JP4574199B2 - Vehicle swing arm suspension system - Google Patents

Description

  The present invention relates to a swing arm type suspension device for a vehicle including a swing arm that supports a wheel and a cushion unit attached to the swing arm, and more particularly to an increase in rigidity while suppressing an increase in weight of the swing arm, and an upper link type. It is related with the thing suitable for the rear-wheel suspension apparatus of the motorcycle comprised in this.

2. Description of the Related Art Conventionally, as a swing arm type suspension device for a vehicle, a system having a single cushion unit at the front part (near the swing shaft) of the swing arm has been widely adopted from the viewpoint of performance improvement (for example, Patent Documents). 1).
In the case of such a swing arm type suspension device, it is necessary to increase the bending rigidity and torsional rigidity of the swing arm. Therefore, normally, a reinforcing frame is provided on the two arm parts of the swing arm or a cross member is provided between the arm parts. It is provided. Since the cross member is disposed at a portion avoiding the rear wheel, that is, at the front portion of the swing arm, the cross member is provided with an insertion hole for passing the cushion unit. And in order to suppress the rigidity fall of the swing arm by having provided the penetration hole, providing the cross beam which block | closes all or one part of the penetration hole is also proposed (for example, refer patent document 2).

Here, in Patent Document 1, as a rear wheel suspension device for a motorcycle, a front end of a swing arm that supports a rear wheel is pivotally connected to a center frame that forms a rear end portion of a vehicle body frame by a pivot shaft. A swing arm type in which a cushion unit is vertically arranged with respect to a swing arm, one end side is directly attached to the swing arm, and the other end side is connected to the vehicle body frame and the swing arm via a link mechanism is known. Also known is an upper link type in which the upper end of the cushion unit is connected to the upper part of the swing arm by a cushion arm, and the intermediate part of the cushion arm and the center frame are connected by a vehicle body side connection link.
JP 2002-68066 A JP 2003-11875 A

  However, attaching a reinforcing member such as a cross beam in order to close the insertion hole in the swing arm as described above is not preferable because it causes an increase in the weight of the swing arm, particularly the unsprung weight.

  In the case of the upper link type structure, the cushion arm is linear, and both ends thereof are connected to the swing arm and the cushion unit, and the middle is pulled by the vehicle body side connecting link. The pulling force will work. For this reason, the cushion arm is required to have a rigidity that can sufficiently withstand the pulling by the vehicle body side connection link so as not to deteriorate the performance of the cushion unit. In addition, it is also necessary to reduce the weight as much as possible and not to interfere with the cushion unit when the cushion arm swings.

  Furthermore, when a reserve tank is provided at the end of the cushion unit, it is necessary to take care to avoid interference with the cushion arm, swing arm, rear wheel, and the like. In addition, when the cushion unit is disposed through the through hole provided in the swing arm, it is necessary to improve the attachment property at that time. In addition, it is also desirable to make the through hole as small as possible so as not to reduce the rigidity of the swing arm.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the weight and rigidity of a swing arm in a swing arm type suspension device for a vehicle, and to secure a stroke of a cushion unit to increase a degree of freedom in setting cushion performance. Another object of the present invention is to improve the cushion performance by increasing the rigidity of the link in an upper link type rear wheel suspension device or the like.

As a means for solving the above object, the invention described in claim 1 is a swing arm configured by connecting a pair of arm portions (for example, the arm portion 137 of the embodiment) by a cross member (for example, the cross member 140 of the embodiment). The front end of the swing arm 121 (for example, the embodiment) is pivotably attached to a pivot shaft (for example, the pivot shaft 114 of the embodiment) provided on the vehicle body side (for example, the center frame 113 and the power unit 108 of the embodiment). A wheel (for example, the rear wheel 122 of the embodiment) is attached to the rear end portion of the swing arm, and one end portion of the cushion unit is attached to the swing arm, and the other end portion of the cushion unit is connected to the link mechanism (for example, the embodiment). Swing arm type suspension of a vehicle attached to the vehicle body side via an example link mechanism 124, 224) In location (e.g. a swing arm type suspension apparatus of the embodiment 120, 220), the said cushion unit is arranged behind the cross member, the link mechanism, the cushion with mounted swingably on top of the swing arm A cushion arm (for example, the cushion arm 125 of the embodiment) to which the other end portion of the unit is attached, and a vehicle body side in which one end portion is attached to the cushion arm and the other end portion is attached to a portion below the pivot shaft on the vehicle body side. A connecting link (for example, the vehicle body side connecting link 126 of the embodiment), and an insertion hole (for example, the insertion hole 141 of the embodiment) of the vehicle body side connecting link is provided in the cross member to connect the swing arm and the cushion arm. part of the (top bracket 127 of the example embodiment) is provided in front of the insertion hole And wherein the door.

Further, in the invention described in claim 2, the arm portions (for example, the arm portion 237 of the embodiment) on both sides of the front portion are connected by the cross member (for example, the cross member 240 of the embodiment), and the cantilever arm portion is disposed on one side of the rear portion. The front end of a cantilever swing arm (for example, the swing arm 221 of the embodiment) having the (for example, the cantilever arm portion 237A of the embodiment) is provided on the vehicle body side (for example, the center frame 113 and the power unit 108 of the embodiment). A pivot shaft (for example, the pivot shaft 114 of the embodiment) is swingably attached, and a wheel (for example, the rear wheel 122 of the embodiment) is attached to a rear end portion of the swing arm, and a cushion unit ( For example, one end of the cushion unit 123) of the embodiment is attached, and the other end of the cushion unit is a link mechanism (for example, In a vehicle swing arm suspension device (for example, the swing arm suspension device 320 of the embodiment) attached to the vehicle body via the link mechanism 124) of the embodiment, the cushion unit is disposed behind the cross member. The link mechanism is swingably attached to the upper part of the swing arm and the other end of the cushion unit is attached (for example, the cushion arm 125 of the embodiment), and the cushion arm has one end. A vehicle body side connection link (for example, the vehicle body side connection link 126 of the embodiment) attached at the other end to a portion below the pivot shaft on the vehicle body side, and an insertion hole (for example, implementation) of the vehicle body side connection link. An example insertion hole 141) is provided in the cross member, and the swing arm and the cushion are provided. Connecting portion between N'amu the (top bracket 127 of the example embodiment), characterized in that provided in front of the insertion hole.

According to these swing arm type suspension devices, the cushion unit is arranged behind the cross member of the swing arm, so that the insertion hole through which the cushion unit passes can be eliminated from the cross member.
That is, as in the invention described in claim 3, the vehicle body rear portion of the cushion unit is spatially opened, and the cushion unit and the rear wheel can be brought close to each other.
Further, the distance from the swing arm swing center to the cushion unit becomes longer, and the ratio of the stroke of the cushion unit to the amount of displacement of the rear wheel axle can be increased efficiently.
Further, the cross member may be provided with an insertion hole through which only the vehicle body side connection link is inserted, and the insertion hole of the cross member can be significantly reduced as compared with the case where the cushion unit is passed.
Also, by providing the connecting part between the swing arm and the cushion arm in front of the insertion hole, the cushion arm provided between the cushion unit and the swing arm can be lengthened, and the design freedom of the link mechanism Can be improved.

According to a fourth aspect of the present invention, the length of the insertion hole of the cross member is set to be smaller than the diameter of the cushion unit.

According to the invention described in claim 1 and claim 2, since the insertion hole through which the cushion unit is passed can be eliminated by arranging the cushion unit behind the cross member, the rigidity of the swing arm can be increased, In addition, the weight can be reduced by the optimum design of the swing arm.
Further, since the cushion unit is arranged behind the cross member of the swing arm, it is possible to increase the ratio of the stroke of the cushion unit to the displacement of the rear wheel axle, and the damping force can be easily set and The burden on the link is reduced, the degree of freedom in setting the cushion performance can be increased, and the weight can be reduced by the optimum design of each link.
In addition, the insertion hole of the cross member can be significantly reduced, so that the rigidity of the swing arm can be increased and the weight can be reduced by the optimum design. In addition, when the motorcycle is assembled, the swinging range is restricted because the vehicle body side connecting link is inserted through the insertion hole, and the attachment to the vehicle body is improved.
Also, by providing the connecting portion between the swing arm and the cushion arm in front of the through hole, it becomes possible to improve the design freedom of the link mechanism, and the stroke amount of the cushion unit with respect to the displacement amount of the rear wheel axle is changed. The cushion performance can be easily set.

  According to the invention described in claim 3, since the rear portion of the vehicle body of the cushion unit is spatially opened, the cushion unit and the rear wheel can be brought close to each other. Can be achieved.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the directions such as front, rear, left and right are the same as those in the vehicle unless otherwise specified.

  FIG. 1 is a side view of a motorcycle (vehicle) provided with a swing arm type suspension device according to the present invention. As shown in this figure, a front fork 103 that pivotally supports a front wheel 102 of a motorcycle 101 is attached to a head pipe 106 of a vehicle body frame 105 via a steering stem 104 so as to be steerable. A power unit 108 on the vehicle body side including an engine and a transmission is attached to the lower portion of the main frame 107 of the vehicle body frame 105, and a fuel tank 109 is attached to the upper portion of the main frame 107. A driver's seat 111 and a rear passenger's pillion seat 112 are respectively attached to the upper portion of the seat rail 110 connected to the rear portion of the main frame 107. A swing arm type suspension device 120 according to the present invention is attached to a center frame (vehicle body side) 113 connected to the rear end of the main frame 107.

  The swing arm type suspension device 120 is attached to a pivot shaft 114 provided on the center frame 113 so that the front end portion of the swing arm 121 can swing, and a rear wheel (wheel) 122 is rotated to the rear end portion of the swing arm 121. The lower end portion of the cushion unit 123 is attached to the swing arm 121 and the upper end portion of the cushion unit 123 is attached to the lower end portion of the center frame 113 via the link mechanism 124.

The link mechanism 124 is swingably attached to the upper portion of the swing arm 121 and has a cushion arm 125 to which the upper end portion of the cushion unit 123 is attached. The upper end portion is attached to the cushion arm 125, while the lower end portion is the center frame. The vehicle body side connecting link 126 is attached to a portion below the pivot shaft 114 of 113.
The cushion unit 123 strokes the upper and lower ends of the cushion unit 123 so as to approach and separate from each other, thereby absorbing a load input to the rear wheel 122 and the swing arm 121. The pivot shaft 114 is provided in parallel with the vehicle width direction in the same manner as the axle 115 of the rear wheel 122 (hereinafter also referred to as a rear wheel axle).

  As shown in FIG. 2, an upper bracket (connecting portion) 127 is provided on the upper portion of the swing arm 121, and the front end portion of the cushion arm 125 is rotatably connected to the upper bracket 127 by a first connecting shaft 131. . Further, the rear end portion of the cushion arm 125 and the upper end portion of the cushion unit 123 are rotatably connected by a third connecting shaft 133. Between the front and rear ends of the cushion arm 125, the upper end portion of the vehicle body side connection link 126 is rotatably connected by the second connection shaft 132, and the lower end portion of the vehicle body side connection link 126 is provided at the lower end portion of the center frame 113. It is connected to the link attaching part 129 by the fourth connecting shaft 134. A lower bracket 128 is provided below the swing arm 121, and a lower end portion of the cushion unit 123 is connected to the lower bracket 128 by a fifth connecting shaft 135. Each connecting shaft 131, 132, 133, 134, 135 is provided in parallel with the pivot shaft 114.

  Referring to FIG. 3 together, the swing arm 121 is configured by connecting the front portions of a pair of arm portions 137 and 137 provided in parallel with a cross member 140. Specifically, each arm portion 137 is formed so as to gradually spread in the vehicle width direction as it is located rearward, and a reinforcing frame 138 across the front and rear ends is joined to these lower surfaces (see FIG. 2). And the front end part of each arm part 137 is connected by a pivot pipe 139 extending in the vehicle width direction, and the front part of each arm part 137 and the reinforcing frame 138 is connected by a cross member 140 provided behind the pivot pipe 139. Thus, the swing arm 121 is integrally formed.

  An insertion hole 141 extending substantially in the vertical direction is formed at a position near the rear of the cross member 140, and the vehicle body side connection link 126 is disposed in the insertion hole 141. The vehicle body side connecting link 126 is composed of two plate-like members facing each other in the vehicle width direction. The vehicle body side connection link 126 has an upper end projecting upward from the upper surface of the swing arm 121 (upper surface of the arm portion 137), and a lower end projecting downward from the lower surface of the swing arm 121 (lower surface of the reinforcing frame 138). Yes. Further, the vehicle body side connection link 126 is arranged such that a longitudinal axis 126A connecting the centers of the connection shafts 132 and 134 at both ends thereof is substantially vertical.

  A cushion unit 123 is disposed behind the cross member 140 and in front of the rear wheel 122. That is, the cross member 140 that connects the front portions of the pair of arm portions 137 and 137 is single, and the cross member 140 is not provided between the cushion unit 123 and the rear wheel 122. Therefore, a part of the swing arm 121 behind the vehicle body with respect to the cushion unit 123 is spatially opened. As a result, the cushion unit 123 and the rear wheel 122 can be brought close to each other, and the wheel base of the motorcycle 101 can be shortened.

  The cushion unit 123 has an upper end protruding upward from the upper surface of the swing arm 121 and a lower end protruding downward from the lower surface of the swing arm 121. Further, the cushion unit 123 has a longitudinal (stretching direction) axis line 123A connecting the centers of the connecting shafts 133 and 135 at both ends thereof, which is substantially vertical, that is, substantially parallel to the vehicle body side connecting link 126. Be placed.

Here, the cross section of the vehicle body side connecting link 126 cut perpendicular to the axis 126A is smaller than the cross section of the cushion unit 123 cut perpendicular to the axis 123A, and therefore the insertion hole 141 passes the cushion unit 123. Smaller than that.
The connection point between the vehicle body side connection link 126 and the center frame 113, that is, the center of the fourth connection shaft 134 is the connection point between the lower bracket 128 of the swing arm 121 and the lower end of the cushion unit 123, that is, the fifth connection shaft. It is located above the center of 135. Thereby, the vertical length of the center frame 113 is shortened, and the body frame 105 is reduced in weight. Further, since the load input point from the cushion unit 123 is close to the pivot shaft 114, the efficiency of the link mechanism 124 is improved and the moment generated at the lower portion of the center frame 113 is reduced.

  The cushion unit 123 includes a damper (attenuator) 145 disposed such that the cylinder 143 is on the upper side and a piston rod 144 that strokes together with a piston (not shown) in the cylinder 143 is on the lower side, an upper end of the cylinder 143, and a piston A suspension spring 146 is set between the flange portions 143a and 144a provided at the lower end portion of the rod 144 so as to have a predetermined initial load. A connecting portion 147 to the cushion arm 125 is provided above the cylinder 143, and a connecting portion 148 to the lower bracket 128 is provided below the piston rod 144, and the cushion is provided so that these connecting portions 147 and 148 are brought close to and away from each other. The unit 123 strokes and generates a damping force proportional to the stroke speed. Reference numeral 149 denotes a gas reserve tank filled in the cylinder 143.

  The upper bracket 127 is formed so as to protrude upward from the upper surface of the swing arm 121, and is disposed in front of the cushion unit 123 and the insertion hole 141 in the vicinity of the front end portion of the swing arm 121. Further, the lower bracket 128 is formed so as to protrude downward from the lower surface of the swing arm 121, and is disposed at a portion corresponding to the lower end portion of the cushion unit 123 behind the cross member 140.

A cushion arm 125 is disposed between the upper bracket 127 and the upper end portion of the cushion unit 123, and the upper end portion of the vehicle body side connection link 126 is located between both end portions of the cushion arm 125 and closer to the upper bracket 127. Connected. Thus, the length of the axis 25A connecting the centers of the second connecting shaft 132 and the third connecting shaft 133 of the cushion arm 125 is the same as the length of the axis 25B connecting the centers of the second connecting shaft 132 and the first connecting shaft 131. It is set longer than this. That is, if the center of the first connecting shaft 131 is the first connecting point 131A, the center of the second connecting shaft 132 is the second connecting point 132A, and the center of the third connecting shaft 133 is the third connecting point 133A, The second connection point 132A is located between the first and third connection points 131A and 133A and is offset toward the first connection point 131A.
Here, FIG. 2 shows a state where the cushion unit 123 of the swing arm type suspension device 120 is in the maximum extended position (fully extended state). In this state, the axis 125A of the cushion arm 125 and the axis 123A of the cushion unit 123 The angle R formed by is an acute angle.

Next, the operation of the swing arm type suspension device 120 in this embodiment will be described.
FIG. 4 shows a state where the cushion unit 123 of the swing arm type suspension device 120 is in the maximum contracted position (full bending state). In addition, the swing arm 121 shown by the chain line in the figure indicates the position (the position in FIG. 2) when the cushion unit 123 is fully extended.
As shown in this figure, when the swing arm 121 swings in the direction of moving the rear wheel 122 upward about the pivot shaft 114 with respect to the vehicle body side (the vehicle body frame 105 and the power unit 108), the upper bracket is moved together with the swing arm 121. 127 and the lower bracket 128 move upward along an arc centered on the pivot shaft 114. At this time, the front end portion of the cushion arm 125 connected to the upper bracket 127 also moves upward, but the rear portion of the upper bracket 127 of the cushion arm 125 is connected to the upper end portion of the vehicle body side connection link 126, and Since the lower end portion of the vehicle body side connection link 126 is connected to the vehicle body side, when the front end portion of the cushion arm 125 rises, the cushion arm 125 swings around the second connection shaft 132 so as to move the rear end portion downward.

  Therefore, the upper end portion of the cushion unit 123 is pushed downward by the rear end portion of the cushion arm 125, while the lower end portion of the cushion unit 123 is pushed upward by the lower bracket 128, the cushion unit 123 strokes, and the damper 145 The load is received by the suspension spring 146 while being attenuated by.

  At this time, since the cushion unit 123 is disposed behind the cross member 140 of the swing arm 121, the distance from the pivot shaft 114, which is the swing center of the swing arm 121, to the cushion unit 123 is increased. The ratio of the stroke amount of the cushion unit 123 to the displacement amount of the axle 15 of the rear wheel 122 supported by the rear end portion can be easily increased. If the ratio of the stroke of the cushion unit 123 to the amount of displacement of the rear wheel axle 115 is increased, the degree of freedom in setting the damping force can be improved and the burden on the link mechanism 124 can be reduced.

  Further, since the cushion unit 123 is disposed behind the cross member 140, only the vehicle body side connecting link 126 is inserted into the insertion hole 141. Therefore, the cushion unit 123 attaches the cross member 140 to the conventional case. The insertion hole 141 can be significantly reduced as compared with the case where it has penetrated, and the rigidity of the swing arm 121 can be increased.

  Further, a cushion arm 125 is disposed between the upper end portion of the cushion unit 123 and the upper bracket 127 of the swing arm 121. The cushion unit 123 is disposed behind the cross member 140, and the upper bracket 127 is swung. Since the arm 121 is disposed in the vicinity of the pivot shaft 114 of the arm 121, the cushion arm 125 can be lengthened, and the design freedom of the link mechanism 124 can be improved.

  Specifically, the length of the axis 125A between the second connecting shaft 132 and the third connecting shaft 133 of the cushion arm 125 is set to be longer than the length of the axis 125B between the second connecting shaft 132 and the first connecting shaft 131. Thus, when the cushion arm 125 swings about the second connecting shaft 132, the movement amount of the rear end portion with respect to the movement amount of the front end portion can be increased, and the cushion unit 123 with respect to the displacement amount of the rear wheel axle 115 can be increased. The stroke can be increased. That is, the second connection point 132A, which is the center of the second connection shaft 132, is positioned between the first and third connection points 131A, 133A, which are the centers of the first and third connection shafts 131, 133. In addition, the lever ratio when the cushion unit 123 is stroked by the cushion arm 125 can be earned by being offset toward the first connecting point 131A.

  In addition, the angle R formed by the axis 125A of the cushion arm 125 and the axis 123A of the cushion unit 123 is an acute angle in the fully extended state of the cushion unit 123, whereas the angle R increases as the amount of contraction of the cushion unit 123 increases. The cushion unit 123 is set to be substantially perpendicular at the fully bent state. For this reason, as the cushion unit 123 approaches the fully bent state, the cushion arm 125 efficiently pushes down the cushion unit 123, that is, increases the stroke of the cushion unit 123. In the vicinity of the maximum retracted position of the cushion unit 123, the rear axle The ratio of the stroke of the cushion unit 123 to the amount of displacement 115 increases.

  Since the upper bracket 127 and the cushion arm 125 are disposed close to the pivot shaft 114, the moment around the pivot shaft 114 can be reduced. Further, the link attachment portion 129 of the center frame 113 extends rearward to the lower side of the insertion hole 141 in a side view, and the vehicle body side connection link 126 connected to the link attachment portion 129 is formed in the insertion hole 141 of the cross member 140. Since it is inserted and connected to the cushion arm 125 in a substantially upright posture, the length of the vehicle body side connection link 126 can be suppressed to a minimum length. Further, since the cushion unit 123 is also disposed in a substantially upright posture together with the vehicle body side connection link 126, it is possible to shorten the wheel base by suppressing the front-rear length of these arrangement spaces.

FIG. 5 is a graph showing the relationship between the displacement amount of the rear wheel axle 115 and the stroke amount of the cushion unit 123 in the swing arm type suspension device 120. The vertical axis represents the stroke amount of the cushion unit 123, and the horizontal axis represents the vertical displacement amount of the rear wheel axle 115.
As shown in the figure, when the rear wheel axle 115 starts to be displaced from the fully extended state of the cushion unit 123, the stroke amount of the cushion unit 123 increases almost linearly as the displacement amount of the rear wheel axle 115 increases. To do. When the displacement amount of the rear wheel axle 115 further increases and approaches the fully bent state of the cushion unit 123, the ratio (ratio) of the increase in the stroke amount of the cushion unit 123 to the increase in the displacement amount of the rear wheel axle 115 gradually increases. Become. In other words, in this swing arm type suspension device 120, as the rear wheel axle 115 is displaced upward, the stroke amount of the cushion unit 123 gradually increases, that is, the stroke speed of the cushion unit 123 increases. Yes. As a result, when the amount of contraction of the cushion unit 123 is small (for example, in the riding 1G state), the damping force is reduced and the riding comfort is improved, and the damping force is increased near the maximum contracted position of the cushion unit 123. The bottom of 123 is prevented.

  Next, the attachment of the swink arm type suspension device 120 to the vehicle body side will be described. When the motorcycle 101 is assembled on the production line, the cushion unit 123, the cushion arm 125, and the vehicle body side connection link 126 are attached to the swing arm 121 along the subline or the like. The swing arm suspension device 120 to which the rear wheel 122 and the like are attached is assembled as a sub-assembly so that both ends of the cushion unit 123 can be positioned with respect to the swing arm 121. For this reason, when the subassembly is assembled on the vehicle body side on the main line, the swing arm 121 and the vehicle body side connection link 126 are only attached to the vehicle body side, and the motorcycle 101 can be easily assembled. Moreover, since the swing range is restricted by inserting the vehicle body side connection link 126 into the insertion hole 141 of the cross member 140, the vehicle body side connection link 126 can be easily attached to the vehicle body side when the subassembly is assembled.

  According to the above embodiment, the cushion unit 123 is disposed behind the cross member 140 of the swing arm 121, so that the distance from the pivot shaft 114, which is the swing center of the swing arm 121, to the cushion unit 123 is increased. The ratio of the stroke of the cushion unit 123 to the amount of displacement of the rear wheel axle 115 can be increased. Therefore, the setting of the damping force is facilitated, the burden on the link mechanism 124 is reduced, the degree of freedom in setting the cushion performance can be increased, and the weight can be reduced by the optimal design of the link mechanism 124.

  Further, since the cushion unit 123 is arranged behind the cross member 140, only the vehicle body side connection link 126 is inserted into the insertion hole 141, and the insertion hole 141 of the cross member 140 can be greatly reduced. For this reason, the swing arm 121 can have high rigidity and can be reduced in weight by an optimal design. In addition, when the motorcycle 101 is assembled, the swing of the vehicle body side connection link 126 is restricted, and the motorcycle 101 can be easily attached to the vehicle body side.

  Further, the cushion unit 123 is disposed behind the cross member 140 and the upper bracket 127 is disposed in the vicinity of the pivot shaft 114 of the swing arm 121, whereby the cushion arm 125 can be lengthened. The degree of freedom in design can be improved. For this reason, it is possible to easily set the cushion performance such as changing the stroke amount of the cushion unit 123 with respect to the displacement amount of the rear wheel axle 115.

  Here, as a modification of the above-described embodiment, for example, as in the swing arm type suspension device 220 illustrated in FIG. 6, the upper end portion of the cushion unit 123 is attached to the upper bracket 227 of the swing arm 121, and the lower end portion of the cushion unit 123. May be attached to the lower end of the center frame 113 via a link mechanism 224. Here, the link mechanism 224 attaches the lower end portion of the cushion unit 123 to the cushion arm 225 connected to the lower bracket 228 of the swing arm 121, and attaches the cushion arm 225 to a portion below the pivot shaft 114 of the center frame 113 ( It is attached to the vehicle body side connecting link 226 connected to the link attaching portion 229). In this case, since the vehicle body side connecting link 226 is disposed below the swing arm 121, the insertion hole of the cross member 140 can be eliminated, and the swing arm 121 can be made even more rigid.

  As another modification of the above embodiment, a cantilever type swing arm 221 may be used like a swing arm type suspension device 320 shown in FIG. Specifically, the swing arm 221 has arm portions 237, 237 on both sides of the front portion connected by a pivot pipe 239 and a cross member 240, and a cantilever arm portion 237A on one side of the rear portion. The swing arm type suspension device 320 has a front end portion of the swing arm 221 attached to a pivot shaft 114 of the center frame (vehicle body side) 113 so as to be swingable. ) 122 is attached, the lower end of the cushion unit 123 is attached to the swing arm 221, and the upper end of the cushion unit 123 is attached to the lower end of the center frame 113 via the link mechanism 124. The vehicle body side connection link 126 is arranged in the insertion hole 241 provided in the cross member 240, and the cushion unit 123 is arranged behind the cross member 240 and in front of the rear wheel 122. For this reason, as with the swing arm type suspension device 120, it is possible to increase the degree of freedom in setting the cushion performance and reduce the weight by optimizing the link mechanism 124 and the swing arm 221. Here, the swing arm 221 and the link mechanism 224 can be combined.

Further, a pivot shaft and a link attachment portion may be provided at the rear portion of the power unit 108, and the swing arms 121 and 221 and the vehicle body side connection links 126 and 226 may be attached to the pivot shaft and the link attachment portion, respectively. Furthermore, the swing arms 121 and 221 and the vehicle body side connection links 126 and 226 may be attached to at least one of the vehicle body frame 105 (center frame 113) and the power unit 108. At this time, the center frame 113 may be separate from the body frame 105.
In addition, the insertion holes 141 and 241 are not formed in the cross members 140 and 240, but may use an interval generated by arranging the cross members by dividing them into front and rear.

Next, a second embodiment of the present invention will be described.
FIG. 8 shows a side shape of the motorcycle in this embodiment. In the figure, reference numeral 1 is a front wheel, 2 is a front fork, 3 is a head pipe, 4 is a handle, 5 is a main frame, 6 is a center frame, 7 is a pivot shaft, 8 is a swing arm, 9 is a rear wheel, and 10 is a rear wheel. It is a wheel suspension device (swing arm type suspension device).

  Reference numeral 11 is a fairing, 12 is an intake duct, 13 is a wind guide flap, 14 is an air cleaner, 15 is a radiator, and 16 is a V-type engine. The engine 16 sucks air from the rear end of the air cleaner 14 in the valleys of the front and rear cylinders. Reference numeral 17 denotes a fuel tank, and 18 denotes a seat.

  FIG. 9 shows a side shape of the rear wheel suspension device 10. The rear wheel suspension device 10 includes a swing arm 8 having a substantially trapezoidal shape when viewed from the side and supported by a pivot shaft 7 so as to be swingable with respect to the center frame 6, and a vertical movement so as to intersect with the front portion of the swing arm 8. It is comprised from the cushion unit 20 and the link mechanism which are arranged long in the direction.

  One end of the link mechanism is pivotally supported on the upper part of the swing arm 8 and the other end is pivotally connected to the upper end of the cushion unit 20, and an intermediate portion of the cushion arm 21 and the center frame. 6 comprises a vehicle body side connecting link 22 for connecting a boss 6a provided on the lower back side of the vehicle.

  The cushion unit 20 includes a top portion 23 to which the cushion arm 21 is connected, a damper 25 that is operated by a piston rod 24 that moves forward and backward integrally with the top portion 23, and a top portion 23 and a bottom portion 25 a of the damper 25. A cushion spring 26 provided and a reserve tank 27 extending from a bottom portion 25a of the damper 25 are provided. The bottom portion 25 a is attached to the front bottom portion of the swing arm 8 by a cushion bracket 28.

  If the line connecting the pivot shaft 7 and the rear wheel axle 9a is the swing center line of the swing arm 8, the cushion unit 20 at the fully extended position is A and the most contracted position is B, the swing between AB The arm 8 swings around the pivot shaft 7. Along with this swinging, the cushion unit 20 swings together with the swing arm 8, but the cushion arm 21 swings counterclockwise by the vehicle body side connecting link 22. The cushion arm 21 is contracted to exhibit a damping force, and the damper 25 and the cushion spring 26 absorb the impact load input from the rear wheel 9 side.

  FIG. 10 is a diagram showing a part of the rear wheel suspension device 10 in cross section in order to show the detailed structure thereof. In the center of the front portion of the swing arm 8, a cushion mounting hole 30 opened vertically is formed so as to penetrate therethrough, and the cushion unit 20 is passed vertically. The cushion unit 20 is disposed in parallel with a vehicle body center line C, which will be described later, in plan view, and is disposed so that the center line D of the cushion unit 20 overlaps the vehicle body center line C. In this figure, the cushion unit 20 shows a fully extended state (fully extended state in the first embodiment).

  A bracket mounting step 31 is formed on the bottom of the swing arm 8 so as to form a surface substantially orthogonal to the axis D of the cushion unit 20 so as to protrude downward in a substantially triangular shape in the side view shown in the figure. The cushion cushion 28 is fastened by bolts 32 from below. The cushion bracket 28 has a substantially bowl shape opened upward, and a bearing 33 provided inside supports the joint portion 25b protruding downward from the bottom portion 25a so that the cushion unit 20 is supported by the bearing 33. The top portion 23 side is swingable around the joint portion 25b.

  The bearing 33 is housed inside the collar 34 and can slide on a concave surface provided inside the collar 34. An inner lower portion of the collar 34 is provided with a retaining structure for the bearing 33. A thread groove is formed on the outer peripheral surface of the collar 34, inserted into the through hole provided in the bottom of the cushion bracket 28 from above, and the end protruding downward is fastened with a nut 34a to the bottom of the cushion bracket 28. Fixed.

  The reserve tank 27 penetrates the cushion bracket 28 from the lower end portion of the bottom portion 25a and exits to the rear of the cushion bracket 28. Here, the substantially cylindrical tank portion is placed horizontally with its axis line directed in the vehicle width direction. Has been placed. The lateral width of the cushion bracket 28 is wider than the opening width of the cushion mounting hole 30 and a sufficient clearance d is formed between the cushion bracket 28 and the rear wheel 9 (see FIG. 9).

  Reference numerals 29a and 29b denote ribs that are integrally formed in the swing arm 8 and extend in the vertical direction. Of these, the rib 29a bends in a stepped manner, and a substantially horizontal plane portion of the rib 29a forms a step portion 42 drawn downward from the upper opening of the cushion mounting hole 30 and a part of the swing arm 8 facing the step portion 42. Forms a standing wall 35. A rear end portion 21 a of the cushion arm 21 is connected to the standing wall 35 by a first mounting shaft 36.

  As will be described later, the vehicle body side connecting link 22 has a pair of left and right parallel bars, and is disposed in the cushion mounting hole 30 of the cushion unit 20 in an obliquely vertical direction. It intersects with the swing arm 8 in a side view. The upper end 22 a of the vehicle body side connection link 22 sandwiches the intermediate portion 21 b of the cushion arm 21 from the left and right, and is connected to each other by the second mounting shaft 37. The front and back inner walls facing the cushion mounting hole 30 have their shoulders with the step portions 42 of the ribs 29a forming the lower portion of the front side wall portion and the rear side wall portion so as to allow the swing of the vehicle body side connecting link 22 respectively. Slopes 30a and 30b are formed.

As will be described later, the front end 21c of the cushion arm 21 has a bifurcated shape, sandwiches the leading end protruding portion 23a of the top portion 23 from the left and right, and is connected by a third mounting shaft 38.
The lower end portion 22b of the vehicle body side connection link 22 is connected to the boss 6a by an attachment shaft 39. These mounting shafts are appropriately constituted by long bolts or the like.

  In the figure, 17a is a tank extension that continuously extends from the rear end of the fuel tank 17 to the lower side of the seat 18, and its bottom 17b is recessed upward to avoid interference with the top 23 and the cushion unit 20. .

  FIG. 11 shows a side view shape of the swing arm 8, and FIG. 12 shows a plan view shape of the swing arm 8. In these figures, the swing arm 8 is connected and integrated on the left and right sides at the front half 8a. The basic portions of the front half 8a and the rear half 8b are formed in a hollow shape by welding a plurality of divided members made of a light alloy or the like. A reference numeral 40 shown in FIG. 11 is a pivot pipe portion through which the pivot shaft 7 is passed, and 41 is a side recess for passing a chain (not shown).

  The bracket mounting step 31 is integrally formed with a bottom portion of a center bottom portion 8f, which will be described later, forming a part of the swing arm 8, and a boss portion 31a is provided at a part thereof, and the cushion bracket 28 is attached to the boss portion 31a. A nut portion 31b to be a fastening partner of the bolt 32 to be attached is formed.

  As shown in FIG. 12, a cushion mounting hole 30 is formed in the center of the front half 8a so as to penetrate in the vertical direction, and the rear half 8b has a bifurcated shape so as to surround the left and right of the rear wheel 9. . Side protrusions 8c, 8d, 8e, etc., which are formed separately from the central portion, are integrated on the left and right sides of the front half 8a by welding. Further, C in FIG. 12 is a vehicle body center line when the vehicle body is assembled.

  As shown in FIG. 12, a stepped portion 42 is provided at the rear of the cushion mounting hole 30 in the shape of a recess opened upward, and a pair of standing walls 35 parallel to the upper surface extend in the front-rear direction and upward. The rear end portion 21 a of the cushion arm 21 formed between the pair of standing walls 35 is connected to the standing wall 35 by the first mounting shaft 36.

  13 is a cross-sectional view taken along line 6-6 of FIG. 11, and a pair of standing walls 35 is formed with a through hole 44 through which the first mounting shaft 36 for mounting the rear end portion 21a of the cushion arm 21 is passed. A through hole 45 is formed in the side surface overhanging portion 8c on the axis of the through hole 44 so as to open to the side surface, and the side wall 46 of the central upper portion 8g in which the step portion 42 is formed is also passed through the through hole 44 corresponding to the through hole 44. A hole 47 is provided. The first mounting shaft 36 is inserted from the side of the vehicle body through these through holes 44 and 47 to connect the rear end portion 21a of the cushion arm 21 to the standing wall 35.

  The front half 8a of the swing arm 8 shown in the figure has a central portion from the top, a central upper portion 8g, a central intermediate portion 8h, and a central lower portion 8f which are welded and integrated, and each side surface is viewed from the left side of the figure. The side overhanging portion 8c is assembled by integrating the same 8d and 8e from the right side by welding. The rear half 8b side has a similar structure. The side projecting portions 8d and 8e are separated from each other vertically, and a recess space for a chain line is formed therebetween. Further, the central portion in the vehicle width direction of the central lower portion 8f is formed by extending a concave groove having a curved section protruding upward in the front-rear direction. The swing arm 8 can be formed not only by such welding but also by an appropriate material and an appropriate manufacturing method such as casting of a light alloy.

  FIG. 14 shows a side view shape of the cushion arm 21, and FIG. 15 shows the same plan view shape. The cushion arm 21 is formed of an appropriate material and an appropriate manufacturing method, such as casting of a light alloy, and has a substantially arcuate shape in a side view. Here, the substantially arcuate shape means that the shape of the cushion arm 21 as viewed from the side is curved so as to protrude upward in the drawing. However, the curved shape may be a generally R shape such as the upper edge portion 54 or a substantially bent shape such as the lower edge portion 55.

  As shown in FIG. 15, the rear end portion 21a and the intermediate portion 21b of the cushion arm 21 have a boss shape, and the front end portion 21c has a bifurcated shape. Each is connected by a rib 50 arranged along the vehicle body center line C at the time of attachment, and parallel through holes 51, 52, 53 are formed penetrating in the vehicle width direction. A mounting shaft (not shown) is passed through each through hole.

  A nut portion 54 is integrally formed on one side of the bifurcated portion of the front end portion 21c, the tip protruding portion 23a is inserted into the bifurcated portion, and a bolt-shaped third mounting shaft 38 is passed through the through hole 53 from the other side. The screw portion at the tip is fastened to the nut portion 54. Further, the intermediate portion 21 b has the longest vehicle width direction dimension and is longer than the maximum outer diameter of the cushion unit 20 including the top portion 23. Further, the left and right sides of the rib 50 are formed as a lightened recess 54 to reduce the weight of the cushion arm 22 as a whole.

  As shown in FIG. 14, the center of each of these attachment shafts is defined as points O1 to O3. The center line between the points O1 and O3 is p, the point between the points O1 and O2 is q, and the point between the points O2 and O3 is r. There is a relationship of q <r, and the lever ratio p / q is set to an arbitrary ratio larger than 1.

  The point O2 at which the pulling force of the vehicle body side connecting link 22 acts is shifted upward from the straight line p. Further, the upper edge portion 54 passes above the point O2, and the rear end portion 21a and the front end portion 21c are curved upwardly in the drawing to be connected to approximately one R shape. The curvature of the upper edge portion 54 protrudes to the side opposite to the pulling direction E by the vehicle body side connecting link 22. The lower edge portion 55 of the cushion arm 21 is not also one R-shape, but also bends in a curved shape passing below the point O2 to connect the rear end portion 21a and the front end portion 21c. Further, the point O2 that is the intersection of the straight lines r and q is offset by an amount of a dimension t from the point P obtained by dividing the straight line p into two equal parts to the point O1 side. u is a bisector of a straight line p passing through the point P.

  Of the lower edge portion 55, the rear portion 55 a between the intermediate portion 21 b and the rear end portion 21 a of the cushion arm 21 is substantially linear and is located on the lower side of the drawing with respect to the straight line p. On the other hand, the intermediate portion 21b and the front end portion 21c form an intermediate portion 55b corresponding to a substantially linear extension of the rear portion 55a up to the vicinity of the front end portion 21c. Most of the intermediate portion 55b is located above the straight line p in the drawing. The front portion of the intermediate portion 55b is bent to form a front portion 55c that is obliquely connected to the front end 21c. The front portion 55c is bent so as to protrude toward the pulling direction E side rather than the extension of the virtual straight line s approximating the rear portion 55a and the intermediate portion 55b. The virtual straight line s substantially corresponds to a common tangent to the outer periphery of each circular part of the rear end part 21a and the intermediate part 21b. At this time, the point O3 is at a position shifted to the pulling direction E side from the straight line p as well as the straight line s.

  16 shows a side view shape of the vehicle body side connecting link 22, and FIG. 17 shows the same plan view shape in a partial cross section. As shown in these drawings, the vehicle body side connecting link 22 is also formed by a suitable material and a suitable manufacturing method, such as casting of a light alloy, and includes a pair of left and right arm portions 60 and a cross portion 61 that connects one end of each. . Two arm portions 60 are arranged symmetrically with respect to the vehicle body side connection link 22 from the vehicle body center C, and are connected with the cushion arm 21 interposed therebetween. The distance between the left and right arm parts 60 is approximately the same as the width of the intermediate part 21b that is the widest part of the cushion arm 21, and is larger than the outer diameter of the cushion unit 20.

  The arm portion 60 is formed in a solid shape, and a through hole 62 for the second mounting shaft 37 is formed in a portion corresponding to the upper end 22a that is one end portion thereof, and the through hole 52 in the intermediate portion 21b of the cushion arm 21 is formed. Coaxially adjusted. Moreover, the cross part 61 comprises the lower end part 22b of the vehicle body side connection link 22, The through-hole 63 extended in the left-right direction is formed here, and the attachment shaft 39 is penetrated through the bearing which is not shown here. The center of the mounting shaft 39 is defined as a point O4.

  Here, the connection point between the vehicle body side connection link 22 and the center frame 6, that is, the center O4 of the attachment shaft 39 is a connection point between the cushion bracket 28 of the swing arm 8 and the joint portion 25b which is the lower end of the cushion unit 20. That is, it is located above the center of rotation (swing) of the joint portion 25b. Thereby, the vertical length of the center frame 6 is shortened, the efficiency of the link mechanism is improved, and the moment to the center frame 6 is reduced.

  FIG. 18 is a view showing an outer shape of the cushion unit 20 as viewed from the rear side of the vehicle body when the cushion unit 20 is attached. As is clear from this figure, the reserve tank 27 is fastened and integrated with a bolt 70 at the bottom of the bottom portion 25a. The reserve tank 27 has a cylindrical shape, and is horizontally oriented so that its axis F is perpendicular to the axis D of the cushion unit 20 and is in the left-right direction in the figure.

  Next, the operation will be described. FIG. 19 is a diagram illustrating the operation of the rear wheel suspension device 10. When the swing arm is in the position A where the cushion unit 20 is fully extended, the lower end of the cushion unit 20 is fixed to the swing arm, so the top portion 23 is at the position of the solid line that extends upward. At this time, an angle (indicated by a diagonal) formed by the straight line p connecting the points O1 and O3 and the center line D of the cushion unit 20 forms α. The degree of the acute angle α is appropriately set according to the specification.

  When the swing arm swings from the fully extended position A toward the most contracted position B toward the contracted side, the swing arm swings counterclockwise around the pivot shaft 7. At this time, the cushion unit 20 and the cushion arm 21 also swing together with the swing arm. However, since the vehicle body side connection link 22 is connected to the boss 6a at one end, the cushion arm 21 is further rotated counterclockwise. The distal end 21c of the cushion unit 20 pushes the distal end protruding portion 23a of the top portion 23 downward to contract.

  Eventually, when the swing center line of the swing arm reaches the B position and the cushion unit 20 is in the most contracted state indicated by the phantom line (the fully bent state in the first embodiment), the cushion unit 20 is tilted forward and the tip protrusion 23a is centered. Near the shoulder of the frame 6, the point O3 is located considerably below the initial position, and the angle formed by the center line D and the straight line p increases to approximately the vicinity of a right angle.

  Further, as the swing angle of the swing arm increases, the angle α formed by the straight line p and the center line D of the cushion unit 20 gradually increases, so that a point O3 having a radius of the straight line p around the point O1 is drawn. The tangent of the point O3 in the arc gradually approaches a state parallel to the center line D of the cushion unit 20. For this reason, the movement change amount on the center line D of the point O3 that presses the top portion 23 of the cushion unit 20 gradually increases as the swing angle of the swing arm increases, resulting in a change in the swing angle of the swing arm. On the other hand, the progressive effect that the stroke amount of the cushion unit 20 changes nonlinearly is exhibited.

  At this time, the cushion arm 21 has a substantially arcuate shape in a side view in which the upper edge portion 54 side curves to the opposite side to the pulling direction E so as to surround the point O2 where the pulling force of the vehicle body side connecting link 22 acts. Therefore, the vehicle body side connecting link 22 has sufficient rigidity with respect to the tensile load direction. As a result, since the rigidity of the entire suspension device is increased, good cushion performance can be maintained. In addition, a highly rigid upper link type can be formed. Further, when the same level of rigidity is sufficient, the weight can be further reduced. Furthermore, if the lower edge 55 side has an R shape resembling the upper edge part 54 side, the width between the upper and lower edge parts 54 and 55 in a side view is reduced, so that it is possible to reduce the weight.

  In addition, as described above, it is preferable that the angle α formed by the straight line p in the fully extended state and the center line D of the cushion unit 20 is an acute angle. The top portion 23 and the front end portion 21c of the cushion arm 21 are likely to interfere with each other. However, in this embodiment, of the front end portion 21c that is the end portion in the length direction of the cushion arm 21 connected to the cushion unit 20, the front portion 55c is inclined in the contraction direction of the cushion unit 20 rather than the extension of the virtual straight line s. Since it bends and projects, the front end 21c of the cushion arm 21 can more reliably avoid interference with the cushion unit 20 during operation.

  Moreover, as is apparent from FIG. 19, the position of the point O3 is the uppermost position at the extended position A, and gradually decreases toward the contraction side. Therefore, if the cushion arm 21 and the top portion 23 of the cushion unit 20 are set so as not to interfere with other vehicle body side members located above the swing arm at the fully extended position A, the swing arm then moves upward. Even if it swings, interference between these members can be avoided.

  Further, since the two arm portions 60 are arranged symmetrically when the vehicle body side connecting link 22 is viewed from the vehicle body center C, the cushion unit 20 has high rigidity. In addition, since the vehicle body side link 22 is arranged symmetrically as viewed from the vehicle body center C, the operation of the cushion unit 20 can be made accurate. In addition, since the distance between the left and right arm portions 60 is equal to or greater than the dimension of the intermediate portion 21b that is the widest in the vehicle width direction, the vehicle body side connecting link 22 can also be prevented from interfering with the cushion unit 20.

  Further, since the reserve tank 27 is attached to the lower part of the cushion unit 20 and disposed below the swing arm 8, it is disposed so as to avoid interference with the cushion arm 21 and the vehicle body side member above the swing arm 8, such as the fuel tank 17 and the like. And an upper link layout becomes easy.

  In addition, without placing the reserve tank 27 in the cushion mounting hole 30 provided in the swing arm 8, only the cushion unit 20 is inserted into the cushion mounting hole 30 from below the swing arm 8, and the cushion bracket 28 is mounted on the mounting bracket mounting step of the swing arm 8. The reserve tank 27 can be mounted without passing it into the cushion mounting hole 30 by being bolted to the portion 31. For this reason, the mountability and maintainability are improved, and the cushion mounting hole 30 of the swing arm 8 can be made as small as possible, and the rigidity of the swing arm 8 can be easily ensured.

  Further, in the cushion arm 21, a point O 2 that is a connection point of the vehicle body side connection link 22 is located between O 1 and O 3 that are connection points of the swing arm 8 and the cushion unit 20, and Since it is offset to the point O1 which is the connection point, the lever ratio when the swing of the swing arm 8 is transmitted to the cushion unit 20 by the cushion arm 21 to make a stroke can be gained, and the swing arm 8 has a small swing. The cushion unit 20 can be stroked greatly by movement.

  In addition, since the reserve tank 27 is placed horizontally, a sufficient ground clearance can be secured even though the reserve tank 27 is disposed below the swing arm 8. In addition, it can be disposed close to the rear wheel 9 and the positional relationship with the rear wheel 9 is substantially constant even when the cushion unit 8 swings, so that it can be disposed avoiding interference with the rear wheel 9, and the reserve tank 27 can be disposed. The layout in the case where the swing arm 8 is disposed below can be facilitated, and the degree of freedom in setting the wheel base can be increased.

  The present invention is not limited to the above embodiments, and various modifications and applications can be made within the principle of the invention. For example, as the substantially arcuate shape of the cushion arm, both the upper edge portion 54 and the lower edge portion 55 can be formed into a substantially uniform R shape, and conversely, the shape does not change uniformly but changes irregularly. You can also. In short, it is sufficient that the intermediate portion bends to the opposite side to the pulling direction and the both ends in the length direction relatively extend in the pulling direction. Furthermore, the present invention can be applied to various vehicles other than motorcycles such as buggy cars. Moreover, if it is a swing arm type | formula, it can utilize also with respect to a front-wheel suspension apparatus.

1 is a side view of a motorcycle according to a first embodiment of the present invention. It is an enlarged side view of the swing arm type suspension device portion in the vehicle. It is a top view of the swing arm in the said suspension apparatus. It is a side view which shows the cushion unit full bending state of the said swing arm type suspension apparatus. It is a graph which shows the relationship between the stroke amount of the said cushion unit, and the displacement amount of a rear-wheel axle. It is a side view which shows the modification of the said 1st Example. It is a side view which shows the other modification of the said 1st Example. It is a side view of a motorcycle in the second embodiment of the present invention. It is an enlarged side view of the rear-wheel suspension apparatus part in the said vehicle. It is sectional drawing of the said part. It is a side view of the swing arm in the said suspension apparatus. It is a top view of the said swing arm. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is a side view of the cushion arm in the said suspension apparatus. It is a plane sectional view of the above-mentioned cushion arm. It is a side view of the vehicle body side connection link in the said suspension apparatus. It is a plane sectional view of the above-mentioned body side connection link. It is a figure which shows the cushion unit of the said suspension apparatus. It is operation | movement explanatory drawing in a 2nd Example.

Explanation of symbols

1 Front wheel 2 Front fork 3 Head pipe 5 Main frame 6,113 Center frame (vehicle side)
7,114 Pivot shaft 8,121,221 Swing arm 9,122 Rear wheel 10 Rear wheel suspension device (swing arm type suspension device)
20,123 Cushion unit 21,125 Cushion arm 22,126 Car body side connection link O1, 131A First connection point O2, 132A Second connection point O3, 133A Third connection point 27 Reserve tank 28 Cushion bracket
108 Power unit (vehicle side)
120, 220, 320 Swing arm type suspension device 124, 224 Link mechanism 127 Upper bracket (connection part)
137,237 Arm part 140,240 Cross member 141 Insertion hole 237A Cantilever arm part

Claims (4)

A front end portion of a swing arm configured by connecting a pair of arm portions with a cross member is swingably attached to a pivot shaft provided on the vehicle body side, and a wheel is attached to the rear end portion of the swing arm. In the swing arm type suspension device for a vehicle, one end of a cushion unit is attached to the swing arm, and the other end of the cushion unit is attached to the vehicle body via a link mechanism.
The cushion unit is arranged behind the cross member ,
The link mechanism is swingably attached to the upper part of the swing arm and the other end of the cushion unit is attached, and one end is attached to the cushion arm and the other end is pivoted on the vehicle body side. A vehicle body side connection link attached to a portion below the shaft, and an insertion hole for the vehicle body side connection link is provided in the cross member;
A swing arm type suspension device , wherein a connecting portion between the swing arm and the cushion arm is provided in front of the insertion hole . A front end of a swing arm having a cantilevered arm portion on one side of the rear portion is connected to a pivot shaft provided on the vehicle body side so as to be swingable. A wheel is attached to the rear end of the swing arm, one end of a cushion unit is attached to the swing arm, and the other end of the cushion unit is attached to the vehicle body via a link mechanism. In swing arm type suspension system,
The cushion unit is arranged behind the cross member ,
The link mechanism is swingably attached to the upper part of the swing arm and the other end of the cushion unit is attached, and one end is attached to the cushion arm and the other end is pivoted on the vehicle body side. A vehicle body side connection link attached to a portion below the shaft, and an insertion hole for the vehicle body side connection link is provided in the cross member;
A swing arm type suspension device , wherein a connecting portion between the swing arm and the cushion arm is provided in front of the insertion hole .   The swing arm type suspension device according to claim 1 or 2, wherein a rear part of the vehicle body of the cushion unit is spatially open. The swing arm type suspension device according to any one of claims 1 to 3, wherein the insertion length of the cross member is set to have a length in a front-rear direction smaller than a diameter of the cushion unit. .

Images