JP4594194B2 - Motorcycle rear wheel suspension system - Google Patents

Description

  The present invention relates to an improvement in a rear wheel suspension device for a motorcycle.

As a conventional rear wheel suspension device for a motorcycle, there is known one in which a lower end of a rear cushion unit that performs a buffering action, a swing arm that supports a rear wheel, and a vehicle body frame are connected via a link mechanism (for example, (See Patent Document 1).
Japanese Patent Laid-Open No. 10-71982

In FIG. 5 of Patent Document 1, a swing arm 13 that supports a rear wheel is swingably attached to a lower portion of a center pipe 42 that constitutes the vehicle body frame 2, and one end of a first link 69 b is swung to the lower end of the center pipe 42. The second link 69c is swingably connected to the other end of the first link 69b, and the lower end of the rear cushion unit 15 and the lower portion of the swing arm 13 are swingably attached to the second link 69c. Are listed.
The first link 69 b and the second link 69 c are members that constitute the link mechanism 69.

  Further, in FIG. 2 of Patent Document 1, a vehicle body frame 2 is described. The vehicle body frame 2 extends a main pipe 41 rearward and obliquely downward from the head pipe 3, extends a center pipe 42 downward from the rear end of the main pipe 41, and extends a down tube 43 substantially downward from the head pipe 3, The lower pipe 44 extends rearward from the lower end of the down tube 43, and the rear end of the lower pipe 44 is connected to the lower end of the center pipe 42. Reference numeral 51 in the figure denotes a hanger for attaching the upper end of the rear cushion unit 15.

2 and 5 of Patent Document 1, the first link 69b is substantially perpendicular to the center pipe 42. Therefore, when the swing arm 13 swings up and down, the center is interposed via the second link 69c and the first link 69b. A force in the longitudinal direction of the vehicle body acts on the pipe 42.
Since the lower end of the center pipe 42 is supported by the lower pipe 44, the force can be supported even when a force in the front-rear direction is applied.

  For example, in a vehicle body frame having a structure in which the lower pipe 44 is not provided and the lower end of the center pipe 42 and the lower end of the down tube 43 are not connected, when a longitudinal force acts on the lower portion of the center pipe 42, the center pipe 42 It is expected that the deformation will be large, and a reinforcing material is required. Therefore, the weight increases and the cost increases.

  An object of the present invention is to reduce the weight and cost of a body frame by improving a rear wheel suspension device of a motorcycle.

According to the first aspect of the present invention, the main frame extends from the head pipe to the rear of the vehicle body along the center of the vehicle width above the engine, and further bent to the pivot portion of the swing arm for supporting the rear wheels at the rear of the engine. The rear cushion unit is connected to the swing arm and the main frame via a link mechanism including a vehicle body side link connected to the main frame side and a swing arm side link connected to the swing arm side. In the rear wheel suspension system of the motorcycle connected to the vehicle body, the longitudinal direction of the vehicle body side link is arranged so as to be substantially along the longitudinal direction of the lower portion of the main frame, and the attachment portion of the vehicle body side link to the vehicle body side is the main frame. It consists of a bracket that protrudes rearward from the lower part of the swing arm, and an upper bracket is installed on the upper part of the swing arm. The upper bracket has a bottom plate attached to the upper surface of the swing arm, and the swing arm side link connects the front end to the vehicle body side link, connects the rear end to the lower end of the rear cushion unit, and swings the middle. It is connected to the upper bracket of the arm .

As a function of the rear wheel suspension device, since the longitudinal direction of the vehicle body side link is substantially along the longitudinal direction of the lower part of the main frame, when the swing arm swings up and down, the vertical force of the swing arm passes through the swing arm side link. To the vehicle side link. The direction of the force acting on the vehicle body side link coincides with the longitudinal direction of the vehicle body side link. Therefore, the direction of the force acting on the main frame from the vehicle body side link is the direction along the longitudinal direction of the lower part of the main frame.
In addition, one end of the vehicle body side link is attached to the bracket protruding rearward from the lower part of the main frame so that the longitudinal direction of the vehicle body side link is substantially along the longitudinal direction of the lower part of the main frame. It becomes difficult to interfere, and the occupied space in the longitudinal direction of the vehicle body side link is reduced.
Further, when the swing arm swings up and down, the vertical force at this time is transmitted to the middle of the swing arm side link, transmitted from the front end of the swing arm side link to the vehicle body side link, and from the rear end of the swing arm side link to the cushion unit. It is transmitted.
Therefore, the share of the force transmitted to the vehicle body side link and the rear cushion unit is determined according to the distance from the connecting portion between the swing arm side link and the swing arm to the front end or the rear end of the swing arm side link.

The invention according to claim 2 is characterized in that the attachment portion of the vehicle body side link to the vehicle body side is constituted by a bracket protruding rearward from the lower portion of the main frame.
As for the action of the bracket, one end of the vehicle body side link is attached to the bracket protruding backward from the lower part of the main frame so that the longitudinal direction of the vehicle body side link is substantially along the longitudinal direction of the lower part of the main frame. Is less likely to interfere with the main frame, and the occupied space in the longitudinal direction of the vehicle body side link is reduced.

The invention according to claim 2 is characterized in that the main frame is connected to the engine below the bracket.
As an effect of the connection position of the main frame and the engine, the main frame is supported by the engine by connecting the main frame to the engine, and the engine serves as a reinforcing member. Furthermore, since the main frame is supported below the bracket, the main frame can be effectively supported.

The invention according to claim 3 is characterized in that the swing arm side link is formed of a member having a substantially “H” shape in a side view.

Since the swing arm side link is bent in a “H” shape, the connecting part (bolt) that connects to the lower end of the rear cushion unit is the upper part provided on the upper part of the swing arm with respect to the upper end of the rear cushion unit. From this state, for example, when the swing arm swings upward, the swing arm side link swings counterclockwise around the connection portion (bolt) and When the connecting part (bolt) that connects to the lower end of the cushion unit is positioned almost directly beside the connecting part (bolt) of the upper bracket provided on the upper part of the swing arm, the swing arm has a more constant swing than at the beginning. The change in the moving distance of the lower end portion of the rear cushion unit gradually increases with respect to the angle change.
That is, since the stroke amount to the contraction side of the rear cushion unit is increased, the moving speed of the piston provided in the rear cushion unit is gradually increased, and the damping force generated in the rear cushion unit is gradually increased.

Therefore, since the damping force becomes very large near the maximum contraction position of the rear cushion unit, it is possible to prevent the bottom of the piston of the rear cushion unit, and the damping force is small at a position where the rear cushion unit is small in the contraction amount. Therefore, ride comfort can be improved.

In the invention according to claim 1, since the longitudinal direction of the vehicle body side link is arranged so as to be substantially along the longitudinal direction of the lower portion of the main frame, the force transmitted from the vehicle body side link to the main frame acts in the longitudinal direction of the main frame. Since only a tensile force or a compressive force acts on the main frame, a large force can be supported by the main frame. Accordingly, it is not necessary to reinforce the main frame, and the vehicle body frame can be reduced in weight and cost.
In addition, the mounting part of the vehicle body side link to the vehicle body side is composed of a bracket that protrudes backward from the lower part of the main frame, so that the vehicle body side link interferes with the main frame by the bracket that protrudes backward from the lower part of the main frame. Without being done, it can be arranged along the main frame, and the vehicle body side link is less likely to protrude forward and backward, so the space around the main frame can be used effectively.
In the present invention, the front end of the swing arm side link is connected to the vehicle body side link, the rear end of the swing arm side link is connected to the lower end of the cushion unit, and the middle of the swing arm side link is connected to the upper bracket of the swing arm. So, the position of the connecting part with the swing arm can be changed between the front end and the rear end of the swing arm side link, and the share of the force acting on the vehicle body side link and the rear cushion unit can be changed, The degree of freedom in designing the rear wheel suspension device can be increased.

In the invention according to claim 2, since the main frame is connected to the engine below the bracket, the main frame is supported by the engine by connecting the main frame to the engine, and the engine serves as a reinforcing member. do. Furthermore, since the main frame is supported below the bracket, the main frame can be effectively supported.

In the invention according to claim 3, since the swing arm side link is bent in a “h” shape, the connecting portion (bolt) connected to the lower end portion of the rear cushion unit is connected to the upper end portion of the rear cushion unit. It is in a position farther from the connecting part (bolt) of the upper bracket provided on the upper part of the swing arm. From this state, for example, when the swing arm swings upward, the swing arm side link is centered on the connecting part (bolt). When the connecting part (bolt) that swings counterclockwise and is connected to the lower end of the rear cushion unit is located almost beside the connecting part (bolt) of the upper bracket provided on the upper part of the swing arm, The change in the movement distance of the lower end of the rear cushion unit is gradually greater with respect to a constant swing angle change of the swing arm. No longer, since the stroke of the compression-side of the rear cushion unit is increased, the moving speed of the piston provided in the rear cushion unit gradually increases the damping force generated by the rear cushion unit gradually increases.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a vehicle equipped with a rear wheel suspension device according to the present invention. A motorcycle 10 as a vehicle includes a body frame 11 serving as a skeleton, a front wheel 12, and a front wheel 12 at a front portion of the body frame 11. A front wheel steering suspension mechanism 13 mounted to steer and suspend the vehicle, an engine 14 and a transmission 15 mounted substantially at the center of the vehicle body frame 11, a rear wheel 17, and a rear wheel 17 suspended from the rear lower portion of the vehicle body frame 11. A rear wheel suspension 18 attached to the engine 14, an intake device 22 attached to the rear portion of the cylinder head 21 of the engine 14 to supply air and fuel to the engine 14, and exhaust gas of the engine 14 is purified and discharged. Therefore, an exhaust device 23 attached to the front portion of the cylinder head 21, a fuel tank 24 and a driver seat 25, and a passenger seat 26 attached to the upper portion of the vehicle body frame 11 Ranaru.

  FIG. 2 is a side view of the vehicle body frame according to the present invention (the arrow (FRONT in the figure represents the front of the vehicle; the same applies hereinafter)), and the vehicle body frame 11 includes a head pipe 31 provided at the front end and the head. One main frame 32 extending obliquely downward and rearward from the pipe 31, a pair of left and right seat rails 33, 33 extending from the rear upper part of the main frame 32 to the rear (only the reference numeral 33 on the front side is shown), and these A pair of left and right sub-frames 34 (34 only shown on the front side) passed to the rear ends of the seat rails 33, 33 and the main frame 32, and the head pipe 31 below the main frame 32. A reinforcing pipe 36 whose tip is connected to the main frame 32 by extending obliquely upward rearward, and a pair of left and right dashes extending downward from the reinforcing pipe 36. Consisting Npaipu 37, 37 (shown only the near side of the code 37.).

  The main frame 32 is a member provided with a pivot shaft 38 that supports the rear wheel suspension device 18 (see FIG. 1), and pivot support members 39, with both ends of the pivot shaft 38 attached to both sides of the main frame 32, Further support is provided at 39 (see FIG. 1; only the reference numeral 39 on the front side is shown). Reference numerals 11a to 11c are reinforcing members, 11d is a reinforcing frame, 11e to 11g are engine hangers, 11h is a step bracket, and 83 is a link support bracket described in detail later.

  Returning to FIG. 1, the engine 14 and the transmission 15 are integrally provided power units, and the power units are supported by the main frame 32 and the down pipe 37.

  The front wheel steering suspension mechanism 13 includes a front fork 41 that is steerably attached to the head pipe 31 and a bar handle 42 that is attached to the upper end of the front fork 41. The front wheel 12 is rotatably attached to the lower end of the front fork 41. .

  The rear wheel suspension device 18 includes a swing arm 45 swingably attached to a lower rear portion of the main frame 32 via a pivot shaft 38, a rear cushion unit 47 having one end attached to the main frame 32 via a bracket 46, and And a link mechanism 48 for connecting the swing arm 45 and the rear cushion unit 47 to the main frame 32 side.

  The intake device 22 includes an air cleaner 51 and a throttle body 52 that has a rear end attached to the air cleaner 51 and a front end attached to the cylinder head 21. The throttle body 52 includes a throttle valve and a fuel injection valve.

  The exhaust device 23 extends from the front portion of the cylinder head 21 downward and rearward for each cylinder, and is gathered along the way and further extended rearward by one, and attached to the rear end of the exhaust pipe 54. It consists of a muffler 56.

The pivot support member 39 is attached to the main frame 32 at two upper and lower positions, supports and reinforces the pivot shaft 38, and supports a step support member 63 including a driver step 61 and a passenger step 62. The step support member 63 is provided with a change pedal 65 for swinging the transmission 15 so as to be swingable.
The change pedal 65 is a member connected to the transmission 15 side via a link mechanism 66, and the change pedal 65 and the link mechanism 66 constitute a shift operation device 67.

  Here, reference numeral 15A denotes an output shaft of the transmission 15, and a chain 70 is stretched between a drive sprocket 68 attached to the output shaft 15A and a driven sprocket 69 provided on the rear wheel 17, whereby the rear wheel 17 Tell the driving force to.

  FIG. 3 is a side view of the main part of the rear wheel suspension device according to the present invention. The link mechanism 48 has one end connected to the lower end 47a of the rear cushion unit 47 and an intermediate part provided on the upper part of the swing arm 45. A swing arm side link 82 connected to the upper bracket 81 and a vehicle body side link 84 having one end connected to the other end of the swing arm side link 82 and the other end connected to a link support bracket 83 provided at the lower portion of the main frame 32. It consists of.

  In the drawing, 86 is a connecting shaft between the lower end portion 47a of the rear cushion unit 47 and the swing arm side link 82 and a bolt with a hexagonal hole to be a swing shaft, and 87 is a connecting shaft between the swing arm side link 82 and the upper bracket 81. A bolt with a hexagon socket serving as a swing shaft, 88 is a connecting shaft between the swing arm side link 82 and the vehicle body side link 84, a bolt with hexagon socket serving as a swing shaft, and 89 is a link between the vehicle body side link 84 and the link support bracket 83. It is a bolt (hexagon bolt) which becomes a connecting shaft and a swing shaft. 90a and 90b are bolts and nuts for attaching the upper end portion 47b of the rear cushion unit 47 to the bracket 46, and 91 is a reinforcing plate.

The swing arm side link 82 is a member having a substantially “U” shape in a side view, and is a distance L1 from the bolt 87 to the bolt 86 (specifically, an axis 86a of the bolt 86 (the part indicated by a black circle. The other axis). The same is the distance in the direction of extension of the straight line 92 passing through the axis 88a of the bolt 88 and the distance between the axis 87a of the bolt 87 and the axis 86a of the bolt 86. If the distance L2 (specifically, the distance in the direction in which the straight line 92 extends and the distance between the axis 87a of the bolt 87 and the axis 88a of the bolt 88), the ratio between these distances L1 and L2, that is, The lever ratio R is R = L1 / L2.
By changing the lever ratio R, it is possible to change the share of force acting on the rear cushion unit 47 and the vehicle body side link 84 when the swing arm 45 moves up and down.

  The vehicle body side link 84 has a substantially gourd shape when viewed from the side, and is a member in which a straight line 93 passing through the axes 88a and 89a of the bolts 88 and 89 is arranged substantially parallel to the longitudinal direction of the lower straight portion 32a of the main frame 32. is there.

In the rear wheel suspension device 18 including the link mechanism 48 described above, the swing arm side link 82 is bent in a “h” shape, so that the bolt 86 is positioned farther from the upper end 47b than the bolt 87. Yes, for example, when the swing arm 45 swings upward from this state, the swing arm side link 82 swings counterclockwise around the bolt 87, and the bolt 86 is positioned almost beside the bolt 87. The change in the moving distance of the lower end portion 47a of the rear cushion unit 47 is gradually increased with respect to the constant swing angle change of the swing arm 45 than at the beginning. That is, since the stroke amount to the contraction side of the rear cushion unit 47 is increased, the moving speed of the piston provided in the rear cushion unit 47 is gradually increased, and the damping force generated in the rear cushion unit 47 is gradually increased.

  As described above, the damping force becomes very large near the maximum contraction position of the rear cushion unit 47, so that the bottom of the piston of the rear cushion unit 47 can be prevented, and the contraction amount of the rear cushion unit 47 is small. Since the damping force is small, the ride comfort can be improved.

  As described above, the characteristic that the damping force increases as the rear cushion unit 47 contracts is referred to as “progressive effect”. The rear wheel suspension device 18 including the link mechanism 48 having such characteristics is referred to as “pro link suspension”. Called.

4 is a cross-sectional view taken along line 4-4 of FIG. 3. A connecting portion between the rear cushion unit 47 and the swing arm side link 82 is formed in a through hole 47c opened in a lower end portion 47a of the rear cushion unit 47, and a collar 95. The needle bearing 96 and the seal members 97 and 98 disposed on the outer peripheral side of the collar 95 are fitted, and bolt insertion holes 82c and 82d are respectively provided in the first arm portions 82A and 82B provided at one end of the swing arm side link 82. The bolt 86 with a hexagonal hole is opened, passed through the bolt insertion hole 82c, the hole 95a of the collar 95, and the bolt insertion hole 82d, and the nut 101 is screwed to the male screw 86b provided at the tip of the bolt 86.
A cylindrical head portion 86c of the bolt 86 is fitted into the bolt insertion hole 82c, and a shaft portion 86d of the bolt 86 is fitted into the bolt insertion hole 82d.

The connecting portion between the swing arm side link 82 and the upper bracket 81 on the swing arm 45 (see FIG. 3) side has a through hole 82f in the middle portion of the swing arm side link 82, and large at both ends of the through hole 82f. Diameter holes 82g and 82h are provided, the collar 105 is passed through the through hole 82f, and needle bearings 106 and 107 are fitted to the outer peripheral portions of both ends of the collar 105 and the large diameter holes 82g and 82h, respectively. The first plate provided on the U-shaped upper bracket 81 by fitting the seal members 108 and 109 to the outer peripheral portions of both ends of the collar 105 and the large-diameter holes 82g and 82h, respectively, outside the bearings 106 and 107. Bolt insertion holes 81c and 81d are formed in the part 81a and the second plate part 81b, respectively, and the bolts 87 with hexagonal holes are DOO insertion hole 81c, the hole 105a of the collar 105, through the bolt insertion holes 81d, a portion of the nut 101 and screw-coupled to the male screw 87b provided at the tip portion of the bolt 87. Reference numeral 81 f denotes a bottom plate portion of the upper bracket 81, which is a portion attached to the upper surface of the swing arm 45.

  The head portion 87c of the bolt 87 is fitted in the bolt insertion hole 81c, and the shaft portion 87d (the portion where the male screw 87b is formed) of the bolt 87 is fitted in the bolt insertion hole 81d. Reference numeral 111 denotes a reinforcing plate attached to the first plate portion 81a.

A connecting portion between the swing arm side link 82 and the vehicle body side link 84 is formed in a through hole 84a opened in one end of the vehicle body side link 84, a collar 95, a needle bearing 96 disposed on the outer peripheral portion of the collar 95, a seal member 97, 98, and bolt insertion holes 82m and 82n are formed in the second arm portions 82K and 82L provided at the other end of the swing arm side link 82, respectively, and hexagon socket bolts 88 are bolt insertion holes 82m and collars. 95 is a portion in which the nut 101 is screwed to the male screw 88b provided at the tip of the bolt 88 through the hole 95a and the bolt insertion hole 82n.
A cylindrical head portion 88c of a bolt 88 is fitted into the bolt insertion hole 82m, and a shaft portion 88d of the bolt 88 is fitted into the bolt insertion hole 82n.

A connecting portion between the vehicle body side link 84 and the link support bracket 83 on the main frame 32 (see FIG. 3) is formed in a through hole 84 b opened in the other end of the vehicle body side link 84, and a collar 95 and an outer peripheral portion of the collar 95. The needle bearing 96 and the seal members 97 and 98 that are disposed are fitted, and bolt insertion holes 83c and 83d are formed in the first plate portion 83a and the second plate portion 83b provided in the U-shaped link support bracket 83, respectively . portions bolt 89, within the spacer 113, the through bolt insertion holes 83c, the hole 95a of the collar 95, bolt insertion holes 83d, in the spacer 114, and the nut 101 is screwed to the male screw 89b provided at the tip portion of the bolt 89 It is. Reference numeral 83f denotes a bottom plate portion of the link support bracket 83, which is a portion attached to the back surface of the main frame 32.

Next, the operation of the rear wheel suspension device 18 described above will be described.
FIG. 5 is an operation diagram showing the operation of the rear wheel suspension device according to the present invention.
For example, when a force FU1 acts upward on the swing arm 45 as indicated by a solid arrow in the figure, the force FU1 acts on the swing arm side link 82 via the upper bracket 81, and the swing arm side link 82 A force FU2 indicated by a black arrow that compresses the rear cushion unit 47 in the axial direction acts on the bolt 86 that is a connecting portion with the rear cushion unit 47. A bolt 88 that is a connection portion between the swing arm side link 82 and the vehicle body side link 84 is indicated by a black arrow that pulls in the longitudinal direction of the vehicle body side link 84 (the direction in which the straight line 93 (see FIG. 3 extends)). Force FU3 acts.

  Further, for example, when a force FD1 acts downward on the swing arm 45 as indicated by a white arrow in the figure, this force FD1 acts on the swing arm side link 82 via the upper bracket 81, and the swing arm side link A force FD <b> 2 indicated by a hollow arrow that pulls the rear cushion unit 47 in the axial direction is applied to the bolt 86, which is a connecting portion between 82 and the rear cushion unit 47. A force FD3 indicated by a hollow arrow that compresses the vehicle body side link 84 in the longitudinal direction (the direction in which the straight line 93 extends) acts on the bolt 88 that is a connecting portion between the swing arm side link 82 and the vehicle body side link 84. To do.

  Therefore, the force FU3 or FD3 is transmitted from the vehicle body side link 84 via the link support bracket 83 to the lower straight portion 32a of the main frame 32, and a compressive force FU or a tensile force FD is generated in the longitudinal direction.

  As described above with reference to FIGS. 1 and 3, the present invention firstly extends the main frame 32 from the head pipe 31 toward the rear of the vehicle body along the center of the vehicle width and above the engine 14. A vehicle body side link 84 that includes a vehicle body frame 11 that is bent downward to a pivot shaft 38 as a pivot portion that supports a swing arm 45 for supporting a rear wheel and extends downward, and is connected to the main frame 32 side; In the rear wheel suspension device 18 of the motorcycle 10 in which the rear cushion unit 47 is connected to the swing arm 45 and the main frame 32 side via a link mechanism 48 including a swing arm side link 82 connected to the swing arm 45 side, The longitudinal direction of the side link 84 is set to the lower portion of the main frame 32, specifically, the lower straight portion 3. Characterized by being arranged so as to substantially along the longitudinal direction of a.

  As a result, the force transmitted from the vehicle body side link 84 to the main frame 32 can be applied in the longitudinal direction of the main frame 32, and only the tensile force or the compression force is applied to the main frame 32. Can support power. Accordingly, it is not necessary to reinforce the main frame 32, and the body frame 11 can be reduced in weight and cost.

  Secondly, the present invention is characterized in that the attachment portion of the vehicle body side link 84 to the main frame 32 side is constituted by a link support bracket 83 protruding rearward from the lower portion of the main frame 32.

  Thereby, the vehicle body side link 84 can be disposed along the main frame 32 without interfering with the main frame 32 by the link support bracket 83 protruding rearward from the lower portion of the main frame 32. Since the link 84 is less likely to protrude forward and backward, the space around the main frame 32 can be used effectively.

  Thirdly, the present invention connects the front end of the swing arm side link 82 to the vehicle body side link 84, connects the rear end of the swing arm side link 82 to the lower end of the rear cushion unit 47, and connects the middle of the swing arm side link 82. It is connected to the swing arm 45.

  Thus, the position of the connecting portion with the swing arm 45 can be changed between the front end and the rear end of the swing arm side link 82, and the share of the force acting on the vehicle body side link 84 and the rear cushion unit 47 is changed. Therefore, the degree of freedom in designing the rear wheel suspension device 18 can be increased.

Fourthly, the present invention is characterized in that the main frame 32 is connected to the engine 14 via the engine hanger 11g below the link support bracket 83.
Thereby, the engine 14 serves as a reinforcing material, and the deformation of the main frame 32 can be effectively suppressed.

In the present embodiment, as shown in FIG. 3, the upper bracket 81 connected to the middle of the swing arm side link 82 is provided at the upper part of the swing arm 45 , but the present invention is not limited to this, and the swing arm side link 82 is provided. A bracket connected to the middle of the swing arm 45 may be provided at the lower portion of the swing arm 45 .

  Furthermore, although the vehicle body side link 84 is connected so as to extend upward from the link support bracket 83, the present invention is not limited thereto, and the vehicle body side link 84 may be connected so as to extend downward from the link support bracket 83. In short, it is only necessary that the longitudinal direction of the vehicle body side link 84 is substantially along the longitudinal direction of the lower portion of the main frame 32.

  The rear wheel suspension device of the present invention is suitable for a motorcycle.

It is a side view of the vehicle provided with the rear-wheel suspension apparatus which concerns on this invention. It is a side view of the body frame concerning the present invention. It is a principal part side view which shows the rear-wheel suspension apparatus which concerns on this invention. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. It is an operation view showing the operation of the rear wheel suspension device according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vehicle (motorcycle), 11 ... Body frame, 14 ... Engine, 17 ... Rear wheel, 18 ... Rear wheel suspension device, 31 ... Head pipe, 32 ... Main frame, 32a ... Lower part of main frame, 38 ... Pivot part (Pivot shaft), 45 ... Swing arm, 47 ... Rear cushion unit, 47a ... Lower end of rear cushion unit, 48 ... Link mechanism, 81 ... Upper bracket, 82 ... Swing arm side link, 82f ... Bottom plate, 83 ... Bracket ( Link support bracket), 84...

Claims (3)

Mainframe (32) from a head pipe (31) along a vehicle width center to the rear of the vehicle body extending above the engine (14), further engine backwards, the rear wheel supporting swing arm (45) (14) A vehicle body frame that extends downward by bending the main frame (32) to the pivot portion (38) ,
A rear cushion unit ( 48) via a link mechanism (48) comprising a vehicle body side link (84) connected to the main frame (32) side and a swing arm side link (82) connected to the swing arm (45) side. 47) a rear wheel suspension device for a motorcycle in which the swing arm (45) is connected to the main frame (32) side.
The longitudinal direction of the vehicle body side link (84) is arranged so as to be substantially along the longitudinal direction of the lower part (32a) of the main frame (32) ,
A mounting portion of the vehicle body side link (84) on the vehicle body side is constituted by a bracket (83) protruding rearward from the lower portion (32a) of the main frame (32),
An upper bracket (81) is provided on the top of the swing arm (45), and the upper bracket (81) has a bottom plate (81f) attached to the upper surface of the swing arm (45),
The swing arm side link (82) has a front end connected to the vehicle body side link (84) (88) and a rear end connected to the lower end (47a) of the rear cushion unit (47) (86). The middle is connected (87) to the upper bracket (81) of the swing arm (45),
A motorcycle rear wheel suspension system characterized by the above. The rear wheel suspension system for a motorcycle according to claim 1, wherein the main frame (32) is connected to the engine (14) below (11g) below the bracket (83) . The rear wheel suspension device for a motorcycle according to claim 1, wherein the swing arm side link (82) is formed of a member having a substantially "H" shape in a side view.

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