JPS63167022A - Arrangement structure of exhauster in motorcycle and motor tricycle - Google Patents

Abstract

PURPOSE:To prevent an exhaust pipe from projecting to the outside of a car body by providing a noise eliminator below the car body and disposing an exhaust pipe, one end of which is connected to an engine, downward in such a manner as to pass through a vertically extending recess portion formed on a crankcase. CONSTITUTION:A transverse engine comprising a crankshaft 22 disposed in the longitudinal direction of a vehicle is mounted at the central portion of a car body frame. A crankcase is connected to the lower portion of a cylinder of an engine. In this case, a main noise eliminator 36a forming a noise eliminator of an exhauster 34 is disposed between a cover 25 of the crankcase and a rear wheel, and a sub-noise eliminator 36b is disposed below a sel-motor 24a. An exhaust pipe 35 of the exhauster 34 is formed L-shaped, and the longitudinal side portion thereof is passed through an annular recess portion 37 formed by a flywheelmagnet chamber 32a of the crankcase, a crank chamber 13a and a gear chamber 32b and extended downward. The lateral side portion 35d following the longitudinal side is inserted in the main noise eliminator 36a.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to the arrangement structure of an exhaust system around the engine of a motorcycle or tricycle, and particularly to a longitudinally mounted engine in which the crankshaft is arranged in the longitudinal direction of the vehicle. In case of
This invention relates to a structure that makes it possible to make the layout of an exhaust pipe more compact by utilizing so-called dead space.

[Conventional technology]

An exhaust system for discharging exhaust gas from an engine into the atmosphere in a motorcycle or tricycle is composed of an exhaust pipe connected to the engine and a muffler connected to the rear end of the exhaust pipe. Conventionally, the arrangement of this exhaust system is such that the exhaust pipe is led out from the exhaust port of the engine and passes along the side of the rear engine, and a muffler is also placed at the rear of the vehicle. It is true. For relatively large displacement motorcycles, there is relatively sufficient space for the above-mentioned exhaust system, etc., so there is no problem, but for small displacement motorcycles and tricycles, the vehicle itself is small. Therefore, there is a need to make the parts other than those used for passenger riding as compact as possible, and it is desirable to make the exhaust system as compact as possible, for example, regarding the arrangement of the exhaust pipe.

[Problem that the invention seeks to solve]

By the way, especially small models may adopt a vertical engine with a crankshaft placed in the longitudinal direction of the vehicle, but due to the structure of this vertical engine, the exhaust port is located on the side of the vehicle. There is. Therefore, when connecting the exhaust pipe to the engine, if the exhaust pipe is guided outward as it is according to the above-described structure, the exhaust pipe will protrude significantly outward from the side of the vehicle, making it impossible to meet the demand for compactness.

In view of the above-mentioned demands, an object of the present invention is to provide an arrangement structure for an exhaust system in a motorcycle or tricycle that can make the arrangement of the exhaust pipe around the engine more compact when a vertically installed engine is employed.

[Means for solving problems]

This invention is in front of the crank chamber of the crankcase.

Later, there is a flame mag housing section with a larger diameter than the crank chamber. A motor vehicle equipped with a vertically mounted engine that has a gear housing and a crankshaft that extends in the longitudinal direction of the vehicle.

In a tricycle, the exhaust pipe, one end of which is connected to the engine, is placed in the above-mentioned flamag housing part of the crankcase. An arrangement of an exhaust system characterized in that the exhaust pipe is disposed facing downward so as to pass through a recess formed by a crank accommodating part and a gear chamber, and the other end of the exhaust pipe is connected to a muffler disposed at a lower part of a vehicle. It is a structure.

[Effect]

According to the arrangement structure of the exhaust system for motorcycles and tricycles according to the present invention, the exhaust pipe is installed by utilizing the vF characteristic of a vertically-mounted engine, that is, by utilizing the concave part of the crankcase, which was conventionally a concave dead space. Because of this arrangement, the exhaust pipe does not protrude laterally and outwardly from the engine, and therefore the arrangement of the exhaust pipe around the engine can be made more compact.

〔Example〕

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

1 to 5 are diagrams for explaining the arrangement structure of an exhaust system according to an embodiment of the present invention. In FIG. 0, which is an example in which this embodiment is applied to a motorcycle with a foot pedal, l is This is a motorcycle to which the structure of this embodiment is applied, and a steering shaft cylinder 4 is fixed to the front end of a body frame 2 of the motorcycle l, and the upper end of a front fork 5 rotatably supported by this is fixed to the front end of a body frame 2 of the motorcycle l. A steering handle 6 is fixed, and a front wheel 7 is pivotally supported at the lower end. Further, a seat 30 is mounted on the upper center of the vehicle body frame 2, and a back stay 3 is fixed diagonally downward to the rear end. A gear case 9 housing a bevel gear device is attached to the lower end of the backstay 3, and a rear wheel 8 is pivotally supported by the gear case 9.

Further, a vertically mounted engine 1 having a crankshaft 22 disposed in the longitudinal direction of the vehicle is located approximately at the lower center of the vehicle body frame 2.
2 is installed, and the cylinder 12a of the engine 12
A crankcase 13 is connected to the lower part of the engine. The approximate center of the crankcase 13 in the longitudinal direction of the vehicle, that is, the lower portion of the cylinder 12a is a crank chamber 13a that accommodates the crank arm 22a of the crankshaft 22. The crank chamber 13a is formed to have a slightly larger diameter than the crank arm 22a, and has ball bearings 22 disposed on the front and rear walls of the crank chamber 13a.
b rotatably supports the front and rear portions of the crank arm 22a.

In the front part of the crank chamber 13a, there is a flame mag storage part 13c.
A wind guide cover 31 for introducing cooling air into the engine 12 is attached to the front end of the flame mag housing section 13C, thereby forming a crank chamber 32a having a larger diameter than the crank chamber 13a. . This crank chamber 3
- A flywheel magneto 26 attached to the front part of the crankshaft 22 is housed in 2a, and a stator coil 26a of the flywheel magneto 26 is fixed to the front wall of the crank chamber 13a with bolts. and is in contact with an oil seal 22c disposed in front of the ball bearing 22b. Further, a blower blade 33 is fixed to the front surface of the rotating magnet 26b of the flywheel magneto-26.

A gear accommodating portion 13b is integrally formed at the rear of the crank chamber 13a, and a case cover 25 is removably attached to the rear surface of the gear accommodating portion 13b. 32b is configured. A starter device 24. Deceleration bag? &23 is accommodated, and the starting bag W, 24 is configured to transmit the rotation of a starter motor 24a attached to the lower part of the crank chamber 13a to the crankshaft 22 via an intermediate gear 24b and a one-way clutch 24C. There is. Further, the speed reduction device 23 is configured to transmit the rotation of the crankshaft 22 to the output gear 23C via the centrifugal clutch 23a and the intermediate gear 23b. Although not shown, the intermediate gear 23b and the output tooth 1 [23c are rotatably supported by the case cover 25, and the output gear 23C is rotated via a transmission shaft disposed within the rear arm 16. and is transmitted to the rear wheels 8.

The exhaust port 12b of the cylinder 12a is located on the side of the vehicle and above the crank chamber 13a, and is bent downward. This exhaust port 12b has an exhaust device 3.
4 exhaust pipes 35 are connected. A flange portion 35a is provided at the connecting end of the exhaust pipe 35 and the exhaust port 12b, respectively.
12c is formed, and a stand bolt 35b planted in the flange portion 35a of the exhaust pipe 35 is inserted into a bolt hole formed in the flange portion 12c on the side of the exhaust port 12b, and tightened with a fixing nut 12d. .

The muffler 36 of the exhaust device 34 consists of a main muffler 36a and a sub muffler 36b, both of which are connected by a connecting pipe 36C. This main muffler 36a is located between the case cover 25 and the rear wheel 8, and the sub muffler 36b is located below the starter motor 24a. And the above exhaust pipe 3
5 has an abbreviated shape, and its vertical side 35C is connected to the flame mag chamber 32a of the crank case 13 and the crank chamber 13.
a and the gear chamber 32b, and extends downward through the vehicle right side of the annular recess 37 formed by the gear chamber 32b.
is inserted and fixed into the main muffler 36a. In addition,
Reference numeral 17 denotes a pedal shaft disposed so as to pass through the gear chamber 32b in the vehicle width direction, and a drive sprocket 20a fixed to the pedal shaft extends from the outside of this so as to cover the longitudinal side 35C of the exhaust pipe 35. It is placed on the side.

Next, the effects of the structure of this embodiment will be explained.

As mentioned above, in a vertically mounted engine, the exhaust port is located on the side of the vehicle, so there is a problem in that the exhaust pipe tends to protrude outward from the side. Since it is arranged so as to pass through the annular recess 37 formed approximately in the middle, the exhaust pipe can be prevented from protruding while making effective use of dead space that was previously unused, making the engine area of the exhaust system more compact. can.

Further, as a connection structure between the exhaust pipe and the exhaust port, it is common to install a stand bolt on the side of the exhaust port to fix the flange portion of the exhaust pipe.

However, in this embodiment, since the drive sprocket 20a fixed to the pedal shaft 17 is located at this connection part, this drive sprocket 17 makes the connection work difficult when the above-mentioned conventional structure is adopted. On the other hand, in this embodiment, a stud pole l-35b is provided on the exhaust pipe 35 side.
Since the drive sprocket 20a is installed, the above-mentioned work is not obstructed by the drive sprocket 20a, and the connection work can be easily performed.

Furthermore, the oil seal 22c on the outside of the ball bearing 22b that supports the crankshaft 22 is susceptible to the high pressure inside the crank chamber 13a and easily moves outward, so a structure that can resist this pressure is required. In this embodiment, the stator coil 26a of the flywheel magneto 26 is connected to the oil seal 22.
Since it is also used as a stopper for C, the movement of the oil seal 22c can be prevented without complicating the structure.

〔Effect of the invention〕

As described above, according to the arrangement structure of the exhaust system for a motorcycle or tricycle according to the present invention, the exhaust pipe is disposed facing downward so as to pass through the recess formed in the crankcase.
This has the effect of making the engine area more compact by effectively utilizing dead space and preventing the exhaust pipe from protruding outward from the vehicle.

[Brief explanation of the drawing]

1 to 5 are diagrams for explaining the arrangement structure of an exhaust system according to an embodiment of the present invention, in which FIG. 1 is a partially sectional front view, FIG. 2 is a side view, and FIG. FIG. 4 is a cross-sectional side view thereof, FIG. 4 is a rear view thereof, and FIG. 5 is a side view of a motorcycle to which the structure of the embodiment is applied. In the figure, 1 is a motorcycle, 12 is an engine, 13 is a crankcase, 13a is a crank chamber, 13b is a gear housing part, 13C is a flame mag housing part, 22 is a crankshaft, 2
2a is a crank arm, 23 is a reduction gear device, 26 is a flywheel magneto, 234 is an exhaust device, 35 is an exhaust pipe, 36 is a muffler, and 37 is a recess. Patent Applicant Yamaha Motor Co., Ltd. Agent Patent Attorney Tsutomu Tsutomu Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) Equipped with a vertical engine with a crankshaft arranged in the front-rear direction of the vehicle, the crankcase of the engine is divided into a frame magnet housing section that accommodates a flywheel magneto attached to one end of the crankshaft, and A gear accommodating part for accommodating a reduction gear device attached to the other end, and a crank chamber for accommodating the crank arm portion of the crankshaft, located between the above-mentioned flare magnet accommodating part and the gear accommodating part, and having a smaller diameter than both the accommodating parts. An arrangement structure of an exhaust device for discharging exhaust gas from the engine into the atmosphere in a motorcycle or a tricycle constructed from the above, wherein a muffler is disposed at the bottom of the vehicle, and
The exhaust pipe, one end of which is connected to the engine, is disposed so as to face downward so as to pass through a groove-shaped recess extending in the vertical direction formed by the flare magnet housing part, crank housing part, and gear housing part of the crankcase, and the other end is connected to the engine. An arrangement structure for an exhaust system in a motorcycle or tricycle, characterized in that: is connected to the above-mentioned silencer.