JPH0425432Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a fuel tank support mechanism for a motorcycle.

(Prior art) The frame structure of a motorcycle is generally such that a pair of left and right main frames extend downward from the upper end of a head pipe at the front end of the frame, and a suspension tube that also serves as an engine hanger extends downward from the lower end of the head pipe. However, a so-called diamond-shaped frame is also widely known in which the down tube is abolished and the engine is suspended on the main frame via an engine hanger (for example, Japanese Utility Model Publication No. 59-30783). However, diamond-shaped frames require the main frame to have sufficient rigidity, and various types of main frames have already been proposed in which the vertical width is sufficiently larger than the horizontal width. 61−
202987, 278480, 278481). On the other hand, as the vertical width of the main frame increases, it becomes difficult to approach the space between the left and right main frames from the side, so the extent to which the engine cylinder part is lowered forward is increased, and maintenance and inspection of plugs and other attached parts is required. The entire engine would need to be redesigned to make it easier.

(Purpose of the invention) The present invention was designed to cover the entire space between the main frames so that the front half of the space between the left and right main frames, which have a large vertical width, can be used as a storage room for a removable air cleaner. It is an object of the present invention to shorten the overall length of a fuel tank toward the rear, and to support the fuel tank so as to project forward so as not to interfere with the air cleaner storage chamber.

(Structure of the invention) The invention consists of a pair of main frames with a rectangular cross section whose vertical width is sufficiently larger than the width, extending downward from the head pipe at the front end of the frame, and connecting a cast swing arm bracket to the rear end. The first half of the space between the two main frames is used as an air cleaner storage chamber, and one horizontal pin is integrally installed on the opposite inner side of the swing arm bracket, and the second half of the rubber damper fitted to this pin is used to store the fuel. The fuel tank is characterized by fitting the front-opening seats on both sides of the tank and fixing the bracket at the rear end of the fuel tank on the frame, so that the fuel tank is supported at three points in the rear so as to extend forward to the vicinity of the air cleaner storage chamber. This is a fuel tank support mechanism for motorcycles.

To mount the fuel tank on the frame, first fit a rubber damper onto the horizontal pins of the swing arm bracket, insert the fuel tank from the rear into the space between the main frames, and attach the seat (tank bracket) on the side wall of the fuel tank. By fitting the fuel tank into the rubber damper and bolting the bracket at the rear end of the tank bracket to a cross member or the like on the frame, the fuel tank can be supported as if it were cantilevered forward.

(Example) Fig. 1 is a left side view showing the main parts of the frame of a motorcycle to which the present invention is applied, in which a pair of main frames 3 extend downward from the head pipe 2 at the front end of the frame 1 to the rear (down to the right in Fig. 1). ), and a cast inverted L-shaped swing arm bracket 4 is connected to the rear end thereof, and rear frames 5 and 6 extend rearward from the swing arm bracket 4, all of which are made of aluminum alloy. An engine 8 is suspended below the main frame 3 by a hanger bracket, which will be described later, and a part of the cylinder head portion 9 at the front end of the engine and the spark plug 10 are located in the space between the pair of left and right main frames 3, 3. 11 (Fig. 2), a carburetor 12 is fixed to the rear upper part of the cylinder head portion 9, a rear case 14 of an air cleaner 13 is fixed to the carburetor 12, and an air cleaner is attached to the front side of the rear case 14. 1
3 detachable front cases 15 are detachably connected. The lower half of the air cleaner 13 is located in the front half of the space 11 (FIG. 2), and a downwardly opening bracket 16 provided at the front end of the front case 15 is connected to the cross member 1.
7 (Fig. 3). Both ends of the cross member 17 are fixed to the inner surfaces of the pair of main frames 3. The connecting structure of the front and rear cases 15 and 14 is as shown in FIG.
The front and rear cases 15,
14 are pressed together via a seal 26. bolt 23
For example, three are arranged above the main frame 3. 27 is an element.

A fuel tank 2 is located behind the air cleaner 13.
8 is arranged, and this fuel tank 28 has a substantially inverted L shape when viewed from the side so that the lower half enters into the frame 1.
It is supported at three points, the left and right swing arm brackets 4 and the rear frame 5, in a forward-protruding manner by a mechanism to be described later. A removable cover 29 made of resin that smoothly continues on the top surface of the fuel tank 28
is attached to the fuel tank 28 and the frame 1.
This cover 29 is located below and at the rear (fuel tank 28
side), and the rear end edge is connected to the mating flange 3 of the fuel tank 28 on the upper side of the main frame 3.
0 (Figure 4) with multiple (for example, 3) bolts 3
Fixed by 1. Forward facing flange 3 of the front half
2 abuts on a gusset 3 connecting the front ends of the main frame 3, and is fixed by other fasteners 34 such as bolts, nuts, and well nuts (not shown). When the cover 29 and the front case 15 of the air cleaner 13 are removed, the spark plug 10 is exposed and accessible from above.

Next, the connection structure between the engine and frame will be explained. In FIG. 5 showing the left side of the main part, a rib-shaped bracket 36 (FIG. 6) is welded to the lower surface of the front half of each main frame 3.
A substantially rectangular engine bracket 37 is installed at the front and rear ends of 6.
(Engine hanger) is fixed with two bolts 38, and pins protrude from the left and right sides of the radiator 40 in the left and right lateral directions (perpendicular to the plane of the paper in FIG. 5) in holes 39 at two locations above and below the front edge of the engine bracket 37. 41 (FIG. 7) is fitted and supported via a rubber damper 42. The pin 41 has a slightly tapered shape, and the rubber damper 42 has a hat-shaped cross section that fits the pin 41.

A pair of bosses 44 protrude forward from the front end of the cylinder head portion 9 of the engine 8. Each boss 44 is joined to the opposing inner surfaces of a pair of engine brackets 37, and a mount bolt 45 and a nut 46 (eighth
The front end of the engine is suspended from the main frame 3 via a bracket 37. engine 8
The two upper and lower rear end points are suspended by mount bolts 51 and 52 on the front ends of brackets 49 and 50 that protrude forward from cross pipes 47 and 48, respectively.

Next, the connection structure between the fuel tank and the frame will be explained. In FIG. 9 showing the left side surface of the main part, reference numeral 54 denotes a horizontal pin provided concentrically on the opposing inner surface of the swing arm bracket 4 (see FIGS. 10 and 11).
), a rubber damper 55 is fitted to this pin 54,
Front-opening seats 56 (tank brackets) on both sides of the fuel tank 28 are fitted into the rear half of the rubber damper 55 from behind. 57 is a support hole for the swing arm fulcrum pin. As shown in FIG. 11, the seat 56 has a shape obtained by cutting out one side wall of a shallow cup-shaped sheet metal member, and has a bottom plate welded to the side wall surface of the fuel tank 28. A bracket 58 having an L-shaped cross section is welded to the rear wall of the fuel tank 28, and a bracket 58 is attached to the upper surface of the central portion of a cross member 59 installed between the pair of rear frames 5, 5 as shown in FIG. are in contact with each other, and the bracket 58 is secured by the bolt 60.
is fixed. Therefore, the fuel tank 28 is supported by a total of three points, the left and right pins 54 and the rear end bracket 58, so as to project forward.

Next, the cross-sectional shape of the main frame will be explained. In FIG. 12 showing the left side of the main part, reference numeral 62 denotes a pair of upper and lower recessed steps, which extend back and forth parallel to the upper and lower edges of the main frame 3, and which correspond to the vertical width dimension H (FIG. 13) of the main frame 3. It is provided approximately in the vicinity of 1/4 and 3/4, and the recessed side wall portion 63 between the upper and lower recessed step portions 62, 62 is recessed by a slight step S (for example, 3 mm) from the outer wall 64. . The inner wall 65 is left flat in the illustrated embodiment. The respective central portions of the recessed side wall portion 63 and the inner wall 65 are integrally connected by a horizontal rib 66, so that the space within the main frame 3 is divided into two, upper and lower.

Main frame 3 vertical width dimension H and horizontal width dimension L
The ratio H/L is approximately 4 or more. Specifically, H
In the case of 120 mm, L is 26 to 30 mm, and the vertical dimension _H1 of the head pipe 2 is, for example, 190 mm.
When H/L is less than 4, it is difficult to form a perfect diamond-shaped vehicle body due to insufficient rigidity.
When H/L becomes larger than the vertical dimension _H1 of the head pipe 2, it becomes difficult to completely close the main frame 3 at the joint with the head pipe 2.

(Effects of the invention) In the present invention, the front half of the space 11 between the pair of main frames 3, 3 having a large vertical width can be widely used as a storage chamber for the removable air cleaner 13. By removing it, the spark plug 10 in the space 11 can be easily accessed from above. Therefore, it is possible to use a conventional type engine 8 in which the cylinder head portion 9 stands upward.
Further, the pin 54 for supporting the fuel tank 28 is
Swing arm bracket 4, which is an aluminum casting product
Since the fuel tank 28 is integrally formed with the fuel tank 28, the pin 54 can be provided accurately and concentrically, and the strength of the pin 54 is also increased, so that it can support both sides of the rear end of the fuel tank 28. As a result, the rear end of the fuel tank 28 becomes 1
By simply attaching two brackets 58 to the cross member 59, the fuel tank 28 can be supported at three points at the rear in a projecting manner forward, and the holding rigidity of the fuel tank 28 is also increased. Since the rubber damper 55 is fitted onto the pin 54 to support the seat 56, transmission of vibration to the fuel tank 28 can be minimized.
It also has the advantage of easily absorbing assembly errors.

[Brief explanation of drawings]

Fig. 1 is a left side view of the main part of the fuel tank support mechanism to which the present invention is applied, Fig. 2 is a schematic plan view taken in the direction of the arrows showing the state in which the cover is removed from Fig. 1, and Fig. 3 shows the air cleaner coupling structure. 4 is a partially longitudinal side view showing the coupling structure between the fuel tank and the cover, FIG. 5 is a left side view of the main part showing the coupling structure between the engine and the frame, and FIG. 6 is the same plane. 7 is an enlarged sectional view of FIG. 5, FIG. 8 is an enlarged sectional view of FIG. The figure is the same plan view, and Figure 11 is XI-XI of Figure 9.
An enlarged cross-sectional view, Fig. 12 is a left side partial view showing details of the main frame, and Fig. 13 is an enlarged cross-sectional view of Fig. 12.
It is an enlarged view of the X section. 1...frame, 2...
Head pipe, 3... Main frame, 4... Swing arm bracket, 11... Space, 13...
...Air cleaner, 28...Fuel tank, 54...
...Pin, 55...Rubber damper, 56...Catch (tank bracket), 58...Bracket.

Claims (1)

[Scope of utility model registration request] 1 with a rectangular cross section where the vertical width is sufficiently larger than the horizontal width
The pair of main frames are extended backwards and downwards from the head pipe at the front end of the frame, and a cast swing arm bracket is connected to the rear end.The front half of the space between the two main frames is used as an air cleaner storage chamber, and the swing arm bracket is One sideways pin is integrally provided on each opposing inner side, and the front-opening seats on both sides of the fuel tank are fitted to the rear half of the rubber damper fitted to these pins, and the bracket at the rear end of the fuel tank is mounted on the frame. and fix the fuel tank to the rear 3
A fuel tank support mechanism for a motorcycle, characterized in that the fuel tank is supported in a forward extending manner up to the vicinity of an air cleaner storage chamber at a point.