JP2010036615A - Swing arm for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress variations in quality by simplifying processing, since a structure of a conventional art in which a slit is formed at a rear end of a rear swing arm and an end-piece plate material is sandwiched therebetween to integrate the rear swing arm requires much effort in formation and is liable to cause variations in quality. <P>SOLUTION: A rear edge of an arm 15 is press-molded into a near-crank shape to form a crank-shaped portion 30, an insertion space 33 formed between an outer vertical wall 31 and an inner vertical wall 32 is made narrower, and a rib-like upper wall 34 and a rib-like lower wall 35 are projected from the top and the bottom thereof. A tabular member is press-molded into an end-piece 16 in which an insertion portion 40 inserted into the insertion space 33, slits 47 and 48 fitted into the upper wall 34 and the lower wall 35, respectively, an upper arm 41 to contact with the top of the upper wall 34, and a lower arm 42 to contact with the lower wall 35 are integrally formed. The insertion portion 40 is inserted into the insertion space 33, and a joint between the end piece 16 and each rear edge of the outer vertical wall 31 and the inner vertical wall 32 is welded to each other to be integrated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a vehicle swing arm used for supporting a rear wheel of a motorcycle or the like, and more particularly to a vehicle equipped with an end piece for supporting an axle.

A slit in the vertical direction is provided at the rear end of the square pipe arm that constitutes the swing arm, and the front end of the flat end piece is inserted into this slit and welded, and the rear end of the axle hole provided in this end piece. A vehicle swing arm is known in which a rear wheel is supported on an arm portion through an end piece through an axle of a wheel (see Patent Document 1).
Japanese Utility Model Publication No. 5-41996

In the case of the conventional example, when providing a slit at the rear end of the arm part, a large slit having a substantially V shape is formed in advance, and then the side wall is bent so that the slit width is about the plate thickness of the end piece. Since it is necessary to make the rear end thinner, the processing of the swing arm becomes complicated. In particular, since the slit has an L shape at the front and a substantially V shape that expands toward the rear, the slit processing becomes complicated.
Further, since the end pieces are inserted into the slits provided in the upper wall and the lower wall at the rear end portion of the square pipe, there is a problem of maintaining the machining accuracy in order to align the upper and lower slit positions.
Furthermore, since the end piece supports the rear axle with the axle hole, it receives a large upward force, but in the conventional example, the force is received only at the welded part, so welding is performed to increase the rigidity of the welded part. It is necessary to increase the width.
Therefore, the present application aims to solve such problems.

In order to solve the above problems, the invention according to claim 1 relating to a vehicle swing arm is inserted into a pipe arm portion that swings around a front end as a fulcrum and an opening provided at the rear end of the arm portion and welded. In a vehicle swing arm that includes a plate-like end piece coupled to each other and supports the rear wheel through the axle of the rear wheel through an axle hole provided in the end piece,
While press-molding the rear end portion of the arm portion to reduce the opening area,
An insertion portion to be inserted into the rear end opening portion of the arm portion and an upper arm portion that comes into contact with an upper wall of the rear end portion of the arm portion from above are provided at the front portion of the end piece.

  According to a second aspect of the present invention, in the first aspect, the end piece includes a lower arm portion that comes into contact with a lower wall of the rear end portion of the arm portion from below, and a contact area between the lower wall and the lower arm portion. The contact area between the upper wall and the upper arm is larger than that.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the upper arm portion protrudes longer than the insertion portion.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the insertion portion has a width that decreases toward the front portion in a side view.

  According to a fifth aspect of the present invention, in the fourth aspect of the invention, the front portion of the insertion portion has a protruding portion that protrudes forward, and the protruding portion has an arc shape.

The invention of claim 6 is characterized in that, in the above-mentioned claim 2 or 3, there is a gap between the lower wall of the arm part and the lower part of the insertion part, and it opens toward the rear.

According to invention of Claim 1, since the part which attaches the end piece of an arm part was formed by press molding, a process becomes easy. Moreover, since the end piece is inserted into the opening that has been reduced by press molding of the arm portion, it is possible to suppress variations in quality compared to the case where the slits are provided separately on the upper wall and the lower wall, respectively. .
Furthermore, since the upper arm part that comes into contact with the upper wall of the rear end of the arm part is provided on the end piece, the upward force applied to the end piece can be received by the upper wall, and the welding width can be reduced. Thus, assembly processing by welding is facilitated.

  According to the invention of claim 2, since the lower arm portion is also provided, the force applied to the end piece can be received by the upper wall and the lower wall of the swing arm. For this reason, it becomes possible to make the whole welding width smaller, and the assembly process by welding becomes still easier. In addition, since a large force is applied to the end piece in the upward direction, the upward force can be effectively applied while avoiding an unnecessarily large end piece by extending the upper arm part and increasing the contact area. Can be received on the upper wall.

  According to the invention of claim 3, when the end piece is inserted into the rear end opening of the arm portion, the upper arm portion can be used as a guide for insertion by contacting the upper arm portion with the upper wall, and the end piece is attached to the swing arm. Work efficiency can be improved.

  According to the fourth aspect of the present invention, the width of the insertion portion of the end piece insertion portion decreases toward the front portion when viewed from the side, so that the insertion into the opening at the rear end of the arm portion is facilitated.

  According to the fifth aspect of the present invention, the front part of the insertion part is a projecting part that protrudes forward, and the projecting part has an arc shape. Therefore, the insertion part can be smoothly inserted into the opening at the rear end of the arm part. Therefore, the insertion into the opening becomes easier.

According to the sixth aspect of the present invention, the water that has entered the swing arm enters the gap between the lower portion of the insertion portion and the inner surface of the lower wall, travels along the lower wall, and is the rear end portion of the gap that is opened rearward. Since it is discharged to the outside, the gap between the lower part of the insertion part and the inner surface of the lower wall can be used effectively as a drainage passage, eliminating the need for a dedicated drainage hole as in the past, reducing the number of processing steps it can.

  An embodiment will be described below with reference to the drawings. FIG. 1 is a side view of a motorcycle according to the present embodiment, and FIG. 2 is a side view of a main part with a vehicle body cover removed. In these drawings, a head pipe 2 is provided at the front end of a vehicle body frame 1, and a handle shaft 3 is rotatably supported by the head pipe 2 and is rotated by a handle 4 attached to the upper end thereof. A front wheel 6 is supported on a lower end portion of a front fork 5 attached to the lower portion of the handle shaft 3.

The vehicle body frame 1 includes a main frame 7 that extends rearward and obliquely downward from the head pipe 2, and an engine 8 is supported below the main frame 7. An air cleaner 9 is provided in the vicinity of the head pipe 2 of the body frame 1 above the engine 8.
A rear frame 10 extending obliquely upward is provided above the rear end of the engine 8, and a seat 11 and a fuel tank 12 below the seat 11 are supported here. Reference numeral 29 in the drawing is a pair of left and right subframes connecting the middle portion of the main frame 7 and the upper portion of the rear frame 10 obliquely upward, and the subframe 29 and the rear frame 10 serve as a seat 11 and fuel below it. The tank 12 is supported.

  A pair of left and right pivot frames 13 are provided at the rear end of the main frame 7. A rear swing arm 14, which is a vehicle swing arm of the present invention, is provided by a pivot 13 a at a middle portion in the vertical direction. Each front end portion of the pair of left and right arm portions 15 is supported so as to be swingable in the vertical direction. The arm portion 15 is a square pipe made of iron or light alloy and having an appropriately long vertical cross section, and its front end swings around a fulcrum (pivot 13a), and a rear swing arm 14 is similarly mounted on each rear end. A rear wheel 18 is supported at the rear end of the rear swing arm 14 via a rear wheel axle 17 that is integrated with the constituting end piece 16 and supported between the left and right end pieces 16. An axle adjustment mechanism 20 that adjusts the position of the rear wheel axle 17 in the front-rear direction is provided at the rear end of the end piece 16.

  The rear wheel 18 is provided with a driven sprocket 21 coaxially with the rear wheel axle 17 and is driven by an output sprocket 23 of the main frame 7 via a chain 22. The chain 22 is accommodated and covered in a chain case 24. The chain case 24 is divided into upper and lower parts, which are arranged vertically with the arm portion 15 in between, and supported by the rear swing arm 14. The rear side of the support portion is supported by upper and lower attachment portions 25 and 26 provided on the end piece 16.

  Reference numeral 27 in the figure denotes a rear cushion unit, the lower end portion of which is attached to and supported by the end piece 16, and the upper end portion thereof is supported in the vicinity of the upper end portion of the rear frame 10. Reference numeral 28 denotes a loading platform. A rear portion of the rear frame 10 is disposed on the rear fender 19 below the loading platform 28.

  3 is an enlarged side view of the end piece 16 coupled to the rear end portion of the arm portion 15, FIG. 4 is a sectional view taken along line 4-4 in FIG. 3, and FIG. 5 is a sectional view taken along line 5-5 in FIG. As shown in these figures, the U-shaped portion 30 that is the rear end portion of the arm portion 15 that is the attachment portion of the end piece 16 is a substantially U-shape that opens outward (on the opposite side to the rear wheel 18). A portion corresponding to the vertical portion of the U-shape forms a pair of outer vertical wall 31 and inner vertical wall 32 facing each other with an interval in the left-right direction.

  An insertion space 33 is formed between the U-shaped portion 30 and the outer vertical wall 31. A portion corresponding to a laterally protruding portion above and below the U-shape has an upper wall 34 and a lower wall 35. The upper wall 34 and the lower wall 35 face each other in the vertical direction, respectively, protrude horizontally outward from the upper or lower end of the outer vertical wall 31 and function as reinforcing ribs. Further, since the U-shaped portion 30 is formed in a substantially U shape by recessing the outer vertical wall 31 by press molding, the width of the upper wall 34 and the lower wall 35 is the upper wall and lower wall of the arm portion 15. Is substantially the same as the width of the general surface and is constant in the front-rear direction, so that the appearance of the arm portion 15 including the U-shaped portion 30 can be improved.

  The end piece 16 inserts the insertion portion 40 formed at the front portion into the insertion space 33 and simultaneously fits the upper wall 34 and the lower wall 35 into slits (described later) formed above and below the insertion portion 40, The upper arm portion 41 and the lower arm portion 42 that are formed to protrude forward and downward from the upper and lower portions 40 are overlapped on the upper wall 34 and the lower wall 35, respectively, and the force applied from the rear wheel axle 17 to the end piece 16 from the upper arm portion 41. By transmitting to the contact portion of the upper wall 34 and similarly transmitting from the lower arm portion 42 to the contact portion of the lower wall 35, the force is received at the contact portions of the upper wall 34 and the lower wall 35. .

  The upper arm portion 41 and the lower arm portion 42 are welded to the upper wall 34 and the lower wall 35, respectively, and the rear end portions of the outer vertical wall 31 and the inner vertical wall 32 and the inner and outer surfaces of the end piece 16 that is the base portion of the insertion portion 40. The welded portion is integrally welded in the vertical direction. Reference numeral 43 (FIGS. 3 and 4) denotes a welded portion. In addition, as shown by 43a, the outer vertical wall 31 (and the inner vertical wall 32 or one of them) may be perforated and welded from the outside to be combined with the insertion portion 40 whose surface is in contact with the inside. it can. Reference numerals 43b and 43c denote welds of the upper arm portion 41 and the upper wall 34 and the lower arm portion 42 and the lower wall 35, respectively. If the contact length of the upper arm portion 41 and the upper surface of the upper wall 34 is b, and the contact length of the lower arm portion 42 and the lower surface of the lower wall 35 is c, then b> c.

  As shown in FIG. 5, the vertical width W1 on the base side of the insertion portion 40 is smaller than the vertical width W2 of the insertion space 33 (W1 <W2), and when the insertion portion 40 is inserted into the insertion space 33, a gap 45 is vertically formed. , 46 are formed. Further, as shown in FIG. 3, curved portions 49 and 50 are formed at the base portion of the insertion portion 40 (portion connecting to the upper arm portion 41 and the lower arm portion 42), and between the rear end portion of the U-shaped portion 30. A hole-like space is formed through the end piece 16 in the front and back direction in the figure. The spaces inside these curved portions 49 and 50 form spaces that communicate with the gaps 45 and 46. In particular, a portion that leads from the gap 46 on the lower wall 35 side to the bending portion 50 forms a drainage passage 51, and water that has entered the rear swing arm 14 passes through the drainage passage 51 and is U-shaped from the bending portion 50. The water is drained by going out of the shaped part 30 and falling downward. Moreover, it is not necessary to form a special drain hole as in the prior art.

  The U-shaped portion 30 and the end piece 16 are positioned when the lower end surface of the upper arm portion 41 and the upper wall 34 and the upper end surface of the lower arm portion 42 and the lower wall 35 are in contact with each other. Even if it fits into the insertion space 33 with the gaps 45 and 46 in the vertical direction, it can be accurately positioned. However, on the base side near the curved portion 49 in the lower end surface of the upper arm portion 41, a relief portion 52 is formed that is drawn upward from the rear surface of the upper wall 34.

  A long axle-shaped axle hole 54 that is long in the front-rear direction is formed in the center portion of the end piece 16, and the rear wheel axle 17 is fitted therein so that the movement can be adjusted in the front-rear direction. The axle adjustment mechanism 20 that adjusts the position of the rear wheel axle 17 has a long adjustment shaft 55 in the front-rear direction and a loop portion that penetrates the rear wheel axle 17 at the front end thereof, as shown in FIG. The rear wheel axle 17 is fixed by fastening an axle nut 57 to a threaded portion provided at the tip of the rear wheel axle 17 that is provided through the loop portion 56. A screw portion 58 is formed on the rear end side of the adjustment shaft 55, supported in a recess 60 of a flange 59 formed integrally with the rear end portion of the end piece 16, and by fastening a nut 61 to the screw portion 58, The front-rear direction position of the rear wheel axle 17 is determined.

  When the tension of the chain 22 is loosened, when the axle nut 57 is loosened and the nut 61 is tightened, the rear wheel axle 17 is pulled rearward in the elongated hole 54 and stops when the chain 22 reaches a predetermined tension. By tightening the axle nut 57 again, the position of the rear wheel axle 17 can be adjusted so that the chain 22 is properly tensioned. However, the present invention is not limited to this, and various known types of axle adjusting mechanisms 20 are possible.

Reference numeral 62 in FIG. 3 is an adjustment scale provided along the upper edge of the long hole 54. Reference numeral 63 denotes an attachment shaft for attaching the lower end of the rear cushion unit 27. Reference numeral 25a denotes a mounting hole for the mounting portion 25 for mounting the rear lower side of the upper chain case 24.
Similarly, 26 a is a mounting hole for the mounting portion 26 for attaching the rear upper side of the lower chain case 24, but is formed in the lower arm portion 42.

  As shown in FIG. 4, the outer vertical wall 31 of the U-shaped portion 30 is formed so as to be recessed from the outer side into the inner vertical wall 32 by press molding. At this time, the outer vertical wall of the arm portion 15 is formed. The rear part of 15a is bent to the inner vertical wall 32 side with a curved surface 64, and is parallel to the inner vertical wall 32 at the bent part 65 to form the right and left width of the insertion space 33 that substantially matches the plate thickness T of the end piece 16. .

  FIG. 6 is a view showing a method for forming the U-shaped portion 30, and A shows the state of the raw pipe before the rear end portion of the arm portion 15 is substantially U-shaped. The arm portion 15 in this state is a square pipe having a uniform cross section in the entire length direction, and the rear end portion is similar to other front portions in that the outer vertical wall 15a, the inner vertical wall 15b, the upper wall 15c, and the lower wall 15d are spaces. 15e is enclosed. The U-shaped portion 30 is formed by deforming the outer vertical wall 15a at the rear end portion toward the inner vertical wall 15b by press molding.

6B shows a state after the deformation, and the outer vertical wall 15a is recessed into the inner vertical wall 32, and is parallel to the inner vertical wall 32 through the curved surface 64 and the bent portion 65 from the general surface of the outer vertical wall 15a. The outer vertical wall 31 is formed.
At this time, the inner vertical wall 32, the upper wall 34, and the lower wall 35 form the same continuous surface as the general surfaces of the inner vertical wall 15b, the upper wall 15c, and the lower wall 15d. However, the rear part of the upper wall 15c and the lower wall 15d becomes the upper wall 34 and the lower wall 35 by the formation of the curved surface 64 and the outer vertical wall 31, and forms a rib shape projecting outward. When the outer vertical wall 15a is recessed into the inner vertical wall 15b, the upper wall 34 and the lower wall 35 have a double structure because their upper and lower portions are bent and overlapped inside the upper wall 15c and the lower wall 15d. The rigidity of the upper wall 34 and the lower wall 35 is increased.

In addition, the insertion space 33 is formed in advance by sandwiching the spacer plate 66 in the space 15e and extracting the spacer plate 66 after the outer vertical wall 15a is press-molded. Form. The spacer plate 66 has a plate thickness that matches the plate thickness T of the end piece 16, and has a vertical width that is about the length of the outer vertical wall 31 and a length in the front-rear direction that can protrude slightly forward from the bent portion 65.

7 is a side view of the end piece 16, and FIG. 8 is a sectional view taken along line 8-8 of FIG. The end piece 16 is also obtained by press-molding an appropriate metal plate such as iron or light alloy. At this time, the slit 47, slit 48, curved portion 49, curved portion 50, etc. are formed at the same time, and the mounting hole 25a, the mounting hole 26a, the mounting hole 63a of the mounting shaft 63 of the rear cushion unit, and the long hole 54 are formed. .
Further, the flange 59 portion is formed by first forming a developed shape, and simultaneously forming the recess 60 with a press, and then bending it into a substantially L shape.

  The forward protruding lengths of the insertion portion 40, the upper arm portion 41, and the lower arm portion 42 are different, and if the forward protruding lengths based on the positions of the respective curved portions 49 and 50 are L1, L2, and L3, L1 <L2 <L3, the lower arm portion 42 protrudes forward slightly longer than the insertion portion 40, and the upper arm portion 41 protrudes forward longer than the lower arm portion 42. When the upper arm portion 41 is lengthened, when the insertion portion 40 is inserted into the insertion space 33, the upper arm portion 41 first comes into contact with the upper wall 34 to serve as an insertion guide, and work efficiency during assembly can be improved. . The contact area between the upper arm portion 41 and the upper wall 34 is larger than the contact area between the lower arm portion 42 and the lower wall 35.

  Thus, by increasing the upper contact area, it is possible to reliably receive the upward force applied by the end piece 16. The entire lower end piece 16 is made as compact as possible by reducing the lower abutting portion in accordance with the fact that the downward force applied to the end piece 16 is relatively small. Further, by receiving the force applied to the end piece 16 by the upper wall 34 and the lower wall 35, it becomes possible to reduce the entire welding width between the end piece 16 and the U-shaped portion 30, and by welding. Assembly processing is further facilitated.

  Slits 47 and 48 for fitting the upper wall 34 and the lower wall 35 are formed between the insertion portion 40 and the upper and lower upper arm portions 41 and the lower arm portion 42, respectively. The end portions of the slits 47 and 48 form curved portions 49 and 50, and communicate with the gaps 45 and 46 when fitted to the rear end portion of the U-shaped portion 30.

  The insertion portion 40 has a width that is smaller than the width W1 of the base portion so that the width decreases toward the front portion in a side view, and a protrusion portion 44 that protrudes forward is provided at the tip. Has an arc shape. For this reason, when the insertion part 40 of the end piece is inserted into the insertion space 33 of the U-shaped part 30, the insertion is facilitated, and the protrusion 44 is inserted into the opening of the insertion space 33 by forming an arc shape. Since it can be smoothly inserted without being caught sometimes, the insertion into the opening becomes easier.

The upper edge portion 41a of the upper arm portion 41 is gently curved so as to gradually spread upward, and the vertical width of the center portion of the end piece 16 is increased so as to form a space for forming the attachment hole 63a and the attachment hole 25a. Secured.
The lower arm portion 42 has a mounting hole 26a projecting downward in a boss shape, the lower edge of the end piece 15 on the rear side is inclined obliquely upward toward the rear, and the lower portion has a lower overhang than the elongated hole 54. ing.

Next, the operation of this embodiment will be described. 7 is inserted into the insertion space 33 with respect to the press-shaped U-shaped portion 30 shown in FIG. 6B, first, the upper arm portion 41 is brought into contact with the upper surface of the upper wall 34. This makes the vertical direction fixed and guides the insertion of the end piece. Further, since the distal end of the insertion portion 40 is a protruding portion 44, it is easily inserted into the insertion space 33, and at the same time, the upper wall 34 and the lower wall 35 of the U-shaped portion 30 enter the slit 47 and the slit 48.
Since the lower end surface of the upper arm portion 41 and the upper end surface of the lower arm portion 42 are in contact with the upper surface of the upper wall 34 and the lower surface of the lower wall 35, respectively, the U-shaped portion 30 is accurately positioned between the upper arm portion 41 and the lower arm portion 42. Positioned. Further, when the rear end portion of the U-shaped portion 30 reaches a portion where the rear end of the slit 47 changes to the curved portion 49, the front-rear direction is also positioned. Therefore, the upper arms 41 and the upper surfaces of the upper walls 34 and the lower arms 42 and the lower surfaces of the lower walls 35 are also welded. When the joints between the rear end portions of the outer vertical wall 31 and the inner vertical wall 32 and the side surfaces of the end piece 16 are welded, the end piece 16 is integrated with the U-shaped portion 30 and the assembly is completed.

  Thus, since the U-shaped part 30 was formed by press molding, processing becomes easy. Further, since the end piece 16 insertion portion 40 is inserted into the opening of the insertion space 33 which has been reduced by press molding of the arm portion, the upper wall 34 and the lower wall 35 are separated from each other by separate slits as in the conventional example. Compared to the case where the slit is provided, the slits are not likely to be displaced up and down, so that variation in quality can be suppressed.

  Further, since the upper arm portion 41 is long in contact with the upper surface of the upper wall 34, a large upward force applied from the rear wheel axle 17 to the end piece 16 is transmitted from the upper arm portion 41 to the contact portion of the upper wall 34, and a large contact area. It can be received by the upper wall 34 having On the other hand, when a relatively small downward force is applied to the end piece 16, this force is similarly transmitted from the lower arm portion 42 to the contact portion of the lower wall 35, and a relatively large contact area that is smaller than the upper wall 34 side. It can fully be received by the lower wall 35 having Therefore, the width of welding can be reduced, and assembly processing by welding is facilitated.

  Furthermore, by making the upper arm portion 41 protrude longer than the lower arm portion 42 to increase the contact area, the upper arm portion 42 and the lower wall 35 to which a larger force is applied and a smaller force is reliably received. By reducing the size of the abutting portion in conformity with the substance, the end piece 16 can be made as small and light as possible.

  Further, the insertion portion 40 of the end piece 16 is provided with a projecting portion 44 having a convex arc shape toward the front portion at the front end portion so that the width decreases toward the front portion in a side view. Is easy to insert. Moreover, since the projecting portion 44 has a forwardly convex arc shape, it can be smoothly inserted without being caught when inserted into the opening portion of the insertion space 33, so that the insertion into the opening portion is further facilitated.

  In addition, since the drainage passage 51 is formed by the gap 46 and the curved portion 50, the water that has entered the arm portion 15 enters the gap 46 between the lower portion of the insertion portion 40 and the inner surface of the lower wall 35, and the lower wall 35. Is discharged to the outside through the curved portion 50 from the rear end portion of the gap 46 opened rearward. Therefore, the gap 46 between the lower portion of the insertion portion 40 and the inner surface of the lower wall 35 and the curved portion 50 connected thereto can be effectively used as the drainage passage 51, and there is no need to provide a dedicated drainage hole as in the prior art. Processing man-hours can be reduced.

The present invention is not limited to the above-described embodiments, and various modifications and applications can be made within the principle of the invention. For example, the arm portion 15 can be applied not only to a square pipe but also to a round pipe. Further, the front end portion of the rear swing arm 14 is not only supported by the vehicle body frame, but may be directly supported by, for example, a transmission case of the engine.

Side view of motorcycle according to this embodiment. Side view of the main part with the body cover removed Enlarged side view of the end piece joined to the rear end of the arm Sectional view taken along line 4-4 in FIG. Sectional view along line 5-5 in FIG. The figure which shows the molding method of the U-shaped part Side view of end piece Sectional view taken along line 8-8 in FIG.

Explanation of symbols

1: Body frame, 2: Head pipe, 6: Front wheel, 7: Main frame, 8: Engine, 14: Rear swing arm, 15: Arm part, 16: End piece, 30: U-shaped part, 31: Outside vertical Wall: 32: inner vertical wall, 33: insertion space, 34: upper wall, 35: lower wall, 40: insertion part, 41: upper arm part, 42: lower arm part, 45: gap, 46: gap, 47: slit , 48: slit, 51: drainage passage

Claims (6)

A pipe-shaped arm portion that swings around the front end and a flat end piece that is inserted into an opening provided at the rear end of the arm portion and joined by welding are provided on the end piece. In the vehicle swing arm that supports the rear wheel through the axle of the rear wheel through the axle hole,
While press-molding the rear end portion of the arm portion to reduce the opening area,
A vehicle characterized in that an insertion portion inserted into a rear end opening portion of the arm portion and an upper arm portion that comes into contact with an upper wall of the rear end portion of the arm portion from above are provided at a front portion of the end piece. Swing arm.   The end piece includes a lower arm portion that comes into contact with a lower wall of the rear end portion of the arm portion from below, and a contact area between the upper wall and the upper arm portion is larger than a contact area between the lower wall and the lower arm portion. The swing arm for a vehicle according to claim 1, wherein the contact area is larger.   The swing arm for a vehicle according to claim 1, wherein the upper arm portion protrudes longer forward than the insertion portion.   4. The vehicle swing arm according to claim 1, wherein the insertion portion has a width that decreases toward a front portion in a side view. 5.   5. The vehicle swing arm according to claim 4, wherein a front portion of the insertion portion has a protruding portion that protrudes forward, and the protruding portion has an arc shape.   4. The vehicle swing arm according to claim 2, wherein there is a gap between a lower wall of the arm part and a lower part of the insertion part, and the rear part opens toward the rear.

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