JPH03271091A - Motorcycle - Google Patents

Abstract

PURPOSE:To linearize an exhaust pipe as far as possible, thereby improving the extent of engine power, and enlarge the degree of freedom for piping as well as to reduce a thermal effect to a buffer by forming a buffer supporting part into an almost semicircular cylindrical form covering the upper front of the buffer. CONSTITUTION:A buffer supporting part 7 is an almost semicircular section hollow member covering a buffer 6 along the upper first half side, and it is formed by means of casting a lot of ribs 21 are installed in the inner part, and the front side is formed into a shielding wall 22 formed up to an upper end from a connecting part with a cross-member 20, while the rear side is formed into a recess space 23 to house the front side of the buffer 6. Since the buffer supporting part 7 is formed into the almost semicircular cylindrical form, the external form becomes reduced as small as possible, whereby an space at the side becomes sufficient magnitude as a piping space. In addition, since a central axis of the buffer supporting part 7 is offset so as to be accorded with the central line of a rear bank cylinder 11, both exhaust pipes 12, 13 are arranged on an almost straight line as far as possible without interfering with the buffer supporting part 7, and also the degree of freedom for piping grows larger.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a two-wheeled motor vehicle, and particularly to a motorcycle that simultaneously improves engine output and reduces the thermal influence of the engine on a shock absorber. [Prior Art] Japanese Unexamined Patent Publication No. 1-229791 discloses a pair of left and right main frames disposed in the front-rear direction between front and rear wheels, a cross member connecting the rear parts of the left and right main frames, and an intermediate portion between the cross members. a shock absorber support section extending upwardly from the main frame; a swing arm swingably connected to the rear part of the main frame; a shock absorber having one end supported by the shock absorber support section and the other end supported by the swing arm; It is equipped with a multiple cylinder engine arranged in front of the shock absorber, and a plurality of exhaust pipes extending rearward from each cylinder of the engine and passing on both sides of the shock absorber support, and these exhaust pipes are arranged in a substantially straight line. A two-wheeled motor vehicle is shown that is provided with a generally oar-shaped shock absorber support portion so as to extend rearward. [Problems to be Solved by the Invention] According to the above structure, since the exhaust pipe can be made substantially straight, the output of the engine can be improved. However, since the shock absorber support part is roughly turret-shaped and relatively large, it is necessary to lower the vehicle body width slightly in order to secure space on the side for passing the exhaust pipe, but piping space is still limited. This reduces the degree of freedom in piping. Furthermore, since the shock absorber support portion faces the engine, the hot air from the engine directly reaches the front surface of the upper portion of the shock absorber, resulting in considerable thermal effects. Therefore, the present invention aims to solve this problem. [Means for Solving the Problems] In order to solve the above problems, the present invention provides a two-wheeled motor vehicle of the above type, in which the shock absorber support portion is configured to have a substantially semi-cylindrical shape that covers the upper front surface of the shock absorber. It is characterized by what it did. [Operation of the Invention] Since the shock absorber support part has a substantially semi-cylindrical shape, the outer shape can be made as small as possible, and the piping space for the exhaust pipe formed on the side becomes larger accordingly. In addition, hot air flowing rearward from the engine toward the shock absorber is blocked by the wall of the shock absorber support that covers the front of the upper part of the shock absorber, and does not reach the top of the shock absorber directly, so the heat of the engine against the shock absorber is blocked. The impact is also reduced. [Embodiment] An embodiment is shown in Figs. 1 to 5. Fig. 1 shows a side view of the main parts of a two-wheeled motor vehicle equipped with a V-type four-cylinder engine, where 1 is a front wheel, 2 is a front fork, 3 is the mainframe, 4
is the pivot plate, 5 is the rear fork, 6 is the shock absorber,
7 is a shock absorber support part, 8 is a seat rail, and 9 is a rear wheel. A V-type four-cylinder engine 10 is supported on the main frame 3. 2 from left and right 2 cylinders rear bank cylinder 11
A main exhaust pipe 12 (13) extends rearward, passes through the side of the shock absorber 6, and is connected to a muffler 14 (15). Similarly, two exhaust pipes 17 and 18 extend rearward from the two left and right front bank cylinders 16 passing below the engine 1O, and further diagonally cross the rear fork 5 and rising upward to connect to the muffler 19. are doing. FIG. 2 is a diagram showing the planar shape of the main part of the vehicle body, and the rear end portions of the main frame 3, which are branched left and right in a varnish-like manner, are connected by a cross member 20 at the upper part of the pivot plate 4. A shock absorber support part 7 whose lower part is welded is provided in the middle part of the cross member 20 so as to protrude upward. The shock absorber support part 7 has a substantially semi-cylindrical shape, like a cylinder divided vertically, and its center n c + is located at the rear bank cylinder 11.
By aligning the center line C8 of the vehicle body with the center line C8 of
, only the flood is on the side (left side of the vehicle body) on the cross member 20.
offset to Therefore, the exhaust pipes 12 and 13 extending rearward from each cylinder of the rear bank cylinder 11 are arranged in a substantially straight line and pass through each side of the shock absorber support part 7. Further, the shock absorber support portion 7 is located between the exhaust pipes 12 and 13 and directly faces the rear bank cylinder 11. FIG. 3 is an enlarged view showing the side shape of the shock absorber support 7 together with the main frame 3 and pivot plate 4, etc., and FIG. 4 is a horizontal cross-sectional view of the shock absorber support 7 in relation to the exhaust pipes 12 and 13. The figure shown in FIG. 5 is a view taken from the direction of the X arrow in FIG. 3. As is clear from these figures, the shock absorber support part 7 is
It is a hollow member with a substantially semicircular cross section that covers the upper front half of the container 6, and is formed by casting with a large number of ribs 21 provided inside (FIG. 4). Its front side (the side facing the rear bank cylinder ll) forms a shielding wall 22 that is continuously formed from the connection part with the cross member 20 to the upper end, and its rear side is a recessed space that accommodates the front side of the shock absorber 6. 23
It has become. A hole 25 is opened in the center of the top wall 24 formed at the top (see FIG. 2), and a female thread is formed on the inner surface of the hole 25. Bosses 26 are formed on the left and right rear end portions of the top wall 24 to protrude rearward, and the front end of the seat rail 8 is connected to the bosses 26 (FIG. 1). A bracket 27 formed on the upper part of the shock absorber 6 and having a male threaded portion on the outer periphery is fitted into the hole 25 of the top wall 24, is supported in a height-adjustable manner, and is secured by a tightening nut 28. The shock absorber 6 is firmly fixed (FIG. 3), but as shown in FIG. 5, the shock absorber 6 is also offset with respect to the center line C8 of the vehicle body due to the offset of the shock absorber support portion 7. Next, the operation of this embodiment will be explained. As shown in FIG. 2, etc., the shock absorber support part 7 is formed into a substantially semi-cylindrical shape, so that its outer shape is as small as possible, and the space on the sides of the shock absorber support part 7 is large enough to serve as a piping space. Also, the center of the vehicle body should be adjusted so that the central axis C3 of the shock absorber support part 7 coincides with the center line C1 of the rear bank cylinder 11! IIC
, and face the center of the rear bank cylinder 11. Therefore, the exhaust pipes 12 and 13 extending from the rear bank cylinder 11 are made as substantially straight as possible without interfering with the shock absorber support part 7. The rear bank cylinder 11 and the engine 10 as a whole achieve an increase in output. Furthermore, the expansion of piping space increases the degree of freedom in piping. Furthermore, by shortening the cross member 20, it is possible to narrow the vehicle body width and make it slim. Furthermore, since the upper front surface of the shock absorber 6 is covered by the shielding wall 22 of the shock absorber support part 7, the shock absorber 6 is located between the left and right exhaust pipes 12, 13 and behind the rear bank cylinder 11. Nevertheless, the hot air flowing rearward from the rear bank cylinder 11 is blocked by the shielding wall 22 interposed in the middle, splits to both sides of the shock absorber support part 7, flows rearward, and does not directly reach the shock absorber 6. Therefore, the thermal influence of the engine on the buffer 6 is reduced. [Effects of the Invention] The present invention makes the shock absorber support section provided on the cross member approximately semi-cylindrical in shape, thereby reducing the outer diameter of the shock absorber support section as much as possible and saving the piping space on its side. By enlarging the exhaust pipe, it is possible to make the exhaust pipe as straight as possible to improve engine output, and the degree of freedom in piping can be increased. Moreover, since the wall portion of the shock absorber support portion covers the upper front part of the shock absorber, hot air from the engine is not directly applied to the shock absorber, so that the thermal influence of the engine on the shock absorber can be reduced as much as possible.

[Brief explanation of drawings]

Figures 1 to 5 show examples. Figure 1 is a side view of the main parts of a motorcycle, Figure 2 is a plan view of the main parts, Figure 3 is an enlarged side view of the main parts, and Figure 4 is a side view of the main parts. A sectional view of the main part, FIG. 5 is a view in the X direction of FIG. 3. (Explanation of symbols) 3... Main frame, 4... Pivot plate,
5... Rear fork, 6... Buffer, 7... Buffer support part, 10... Engine, 11... Rear bank cylinder, 12, 13... Exhaust pipe, 16... Front bank cylinder, 20... cross member, 22... shielding wall.

Claims (1)

[Claims] A pair of left and right main frames arranged in the front-rear direction between the front and rear wheels, a cross member connecting the rear parts of the left and right main frames, a shock absorber support part extending upward in the middle part of the cross member, and a main frame. A swing arm swingably connected to the rear of the frame, a shock absorber having one end supported by a shock absorber support and the other end supported by the swing arm, and a multi-cylinder engine disposed in front of the shock absorber. In a motorcycle equipped with a plurality of exhaust pipes extending rearward from each cylinder of the engine and passing on both sides of a shock absorber support, the shape of the shock absorber support is approximately half-half that covers the upper front surface of the shock absorber. A two-wheeled motor vehicle characterized by its cylindrical shape.