JPH05278661A - Motorcycle - Google Patents

Abstract

PURPOSE:To provide a motorcycle in which space efficiency can be improved and a reduction in road clearance due to leaf spring can be suppressed. CONSTITUTION:In a motorcycle, an engine 12 is mounted on a vehicle frame, and a buffer spring for absorbing shock exerted on a rear wheel from a road surface and a rear suspension device 29 provided with a damper for suppressing irregular vertical vibration of a rear wheel 26 are provided between a rear arm 21 and a down tube 6. In this case, the damping spring is located under the engine 12 in the longitudinal direction as a strip shaped leaf spring 31, and the damper is located near a pivot shaft 27 of the rear arm 21 as a rotary damper 30. Then a main shaft (clutch shaft) 12b in which a clutch mechanism is installed is located above a straight line A connecting the axis center of the pivot shaft 27 to that of the crankshaft 12a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle and is capable of suppressing a decrease in load clearance (minimum ground clearance) due to a plate spring when the buffer spring is arranged below the engine as a plate spring. The improvement of the arrangement structure of the clutch shaft etc.

[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, a structure has been adopted in which the shock absorber is one, the upper end of the shock absorber is connected near the rear end of the tank rail extending from the head pipe, and the lower end is connected near the pivot axis of the rear arm directly or through a link mechanism. This is generally done (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 above-mentioned buffer occupies the space, so that the layout of the intake system is restricted, the capacity of the air cleaner cannot be sufficiently secured, and it is difficult to secure a space for arranging other vehicle-mounted parts such as a battery. There is a problem of inefficiency.

On the other hand, the present inventors are currently studying the use of a leaf spring instead of the coil spring. When the structure in which the leaf spring is arranged below the engine in the front-rear direction of the vehicle is adopted, it is necessary to arrange the leaf spring at a space that can avoid interference with the bottom surface of the crankcase of the engine. Therefore, the load clearance may be insufficient depending on the arrangement structure of the leaf springs.

The present invention has been made in view of the above-mentioned conventional problems and problems in arranging leaf springs, and it is possible to improve space efficiency and suppress a decrease in load clearance due to the leaf springs. The purpose is to provide motorcycles.

[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 provided with a rear wheel suspension device having a damper that suppresses regular vertical vibration, the buffer spring is arranged in the front-rear direction below the engine as a strip plate-shaped plate spring, and the damper is a rotary damper. Is arranged near the pivot shaft of the rear arm, and the clutch shaft equipped with the clutch mechanism is arranged above a straight line connecting the pivot shaft and the crank shaft.

[0007]

According to the motorcycle of the present invention, since the buffer spring is changed from the conventional coil spring to the strip plate-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 center 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 general, since the clutch mechanism has a large diameter, the clutch mechanism portion on the bottom surface of the crankcase often bulges downward, and the bulge portion extends over a considerable range in the vehicle width direction. .. Therefore, when the leaf spring is arranged below the engine, there is concern that the height position of the leaf spring may be restricted by the bulging portion. In the present invention, since the clutch shaft is arranged above the straight line connecting the pivot shaft of the rear arm and the crank shaft, the bulging amount becomes small or there is no need to bulge, and the leaf spring can be arranged above that much. As a result, it is possible to suppress a decrease in load clearance when the leaf spring is arranged below the engine.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 10 are views for explaining a motorcycle according to an embodiment of the present invention, FIGS. 1 and 2 are right side views and left side views, and FIG. 3 is a left side view of a rear wheel suspension system, 4, 5 and 6 are a plan view of the damper part, a left side view, a sectional front view, FIGS. 7 and 8 are a side view and a sectional front view of the leaf spring mounting part, and FIG. 9 is a sectional plan view of the link mechanism part. FIG. 10 and FIG. 10 are sectional bottom views of the pillow mounting portion.

In the figure, reference numeral 1 is a motorcycle of the present embodiment. The motorcycle 1 has a front fork (not shown) pivotally supported left and right by a head pipe 3 of a vehicle body frame 2 and is left. , The right rear arm brackets 5, 5 ′ pivotally support the rear arm 21 that pivotally supports the rear wheel 26 so that the rear arm 21 can swing up and down.
2 is mounted on the fuel tank 10 above the engine 12.
And a seat 11 mounted on the back of the tank 10. In addition, 14a and 14b are vaporizers,
It is an air cleaner. Further, 73 is a radiator, and 74 is a radiator cover.

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 left and right rear arm brackets 5 and 5 '. And a tension pipe 7 that connects the down tube 6 and the tank rail 4 to each other. Reference numerals 8 and 9 denote a seat rail and a back stay, which are integrated with each other, and these are detachably bolted to the tank rail 4 and the rear arm brackets 5 and 5 '.

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. And gradually expanded. The tank rail 4 is straight in a side view, and the front half 4
The front end of a is welded and fixed to the head pipe 3.

Each of the rear arm brackets 5 and 5'has a rectangular cross section and is made by sheet metal left and right halves which are butted against each other and welded to each other. The left and right rear arm brackets 5, 5'are welded to each other by upper and lower cross pipes 5b, 5c made of a round pipe.

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 is composed 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 welded to the lower cross pipe 5c. Further, the lower ends of the left and right rear arm brackets 5 and 5'are welded to the rear end side surfaces of the left and right side tubes 6a (see FIG. 10).

As shown in FIG. 2, the left rear arm bracket 5 has a pivot shaft 27 of the rear arm 21.
It inclines slightly to the front side from directly above, and its upper end is welded to the rear end of the rear half 4b of the tank rail 4. The reason why the left rear arm bracket 5 is tilted slightly forward in this way is to facilitate the adjustment work of the damping characteristics of the damper 30, which will be described later.

On the other hand, as shown in FIG. 1, the right rear arm bracket 5'is bent backward from the pivot shaft 27 and its upper end is welded to the rear end of the rear half 4b. The reason why the right rear arm bracket 5'is bent rearward in this manner is to secure a space for disposing the kick shaft 75a of the kick arm 75.

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 portion and the bottom boss portions 13a and 13b of the crankcase 13 are bolted to the support brackets 61 and 6c fixed to the rising portion and the bottom portion of the side tube 6a, respectively. Further, the rear boss portion 13c of the crankcase 13 is connected to the pivot shaft 2 described above.
Support at 7. 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.

In the crankcase 13 of the engine 12, a crankshaft 12a for converting vertical movement of a piston into rotational movement, and a main shaft 12b for transmitting the rotational movement of the crankshaft 12a through a clutch mechanism, It has a secondary side transmission gear that meshes with a primary side transmission gear mounted on the main shaft 12b, and is arranged in parallel with a drive shaft 12c for taking out an output.

Here, the main shaft 12b and the drive shaft 12c are the crankshaft 12a and the pivot shaft 2, respectively.
7 is arranged above the straight line A connecting the axes of the shafts 7.
The clutch mechanism is mounted on the right end of the main shaft 12b, and the clutch mechanism is mounted on the crankcase 1
It is surrounded by a case cover 13d mounted on the right side surface of No. 3.

A brake pedal 76 is arranged on the outside of the case cover 13d so as to be vertically rotatable.
An arm 76a formed on the pedal 76 is connected to a master cylinder 77. The master cylinder 77 is bolted and fixed to the rear portion of the right rear arm bracket 5 ', and is connected to a reserve tank 79 by a reserve hose 78. This reserve tank 79
It is attached near the upper end of the back stay 9.

As shown in FIGS. 7 and 8, the support bracket 61 integrally connects left and right flange portions 61a having a substantially triangular shape in a side view with upper and lower connecting portions 61b and 61c. Each of the flange portions 61a is fixed to the side tube 6a of the down tube 6 by a pair of upper and lower bolts 61d.

The rear arm 21 is pivotally supported up and down by the left and right rear arm brackets 5 and 5 '. 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. Member 2
4, the rear wheel 26 is pivotally supported by an axle 25 that is inserted and fixed between the rear ends of the left and right arm bodies 22a and 22b. 25a is the rear wheel 2
It is a chain that drives the 6. The pivot shaft 27 is inserted through the pivot portion 23, and the pivot shaft 27 is attached to the left and right rear arm brackets 5 and 5 ′ by the nut 2.
It is fastened and fixed at 7a. 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 provided from the front part of the rear arm 21 to the lower part of the engine 12. The rear wheel suspension device 29 is arranged between the rear arm 21 and the rear arm brackets 5 and 5 ', and
A rotary damper 30 for suppressing the irregular vertical vibration of 6;
A leaf spring 31 arranged between the rear arm 21 and the down tube 6 of the vehicle body frame 2 to reduce a shock applied to the rear wheel 26 from the road surface, and the leaf spring 31, and the damper 30 and the rear arm 21 are connected. And a link mechanism 56 that operates.

The rotary damper 30 has the following structure. A substantially plate-shaped wing-shaped piston 33 that defines two chambers inside the case is housed in a damper case 32 that is substantially fan-shaped in a side view and includes a case body 32a and a lid 32b. A rotary shaft 34 is inserted and spline-fitted into the lower end portion 33a of the vane piston 33, and the rotary shaft 34 is rotatably supported by the damper case 32. Further, a plurality of oil passages 70a to 70d for communicating both chambers defined by the piston 33 are formed in the lid 32b, and throttle mechanisms 71a to 71d are arranged in the passages. When the piston 33 is rotated around the rotary shaft 34, the working oil flows from one chamber to the throttle mechanism 71a.
It moves to the other chamber through ~ 71d, and this damper 30 generates a damping force.

The damper case 32 includes 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 damper case 32 has a reservoir 65 for absorbing the expansion amount of the hydraulic oil due to the temperature rise.
Are arranged and connected so as to be located between the damper case 32 and the right rear arm bracket 5 '. The reservoir 65 has a structure in which a free piston 68 is housed in a cylinder 67 connected to the damper case 32 via a bracket 66. One chamber defined by the free piston 68 of the cylinder 67 is filled with high-pressure gas, and the other chamber communicates with the inside of the damper case 32 via a passage 66a. In addition, the passage 66a
A passage area adjustment valve 69 is disposed in the middle of the path. Reference numeral 54 denotes a stopper mounted on the bracket 32f of the damper case 32, which restricts the maximum stroke of the rear arm 21.

Here, the lid 32b of the damper 30 faces the left side of the vehicle. The damper 30 is arranged rearward of the pivot shaft 27 of the rear arm 21, and the left rear arm bracket 5 is formed so as to incline forward from the pivot shaft 27 as it is. Therefore, the diaphragm mechanisms 71a to 71 arranged on the lid 32b.
d faces the left side of the vehicle without the front surface being blocked by the left rear arm bracket 5.

The rear end 31a of the leaf spring 31 is supported by the rear arm 21 via the link mechanism 56 described later, and the front end 31b is 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 stress concentration when the resin plate spring is sandwiched between the metal brackets.

The initial load adjusting mechanism 57 has the following structure. Side tube 6 of the down tube 6
The left and right guide brackets 58 are fixed to a, and the support 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 6
No. 0 screw portion 60b is inserted into the lower connecting portion 61c of the support bracket 61, and the adjusting nut 60 is attached to the screw portion 60b.
It has a structure in which c is screwed.

Further, the support bolt 59 is provided with a connecting portion 47d of the front spring bracket 47a and the adjusting bolt 6a.
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 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 connection portion of the side tube 6a with the rear arm bracket 5 by selecting the position in the front-rear direction. As shown in FIG. 3, the block 62d of the front pillow 62 is set in size and mounting position so as to contact the upper surface of the leaf spring 31 even at the lowermost 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 a mounting plate 63 in which a fixing bolt 63c is fixed to a connection point between the side tube 6a and the lower cross pipe 5c.
By being screwed into any of the mounting screw holes 63e of d, the position in the front-rear direction is selected and fixed. The size and mounting position of the rear pillow 63 are set so that the leaf spring 31 comes into contact with the block 63b from the time when the rear arm 21 is lifted by a predetermined amount, that is, there is a gap between the two at the most lowered position. ing.

A dustproof plate 31c is attached to a portion of the leaf spring 31 facing the block 63b. The dustproof plate 31c is for preventing foreign matter from being caught between the leaf spring 31 and the block 63b by filling the gap. The dustproof plate 31c is formed of a member such as a sponge that is easily compressed so as not to affect the spring characteristics of the leaf spring 31.

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 members having a substantially triangular shape in a side view, and connecting collars 38f, 38g are interposed between the 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 to be integrally connected.

A supporting 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.

The lower ends 37a of the pair of left and right levers 37 are rotatably connected to the connecting collar 38g fitted on 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 is further bent around the rear pillow 63 as a fulcrum (see the chain double-dashed line in FIG. 3), 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 mechanisms 71a to 71d of the oil passages 70a to 70d, and the irregular vertical vibration of the rear wheel 26 is generated. Suppressed. The thermal expansion of the hydraulic oil is stored in the reservoir 65 through the passage 66a.

According to the two-wheeled motor vehicle 1 of the present embodiment that performs such an operation, the buffer springs and dampers are changed from the conventional coil springs and expansion / contraction dampers to strip-shaped plate springs 31 and rotary dampers 30. Is disposed below the engine in the front-rear direction, and the rotary damper 30 is disposed near the pivot portion. Therefore, a space is created in the center of the vehicle where the conventional coil spring and the like are disposed, and the air cleaner 14b is utilized by utilizing the space.
Vehicle-mounted parts such as the air cleaner 14b,
It is possible to arrange the intake system including the carburetor 14a in a straight line, and the space efficiency is improved accordingly. Further, since the tank rail 4 is separated into the left and the right just above 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 central portion of the vehicle.
From this point as well, the space efficiency is improved.

When the leaf spring 31 is arranged below the engine, the main shaft 1 equipped with the clutch mechanism is mounted.
Since 2b is arranged above the straight line A that connects the shaft cores of the crankshaft 12a and the pivot shaft 27, downward bulging due to the clutch mechanism of the crankcase 13 can be suppressed, and accordingly, the leaf spring 31 can be arranged at a higher position. .. As a result, it is possible to suppress the reduction of the load clearance due to the leaf spring arranged below the engine.

Further, the conventional telescopic damper is changed to 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 the 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, when the damper 30 is arranged, the lid 32 having the diaphragm mechanisms 71a to 71d is arranged.
Since b is directed to the left side of the vehicle and the left rear arm bracket 5 is inclined to the front side, the adjustment work of the diaphragm mechanism can be easily performed.

[0046]

As described above, according to the motorcycle of the present invention, since the leaf spring and the rotary damper are adopted, the space can be provided at the center of the vehicle body, so that the space efficiency can be improved and the clutch can be used. Since the shaft is positioned above the straight line connecting the crank shaft and the pivot shaft, downward bulging of the bottom of the crankcase can be suppressed, and the leaf spring can be arranged at a higher place as a result, so that the leaf spring can be placed below the engine. While arranging it, it has the effect of suppressing the decrease in load clearance.

[Brief description of drawings]

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

FIG. 2 is a left side view of the motorcycle of the above embodiment.

FIG. 3 is a left side view of a rear wheel suspension device adopted in the motorcycle.

FIG. 4 is a plan view of a damper portion of the rear wheel suspension device.

FIG. 5 is a left side view of the damper.

FIG. 6 is a sectional front view of the damper.

FIG. 7 is a side view of a front end support mechanism portion of the suspension device.

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

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

10 is a sectional view taken along line XX of FIG.

[Explanation of symbols]

 1 Motorcycle 2 Body Frame 12 Engine 12a Crankshaft 12b Main Axis (Clutch Axis) 21 Rear Arm 26 Rear Wheel 27 Pivot Axis 29 Rear Wheel Suspension 30 Rotational Damper 31 Leaf Spring A Straight

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 above, the buffer spring is arranged in the front-rear direction below the engine as a strip plate-shaped plate spring, the damper is arranged as a rotary damper near the pivot shaft of the rear arm, and the clutch shaft equipped with the clutch mechanism is mounted on the pivot shaft. A motorcycle characterized by being arranged above a straight line connecting a shaft and a crankshaft.