JP2005271607A - Vehicular swing arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular swing arm capable of increasing the flexibility of the design of a vehicle body frame and the swing arm, enhancing the ride quality of a vehicle, and reducing the cost and the weight of a suspension. <P>SOLUTION: In a vehicle in which a swing arm 22 is mounted on a main frame 21 in a vertically swinging manner, an axle 23 is mounted on a tip of the swing arm 22, and a rear wheel 26 is mounted on the axle 23, the swing arm 22 is formed of a leaf spring, and a part in a vicinity of a mounting part on the main frame 21 is supported by a second bush 68 and a third bush 69, and the swing arm 22 has a function of a suspension spring. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle swing arm.

As a conventional vehicle swing arm, one made of a leaf spring is known (for example, see Patent Document 1).
U.S. Pat. No. 4,405,027

FIG. 7 will be described with reference to FIG. In addition, the code | symbol was reassigned.
FIG. 12 is a side view of a vehicle showing a conventional swing arm. A power unit 304 is suspended from a rear upper part of a frame 301 via brackets 302 and suspension plates 303 and 303 (only the reference numeral 303 is shown). The leaf springs 306 and 306 (only the reference numeral 306 on the front side) are extended rearward from the lower rear portion of the 301, and from the power unit 304 via the rubber mount 307 and the ball bearing 308 at the rear ends of the leaf springs 306 and 306, respectively. It shows that rear axles 311 and 311 (only reference numeral 311 on the front side) extending left and right are rotatably supported, and rear wheels 312 are attached to these rear axles 311 and 311 respectively.

  In the above conventional technique, since the power unit 304 is suspended from the frame 301, a frame side mounting portion for attaching the bracket 302 is provided on the frame 301 side, and the suspension plates 303 and 303 are disposed on the power unit 304 side that moves up and down together with the leaf spring 306. It is necessary to provide a power unit side mounting portion for mounting. If the power unit 304 is not suspended from the frame 301, the above-described frame side mounting portion and power unit side mounting portion need not be provided, and the degree of freedom of the shape of the frame 301 and the power unit 304, that is, the degree of design freedom can be increased.

  The leaf spring 306 is a member that is easily bent up and down. However, in order to connect the frame 301 and the power unit 304 with the bracket 302 and the suspension plates 303 and 303, the vertical swing of the leaf spring 306 is restrained, and the rear wheel 312. The vertical stroke amount of the vehicle becomes small, and the ride comfort of the vehicle is impaired.

  Further, it is desired to reduce the cost and weight of the suspension for the rear wheel 312 described above.

  An object of the present invention is to increase the degree of freedom in designing a vehicle body frame and a swing arm in a vehicle swing arm, improve the riding comfort of the vehicle, and further reduce the cost and weight of the suspension.

  According to the first aspect of the present invention, in a vehicle in which a swing arm is attached to a body frame so as to be swingable up and down, an axle is attached to the tip of the swing arm, and a wheel is attached to the axle, the swing arm is used as a leaf spring to the body frame. The vicinity of the mounting portion is supported by a support member from above and below, and the swing arm has a function of a suspension spring.

  For example, in the present invention, compared with the conventional case, when a support member or a suspension spring is passed between the swing arm side and the frame side, the mounting position on the swing arm side and the frame side is required. Since there is nothing to attach to the front end side and the frame side, the shapes of the swing arm and the frame are not limited.

  Moreover, since the swing arm is a leaf spring, the swing amount of the swing arm can be increased, and the swing arm itself can also serve as a suspension spring.

The invention according to claim 2 is characterized in that the support member is a tube bush made of an inner cylinder, an outer cylinder, and rubber interposed between the inner cylinder and the outer cylinder.
The vibration energy transmitted to the body frame is absorbed by the damping force of the rubber of the tube bushing while the impact and vibration are transmitted from the road surface to the body frame by the elastic force of the leaf spring.

The invention according to claim 3 is characterized in that an engine for driving wheels is attached to the swing arm.
By attaching the engine to the swing arm, engine vibration can be mitigated by the swing arm, and vibration transmitted to the body frame can be suppressed.

The invention according to claim 4 is characterized in that a stopper for stopping the upward swing of the swing arm is provided at the rear end of the vehicle body frame.
It is easy to provide a stopper at the rear end of the vehicle body frame, and it is possible to stop the swing arm from swinging with a simple configuration.

  In the invention according to claim 1, since there is nothing attached to the tip side and the frame side of the swing arm, the shapes of the swing arm and the frame are not limited, and the design freedom of the swing arm and the frame is increased. it can.

  Further, since the swing arm is a leaf spring, the swing amount of the swing arm can be increased, the vertical stroke of the wheel can be increased, and riding comfort can be improved.

  Furthermore, since the swing arm is a leaf spring, the swing arm itself can also serve as a suspension spring, and it is not necessary to provide a special suspension spring. Therefore, the suspension supporting the wheels can be simplified, and the vehicle Can be reduced in cost and weight.

  In the invention according to claim 2, vibration energy transmitted to the vehicle body frame can be absorbed by the damping force of the rubber of the tube bushing while relaxing the impact and vibration transmitted from the road surface to the vehicle body frame by the elastic force of the leaf spring. .

  In the invention according to claim 3, since the engine is attached to the swing arm, the engine vibration can be mitigated by the swing arm, and the vibration transmitted to the vehicle body frame can be suppressed.

  In the invention according to claim 4, since the stopper is provided at the rear end of the vehicle body frame, the stopper can be easily provided on the vehicle body frame, and the upward swing of the swing arm can be stopped with a simple configuration. Can be suppressed.

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 according to the present invention. In the vehicle 10, a steering stem 13 is rotatably attached to a head pipe 12 that constitutes a front end portion of a vehicle body frame 11, and a front fork 14 is mounted below the steering stem 13. A front wheel 16 is attached to the lower portion of the front fork 14, a handle post 17 is attached to the upper end of the steering stem 13, a handle 18 is attached to the handle post 17, and a vehicle body frame is formed in an S shape rearward from the head pipe 12. 11 is extended, a swing arm 22 made of a leaf spring is extended rearward from the center of the main frame 21, and an axle 23 is rotatably attached to the rear end of the swing arm 22. At each end, rear wheels 24 and 26 (only the reference numeral 24 on the front side is shown) are attached. An engine 27 is attached to the middle part of the swing arm 22, and the output of the engine 27 is transmitted to the rear wheels 24 and 26 by a chain 28. A main post 31 is attached to the rear part of the main frame 21, and can slide on the main post 31. This is a tricycle in which a seat post 32 is attached to the seat post 32 and a saddle 33 is attached to the seat post 32.

  The main frame 21 is composed of a square pipe, and extends from the head pipe 12 so as to form a circular arc in a convex shape downward from the lower end of the front linear portion 35, and the front linear portion 35 extending linearly downward from the head pipe 12. A front arc portion 36, a central straight portion 37 extending obliquely rearward and upward from the rear end of the front arc portion 36, and a rear portion extending in a convex arc from the rear end of the central straight portion 37 This is a member constituted by the arc portion 38.

The front straight part 35 is a part in which the tip is attached to the head pipe 12 and the attachment part is reinforced by the reinforcing members 41 and 42.
The front arc portion 36 is a portion where floor support portions 44 and 45 (only the reference numeral 44 on the front side is shown) for supporting a step floor (not shown) on which the driver 43 puts his / her foot on the bottom portion 36a is attached. The lowest part of the front arc part 36, that is, the bottom part 36a is a leg straddle part where the driver straddles his / her foot.

The front arc portion 36 and the central straight portion 37 are portions that support the swing arm 22.
The rear arc portion 38 is a portion where the main post 31 is attached to the top portion 38a.
The front arc portion 36 and the rear arc portion 38 described above are portions having the same arc radius for facilitating the manufacture of the main frame 21.

  Here, 51 is a front fender that covers the upper side of the front wheel 16, 52 and 53 are brake discs and brake calipers that constitute the front disc brake 54, and 56 and 57 are brake discs and brake calipers that constitute the rear disc brake 58.

  2 is a rear side view of the vehicle according to the present invention (the rear wheel 24 (see FIG. 1) on the front side is omitted). The main frame 21 has pivot plates 61 and 62 (the front pivot plate 61 is not provided). The pivot shaft 64 and the support shafts 65 and 66 are passed to the pivot plates 61 and 62, and one end of the swing arm 22 is wound around the pivot shaft 64 via the first bush 67 and swings in the vicinity of the pivot shaft 64. The arm 22 is sandwiched up and down by a second bush 68 and a third bush 69 attached to the support shafts 65 and 66, the other end of the swing arm 22 is wound around a bearing member (not shown), and an engine A drive sprocket 72 attached to an output shaft (not shown) of the engine 27, Indicating that looped chain 28 and driven sprocket 74 mounted via a sprocket support flange 73 to 23.

  Here, 76 is a first stopper attached to the main frame 21 and the pivot plates 61 and 62 for restricting the upward movement amount of the second bush 68, and 77 is a main frame for restricting the upward swing amount of the swing arm 22. 21 is a bolt for attaching the driven sprocket 74 to the sprocket support flange 73.

3A and 3B are cross-sectional views showing a swing arm mounting portion of a vehicle according to the present invention. FIG. 3A is a cross-sectional view taken along a plane orthogonal to the pivot shaft 64, and FIG. Is cut along the line.
In (a), the first bush 67 includes an inner cylinder 81 fitted to the pivot shaft 64, an outer cylinder 82 fitted inside the winding portion 22a provided at one end of the swing arm 22, and these A rubber 83 vulcanized and bonded to the inner cylinder 81 and the outer cylinder 82 is provided.

The second bushing 68 has the same structure as that of the first bushing 67 (reference numerals are separately provided for convenience), and the outer cylinder 82 is applied to the upper surface 22 b of the swing arm 22.
The third bush 69 includes an inner cylinder 85 fitted to the support shaft 66, and a rubber 86 vulcanized and bonded around the inner cylinder 85, and the rubber 86 is applied to the lower surface 22c of the swing arm 22. is there.

  The first stopper 76 includes a stopper support member 76a extending downward from the main frame 21 and an arcuate stopper body 76b attached to the lower end of the stopper support member 76a.

  As described above, the vicinity of the pivot shaft 64 of the swing arm 22 is vertically sandwiched between the second bush 68 and the third bush 69 to limit the vertical swing of the swing arm 22 and in addition to the elastic force of the swing arm 22 itself. By the elastic force and damping force of the second bush 68 and the third bush 69, the impact and vibration transmitted from the rear wheels 24 and 26 (see FIG. 2, rear wheel 24 not shown) to the main frame 21 are absorbed.

  In (b), the first bush 67 vulcanizes and bonds rubber 83 between the inner cylinder 81 and the two outer cylinders 82, and the third bush 69 adds rubber 86 to two locations of the inner cylinder 85. The first bush 67 and the third bush 69 are disposed between the two pivot plates 61, 62, the shaft insertion holes 61a, 61b are opened in the pivot plate 61, and the shaft insertion holes are formed in the pivot plate 62. 62a and 62b are opened, the pivot shaft 64 as a bolt is passed through the shaft insertion hole 61a, the inner cylinder 81 and the shaft insertion hole 62a, and the first nut 88 is screwed into the male screw 64a provided at the tip of the pivot shaft 64. The pivot shaft 66, which is a bolt, is passed through the shaft insertion hole 61b, the inner cylinder 85, and the shaft insertion hole 62b, and a second nut 91 is screwed into a male screw 66a provided at the tip of the support shaft 66 to pivot. Attaching the first bushing 67 and third bushing 69 to 61 and 62. The second bush 68 (see (a)) is attached in the same manner as the first bush 67 and the third bush 69.

  4 is a cross-sectional view taken along line 4-4 of FIG. 1. A bearing member 94 is attached to the rear end of the swing arm 22, and the axle shaft 23 is rotatably passed through the bearing member 94 via bearings 95 and 96. A sprocket support flange 73 and a wheel 97 constituting the rear wheel 24 are spline-coupled to a male spline 23a provided at one end of the axle 23, and a disk support flange is connected to the male spline 23b provided at the other end of the axle 23. 98 and the wheel 101 constituting the rear wheel 26 are spline-coupled, nuts 102 and 103 are screwed to both ends of the axle 23, a driven sprocket 74 is attached to the sprocket support flange 73, and a screw 105 is attached to the disk support flange 98. The brake disc 56 is attached to the projecting portion 106 provided at one end of the bearing member 94 with bolts 107 and 10. In indicating that attaching the brake caliper 57. In addition, 108 ... are nuts screwed into bolts 78 ... for attaching the driven sprocket 74.

  The bearing member 94 is formed with annular convex portions 94a and 94b for winding the winding portion 22d of the swing arm 22, and by arranging the swing arm 22 between these annular convex portions 94a and 94b, The axial movement of the bearing member 94 with respect to the swing arm 22 is prevented. Reference numeral 111 denotes an anti-rotation portion formed integrally with the bearing member 94 in order to prevent the bearing member 94 from rotating with respect to the swing arm 22.

  As described above, the driven sprocket 74 is disposed in the vicinity of the inner side of the rear wheel 24, and the brake disk 56 and the brake caliper 57 are disposed in the vicinity of the inner side of the rear wheel 26. The caliper 57 is difficult to see from the side of the vehicle body, and the appearance can be improved.

  5 is a cross-sectional view taken along line 5-5 of FIG. 1. A fan 122 is attached to one end of a crankshaft 121 rotatably mounted in the engine 27 with a nut 123, and is integrally protruded laterally from the fan 122. The weights 124 are swingably attached to the shafts 122a, and the weights 124 are surrounded by the drum 126, so that the centrifugal clutch is removed from the shafts 122a, weights 124, and the drum 126. 127, a bearing portion 128 is disposed outside the crankcase 27a of the engine 27, and an output shaft 132 integrally formed with the drum 126 via the bearing 131 is rotatably attached to the bearing portion 128. The drive sprocket 72 is spline-coupled to the male spline 132 a provided on the shaft end on the outer side of the bearing portion 128. The shaft end receiving portion 134 supports the tip end portion of the output shaft 132 through a bearing 135, and the engine support member 71 is disposed below the engine 27. The engine support member 71 .., And a boss provided on the crankcase 27 a on the other end side of the crankshaft 121. Side support members 143 are attached to the portions 27b and 27b via spacers 141, 141, 142, and 142 with bolts 144, and the side support members 143 are also attached to the end portions of the side protrusions 71b of the engine support member 71. Is attached with bolts 146.

  Here, 151 is a bolt that prevents the weight 124 from coming out of the shaft portion 122a, 152 is a shoe provided at the end of the weight 124 so as to contact the inner peripheral surface of the drum 126, and 153 and 154 fix the bearing 131. 156, 157 are collars for positioning the drive sprocket 72 to the output shaft 132, 161, 162 constitute an engine support member 71 and upper and lower support members that sandwich the swing arm 22, 163 ... Are bolts that fasten the upper support member 161 and the lower support member 162 in order to sandwich the swing arm 22.

6 is a cross-sectional view taken along line 6-6 of FIG. 1, and shows a handle mounting structure of the vehicle 10 (see FIG. 1).
That is, the steering stem 13 is rotatably supported by an upper bearing 171 provided at the upper end of the head pipe 12 and a lower bearing 172 provided at the lower end of the head pipe 12 (see FIG. 1). A spacer 174 is positioned on the upper portion of the handle post 17, a handle support plate 176 is applied to the upper portion of the spacer 174, and a pair of handle bars 177 and 178 attached so as to penetrate through the handle support plate 176 are respectively spacers. 174 and the handle post 17 are passed through in this order, and a handle support plate 176 between the two handle bars 177 and 178 and a spacer 174 are passed through one handle mounting bolt 182 and mounted in the upper end of the steering stem 13. Tsu preparative member at 183 screwing the handle mounting bolts 182 to indicate that the attached handle 18 of the handle bar 177, 178 to the steering stem 13.
The handle support plate 176 and the handle bars 177 and 178 are members constituting the handle assembly 184.

  Here, reference numeral 186 denotes a lock nut for fixing the upper bearing 171 to the steering stem 13 side, reference numeral 187 denotes a hollow portion provided in the handle post 17 for inserting the steering stem 13, and reference numerals 188 and 191 denote the handle bars 177 and 178, respectively. Handle insertion holes provided in the handle post 17, 192 and 193 are handle through holes opened in the spacer 174 to penetrate the handle bars 177 and 178, and 194 and 196 are handles to penetrate the handle bars 177 and 178 Handle through hole opened in the support plate 176, 201 is a bolt insertion hole opened in the spacer 174 for passing the handle mounting bolt 182, 202 is a bolt insertion hole opened in the handle support plate 176 for passing the handle mounting bolt 182, 203 is handle removal A bolt 182 is a female thread formed on the nut member 183 to screw connection.

  7 is a cross-sectional view taken along the line 7-7 in FIG. 6. The concave portions 205 and 206 are formed on the lower surface of the spacer 174, the convex portions 207 and 208 are integrally formed on the upper end of the nut member 183, and the convex portions 205 and 206 are convex. It shows that the spacer 174 is positioned with respect to the nut member 183 by fitting the portions 207 and 208.

FIGS. 8A and 8B are perspective views showing a vehicle handle mounting structure according to the present invention. FIG. 8A is a perspective view of a spacer 174 and a handle assembly 184. FIG. 8B is a handle post 17 and a nut. 3 is a perspective view of a member 183. FIG.
In (a), the spacer 174 is a member in which concave portions 205 and 206 are formed on the lower surface 174a at a position sandwiching the bolt insertion hole 201 and before and after the bolt insertion hole 201.
In (b), it is shown that the nut member 183 is formed with convex portions 207 and 208 at the upper end so as to face each other so as to sandwich the female screw 203 therebetween.

  As shown in (a) and (b) above, the recesses 205 and 206 are formed in the spacer 174, and the protrusions 207 and 208 are formed in the nut member 183, so that the handle assembly 184 is attached to the handle post 17. When assembled, the spacer 174 can be easily positioned on the handle post 17. With the spacer 174 positioned on the handle post 17, the handle through holes 192 and 193 (see FIG. 6) of the spacer 174 and the handle post 17 The handle bars 177 and 178 of the handle assembly 184 can be easily passed through the handle insertion holes 188 and 191.

FIG. 9 is a sectional view showing an engine of a vehicle according to the present invention.
The engine 27 includes an engine main body 261. The engine main body 261 includes a cylinder block 262 integrated with a cylinder head and a crankcase 27a joined to a lower end surface of the cylinder block 262.

The cylinder block 262 includes a single cylinder 266 that houses the piston 264 at the center.
The crankcase 27a is a member in which a pair of upper and lower case halves 263a and 263b are joined by a plurality of bolts. Is attached rotatably. A connecting rod 272 connects the piston 264 to the crankshaft 121, and a fuel tank 273 is attached to the lower portion of the crankcase 27a.

The crankcase 27 a includes a crank chamber 275 provided in the center, and an oil reservoir chamber 276 and a valve operating chamber 277 respectively disposed on the side of the crank chamber 275.
The crank chamber 275 is where the crank portion 271a of the crankshaft 121 is disposed.
The oil reservoir chamber 276 is a place where a predetermined amount of lubricating oil is stored, and houses an oil slinger 278 attached to the crankshaft 121 for stirring and scattering the lubricating oil (that is, generating oil mist).

  The oil slinger 278 includes a plurality of long arm blades 278a and a plurality of short arm blades 278b, and the long arm blades 278a and the short arm blades 278b are bent in directions opposite to each other in the axial direction of the crankshaft 121. .

  As described above, the oil reservoir chamber 276 provided with the oil slinger 278 is provided in the crankcase 27a, so that the lubricating oil in the oil reservoir chamber 276 is agitated by the rotation of the oil slinger 278 in any operating posture of the engine 27. Thus, oil mist can always be generated.

  The valve operating chamber 277 extends through one side of the cylinder block 262 to the head, and includes a valve operating device 281 that opens and closes the intake valve and the exhaust valve on the valve operating chamber 277. Reference numeral 282 denotes a head cover that covers the upper portion of the cylinder block 262, and reference numerals 283 and 284 denote rocker shafts and rocker arms that constitute the valve gear 281.

The crank chamber 275 and the oil reservoir chamber 276 are communicated with each other via a through hole 271b opened in the crankshaft 121.
Since the opening to the oil reservoir chamber 276 is disposed at the center of the oil reservoir chamber 276, the through hole 271b can store the lubricating oil in the oil reservoir chamber 276 in any inclined or inverted state of the engine 27. The opening is set so as not to sink.

The crankcase 27 a includes a valve chamber 286 that communicates with the valve operating chamber 277 and an oil return chamber 287 that surrounds the valve chamber 286.
The valve chamber 286 is a portion provided with a one-way valve 291 that communicates with the bottom of the crank chamber 275 via the valve hole 288 and opens and closes the valve hole 288.

The one-way valve 291 is a member that closes the valve hole 288 when the pressure is reduced and opens the valve hole 288 when the pressure is increased according to the pressure pulsation in the crank chamber 275.
The oil return chamber 50 communicates with the oil reservoir chamber 276 through the through hole 292, and also communicates with the valve operating chamber 277 through an orifice (not shown).
In the figure, 293 is a recoil starter, and 294 is an ignition coil.

Next, the operation of the engine 27 described above will be described.
While the engine 27 is in operation, when the oil slinger 278 stirs the lubricating oil in the oil reservoir chamber 276 by the rotation of the crankshaft 121 to generate oil mist, when the crank chamber 275 is depressurized by the upward movement of the piston 264, The oil mist is sucked into the crank chamber 275 through the through hole 271b and lubricates around the crank portion 271a and the piston 264.

  Further, when the crank chamber 275 is pressurized by the downward movement of the piston 264, the oil mist is blown from the valve hole 288 and the valve chamber 277 together with the blow-by gas generated in the crank chamber 275 by opening the one-way valve 291. The oil mist and blow-by gas are separated in the valve operating chamber 277, the oil mist lubricates each part of the valve operating device 281 and the blow-by gas is discharged to the air cleaner.

  Further, the oil mist sent to the valve operating chamber 277 returns to the oil reservoir chamber 276, and the lubricating oil liquefied in the valve operating chamber 277 returns to the oil return chamber 287 through an orifice (not shown). Then, the recirculation of the oil mist and the liquefied lubricating oil is performed without any problem even when the engine 27 is inclined. Further, even if the engine vibrates due to road surface unevenness during running, the oil mist and lubricating oil can be recirculated without any problem.

The operation when the swing arm 22 described above swings will be described below.
FIG. 10 is a first action diagram showing the action at the time of swing arm swing of the vehicle according to the present invention.
When the swing amount becomes large when the swing arm 22 swings upward with respect to the main frame 21, the upward movement of the swing arm 22 is stopped by the second stopper 77 provided at the rear end of the main frame 21, and the swing arm 22 Prevent excessive swinging.

FIG. 11 is a second operation diagram showing the operation of the vehicle according to the present invention during a swing arm swing, and the operation of the bush and the stopper will be described.
When the swing arm 22 swings upward, the outer cylinder 82 of the second bush 68 is pushed up by the swing arm 22 and moves upward, so that the rubber 83 of the second bush 68 is deformed to generate elastic force and damping force. . When the upward swing amount of the swing arm 22 is large, the outer cylinder 82 moves upward largely against the elastic force of the rubber 83, and the outer cylinder 82 hits the stopper main body 76 b of the first stopper 76. Therefore, excessive deformation of the second bushing 68, specifically the rubber 83, can be prevented by the first stopper 76, so that the rubber 83 is difficult to sag and the life of the second bushing 68 can be extended.

  As described above with reference to FIGS. 2 and 3, according to the present invention, first, the swing arm 22 is attached to the body frame 11 (see FIG. 1), more specifically, the main frame 21 so as to freely swing up and down. In a vehicle 10 (see FIG. 1) in which an axle 23 is rotatably attached to the front end and rear wheels 24 and 26 (see FIG. 4 for rear wheels 24) as wheels are attached to the axle 23, a swing arm 22 is attached to a leaf spring. The vicinity of the attachment portion to the vehicle body frame 11 is supported from above and below by the second bush 68 and the third bush 69 as support members, and the swing arm 22 has a function of a suspension spring.

  For example, in the present invention, compared with the conventional case, when a support member or a suspension spring is passed between the swing arm side and the frame side, the mounting position on the swing arm side and the frame side is required. Since there is nothing to attach to the front end side of the body 22 and the body frame 11 side, the shapes of the swing arm 22 and the body frame 11 are not limited, and the design freedom of the swing arm 22 and the body frame 11 can be increased. .

  Further, since the swing arm 22 is a leaf spring, the swing amount of the swing arm 22 can be increased, the vertical stroke of the rear wheels 24 and 26 can be increased, and the riding comfort of the vehicle 10 can be improved. .

  Furthermore, since the swing arm 22 is a leaf spring, the swing arm 22 itself can also serve as a suspension spring, and it is not necessary to provide a special suspension spring, so that the suspension for supporting the rear wheels 24 and 26 can be simplified. Therefore, the vehicle 10 can be reduced in cost and weight.

  Secondly, according to the present invention, a second bushing 68 as a tube bush made of an inner cylinder 81, an outer cylinder 82, and a rubber 83 interposed between the inner cylinder 81 and the outer cylinder 82, and an inner cylinder 85. The third bush 69 is a tube bush made of rubber 86 vulcanized and bonded to the inner cylinder 85.

  The vibration energy transmitted to the vehicle body frame 11 is absorbed by the damping force of the rubbers 83 and 86 of the second bushing 68 and the third bushing 69 while the impact force and vibration are transmitted from the road surface to the vehicle body frame 11 by the elastic force of the leaf spring. can do.

Third, the present invention is characterized in that an engine 27 for driving the rear wheels 24 and 26 is attached to the swing arm 22.
Since the engine 27 is attached to the swing arm 22, engine vibration can be reduced by the swing arm 22, and vibration transmitted to the vehicle body frame 11 can be suppressed.

Fourthly, the present invention is characterized in that a second stopper 77 is provided at the rear end of the vehicle body frame 11 as a stopper for stopping the upward swing of the swing arm 22.
Since the second stopper 77 is provided at the rear end of the body frame 11, the second stopper 77 can be easily provided on the body frame 11, and the upward swing of the swing arm 22 can be stopped with a simple configuration. 2 The cost of the stopper 77 can be suppressed.

  The swing arm made of the leaf spring of the present invention is preferably made of spring steel, resin, or FRP (reinforced plastic).

  The vehicle swing arm of the present invention is suitable for tricycles and four-wheel vehicles.

1 is a side view of a vehicle according to the present invention. 1 is a rear side view of a vehicle according to the present invention. It is sectional drawing which shows the swing arm attaching part of the vehicle which concerns on this invention. FIG. 4 is a sectional view taken along line 4-4 of FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6. 1 is a perspective view showing a vehicle handle mounting structure according to the present invention. It is sectional drawing which shows the engine of the vehicle which concerns on this invention. FIG. 6 is a first operation diagram showing an operation at the time of swing arm swing of the vehicle according to the present invention. It is a 2nd operation | movement figure which shows the effect | action at the time of the swing arm swing of the vehicle which concerns on this invention. It is a side view of the vehicle which shows the conventional swing arm.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... Body frame, 22 ... Swing arm, 23 ... Axle, 24, 26 ... Wheel (rear wheel), 27 ... Engine, 68, 69 ... Support member, Pipe bush (2nd bush, 3rd bush) , 77 ... stopper (second stopper), 81, 85 ... inner cylinder, 82 ... outer cylinder, 83, 86 ... rubber.

Claims (4)

In a vehicle in which a swing arm is attached to the body frame so that it can swing up and down, an axle is attached to the tip of the swing arm, and a wheel is attached to the axle.
The swing arm is a leaf spring, and supports the vicinity of the attachment portion to the vehicle body frame from above and below with a support member and has a function of a suspension spring.   2. The vehicle swing arm according to claim 1, wherein the support member is an inner cylinder, an outer cylinder, and a tube bush made of rubber interposed between the inner cylinder and the outer cylinder.   The vehicle swing arm according to claim 1 or 2, wherein an engine for driving the wheel is attached to the swing arm.   4. The vehicle swing arm according to claim 1, wherein a stopper for stopping an upward swing of the swing arm is provided at a rear end of the vehicle body frame. 5.

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