JP2012066760A - Motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily weld a sub-pipe to a pivot plate in a motorcycle.SOLUTION: The motorcycle includes a mono-backbone frame 17, pivot plates 60, 60 provided in rear parts of the mono-backbone frame 17, and a pivot shaft 22 piercing the pivot plates 60, 60 and supporting a rear swing arm. The pivot shaft 22 includes a pivot collar 63, and sub-pipe front parts 21A, 21A extending toward a vehicle rear direction from the pivot shaft 22 are welded to the pivot collar 63. The pivot plates 60, 60 are provided with first notches 71, 71 extending in a vehicle fore and aft direction, the sub-pipe front parts 21A, 21A are fit in a longitudinal direction in the first notches 71, 71, and sub-pipes 21, 21 and the pivot plates 60, 60 are welded in peripheral edges 71B, 71B of the first notches 71, 71.

Description

  The present invention relates to a motorcycle including a pivot plate.

  Conventionally, in a motorcycle, a pipe-shaped sub-pipe (rail stay) that supports left and right seat rails is provided with a pair of left and right pivot plates at the rear of a mono backbone frame as a main frame extending rearward from the head pipe. A structure is known in which the outer surface of the pivot plate is in contact with the outer surface of the pivot plate (see, for example, Patent Document 1).

JP 2008-115761 A

However, in the conventional motorcycle, the sub pipe is attached so that the inner surface of the pipe-shaped sub pipe contacts the outer surface of the pivot plate, and the contact surface between the sub pipe and the pivot plate is the inner surface of the sub pipe. Therefore, there is a problem that it is difficult to weld the sub pipe to the pivot plate.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to enable a sub pipe to be easily welded to a pivot plate in a motorcycle.

To achieve the above object, the present invention provides a head pipe (16), a main frame (17) extending from a rear portion of the head pipe (16), and a pivot plate ( 60, 60) and a pivot shaft (22) that penetrates the pivot plate (60, 60) and supports the rear swing arm (14) so as to swing up and down. The pivot shaft (22) has a pivot collar. (63), in which the front ends (21A, 21A) of the sub pipes (21, 21) extending from the pivot shaft (22) toward the rear of the vehicle are welded to the pivot collar (63), The pivot plate (60, 60) is provided with a first notch (71, 71) extending in the vehicle front-rear direction. The front ends (21A, 21A) of the sub pipes (21, 21) are fitted in the portions (71, 71) in the longitudinal direction, and at the peripheral edges (71B, 71B) of the first notches (71, 71). The sub pipes (21, 21) and the pivot plates (60, 60) are welded.
According to this configuration, the first notch extending in the vehicle front-rear direction is provided on the pivot plate, the front end of the sub pipe is fitted in the first notch in the longitudinal direction, and the periphery of the first notch is Since the sub-pipe and the pivot plate are welded and the periphery of the first notch is in a position where it can be easily welded, the sub-pipe can be easily welded to the pivot plate. Further, the pivot plate can be reduced in weight by the first cutout portion.

In the above configuration, the welding of the peripheral edges (71B, 71B) of the first notches (71, 71) is performed on the outer side in the vehicle width direction from the radial center (C) of the sub pipes (21, 21). May be.
In this case, since the welding of the periphery of the first notch is performed on the outer side in the vehicle width direction than the center in the radial direction of the sub-pipe, welding at the periphery of the first notch is further facilitated.

The pivot plates (60, 60) are provided as a pair of left and right, and a pivot plate rear surface portion (61) for connecting rear ends of the pair of left and right pivot plates (60, 60) is provided. 61) is provided with second notches (72, 72) in which the front ends (21A, 21A) of the sub pipes (21, 21) are fitted in the radial direction, and the second notches (72, 72). The sub pipes (21, 21) and the pivot plates (60, 60) may be welded at the peripheral edges (72A, 72A).
In this case, the sub-pipe can be positioned by the second notch portion on the rear surface portion of the pivot plate, and positioning during welding is facilitated.

Furthermore, it is good also as a structure by which the notch (80, 80) is formed in the said front end (21A, 21A) of the said sub pipe (21, 21) located inside the said pivot plate (60, 60).
In this case, the weight of the sub pipe can be reduced by the notch at the front end of the sub pipe located inside the pivot plate.
The rear swing arm (14) has a pair of left and right arm portions (7, 7) extending in the front-rear direction, and each of the left and right arm portions (7, 7) is a pair of left and right sub-pipes (21 , 21) may be provided outside in the vehicle width direction.
In this case, in the configuration in which the arm portion of the rear swing arm is provided on the outer side in the vehicle width direction than the sub pipe, the sub pipe is provided in the first cutout portion. It can also be arranged inward, and the freedom of layout of the rear swing arm can be improved.

In the motorcycle according to the present invention, the front end of the sub-pipe is fitted in the first notch portion of the pivot plate in the longitudinal direction, and the sub-pipe and the pivot plate are welded at the periphery of the first notch portion. Since the peripheral edge of the notch is in a position where it can be easily welded, the sub-pipe can be easily welded to the pivot plate. Further, the pivot plate can be reduced in weight by the first cutout portion.
Moreover, since welding of the periphery of the 1st notch part is made in the vehicle width direction outer side rather than the radial direction center of a subpipe, welding becomes still easier.

Further, the sub-pipe can be positioned by the second notch portion on the rear surface portion of the pivot plate, and positioning during welding is facilitated.
Furthermore, the weight of the sub pipe can be reduced by the notch at the front end of the sub pipe located inside the pivot plate.
Further, since the sub-pipe is provided in the first cutout portion, the left and right arm portions can be arranged close to the inner side in the vehicle width direction, and the degree of freedom of layout of the rear swing arm can be improved.

1 is a left side view of a motorcycle according to an embodiment of the present invention. It is a left view of a vehicle body frame. It is the top view which looked at the body frame from the upper part. It is the figure which looked at the body frame from back. It is an enlarged view of the vicinity of the pivot frame in FIG. It is the perspective view which looked at the pivot frame from the front side. It is the enlarged view which looked at the vicinity of the pivot frame from the vehicle back. It is the perspective view which looked at the vicinity of a pivot frame from the vehicle front side. In the modification, it is the top view which looked at the circumference of a pivot frame from the upper part.

Hereinafter, a motorcycle according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the up / down, front / rear, and left / right directions are directions seen from the driver of the vehicle.
FIG. 1 is a left side view of a motorcycle 1 according to an embodiment of the present invention.
In the motorcycle 1, an engine 12 is disposed at the front and rear center sides of a body frame 11, a front fork 13 is steerably supported at the front end of the body frame 11, and can swing up and down at a lower portion of the rear portion of the body frame 11. This is a saddle-ride type vehicle in which the rear swing arm 14 is supported.

  The vehicle body frame 11 includes a head pipe 16 that supports the front fork 13 in a steerable manner, a mono backbone frame 17 (main frame) as a main frame that extends rearward and downward from the rear portion of the head pipe 16, and a rear portion from the lower portion of the head pipe 16. A down frame 18 extending downward, a pivot frame 19 provided at the lower part of the mono backbone frame 17, a pair of left and right seat rails 20 extending from the mono backbone frame 17 to the rear of the vehicle, and each seat extending rearward and upward from the pivot frame 19 A pair of left and right sub pipes 21 connected to the rail 20 are provided.

The pivot frame 19 is provided with a pivot shaft 22 that penetrates the pivot frame 19 in the vehicle width direction, and the rear swing arm 14 is pivotally supported by the pivot shaft 22.
The rear swing arm 14 has a pair of left and right arm portions 7 extending in the front-rear direction, and is configured by connecting the left and right arm portions 7 with a cross member 7A provided at the front portion.
A pivot shaft 22 passes through the front end portion 14A of the rear swing arm 14, and the rear swing arm 14 extends rearward with the front end portion 14A serving as a swing center. The rear wheel WR as a driving theory is supported at the rear end of the rear swing arm 14.
The rear cushion 32 that elastically supports the rear swing arm 14 has an upper end connected to an upper support portion 24A provided on the mono backbone frame 17 and a lower end connected to a lower support portion 24B provided on the cross member 7A.

The steering handle 33 is attached to the upper part of the front fork 13, and the front wheel WF is attached to the lower part of the front fork 13. A fuel tank 35 for storing fuel is disposed across the mono backbone frame 17. The fuel tank 35 includes a fuel pump 37 that supplies fuel to the engine 12.
The occupant seat 36 provided across the left and right seat rails 20 is disposed above the seat rail 20 continuously to the rear end of the fuel tank 35 and extends rearward along the seat rail 20.

The engine 12 is an air-cooled four-cycle single-cylinder engine, and includes a crankcase 41 in which a crankshaft (not shown) extending in the vehicle width direction is accommodated, and a cylinder extending slightly upward from the front portion of the crankcase 41. 42. A transmission 45 is integrally provided at the rear portion of the crankcase 41.
Further, the engine 12 includes a front hanger 46 connected to the front portion of the crankcase 41 and fastened to the lower end of the down frame 18, and the rear portion of the crankcase 41 is connected to the support portion 19 </ b> A of the front portion of the pivot frame 19. Fastened and supported by the body frame 11.

A drive sprocket 38 that outputs the rotation of the engine 12 is provided on the left side surface of the rear portion of the crankcase 41. A driven sprocket 39 is provided on the left side surface of the rear wheel WR, and the rear wheel WR is driven by a chain 40 wound around the drive sprocket 38 and the driven sprocket 39.
An exhaust pipe 49 is connected to the front portion of the cylinder 42, and the exhaust pipe 49 extends downward from the front of the crankcase 41 to the right rear side of the vehicle, and at the rear end of the exhaust pipe 49 on the right side surface of the rear wheel WR. A located muffler 50 is connected.

  An air cleaner case 53 that takes in air to be supplied to the engine 12 is provided below the seat 36, and the air cleaner case 53 is connected to a throttle body 52 below the fuel tank 35 via a connecting tube 54. The throttle body 52 includes an injector (not shown) and is connected to an intake port at the rear of the cylinder 42.

  The motorcycle 1 has a vehicle body cover 59 made of resin. The vehicle body cover 59 covers a front cowl 55 covering the front of the head pipe 16, a shroud 56 covering the front side of the mono backbone frame 17, and a mono backbone frame. 17 and a side cover 57 that covers the air cleaner case 53, and a rear cover 58 that covers the rear part of the seat rail 20. A headlight 9 is provided on the front cowl 55. A front fender 8 is provided above the front wheel WF.

FIG. 2 is a left side view of the vehicle body frame 11. FIG. 3 is a plan view of the body frame 11 as viewed from above. FIG. 4 is a view of the vehicle body frame 11 as seen from the rear. Here, in FIG. 4, the rear swing arm 14 is illustrated by a two-dot chain line.
As shown in FIGS. 2 to 4, the mono backbone frame 17 is a pipe-shaped frame having a circular cross section provided as a single piece, and includes a main pipe 17 </ b> A extending downward from the upper part of the rear surface of the head pipe 16, and the main pipe. The center pipe 17B is bent downward from the rear portion of 17A and extends downward.
The down frame 18 extends downward from the lower part of the rear surface of the head pipe 16, and a reinforcing plate 23 that connects the mono backbone frame 17 and the down frame 18 at the front part is provided behind the head pipe 16.

The seat rails 20 and 20 are pipe-shaped frames having a circular cross section, and are connected to the rear portion of the main pipe 17A and extend substantially horizontally, and extend rearward from the front rail portions 20A and 20A. The rear rail portions 20B and 20B extend. The front rail portions 20A and 20A extend from the rear portion of the main pipe 17A so that the distance between them gradually increases in the vehicle width direction, and the rear rail portions 20B and 20B extend to the rear portion in parallel with each other.
The front rail portions 20A and 20A are reinforced by cross plates 25A and 25B that are spanned between the front and rear portions of the front rail portions 20A and 20A, respectively. Further, the rear rail portions 20B and 20B are reinforced by a rear cross plate 25C spanned between the rear rail portions 20B and 20B.

  The pivot frame 19 is a substantially box-shaped frame formed by welding a plurality of plates, and is connected to the lower portion of the center pipe 17B. A lower cross pipe 26 that penetrates the pivot frame 19 in the vehicle width direction is provided below the pivot frame 19. A pivot shaft 22 that penetrates the pivot frame 19 in the vehicle width direction is provided at the upper and lower intermediate portions of the pivot frame 19.

The subpipes 21 and 21 are pipe-shaped frames having a circular cross section, and are connected to the pivot frame 19 and extend rearwardly to the subpipe front portions 21A and 21A (front end of the subpipe) and the subpipe front portions 21A and 21A. Sub-pipe rear portions 21B and 21B that extend rearward and are connected to the rear portions of the front rail portions 20A and 20A. The sub pipes 21 and 21 are connected to the lower surfaces of the seat rails 20 and 20 and support the seat rails 20 and 20 from below.
The sub-pipe front portions 21A and 21A extend substantially parallel to each other, and the sub-pipe rear portions 21B and 21B extend from the rear portions of the sub-pipe front portions 21A and 21A so that the distance therebetween gradually increases in the vehicle width direction. On the lower surfaces of the sub-pipe rear portions 21B and 21B, pillion steps 27 and 27 on which the passenger sitting on the rear side of the driver puts his / her foot on the rear portion of the occupant seat 36 are provided.

FIG. 5 is an enlarged view of the vicinity of the pivot frame 19 in FIG. FIG. 6 is a perspective view of the pivot frame 19 as viewed from the front side. Here, FIG. 6 shows a state before the pivot shaft 22 is fixed to the pivot frame 19.
As shown in FIGS. 4 to 6, the pivot frame 19 includes a pair of left and right pivot plates 60, 60 in the vehicle width direction, and a rear connection plate 61 (pivot) that connects the rear ends of the left and right pivot plates 60, 60. Plate rear surface portion), and these three plates are welded together.

The pivot plates 60, 60 are plates that are substantially symmetrically arranged so as to face each other, and have a plurality of openings. Support portions 19A are respectively formed above and below the front portions of the pivot plates 60, 60, and a cross pipe support hole 62 to which the lower cross pipe 26 is connected is formed behind the lower support portion 19A.
In the upper and lower intermediate portions of the pivot plates 60, 60, first cutout portions 71, 71 each having a long hole shape formed in a side view extending rearward and rearward are formed. The front edges 71A of the first notches 71 and 71 are formed in a substantially arc shape so that the cylindrical pivot shaft 22 is fitted, and the rear edges are open ends. In addition, upper and lower peripheral edges 71B and 71B (peripheries of the first notch part) of the first notch parts 71 and 71 are formed substantially parallel to each other.
The upper edges 60A of the rear portions of the pivot plates 60, 60 are formed so as to incline backward and downward.

The rear connection plate 61 includes a flat plate portion 61A that constitutes the lower half of the rear surface of the pivot frame 19, and a frame connection plate portion 61B that bends and extends along the upper edge 60A of the pivot plates 60 and 60 from the upper portion of the flat plate portion 61A. And have.
Second notches 72 and 72 (see FIG. 6) that open continuously from the rear edges of the first notches 71 and 71 are formed on the left and right edges of the frame connecting plate 61B in the rear connection plate 61. Each is formed. The second notches 72 and 72 are notches extending inward in the vehicle width direction, and are substantially arcuate arc-shaped peripheral edges 72A and 72A (as viewed from the rear so that the cylindrical sub-pipe 21 can be fitted. (Periphery of the second notch).
Sub pipe connection holes 70 and 70 are formed by the first cutout portions 71 and 71 and the second cutout portions 72 and 72 connected to the first cutout portions 71 and 71, respectively. It is connected to the pivot frame 19 by being fitted into the connecting holes 70 and welded.

  In the frame connecting plate portion 61B, a main frame connecting hole 73 into which the center pipe 17B of the mono backbone frame 17 is fitted is formed at the center in the vehicle width direction between the left and right second cutout portions 72, 72. . The center pipe 17 </ b> B is welded to the rear connection plate 61 by a weld bead 73 </ b> A that goes around the substantially circular periphery of the main frame connection hole 73 with the outer peripheral surface fitted in the main frame connection hole 73.

The pivot shaft 22 has a cylindrical pivot collar 63 that penetrates the pivot frame 19 in the vehicle width direction, and a shaft body 64 (see FIG. 4) that extends in the vehicle width direction through the inner diameter portion 63A of the pivot collar 63. is doing. Both end portions 64A and 64A of the shaft body 64 protrude from the left and right ends of the pivot collar 63 and pivotally support the front end portion 14A of the rear swing arm 14. Specifically, the left and right arm portions 7 of the rear swing arm 14 are provided on the outer side in the vehicle width direction than the pair of left and right sub pipes 21 and 21, and the rear swing arm 14 moves the pivot frame 19 in the vehicle width direction. It is arrange | positioned so that it may pinch from the outer side.
The pivot shaft 22 is welded to the first notches 71 and 71 and fixed to the pivot frame 19 in a state where the pivot collar 63 is stretched between the front edges 71A and 71A of the first notches 71 and 71. Is done.

FIG. 7 is an enlarged view of the vicinity of the pivot frame 19 as viewed from the rear of the vehicle. FIG. 8 is a perspective view of the vicinity of the pivot frame 19 as seen from the front side of the vehicle.
As shown in FIGS. 5 and 8, the pivot collar 63 is formed along each front edge 71 </ b> A in a state where the outer peripheral surfaces of both ends are fitted to the front edges 71 </ b> A of the first notches 71 and 71. Welded by a weld bead 81.

  As shown in FIGS. 5, 7, and 8, the weld bead 73 </ b> A that welds the center pipe 17 </ b> B to the pivot frame 19 is on the frame connecting plate portion 61 </ b> B that intersects with the center pipe 17 </ b> B inclined downward in a side view. For example, the length of the weld bead 73A is ensured to be large as compared with the case where the weld bead is provided orthogonal to the center pipe 17B. For this reason, the weld strength of the center pipe 17B can be improved, and the weight of the upper portion of the pivot frame 19 can be reduced by the amount of tilting the frame connecting plate portion 61B downwardly, and the weight can be reduced. The center pipe 17B is welded by a weld bead 82 provided along the front edge 17C in a state where the front edge 17C (see FIG. 8) at the lower end is abutted against the upper surface of the pivot collar 63.

  As shown in FIGS. 5 to 8, the sub pipes 21 and 21 have the sub pipe front portions 21A and 21A fitted in the first notches 71 and 71 in the longitudinal direction, and the sub pipe front portions 21A and 21A are the second pipes 21A and 21A. The pipes are fitted in the notches 72 and 72 in the radial direction, and are welded to the sub pipe connection holes 70 and 70 with the front ends of the sub pipe front parts 21A and 21A being abutted against the rear surface of the pivot collar 63.

  Specifically, the sub-pipe front portions 21A, 21A are formed by welding beads 83 formed between the peripheral edges 71B, 71B and the outer peripheral surface 21D along the upper and lower peripheral edges 71B, 71B of the first notch 71. 1 is welded to the notches 71, 71. Further, the front ends of the sub-pipe front portions 21A and 21A have an arcuate tip 21C along the outer peripheral surface of the pivot collar 63, and the weld collar 84 formed along the periphery of the arcuate tip 21C forms the pivot collar 63. Welded. In the second cutout portions 72, 72, the sub-pipe front portions 21A, 21A are welded by a weld bead 85 formed between the arc-shaped peripheral edge 72A and the outer peripheral surface 21D.

The weld beads 83, 84, 85 for welding the sub pipes 21, 21 to the pivot frame 19 are located on the outer surface of the pivot frame 19 and are welded from the outer direction of the pivot frame 19.
As shown in FIG. 7, the sub pipes 21 and 21 have an axis C (radial center) extending through the radial center, and the sub pipe front portions 21 </ b> A and 21 </ b> A have an axis C with respect to the sub pipe connection holes 70 and 70. Is fitted in the radial direction to a depth located inside the plate surfaces of the pivot plates 60, 60 in the vehicle width direction. That is, the sub-pipe front portions 21A and 21A have a portion of more than half of the radial direction entering the sub-pipe connection holes 70 and 70 in a cross-sectional view perpendicular to the axis C, and the portions protruding outside the pivot plates 60 and 60 are The shape is smaller than a semicircle. Thereby, when welding the sub-pipe front portions 21A, 21A at the first cutout portions 71, 71, the weld beads 83, 84 are formed on the outer side in the vehicle width direction with respect to the axis C. Therefore, the pivot plates 60, 60 The weld beads 83 and 84 can be easily formed from the outside.
However, as in the prior art, for example, when the sub pipes 21 and 21 are simply brought into contact with the outer surfaces of the pivot plates 60 and 60 without forming the sub pipe connection holes 70 and 70, and the contact portions are welded, welding is performed. A bead will be located inside the vehicle width direction beyond the axis C, and welding work will become difficult.

Here, a procedure for welding the mono backbone frame 17 and the sub pipes 21 and 21 to the pivot frame 19 will be described.
First, the pivot plates 60 and 60 and the rear connection plate 61 are welded together, and the pivot collar 63 is provided between the pivot plates 60 and 60 and welded by the weld beads 81, whereby the pivot frame 19 is formed.
Next, the center pipe 17B of the mono backbone frame 17 that is welded integrally with the head pipe 16 and the down frame 18 is fitted into the main frame connecting hole 73 of the pivot frame 19, and in this state, the weld bead 82 and the weld bead 73A. Are welded, and the mono backbone frame 17 is fixed to the pivot frame 19.

Next, the sub pipes 21 and 21 that are welded integrally to the seat rails 20 and 20 are fitted into the sub pipe connection holes 70 and 70 of the pivot frame 19. At this time, the sub pipes 21 and 21 are positioned in the longitudinal direction with the arcuate tip 21C abutted against the pivot collar 63, and the outer peripheral surface 21D is fitted in the arcuate peripheral edge 72A and positioned in the circumferential direction. . For this reason, the subpipes 21 and 21 can be easily positioned, and the workability of welding can be improved.
Subsequently, the sub pipe front portions 21A and 21A are welded to the pivot frame 19 by the weld beads 83, 84, and 85 while being positioned in the sub pipe connection holes 70 and 70. Further, in parallel with the welding of the sub pipe front portions 21A and 21A, the front portions of the seat rails 20 and 20 are welded to the rear portion of the main pipe 17A.

  In the present embodiment, the sub-pipe front portions 21A and 21A are fitted into the first cutout portions 71 and 71 and the second cutout portions 72 and 72, and welding is performed along the peripheral edges 71B and 71B and the arc-shaped peripheral edge 72A. Since the sub-pipes 21 and 21 are welded to the pivot plates 60 and 60 by the beads 83 and 85, the length of the weld bead is longer than that in a configuration in which the sub-pipes 21 and 21 are simply brought into contact with the side surfaces of the pivot plates 60 and 60 for welding. The sub pipes 21 and 21 can be firmly welded to the pivot frame 19.

  As described above, according to the embodiment to which the present invention is applied, the first cutout portions 71, 71 extending in the vehicle front-rear direction are provided in the pivot plates 60, 60, and the subpipe front portions of the subpipes 21, 21 are provided. 21A and 21A are fitted in the first cutout portions 71 and 71 in the longitudinal direction, and the sub pipes 21 and 21 and the pivot plates 60 and 60 are welded at the peripheral edges 71B and 71B of the first cutout portions 71 and 71, Since the peripheral edges 71 </ b> B and 71 </ b> B are easily welded, the sub-pipes 21 and 21 can be easily welded to the pivot plates 60 and 60. Further, since the pivot plates 60, 60 are cut out by the first cutout portions 71, 71, the pivot plates 60, 60 can be reduced in weight.

In addition, since the welding that forms the weld bead 83 at the peripheral edges 71B and 71B of the first notches 71 and 71 is performed on the outer side in the vehicle width direction than the axis C of the subpipes 21 and 21, the first notches Welding at the peripheral edges 71B and 71B of 71 and 71 is further facilitated.
Further, since the sub pipes 21 and 21 can be positioned in the radial direction by the arc-shaped peripheral edges 72A and 72A of the second cutout portions 72 and 72 of the rear connection plate 61, positioning during welding is facilitated.

  Further, in the configuration in which the left and right arm portions 7 and 7 of the rear swing arm 14 are provided outside the sub pipes 21 and 21 in the vehicle width direction, the sub pipes 21 and 21 are provided in the first cutout portions 71 and 71. Accordingly, the left and right arm portions 7, 7 can be arranged closer to the inner side in the vehicle width direction, and the shape of the rear swing arm 14 and the degree of layout can be improved.

In addition, the said embodiment shows the one aspect | mode which applied this invention, Comprising: This invention is not limited to the said embodiment.
In the above-described embodiment, the sub pipes 21 and 21 have been described as being fitted inward to a depth at which the axis C is located on the inner side of the plate surfaces of the pivot plates 60 and 60 in the vehicle width direction. It is not limited, and the sub pipes 21 and 21 may be fitted to the first notches 71 and 71, respectively. Further, the sub-pipes 21 and 21 are fitted inside the first notches 71 and 71 to a depth at which the axis C is at least coincident with the plate surfaces of the pivot plates 60 and 60 in the vehicle width direction. This makes the position easier to weld and facilitates the welding operation. Of course, other detailed configurations of the motorcycle 1 can be arbitrarily changed.

[Modification]
A modification of the embodiment to which the present invention is applied will be described below with reference to FIG. In this modification, the same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. The modification is different from the above embodiment in that the front ends of the sub-pipes 21 and 21 are notched.

FIG. 9 is a plan view of the periphery of the pivot frame 19 as viewed from above in the modified example.
As shown in FIG. 9, the sub-pipe front portions 21A and 21A are welded from the outside by the weld beads 83, 84, and 85. Therefore, portions of the sub-pipe front portions 21A and 21A located inside the pivot frame 19 are sub-pipe 21. , 21 are not contributed to welding for fixing to the pivot frame 19. Therefore, in the modified example, the weight reduction is achieved by providing the notches 80 and 80 in the portions located inside the pivot frame 19 in the sub pipe front portions 21A and 21A.

The notches 80 and 80 are formed by cutting the front ends of the sub-pipe front portions 21A and 21A obliquely so that the front ends of the sub-pipe front portions 21A and 21A are tapered. Specifically, the notches 80 and 80 are formed in portions located inside the pivot frame 19 with respect to the weld beads 83, 84 and 85.
As described above, by providing the notches 80 and 80 in the portions that do not contribute to the welding for fixing the sub pipes 21 and 21 to the pivot frame 19, it is possible to reduce the weight while maintaining the welding strength.

  In this modification, the notches 80 and 80 are formed by cutting the front ends of the sub pipe front portions 21A and 21A obliquely so that the front ends of the sub pipe front portions 21A and 21A have a tapered shape. Although described, the present invention is not limited to this. For example, the notches 80 and 80 may be formed by cutting all the portions located inside the pivot frame 19 in the sub pipe front portions 21A and 21A.

DESCRIPTION OF SYMBOLS 1 Motorcycle 7,7 Arm part 14 Rear swing arm 16 Head pipe 17 Mono backbone frame (main frame)
21,21 Subpipe 21A, 21A Subpipe front (front end of subpipe)
22 Pivot shaft 60, 60 Pivot plate 61 Rear connection plate (Pivot plate rear part)
63 Pivot collar 71, 71 First notch 71B, 71B Periphery (periphery of first notch)
72, 72 Second notch 72A, 72A Arc-shaped peripheral edge (periphery of the second notch)
80, 80 Notch C-axis (radial center)

Claims (5)

A head pipe (16), a main frame (17) extending from a rear portion of the head pipe (16), a pivot plate (60, 60) provided at a rear portion of the main frame (17), and the pivot plate (60 , 60) and a pivot shaft (22) that supports the rear swing arm (14) so as to be swingable up and down. The pivot shaft (22) is provided with a pivot collar (63), and the pivot shaft ( 22) In the motorcycle in which the front ends (21A, 21A) of the sub pipes (21, 21) extending toward the rear of the vehicle from 22) are welded to the pivot collar (63),
The pivot plate (60, 60) is provided with a first notch (71, 71) extending in the vehicle front-rear direction, and the sub-pipe (21, 71) is provided in the first notch (71, 71). 21) The front ends (21A, 21A) are fitted in the longitudinal direction, and the sub-pipes (21, 21) and the pivot plates (71B, 71B) at the peripheral edges (71B, 71B) of the first notches (71, 71) 60, 60) are welded to each other.   The welding of the peripheral edge (71B, 71B) of the first notch (71, 71) is performed on the outer side in the vehicle width direction from the radial center (C) of the sub pipe (21, 21). The motorcycle according to claim 1. The pivot plates (60, 60) are provided in a pair of left and right, and provided with a pivot plate rear surface portion (61) for connecting rear ends of the pair of left and right pivot plates (60, 60),
The pivot plate rear surface portion (61) is provided with second notches (72, 72) in which the front ends (21A, 21A) of the sub pipes (21, 21) are fitted in the radial direction, and the second notches are provided. The motorcycle according to claim 1 or 2, wherein the sub-pipe (21, 21) and the pivot plate (60, 60) are welded to each other at a peripheral edge (72A, 72A) of the portion (72, 72). .   The notches (80, 80) are formed in the front ends (21A, 21A) of the sub-pipes (21, 21) located inside the pivot plates (60, 60). The motorcycle according to any one of 3 above.   The rear swing arm (14) has a pair of left and right arm portions (7, 7) extending in the front-rear direction, and each of the left and right arm portions (7, 7) is a pair of the left and right sub pipes (21, 21). The motorcycle according to any one of claims 1 to 4, wherein the motorcycle is provided on the outer side in the vehicle width direction with respect to the vehicle.

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