inertial supercharging effect can be obtained by the exhaust gas from the exhaust pipes of each other.

As described above, the present invention has the capacity of the exhaust pipe connected to the cylinder head located at the front of the V-type transverse engine, and the volume of the exhaust pipe connected to the cylinder head located at the rear of the engine, respectively. It can be adjusted by adjusting the volumes of the chamber body and the second chamber body, thereby balancing the exhaust efficiency of the cylinder located at the front of the engine and the exhaust efficiency of the cylinder located at the rear of the engine.
Due to the inertial supercharging effect of the first and second chamber bodies, exhaust efficiency can be improved and the output characteristics of the engine can be improved.

[Brief explanation of the drawing]

Figures 1a and b are a conceptual diagram of main parts of a motorcycle and a plan view thereof, respectively showing a conventional exhaust system for a motorcycle, and Figures 2a and b are a diagram showing an exhaust system for a motorcycle according to the present invention, respectively. FIG. 1 is a conceptual diagram of main parts of a two-wheeled vehicle and a plan view thereof. 2... V-type horizontal engine, 2a, 2b, 2c,
2d...Cylinder head, 20, 21, 27, 2
8... Exhaust pipe, 22... First chamber body, 29... Second chamber body, 25, 26, 30, 31... Muffler.

Claims (1)

[Claims for Utility Model Registration] (1) In an exhaust system for a motorcycle equipped with a V-type transverse engine, in which a plurality of cylinders are arranged in the longitudinal direction of the vehicle body, the exhaust of the plurality of cylinders located at the front of the vehicle body. The pipes are respectively connected to a first chamber body, a muffler is connected to the first chamber body, and the exhaust pipes of a plurality of cylinders located at the rear of the vehicle body are connected to a separate body from the first chamber body. A muffler is connected to each of the second chamber bodies, and a muffler is connected to the second chamber body, so that exhaust gas is discharged from a plurality of cylinders located at the front of the vehicle body and exhaust gas is discharged from the rear of the vehicle body. An exhaust system for a motorcycle, characterized in that exhaust gas is collected in the first chamber body and the second chamber body and discharged. (2) The scope of the utility model registration claim, characterized in that the first chamber body is disposed below the crankcase of a V-type transverse engine, and the second chamber body is disposed below the swing arm of a motorcycle. An exhaust system for a motorcycle as described in paragraph (1).