JPH03128787A - Motorcycle - Google Patents

Abstract

PURPOSE:To facilitate ensurance of a mounting space for a muffler and to simplify mounting by a method wherein the whole of the lower part of an engine is covered with a muffler to form an under cowl, and the muffler connected to the exhaust pipe of a flexible pipe is supported to the engine. CONSTITUTION:The whole of the lower pert of an engine 3 is covered with a muffler 27, which functions as an under cowl to protect the engine 3. By mounting the muffler 27, a need for mounting the under cowl for an exclusive use is eliminated. The muffler 27 is supported directly to the engine 3 by means of a bolt 28 in a manner to cover the engine 3 therewith, and connected to a cylinder 9 through an exhaust pipe 29. Thus, since the muffler 27 is vibrated integrally with the engine 3 togetherwith the exhaust pipe 29, mounting structure of the muffler 27 and the exhaust pipe 29 is simplified. The exhaust pipe 29 is formed with a flexible pipe, bending of the exhaust pipe 29 is freely set, and since tolerance of the exhaust pipe 29 and the muffler 27 is absorbed, assembly is facilitated.

Description

[Detailed Description of the Invention] C. Industrial Application Field] The present invention relates to a motorcycle, and more particularly to a motorcycle that covers the lower part of the engine.

[Prior Art] Some motorcycles have an engine mounted on a body frame covered with an under cowl. This under cowl prevents the engine from coming into contact with obstacles, and also prevents water, dirt, etc. from adhering to it.

There is also a muffler connected to the exhaust pipe of the engine, and as disclosed in Japanese Patent Application No. 60-126883, this muffler extends backward and upwardly through the lower part of the engine, and its rear end is It is located to the side of the rear wheel. The front side of the muffleno is connected to and supported by the exhaust pipe on the engine side, and the rear side is supported by the vehicle body frame.

[Problems to be Solved by the Invention] By the way, if an under cowl is provided below the engine or a muffler is arranged, it is not easy to secure space for these arrangements.

Additionally, if the front side of the muffler is connected to and supported by the engine's exhaust pipe, and the rear side is supported by the vehicle body frame, it is necessary to create a support structure that absorbs the tolerances that occur between the engine and the vehicle body frame. It is necessary to support the engine and the vehicle body frame so as to absorb the difference in vibration that occurs between them, and the support structure is complicated.

The present invention was made against the background of the above circumstances, and an object of the present invention is to provide a motorcycle in which the muffler constitutes an under cowl and the support structure for the muffler is simple.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a motorcycle in which an engine is mounted between front wheels and rear wheels, in which an exhaust pipe of the engine is configured with a flexible pipe, and The present invention is characterized in that a muffler connected to the exhaust pipe covers the entire lower part of the engine to form an under cowl, and the muffler is supported by the engine.

[Function] In this invention, the muffler covers the entire lower part of the engine to form an under cowl, eliminating the need for a dedicated under cowl and making it easy to secure a space for installing the muffler.

In addition, the engine exhaust pipe is configured with a flexible pipe, and the muffler connected to this exhaust pipe is supported by the engine, and the assembly tolerance between the engine and muffler can be absorbed by bending the IJ1 trachea. It can be integrated into the engine, making it easy to assemble the muffler.

Furthermore, since the muffler is supported only by the engine and vibrates together with the engine, there is no need for a support structure that absorbs the difference in vibration that occurs between the muffler and the vehicle body frame as in the past, and the muffler support structure is become.

Furthermore, by integrating the exhaust pipe and the muffler, the exhaust pipe can be simplified.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 1 is a side view of the motorcycle, FIG. 2 is a perspective view of the muffler, FIG. 3 is a cross-sectional view of the muffler, and FIG. 4 is a sectional view taken along line IV-rV in FIG. 1.

In the figure, numeral 1 is a motorcycle, and this motorcycle 1
An engine 3 is mounted on a vehicle body frame 2. A front arm 5 is provided on the front side of the engine 3 via a pivot shaft 4, a steering arm 6 is supported on the front arm 5, and a front wheel 7 is supported on the steering arm 6. The steering arm 6 is supported by a cylinder 9 of the engine 3 via a frame 8, and the steering arm 6 is turned left and right by a steering cylinder 10 provided on the front arm 5.

A front fender 11 is provided on the steering arm 5.

A rear arm 13 is provided on the rear side of the engine 3 via a pivot shaft 12, and a rear wheel 14 is supported by this rear arm 13. Engine 3 drive sprocket 1
5 is connected to a drive sprocket 16 of the rear wheel 14 by a chain 17. Rear arm 13 has a fender T8
is provided.

A main frame 19 constituting the vehicle body frame 2 extends from behind the engine 3 to above the front wheels 7. A handle 20 is provided at the tip of the main frame 19, and the steering angle of the handle 20 is detected and the steering is performed. Direction cylinder 10
The steering frame 6 is rotated by driving the steering frame 6.

Above the engine 3 are a carburetor (not shown), an air cleaner,
A fuel tank, a battery, etc. are provided, and these are installed on the cowling 21 and the seat 2 provided on the seat rail (not shown).
2, and a carrier 23 is provided behind the seat 22.

A cover 24 is provided below the main frame 19,
This cover 24 is provided with a step 25.

An oil pan 26 is provided below the engine 3, and a muffler 27 is attached to the engine 3 by inserting bolts 28 into its attachment portion 278 so as to cover the oil pan 26. This muffler 27 is connected to an exhaust pipe 29 connected to the engine 3, and is arranged from the lower front side of the engine 3 to the front of the rear wheel 14.

As shown in FIG. 4, the muffler 27 covers the entire lower part of the engine 3, and extends outward in the vehicle width direction between the pair of left and right main frames 19 on which the rear arms 13 of the rear wheels 14 are pivotally supported. A non-protruding position C is provided, making it easy to secure the bank angle A.

The muffler 27 is formed by joining a lower case 270 and an upper case 271, and the joined portion is fixed by welding or bolts.

The lower case 270 is formed, for example, by die casting or the like so that a free shape can be obtained, and the upper case 271 is formed, for example, by pressing a sheet metal.

A rib 272 is formed on the lower surface of the lower case 270 of the muffler 27 in the vehicle traveling direction to increase the surface area of the lower surface of the muffler 27 and improve cooling performance.

A recess 273 is formed in the upper case 271 of the muffler 27, and the oil pan 26 of the engine 3 is exposed to the muffler 27.
7 covers the lower part of the engine 3, and running air is introduced into a gap 274 between the engine 3 and the muffler 27 to cool the engine 3 and the muffler 27 and improve heat dissipation. As shown in FIG. 4, the lower case 270 of the muffler 27 has a guide portion 27 that guides the running wind.
5 is formed, and a traveling wind introduction window 27 is formed in this guide portion 275.
6 is formed, and this running introduction window 276 allows the running wind to be easily introduced into the gap 274.

The muffler 27 covers the entire lower part of the engine 3 and functions as an under cowl to protect the engine 3.
By providing this muffler 27, there is no need to provide a dedicated under cowl. Also, this muffler 27 is made to cover the engine 3, and the bolt 28 is attached to the engine 3.
The exhaust pipe 29 is directly supported by the cylinder 9 and connected to the cylinder 9 through an exhaust pipe 29. Therefore, since the muffler 27 vibrates together with the engine 3 together with the fJi trachea 29, the mounting structure of the muffler 27 and exhaust pipe 29 is compared to a conventional structure that absorbs the vibration difference between the engine and the vehicle body. It becomes easier. Furthermore, the number of stays and bolts required in the conventional system can be significantly reduced, improving maintainability. Further, by arranging it close to the engine 3, the exhaust system can be made compact, and the muffler 27 can be integrated into the engine 3, improving ease of assembly. Moreover, it becomes possible to centralize mass,
Improves the dynamic characteristics of motorcycles.

The cylinder 9 of the engine 3 is inclined in the vehicle traveling direction, and the front end of the muffler 27 extends upward, so that the exhaust pipe 29 protruding outward is shortened. The exhaust pipe 29 is formed of a flexible pipe, and the bending of the exhaust pipe 29 can be set freely, and tolerances between the exhaust pipe 29 and the muffler 27 can be accommodated, making assembly easy. Furthermore, the exhaust pipe 29 is provided with fins 29a, and the fins 29a improve heat dissipation and the strength of the exhaust pipe 29. Furthermore, by integrating the exhaust pipe 29 and the muffler 27, the exhaust pipe 29 can be simplified.

Inside the muffler 27, as shown in FIG.
．． 281 are provided in two places, and the first expansion chamber 28 is connected from the front side.
2,′! J2 expansion chamber 283. A third expansion chamber 284 is defined and is effective in reducing exhaust noise.

The four-piece exhaust pipe 29 connected to the engine 3 is connected to the collection part 2858 of the diffuser vibe 285, and by pushing the exhaust pipe 29 deep into the muffler 27, the length of the exhaust pipe is secured and the exhaust gas is removed. From the exhaust pipe 29 to the third expansion chamber 284
It is designed to lead to. The third expansion chamber 284 is communicated with the first expansion chamber 282 through a pipe 286, and the first vibe 286 guides exhaust gas from the third expansion chamber 284 to the first expansion chamber 282. This first expansion bow! room 2
82 communicates with the second expansion chamber 283 through a second vibrator 287, and the exhaust gas flows into the first expansion chamber 28 through the second vibrator 287.
2 to the second expansion chamber 283. This second expansion chamber 2
83 is opened to the atmosphere via a tail vibe 288 and discharges exhaust gas to the outside.

The muffler 27 has a recess 277 around the exhaust port of the tail pipe 288, and this recess 277 prevents the exhaust port of the tail vibe 288 from protruding to the outside and guides exhaust gas toward the rear of the vehicle. It has become. Furthermore, the exhaust port of the tail vibe 288 is located at the rear below the step 25 to prevent exhaust gas from hitting the feet.

A through hole 2 is provided in the center of the muffler 27 as shown in FIG.
90 is formed through the through hole 290, and the plug 291 provided at the bottom of the oil pan 26 is removed.
Oil can be changed.

The MS diagram shows a plug 292 on the side of the oil pan 26 of engine 3.
In this embodiment, a through hole 293 is formed in the muffler 27 at a position corresponding to the plug 292 of the oil pan 26. In this case, the motorcycle is placed on a side stand with the plug 292 of the oil pan 26 facing downward, and the oil is drained and the oil replaced.

[Effects of the Invention] As described above, in the present invention, since the muffler covers the entire lower part of the engine to form an under cowl, there is no need for a dedicated under cowl, and it is easy to secure a mounting space for the muffler.

In addition, since the engine exhaust pipe is configured with a flexible pipe and the muffler connected to this exhaust pipe is supported on the engine, assembly tolerances between the engine and the muffler can be absorbed by bending the trachea. It can be made into a unit with the engine, making it easy to assemble the muffler.

Furthermore, since the muffler is supported only by the engine, it can vibrate together with the engine, eliminating the need for a supporting structure that absorbs the difference in vibration between the muffler and the vehicle frame, as was the case in the past.
Supporting the muffler becomes easier.

Furthermore, by integrating the exhaust pipe and the muffler, the exhaust pipe can be simplified.

[Brief explanation of the drawings] Figure 1 is a side view of the motorcycle, Figure 2 is a perspective view of the muffler, Figure 3 is a cross-sectional view of the muffler, and Figure 4 is the I of Figure 1.
V-IV sectional view, FIG. 5 is a sectional view of another embodiment. In the figure, 2 is the body frame, 3 is the engine, 7 is the front wheel,
14 is a rear wheel, 22 is a seat, 26 is an oil pan, 27 is a muffler, and 29 is an exhaust pipe. Patent applicant: Yamaha Motor Co., Ltd., Tomi 2 Old-Nico drawing

Claims (1)

[Claims] In a motorcycle with an engine mounted between front wheels and rear wheels, the exhaust pipe of the engine is formed of a flexible pipe, and a muffler connected to the exhaust pipe covers the entire lower part of the engine to form an under cowl. death,
A motorcycle characterized in that the muffler is supported by the engine.