JPH05246369A - Motorcycle - Google Patents

Abstract

PURPOSE:To improve space efficiency without sacrificing tank capacity and secure the rigidity of a body frame by fitting the upper part of a damper case between a right and a left rear arm brackets, and positioning each fitting part approximately on the extended line of a tank rail. CONSTITUTION:A rear wheel suspension unit 29 is disposed between a rear arm 21 and a rear arm bracket 5. An upper and a lower boss parts 32d, 32e are integrally formed at a damper case 32, and both boss parts 32d, 32e are fixed to an upper and a lower supporting brackets 36a, 36b by fixing bolts 35a, 35b. Since a tank rail 4 is separated laterally around right above an engine, the disposition space of parts can be easily secured to improve space efficiency. Also, since the tank rail 4 is extended in the approximately rectilinear state toward a low fitting position, the rear part of the tank rail 4 passes the low position so as to prevent tank capacity from being sacrificed by the tank rail 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle, and more particularly, to improvement of the shape of a vehicle body frame and the arrangement structure of buffer springs, dampers and the like.

[0002]

2. Description of the Related Art In a motorcycle, a rear wheel suspension provided between a rear arm and a vehicle body frame is provided with a buffer spring for reducing a shock applied to the rear wheel from a road surface and a damper for suppressing irregular vertical vibration of the rear wheel. The device is installed. As this rear wheel suspension device, conventionally, a structure in which a shock absorber composed of a coil spring and a telescopic tubular damper is interposed between a rear arm and a vehicle body frame has been adopted. Recently, one shock absorber is used, the upper end of which is connected near the rear end of one tank rail extending from the head pipe, and the lower end is connected directly to the pivot arm of the rear arm or through a link mechanism. The structure is generally adopted (see, for example, JP-A-59-120585).

[0003]

However, in the above-mentioned conventional device, since the upper end of one vertically long shock absorber is connected to the rear end of the tank rail, the arrangement of parts located in the center of the vehicle is adopted. The space will be occupied by the rear part of the tank rail and the above-mentioned shock absorber, so that the layout of the intake system is restricted, the capacity of the air cleaner cannot be sufficiently secured, and the space for arranging other onboard components such as the battery can be secured. There is a problem that it is difficult and the space efficiency is poor.

Further, due to the structure in which the upper end of the shock absorber is connected to the rear end of the tank rail, the rearward descending angle of the tank rail is made relatively gentle so that the rear end portion is located at a high place and the tank rail is extended to the rear. There is a problem that the fuel tank capacity is likely to be sacrificed as a result.

Furthermore, since the rear end of the tank rail is located at a high place, when connecting the rear arm bracket to the rear end of the tank rail, the connecting part must be bent downward at a steep angle. This is a disadvantage in ensuring the vertical rigidity of the vehicle body frame.

The present invention has been made in view of the above-mentioned conventional problems, and provides a motorcycle which can improve space efficiency, does not sacrifice tank capacity, and is advantageous in securing the rigidity of a vehicle body frame. The purpose is to do.

[0006]

SUMMARY OF THE INVENTION According to the present invention, an engine is mounted on a vehicle body frame, and a buffer spring for cushioning a shock applied to a rear wheel from a road surface is provided between a rear arm and a vehicle body fixing portion, and a rear wheel is provided. In a motorcycle equipped with a rear wheel suspension system that includes a damper that suppresses regular vertical vibration, the vehicle body frame extends rearward and downward from the head pipe in a single state, and extends from directly above the engine to the left and right. It is assumed to have a tank rail which is gradually separated and expanded and which is substantially straight in a side view, and left and right rear arm brackets connected to respective rear end portions of the tank rail, and the buffer spring is strip-shaped. And the front and rear direction below the engine, the damper is a rotary damper, and the upper case of the damper is attached between the left and right rear arm brackets. A mounting portion in a side view is characterized in that is positioned substantially on the extension line of the tank rails.

[0007]

According to the motorcycle of the present invention, since the buffer spring is changed from the conventional coil spring to a strip-shaped plate spring and the plate spring is arranged below the engine in the front-rear direction, the conventional coil spring is arranged. A space is created in the central part of the vehicle, and it is possible to use this space to arrange in-vehicle parts such as an air cleaner and a battery, or to arrange the intake system in a straight line, which improves space efficiency. It In addition, since the tank rails are separated into left and right parts just above the engine, it is easy to secure a space for arranging parts from this point as well, and space efficiency is improved.

Further, the conventional telescopic damper is changed to a small rotary damper as compared with this, and the upper part of the damper is mounted between the rear arm brackets and on the substantially extended line of the tank rail. The mounting position can be lowered compared to the telescopic damper. Further, since the tank rail is extended substantially linearly toward this low mounting position, the rear portion of the tank rail passes through the low position, and therefore the tank capacity is not sacrificed by the tank rail.

Further, the tank rail is gradually separated and expanded from one portion, and extends substantially linearly from the head pipe toward the pivot portion of the rear arm. Therefore, it is not necessary to sharply bend the rear arm bracket connecting portion,
This is advantageous in securing the vertical rigidity of the frame.
Further, since the upper part of the damper is mounted on a substantially extended line of the tank rail, the reaction force of the damper can be directly received by the substantially linear tank rail, which is also advantageous in ensuring the rigidity of the vehicle body frame.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 15 are views for explaining a motorcycle according to an embodiment of the present invention. FIG. 1 is a side view,
2 to 9 are side views, plan views, or sectional views of the vehicle body frame, and FIG. 10 is a side view of the rear wheel suspension portion,
FIG. 15 is a side view, a plan view, or a sectional view of the rear wheel suspension device.

In FIG. 1, reference numeral 1 denotes a motorcycle according to the present embodiment. The motorcycle 1 has a front fork (not shown) pivotally supported left and right by a head pipe 3 of the vehicle body frame 2, The rear arm bracket 5 pivotally supports the rear arm 21 that pivotally supports the rear wheel 26 so as to be vertically swingable, and mounts the engine 12 in the cradle of the vehicle body frame 2.
A fuel tank 10 is provided above the engine 12, and the tank 1
The structure is such that the seats 11 are mounted on the rear side of 0. In addition, 14a and 14b are a vaporizer and an air cleaner.

The body frame 2 is of a so-called semi-double cradle type, and includes the head pipe 3 and
A tank rail 4 extending obliquely rearward and downward from the head pipe 3, left and right rear arm brackets 5 and 5 connected to the rear end of the tank rail 4, and lower ends of the left and right rear arm brackets 5 and It is composed of a down tube 6 that connects the head pipe 3 and a tansion pipe 7 that connects the down tube 6 and the tank rail 4. In addition, 8 and 9 are a seat rail and a back stay.

In the tank rail 4, the front half portions 4a of two rectangular pipes are overlapped in the vehicle width direction, the upper and lower surfaces thereof are welded to be connected to one, and the rear half portion 4b is separated into left and right. It has been gradually expanded and has a straight line in a side view. The front end of the front half portion 4a is welded and fixed to the head pipe 3. Reference numeral 4c is a gusset for reinforcing the connecting portion with the head pipe 3, 4d is a gusset for reinforcing the separating portion, and 4e is a lightening hole for reducing weight formed in the joint portion between the rectangular pipes.

The rear arm bracket 5 has a rectangular cross section in which left and right halves made of sheet metal are butted against each other and welded to each other. The left and right rear arm brackets 5 and 5 are upper pipes made of round pipes. , Lower cross pipe 5b,
It is welded and connected at 5c. 5d is the pivot shaft 2
7 is a pivot boss portion for inserting and supporting 7.

The down tube 6 is composed of a single center tube 6b made of a rectangular pipe and a left end of the center tube 6b.
It consists of two side tubes 6a made of rectangular pipes connected so as to branch to the right, the upper end of the center tube 6b is welded to the head pipe 3, and the rear end of each side tube 6a is the above. It is welded to the lower cross pipe 5c. Further, the lower ends of the left and right rear arm brackets 5 are welded and connected to the rear end side surfaces of the left and right side tubes 6a.

A reinforcing plate 7a having a box-shaped cross section is welded to the rear surface of the center tube 6b, and the upper portion 7b of the reinforcing plate 7a has the head pipe 3, tank rails 4, and Down tube 6
And form a box cross-section. The tension pipe 7 is composed of a single round pipe that connects the reinforcing plate 7a and the portions near the left and right separating portions of the tank rail 4. In addition, 4f and 4g are lightening thinning holes, respectively, a connecting portion between the reinforcing plate 7a and the tank rail 4,
It is formed at the connecting portion between the reinforcing plate 7a and the center tube 6b.

The engine 12 is of a water-cooled two-cycle single-cylinder type, and a cylinder block 14 and a cylinder head 15 are laminated and fastened to the front of a crankcase 13 integrated with a transmission case in a forwardly inclined state. It has a structure. The engine 12 is mounted on the vehicle body frame 2 with the following structure. The front and bottom bosses 13a and 13b of the crankcase 13 are bolted to the support bracket 61 that is bolted to the rising portions of the left and right branch portions 6a of the down tube 6 and the bracket 6c that is welded and fixed to the bottom. Fix it. The rear boss portion 13c of the crankcase 13 is supported by a pivot shaft 27 described later. Further, the suspension boss portion 15a of the cylinder head 15 is bolted and fixed to the tank rail 4 via the suspension bracket 15b.

The support bracket 61 is shown in FIG.
4, as shown in FIG. 15, the left and right flange portions 61a having a substantially triangular shape in a side view are connected to the upper and lower connecting portions 61b and 61c.
The flange portion 61a is connected to the down tube 6 by a pair of upper and lower bolts 61d.
Is fixed to the left and right branch portions 6a.

The rear arm 21 is pivotally supported by the rear arm bracket 5 so as to be vertically swingable. The rear arm 21 has a pair of left and right arm bodies 22a and 22b in the shape of a rectangular tube, and a pivot portion 23 formed at the front end of the arm body 22a and 22b. The members 24 are connected and fixed by members 24, and the left and right arm bodies 22a, 22b
The rear wheel 26 is pivotally supported by an axle 25 that is inserted and fixed between the rear ends. The pivot portion 23 is axially supported by a pivot shaft 27 inserted through the bearing through a bearing, and the pivot shaft 27 is fixed to the left and right rear arm brackets 5 with a nut 27a. The rear boss portion 13c of the crankcase 13 is located between the left and right pivot portions 23, 23.

A rear wheel suspension device 29 is arranged from the front part of the rear arm 21 to the lower part of the engine 12. The rear wheel suspension device 29 is disposed between the rear arm 21 and the rear arm bracket 5, and is provided with a rotary damper 30 for suppressing irregular vertical vibration of the rear wheel 26, the rear arm 21 and the body frame 2. A leaf spring 31 that is arranged between the Dunun tube 6 and reduces the shock applied to the rear wheel 26 from the road surface, and a link mechanism 56 that connects the leaf spring 31, the damper 30 and the rear arm 21.
It consists of and.

The rotary damper 30 includes a case body 32.
A substantially plate-shaped wing-shaped piston 33 that defines two chambers in the case is housed and arranged in a damper case 32 that is substantially fan-shaped in a side view and is composed of a and a lid 32b.
The rotary shaft 34 is inserted into the shaft a and is spline-fitted, and the rotary shaft 34 is rotatably supported by the damper case 32. Although not shown, the lid 32b is formed with a plurality of oil passages that communicate the two chambers defined by the piston 33, and a throttle mechanism is arranged in the passages. .. When the piston 33 is rotated around the rotary shaft 34, the hydraulic oil moves from one chamber through the throttle mechanism to the other chamber, and this damper 30 generates a damping force.

The damper case 32 has upper and lower boss portions 3
2d and 32e are integrally formed, and both boss portions 32 are formed.
d and 32e are fixed to the upper and lower support brackets 36a and 36b with fixing bolts 35a and 35b. The upper and lower support brackets 36a and 36b are located above and below the pivot shaft 27, respectively.
b, fixed to the lower cross pipe 5c by welding. Here, the attachment point of the upper boss portion 32d to the upper support bracket 36a is located on the extension line of the tank rail 4 when viewed from the side of the vehicle.

The rear end portion 31a of the leaf spring 31 is supported by the rear arm 21 via the link mechanism 56 described later, and the front end portion 31b is a front spring bracket 47a.
It is supported by the vehicle body frame 2 via a pivotal support mechanism 47 composed of a support bolt 59 and an initial load adjusting mechanism 57. The front end portion 31b is the front spring bracket 47a.
To the support plate 47 with a rubber sheet 47e interposed.
b, it is fastened and fixed with a fixing bolt 47c. The rubber sheet 47e is for relieving the stress when the resin plate spring is sandwiched between the metal brackets.

The initial load adjusting mechanism 57 has the following structure. Left and right branch portions 6a of the down tube 6
The left and right guide brackets 58 are fixed to each other, the supporting bolts 59 are bridged and inserted between the vertically extending elongated holes 58a of the brackets 58, and fixed by nuts 59a. A connecting hole 60a formed at the lower end of the adjusting bolt 60 is fitted and connected to the central portion of the support bolt 59, and the adjusting bolt 60 is
The threaded portion 60b of the support bracket 61 is inserted into the lower connection portion 61c of the support bracket 61, and the threaded portion 60b is fitted with the adjusting nut 60c.
It has a screwed structure.

The support bolt 59 is provided with a connecting portion 47d of the front spring bracket 47a and the adjusting bolt 6
Collar 59b for restricting lateral movement of 0, and bearing 59
It is rotatably connected via c. As a result, the front spring bracket 47a and thus the front end 31b of the leaf spring 31 are pivotally supported in the front-rear direction with respect to the vehicle body frame 2 and their vertical positions can be adjusted.

Further, above the leaf spring 31 substantially in the center in the longitudinal direction, the leaf spring 31 is caused by the vertical movement of the rear arm 21.
Front and rear pillows 62 and 63, which serve as fulcrums for the deformation, are arranged so that their longitudinal positions can be adjusted.

The front pillow 62 connects a pair of left and right side plates 62a, each having a plurality of mounting screw holes 62c arranged in a row in the front-rear direction, with a base plate 62b, and at the same time, a lower surface of the base plate 62b. A block 62d made of an elastic material such as relatively hard rubber or urethane foam is attached to the. The side plate 62a is fixed by fixing bolts 62e in the vicinity of the connecting portion of the left and right branch portions 6a with the rear arm bracket 5 by selecting the front-rear direction position. As shown in FIG. 10, the block 62d of the front pillow 62 is dimensioned and mounted so as to contact the upper surface of the leaf spring 31 even at the rearmost position of the rear arm 20.

The rear pillow 63 has a block 6 made of the same material as the front block 62d on the lower surface of the base plate 63a.
3b is attached. And the base plate 6
3a is fixed by screwing the fixing bolt 63c into one of the mounting screw holes 63e of the mounting plate 63d fixed to the connection point between the branch portion 6a and the lower cross pipe 5c, by selecting its longitudinal position. ing. This rear pillow 6
3, the respective dimensions and mounting positions are set so that the leaf spring 31 contacts the rubber block 63b from the time when the rear arm 21 is lifted by a predetermined amount.

The link mechanism 56 includes the rear arm 2
A pair of left and right intermediate links 38, 38 pivotally supported by 1;
A pair of left and right levers 37, 37 connected to the intermediate link 38 and rotating the piston 33 of the damper 30;
It is composed of a pair of left and right spring links 39, 39 connecting the respective intermediate links 38 and the leaf spring 31.

The left and right intermediate links 38, 38 are plate-shaped bodies having a substantially triangular shape in a side view, and connecting collars 38f, 38g are interposed between both links, and the connecting holes 38 are formed.
Connection bolts 38c and 38d are inserted into a and 38b, and nuts 38e and 38e are screwed together to be integrally connected.

A support bracket 24a fixed to the lower surface of the cross member 24 is connected to a connecting collar 38f fitted to the connecting bolt 38c via a bearing 24b, whereby the intermediate link 38 is connected to the rear arm 2.
It is pivotally supported at 1. Hereinafter, the connecting bolt 38c will be referred to as a pivot point of the intermediate link 38.

The lower ends 37a of the left and right levers 37 are rotatably connected to the connecting collar 38g fitted to the connecting bolt 38d via bearings. As a result, the lever 37 is rotatably connected to the intermediate arm 38. Incidentally, 37b and 37c are bolts and nuts for fastening and integrating the left and right levers 37 with each other. The upper end 37d of the lever 37 has a rotating shaft 34 of the damper 30.
It is fitted with a spline on the outward protruding end of and is fixed by tightening the nut. This causes the lever 37 to rotate via the intermediate link 38 as the rear arm 21 swings, and the lever 37
Rotates the piston 33 of the damper 30.

On the outer surface of the intermediate link 38, connecting pins 38h are provided in a protruding manner, and the upper ends 39a of the left and right spring links 39 are connected to the connecting pins 38h via bearings. As a result, the spring link 39 is rotatably connected to the intermediate link 38. The rear spring bracket 43 is attached to the lower ends 39b of the left and right spring links 39.
The left and right support pins 43a are inserted through bearings, and the rear end portion 31a of the leaf spring 31 is bolted to the support portion 43b of the rear spring bracket 43.

Next, the function and effect of this embodiment will be described. In the device of this embodiment, when the rear wheel 26 rides on, for example, a convex portion of the road surface, the rear arm 21 is lifted by the impact force, and the rear end portion 31a of the leaf spring 31 is accordingly moved to the intermediate link 38,
The leaf spring 31 is pulled up via the spring link 39, and the leaf spring 31 bends around the front pillow 62 as a fulcrum, and the impact force is alleviated according to the spring constant of the leaf spring 31 in the bending direction. When the rear arm 20 further rises, the leaf spring 31 further bends around the rear pillow 63 as a fulcrum (see the chain double-dashed line in FIG. 10), which increases the spring constant and raises the spring characteristic, so that a so-called progressive effect is obtained.

As the rear arm 21 moves up and down, the lever 37 rotates via the intermediate link 38, and the lever 37 rotates the piston 33 in the damper 30.
As a result, a damping force is generated when the hydraulic oil in one chamber of the damper 30 flows into the other chamber through the throttle mechanism of the oil passage, and irregular vertical vibration of the rear wheel 26 is suppressed.

According to the motorcycle 1 of the present embodiment which performs such an operation, the buffer spring is changed from the conventional coil spring to the strip-shaped plate spring 31 and the plate spring 31 is arranged below the engine in the front-rear direction. Therefore, a space is created in the central portion of the vehicle where the conventional coil spring is arranged, and on-vehicle components such as the air cleaner 14b can be arranged by utilizing the space, and the intake system including the air cleaner 14b and the carburetor 14a is linear. Can be placed in a space, which improves space efficiency. In addition, since the tank rail 4 is separated into the left and the right near the engine, it is easier to secure a space for arranging parts as compared with the conventional structure in which the tank rail is extended to the center of the vehicle. Efficiency is improved.

Further, the conventional expandable damper is replaced with a small rotary damper 30 as compared with this, and the damper 30 is
Since the upper boss portion 32d is fixed to the upper support bracket 36a located substantially on the extension line of the tank rail 4, its mounting position can be made lower than that of the conventional telescopic damper. Since the tank rail 4 is extended substantially linearly in a side view toward this low mounting position, the rear portion of the tank rail 4 passes through the low position, and therefore the tank capacity is not sacrificed by the tank rail 4.

Further, the tank rail 4 is gradually separated and expanded from one portion, and extends substantially linearly from the head pipe 3 toward the pivot shaft 27 of the rear arm, so that the connecting portion with the rear arm bracket 5 is sharply bent. This is advantageous in ensuring the vertical rigidity of the frame. Further, since the upper boss portion 32d of the damper 30 is located on a substantially extended line of the tank rail 4, the damper 30
Can be directly received by the substantially linear tank rail 4, which is also advantageous in securing the rigidity of the vehicle body frame 2. Furthermore, the damper 30 is mounted on the pivot shaft 27,
Since it is fixed to the body frame 2 in the lower position, the damper 3
0 itself acts to improve frame rigidity.

In the above embodiment, the case where the tank rail 4 is a straight line when viewed from the side has been described, but the tank rail of the present invention is not necessarily limited to a perfect straight line, and is a substantially straight line. It may be slightly curved to the extent that

The case where the tank rail 4 is formed by joining two pipe members, the left and the right, to the vehicle width method has been described. However, the tank rail of the present invention has one front half portion and two rear half portions. Including those welded together.

Furthermore, in the above embodiment, the damper 30 is used.
Although the upper boss portion 32d is bolted and fixed to the upper support bracket 36a fixed to the upper cross pipe 5b, the upper mounting structure of the damper 33 is not limited to this. For example, the damper case 32 is also used as a part of the cross pipe, whereby the left and right rear arm brackets 5,
A method of connecting 5 may be adopted.

Further, in the above embodiment, the case where the air is taken in from the rear of the engine and exhausted in the front has been described.
The present invention can of course be applied to other intake and exhaust systems, for example, rear intake and rear exhaust.

[0043]

As described above, according to the motorcycle of the present invention, the leaf spring and the rotary damper are adopted, and the tank rail is separated in the vicinity of directly above the engine to shorten one portion thereof. Since a space is obtained in the center of the vehicle body, space efficiency can be improved, and since the tank rail can be arranged at a low position, the tank capacity can be increased. Further, since the rear half of the tank rail is gradually separated and is made substantially linear in a side view, and the upper mounting portion of the damper is positioned on a substantially extended line of the tank rail, it is possible to make a sudden change in the rear arm bracket portion. In addition to avoiding bending, the reaction force of the damper can be directly received by the linear tank rail, which is advantageous in improving frame rigidity.

[Brief description of drawings]

FIG. 1 is a side view of a motorcycle according to an embodiment of the present invention.

FIG. 2 is a side view of the vehicle body frame of the above embodiment.

FIG. 3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

5 is a sectional view taken along line VV of FIG.

6 is a sectional view taken along line VI-VI of FIG.

7 is a sectional view taken along line VII-VII of FIG.

8 is a sectional view taken along line VIII-VIII of FIG.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a side view of the rear wheel suspension system portion of the above embodiment.

FIG. 11 is a plan view of a damper mounting portion of the above embodiment.

12 is a sectional view taken along line XII-XII in FIG.

13 is a sectional view taken along line XIII-XIII in FIG.

FIG. 14 is a side view of a front end mounting portion of the leaf spring of the above embodiment.

15 is a sectional view taken along line XV-XV in FIG.

[Explanation of symbols]

 1 Motorcycle 2 Body Frame 3 Head Pipe 4 Tank Rail 5 Rear Arm Bracket 12 Engine 21 Rear Arm 26 Rear Wheel 29 Rear Wheel Suspension Device 30 Damper 31 Leaf Spring 32 Damper Case 36a Upper Bracket (Mounting Part)

Claims (1)

[Claims] 1. An engine is mounted on a body frame, and a rear arm and a body frame or an engine (hereinafter,
A motorcycle equipped with a rear wheel suspension device including a buffer spring for damping a shock applied to the rear wheel from the road surface and a damper for suppressing irregular vertical vibration of the rear wheel between the vehicle body fixing portion and the vehicle body fixing portion). In the tank tank, the vehicle body frame extends rearward and downward from the head pipe in a single state, gradually separates and expands from right above the engine to left and right, and is substantially straight in a side view, and the tank. It has left and right rear arm brackets connected to the respective rear ends of the rails, the buffer springs are strip-shaped plate springs and are arranged in the front-rear direction below the engine, and the dampers are rotary dampers. The motorcycle is characterized in that the upper part of the case of the damper is mounted between the left and right rear arm brackets, and the mounting portion is located on a substantially extended line of the tank rail in a side view. .