JP4014603B2 - Motor unit support structure for scooter type motorcycles - Google Patents

Description

  The present invention relates to a power unit support structure suitable for a relatively large scooter type motorcycle.

FIG. 7 shows a conventional power unit support structure for a relatively small scooter type motorcycle. The vehicle body frame 400 connects the front end of one main frame 402 to a head pipe 401 that pivotally supports a front fork, extends the main frame 402 obliquely downward toward the rear of the vehicle body, and further bends backward. A pair of left and right side frames 403, 403 are connected to the part, the side frame 403 extends rearward substantially horizontally, rises obliquely upward, and a suspension bracket 404 is fixed to the rising part. . A swing type power unit is swingably supported by the suspension bracket 404 of the side frame 403, and a footrest portion is formed by the horizontal extension of the side frame 403 (see, for example, Patent Document 1).
JP-A-7-112680

  By the way, when the above power unit support structure is adopted in a relatively large scooter type motorcycle, there is a concern that the rigidity is insufficient as it is.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a power unit support structure for a scooter type motorcycle capable of improving the power unit support rigidity.

The invention according to claim 1, in the power unit support structure for a scooter type motorcycle supports a swing type power unit by a body frame having a low-floor footrest portion between the head pipe and the seat, the suspension to the vehicle body frame connecting one end of the link further connects the end of the compression rod at the bottom than the coupling position of the suspension link, pivotally the power unit by a pivot shaft which is inserted from the vehicle width direction on one side to the other end of the suspension link The other end of the compression rod is connected to a projecting portion projecting to the other side in the vehicle width direction of the pivot shaft .

  The invention of claim 2 is characterized in that, in claim 1, only one compression rod is provided.

A third aspect of the present invention provides the compression rod according to the first or second aspect, wherein the compression rod is formed by connecting a cylindrical member to both ends of a rod-shaped member, and the cylindrical member at one end is connected to the body frame via a bolt , The cylindrical member at the end is connected to the suspension link through the pivot shaft .

The invention of claim 4 is characterized in that, in claim 3 , a rubber bush is interposed between the cylindrical member at one end and the other end and the bolt and pivot shaft .

In the invention of claim 1, connecting the suspension link to the vehicle body frame, and connecting the compression rod to lower even more the coupling position of the suspension link, the power unit by a pivot shaft connecting the said compression rods and the suspension links Since it is supported, the support rigidity of the power unit can be improved.

Further, in the invention of claim 4, since the rubber bush is interposed between the cylindrical member at one end and the other end of the compression rod and the bolt and the pivot shaft , driving and braking are performed while improving the vibration isolation. Changes in engine behavior can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 6 are views for explaining a power unit support structure of a scooter type motorcycle according to an embodiment of the present invention. FIG. 1 is a left side view of the motorcycle, and FIG. 2 is a suspension portion of the power unit. FIG. 3 is a sectional view taken along line III-III in FIG. 2, and FIGS. 4 to 6 are process diagrams for explaining a method of manufacturing a pipe. In the present embodiment, left and right and front and rear refer to left and right and front and rear as viewed in the riding state.

  In the figure, reference numeral 1 denotes a scooter type motorcycle according to the present embodiment, which pivotally supports a swing type power unit 3 at a substantially lower center portion of a vehicle body frame 2 and is equipped with a seat 4 at an upper portion, It has a schematic structure surrounded by a cover 1a.

  A steering shaft is inserted into the head pipe 5 of the vehicle body frame 2. A front fork 33 is fixed to the lower end of the steering shaft, and a front wheel 34 is pivotally supported at the lower end of the front fork 33. A steering handle 35 is attached to the upper end of the steering shaft 30 via a handle holder 36. Reference numeral 43 denotes a handle cover.

  The swing type power unit 3 is a V-belt drive type non-rotating type in which a V-belt 98 is bridged between a drive and driven pulleys 70 and 97 on a water-cooled four-cycle single-cylinder engine body 50 whose cylinder axis is inclined forward. A step transmission 51 is integrally connected, and a rear wheel 52 is pivotally supported at the rear end of the power unit 3. Further, the lower end of the rear cushion 53 is pivotally supported at the rear end portion of the power unit 3, and the upper end of the rear cushion 53 is pivotally supported by the rear frame 15 via a mounting bracket 54.

  The vehicle body cover 1a is made of resin, and includes a front cover 6 and a leg shield 7, and includes a front vehicle body cover 6 'surrounding the outer periphery of the head pipe 5 of the vehicle body frame 2 and a lower portion of the leg shield 7. A footboard 8 which is disposed and forms a footrest; an undercover 9 disposed on the lower surface of the footboard 8; a side cover 10 which covers the upper side of the power unit 3 from the lower left and right sides of the seat 4; It has.

  The body frame 2 has the following structure. A single main frame 11 is connected to the center of the head pipe 5 and extends obliquely downward to the rear of the vehicle body. The front end of a pair of left and right side frames 12, 12 is connected to the lower end of the main frame 11, and each side frame 12 extends obliquely downward to the rear of the vehicle body and then linearly extends substantially horizontally to the rear. It extends.

  Further, the front ends of a pair of left and right down tubes 13 and 13 are connected to the head pipe 5 below the main frame 11. Each of the down tubes 13 has an inclined portion (front side portion) 13a extending downward to the rear of the vehicle body, a linear portion (lower side portion) 13b extending substantially horizontally and linearly rearward from the lower end of the inclined portion 13a, and the linear portion. It is comprised from the bending part 13c extended diagonally upward from the rear end of 13b.

And the rear end portion 12a of each side frame 12 is connected and fixed together by a suspension bracket 1 4 and the bent portion 13c of the respective down tubes 13. Each of the suspension brackets 14 is connected to the front end of a rear frame 15 extending substantially linearly rearward. The upper surface of the rear frame 15 extends rearward and obliquely upward from the front end of the frame 15 and then extends substantially vertically downward. A support pipe 16 extending in the direction is connected.

  Between the upper portions of the left and right suspension brackets 14, suspension links 17 having a substantially U shape in a plan view are installed, and left and right arm portions 17 a and 17 a of the suspension links 17 are attached to the suspension brackets 14 with rubber dampers 18. Are fastened with bolts 19. The power unit 3 is pivotally supported on the base portion 17 b of the suspension link 17 by a pivot shaft 20 so as to be swingable up and down, and a rubber bush 21 is press-fitted between the pivot shaft 20 and the suspension link 17.

  The suspension bracket 14 and the right end portion of the pivot shaft 20, in other words, the protruding portion 20 a protruding from the other side of the pivot shaft 20 are connected by a single compression rod 22. The compression rod 22 has cylindrical members 22b and 22c connected to both ends of a rod member 22a. The cylindrical member 22b on one end side is fixed to the lower portion of the suspension bracket 14 with a bolt 23, and the cylindrical member on the other end side. 22c is mounted on the protruding portion 20a of the pivot shaft 20, and is fixed by a nut 20b. The rear end portion 12a of the side frame 12 is connected between the bolts 23 and 19 of the suspension bracket 14, and the side frame 12 is connected to improve the rigidity against the longitudinal force. A rubber bush 24 is interposed between the cylindrical members 22b and 22c, the bolt 23, and the pivot shaft 20. A gap 24a extending in the circumferential direction is formed at the center of the rubber bush 24 in the radial direction. ing. As a result, the spring constant changes according to the input during acceleration / deceleration and the like, and the engine behavior due to driving and braking is prevented while improving the vibration isolation.

  The bent portions of the side frame 12 and the down tube 13 are connected by a vertical pipe 25, and the bent portions of the left and right side frames 12 and the straight portions are connected by a horizontal pipe 26. The vertical pipe 25 is manufactured by forming a flat plate 25 'punched and formed into a cylindrical body by pressing.

  That is, as shown in FIGS. 4 to 6, a flat plate 25 ′ having a circumferential development dimension (peripheral length) a of the vertical pipe 25 is prepared, and the side frame 12, the down tube 13 and the vertical pipe 25 are brought into contact with each other. The flat left and right end portions of the flat plate 25 'are punched out so that the surface b becomes a developed shape b', the flat plate 25 'is formed into a cylindrical body, and then the butted portions 25a' and 25a 'are welded together. It is a thing. The vertical pipe 25 is formed with a jig hole 25b and a drain hole 25c. The holes 25b and 25c are formed simultaneously with the punching of both end portions of the flat plate 25 '. Of course, it is possible to prepare a plate having a width wider than the circumferential length a as the flat plate 25 'and punch it into the dimension a simultaneously with the punching of the left and right end portions. The horizontal pipe 26 is manufactured in the same manner as the vertical pipe 25.

  Next, the function and effect of this embodiment will be described. In the vehicle body frame 2 of the present embodiment, a main frame 11 is connected to the upper part of the head pipe 5, a pair of left and right side frames 12, 12 extending linearly rearward is connected to the rear end of the main frame 11, and When a pair of left and right down tubes 13 are connected to the lower part of the head pipe 5 and the bent portion 13c of the down tube 13 and the rear end portion 12a of the side frame 12 are connected by the suspension bracket 14, it is used in a large scooter. The rigidity of the body frame can be ensured.

  In addition, since one main frame 11 is connected to the head pipe 5, an empty space can be secured around the head pipe as compared with the case where two main frames are connected, thereby providing a storage portion in the leg shield 7. The volume of can be increased. Further, since the footrest part is formed by the straight part of the left and right side frames 12 and the straight part 13b of the left and right down tubes 13, a large-capacity storage box 167 can be arranged in the tunnel part of the footboard 8.

  Since the bent portions of the side frame 12 and the down tube 13 are connected by the vertical pipe 25, the frame rigidity can be further improved. Further, the suspension link 17 is connected to the upper part of the connection part of the side frame 12 of the suspension bracket 14, the compression rod 22 is connected to the lower part, and the power unit 3 is supported by the connection part therebetween. 14, a triangular suspension structure is formed, and the support rigidity of the power unit 3 can be improved.

In addition, since a rubber bush 24a is interposed between the cylindrical members 22b and 22c and the bolt 23 and the pivot shaft 20, a change in the behavior of the power unit due to driving and braking is suppressed while improving vibration isolation. it can.

  In the manufacturing method of the vertical pipe 25 of the present embodiment, both end portions of the flat plate 25 ′ having the circumferential development dimension a of the vertical pipe 25 are formed on the contact surfaces b of the side frame 12, the down tube 13 and the vertical pipe 25. After the punched shape b ′ is punched and the flat plate 25 ′ is formed in a cylindrical shape, the butted portions 25a ′ are welded to each other. The mating surface accuracy at the time of butt-welding to the tube 13 can be improved, and the dimensional accuracy at the time of attachment can be improved as compared with the case where the end surface of a conventional pipe is cut to form a curved surface. Further, since the jig hole 25b and the water drain hole 25c are formed simultaneously with the punching of the flat plate 25 ', the conventional drilling process can be made unnecessary and the manufacturing cost can be reduced.

1 is a left side view of a power unit support structure of a scooter type motorcycle according to an embodiment of the present invention. It is a left view which shows the suspension part of the power unit of the said Example. It is the III-III sectional view taken on the line of FIG. It is a side view which shows the vertical pipe of the said Example. It is process drawing which shows the manufacturing method of the said vertical pipe. It is an expanded view of the said vertical pipe. It is a figure which shows the conventional general power unit support structure.

Explanation of symbols

1 scooter type motorcycle 2 vehicle body frame 3 swing type power unit 4 sheets 5 head pipe 14 suspension bracket
17 Suspended links
20 Pivot shaft
20a Pivot shaft protrusion 22 Compression rod
22a Bar-shaped member
22b Cylindrical member at one end
22c Cylindrical member at the other end
23 volts
24a Rubber bush

Claims (4)

In the power unit support structure for a scooter type motorcycle supports a swing type power unit by a body frame having a low-floor footrest portion between the head pipe and the seat, connects one end of the suspension link to the vehicle body frame, Furthermore , one end of the compression rod is connected to the lower part from the connection position of the suspension link, and the power unit is pivotally supported by a pivot shaft inserted from one side in the vehicle width direction to the other end of the suspension link. A power unit support structure for a scooter type motorcycle, characterized in that an end is connected to a projecting portion projecting to the other side in the vehicle width direction of the pivot shaft .   The power unit support structure for a scooter type motorcycle according to claim 1, wherein only one compression rod is provided. 3. The compression rod according to claim 1, wherein a cylindrical member is connected to both ends of the rod-shaped member, the cylindrical member at one end is connected to the body frame via a bolt, and the cylindrical member at the other end is connected to the suspension member. A power unit support structure for a scooter type motorcycle, wherein the power unit support structure is connected to a link via the pivot shaft . Oite to claim 3, the one end, the power unit support structure of Sutakuta type motorcycle, wherein a rubber bushing is interposed between the cylindrical member and the bolt, the pivot axis of the other end.

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