CN110962982A

CN110962982A - Swing arm of automatic bicycle

Info

Publication number: CN110962982A
Application number: CN201910875440.4A
Authority: CN
Inventors: 桒原直树; 石坂勇太
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2018-09-28
Filing date: 2019-09-17
Publication date: 2020-04-07
Anticipated expiration: 2039-09-17
Also published as: JP6755917B2; JP2020055362A; DE102019125202A1; BR102019017754A2; CN110962982B; DE102019125202B4

Abstract

The invention provides a swing arm of a motorcycle, which can form an arm part with an opening for a driving part to penetrate through by stamping parts. A swing arm of a motorcycle includes arm portions (51, 61), the arm portions (51, 61) include inner members (53, 63) and outer members (52, 62) that are formed by pressing, at least the outer members (52, 62) are formed by 1 pressing, the outer members (52, 62) and the inner members (53, 63) have openings (70) for driving members that point in the front-rear direction of a vehicle body, a tubular member (71) that communicates the outer members (52, 62) and the inner members (53, 63) is disposed in the opening (70) for driving members, and a driving member (30) that drives a driving wheel (3) is inserted through the opening (70) for driving members.

Description

Swing arm of automatic bicycle

Field of art division

The present invention relates to a swing arm of a motorcycle.

Background

Conventionally, for example, such a structure is disclosed: the swing arm is formed by making the inside of the arm hollow, forming the inside and the lateral portion of the arm by an integral casting, and welding an arm outside portion (cover plate) made of a stamping on the inside of the arm (for example, see patent document 1).

Documents of the prior art

Patent document 1: japanese Kokai publication Hei 03-067290

Disclosure of Invention

However, in the technique of patent document 1, if the arm is simply shaped like an arm in which the driving member (chain) is disposed on the outer periphery of the arm, the swing arm can be configured by a combination of a casting and a pressing that form the lateral portion.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a swing arm of a motorcycle in which an arm portion having an opening through which a driving member is inserted can be formed by a press-molding.

In order to achieve the above object, a swing arm of a motorcycle has a pivot portion 88 at a front end portion thereof for supporting the swing arm to a vehicle body frame 10 in a swingable manner, a drive wheel supporting portion 89 at a rear end portion thereof for supporting a drive wheel 3, the swing arm of the motorcycle has

arm parts

51, 61, the

arm parts

51, 61 have

inner parts

53, 63 and

outer parts

52, 62 formed by pressing parts, at least the

outer parts

52, 62 are formed by 1 pressing part, the

outer members

52, 62 and the

inner members

53, 63 have drive member openings 70 that point in the vehicle body front-rear direction, a tubular member 71 communicating the

outer members

52, 62 and the

inner members

53, 63 is disposed in the driving member opening 70, and the driving member 30 for driving the driving wheel 3 is inserted through the driving member opening 70.

In the above invention, the

outer members

52, 62 may be formed with

upper surface portions

54, 64 and

lower surface portions

55, 65 by bending upper and lower edge portions in the vehicle body inner direction.

In the above-described invention, the

inner members

53, 63 may be formed of 1 piece of stamping, the

upper surface portions

56, 66 and the

lower surface portions

57, 67 may be formed in the

inner members

53, 63 by bending upper and lower edge portions in the vehicle body outer direction, and the

arm portions

51, 61 may be formed by welding the

upper surface portions

56, 66 and the

lower surface portions

57, 67 of the

inner members

53, 63 to the

upper surface portions

54, 64 and the

lower surface portions

55, 65 of the

outer members

52, 62, respectively.

In the invention, a reinforcing member 76 may be provided between the

inner members

53, 63 and the

outer members

52, 62.

In the above invention, the

arm portions

51, 61 may have a pair of left and

right arm portions

51, 61, and a lateral portion 80 connecting the left and

right arm portions

51, 61, and the suspension support portion 85 may be provided on the lateral portion 80.

In the invention, the lateral portion 80 may have a front surface portion 81, a rear surface portion 82, an upper surface portion 83, and a lower surface portion 84, the front surface portion 81, the rear surface portion 82, and the upper surface portion 83 may be formed of a pressed material, the lower surface portion 84 may be formed of a cast material, and the suspension support portion 85 may be provided at the lower surface portion 84.

In the above invention, the

arm portions

51, 61 may have pivot portions 88 formed separately at their front end portions, and the

arm portions

51, 61 may have drive wheel support portions 89 formed separately at their rear end portions.

Effects of the invention

According to the present invention, since the outer member of the arm portion of the swing arm is formed by 1 piece of the pressing member and the opening for the driving member into which the chain is inserted is provided in the arm portion, the appearance can be fashionable even with the pressing member, and the arrangement of the chain can be ensured.

In the above invention, the outer member has the upper surface portion and the lower surface portion formed by bending the upper edge portion and the lower edge portion in the vehicle body inner direction, so that the rigidity of the arm portion can be ensured.

In the above invention, the inner member is formed of 1 piece of pressing material, the upper surface portion and the lower surface portion are formed in the inner member by bending the upper edge portion and the lower edge portion in the vehicle body outer direction, and the arm portion is formed by welding the upper surface portion and the lower surface portion of the inner member and the upper surface portion and the lower surface portion of the outer member, respectively.

In the above invention, the reinforcing member is provided between the inner member and the outer member, and therefore, the reinforcing member can be disposed by utilizing the space between the inner member and the outer member. Further, the reinforcing member can suppress vibration of the arm portion and prevent generation of vibration sound. The reinforcing member is disposed inside the arm portion, and therefore, the appearance is not spoiled.

In the above invention, since the suspension support portion is provided in the lateral portion, the suspension support portion can be provided in the lateral portion.

In the above invention, the lateral portion has the front surface portion, the rear surface portion, the upper surface portion, and the lower surface portion, the front surface portion, the rear surface portion, and the upper surface portion are formed by stamping, the lower surface portion is formed by casting, and the suspension support portion is provided on the lower surface portion.

In the above invention, since the arm portion has the pivot portion formed separately at the front end portion thereof and the drive wheel support portion formed separately at the rear end portion thereof, the swing arm formed of the press member can be formed by welding the pivot portion and the drive wheel support portion formed separately to the arm portion.

Drawings

Fig. 1 is a left side view showing an embodiment of a motorcycle to which a handlebar switch is applied according to the present invention.

Fig. 2 is a left side view of the frame, the swing arm, and the rear wheel of the motorcycle according to the present embodiment.

Fig. 3 is a perspective view of the swing arm portion of the present embodiment as viewed from the left side.

Fig. 4 is a perspective view of the swing arm portion of the present embodiment as viewed from the right side.

Fig. 5 is a side view of the swing arm of the present embodiment.

Fig. 6 is a plan view of the swing arm of the present embodiment.

Fig. 7 is a bottom view of the swing arm of the present embodiment.

Fig. 8 is a front view of the swing arm of the present embodiment.

Fig. 9 is a rear view of the swing arm of the present embodiment.

Fig. 10 is a perspective view of the swing arm of the present embodiment as viewed from obliquely above.

Fig. 11 is a perspective view of the swing arm of the present embodiment as viewed obliquely from below.

Fig. 12 is a perspective view showing a state in which the outer member of the swing arm of the present embodiment is detached.

Fig. 13 is an exploded perspective view of the swing arm of the present embodiment.

Description of the reference symbols

1: a motorcycle; 3: a rear wheel; 10: a frame; 13: swinging arms; 17: a pivot frame; 22: a pivot; 24: a rear suspension; 33: a chain; 51: a left arm portion; 52: a left outer member; 53: a left inner part; 54: a left outer upper surface portion; 55: a left outer lower surface portion; 56: a left inner upper surface portion; 57: a left inner lower surface portion; 58: an opening; 61: a right arm portion; 62: a right outer member; 63: a right inner member; 64: a right outer upper surface portion; 65: a right outer lower surface portion; 66: a right inner upper surface portion; 67: a right inner lower surface portion; 68: an opening; 70: an opening for the driving member; 71: a cylindrical member; 75: a barrel member; 76: a reinforcing member; 80: a transverse portion; 81: a front surface portion; 82: a rear surface portion; 83: an upper surface portion; 84: a lower surface portion; 85: a suspension support portion; 87: a support arm; 88: a pivot portion; 89: a rear wheel support portion.

Detailed Description

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

In the description, the front, rear, left, right, and up and down directions are the same as the directions with respect to the vehicle body unless otherwise specified. In the drawings, the reference numeral "front" denotes the vehicle body front, the reference numeral "upper" denotes the vehicle body upper side, and the reference numeral "left" denotes the vehicle body left side.

Fig. 1 is a left side view of a motorcycle 1 according to an embodiment of the present invention.

The motorcycle 1 is a vehicle: an engine 11 as a power unit is supported on a vehicle body frame 10, a front fork 12 supporting a front wheel 2 is supported at a front end of the vehicle body frame 10 so as to be turnable, and a swing arm 13 supporting a rear wheel 3 is provided at a rear portion of the vehicle body frame 10.

The motorcycle 1 is a saddle-ride type vehicle in which an occupant sits on a seat 14, and the seat 14 is provided above the rear portion of the frame 10.

Fig. 2 is a left side view of the frame 10, the swing arm 13, and the rear wheel 3.

Referring to fig. 1 and 2, a vehicle frame 10 has: a front seat tube 15 provided at a front end of the frame 10; a pair of left and right main frames 16 extending rearward and downward from the front seat pipe 15; a pair of left and right pivot frames 17 extending downward from the rear end of the main frame 16; and a pair of left and right seat frames 18 extending rearward and upward from the upper portion of the pivot frame 17.

The main frame 16 has an engine mount portion 16a that extends downward from a front portion of the main frame 16 and supports the engine 11.

The front fork 12 is pivotally supported by a front seat tube 15 so as to be steerable left and right. A steering handle 21 is provided at an upper end portion of the front fork 12. The front wheel 2 is pivotally supported by an axle 2a provided at a lower end portion of the front fork 12.

The swing arm 13 is pivotally supported by a pivot shaft 22 (supported by the left and right pivot frames 17). The pivot shaft 22 extends horizontally in the vehicle width direction. The swing arm 13 is pivotally supported at its distal end by a pivot shaft 22, and the swing arm 13 swings up and down about the pivot shaft 22.

The rear wheel 3 is pivotally supported by an axle 3a provided at a rear end portion of the swing arm 13.

A rear suspension 24 is provided between the vehicle body and the swing arm 13. The upper end of the rear suspension 24 is coupled to the vehicle body. The upper end of the rear suspension 24 is coupled to the engine 11, which is a vehicle body, via a suspension coupling portion (not shown) that extends rearward from the rear end of the engine 11, for example.

The lower end of the rear suspension 24 is coupled to the swing arm 13 and the lower end of the pivot frame 17 via a link mechanism.

The engine 11 is disposed forward of the pivot frame 17 below the main frame 16 and is fixed to the frame 10.

The engine 11 includes: a crankcase 28 supporting a crankshaft 27 horizontally extending in a vehicle width direction (left-right direction); and a cylinder portion 29 extending forward and upward from the front of the crankcase 28. A piston (not shown) reciprocating in the cylinder portion 29 is housed in the cylinder portion 29. The cylinder axis 29a of the cylinder portion 29 is inclined forward with respect to the vertical direction.

A transmission case portion 28a for accommodating a transmission (not shown) is provided at the rear portion of the crankcase 28. The output of the engine 11 is transmitted to the rear wheel 3 via a drive chain 30 connecting the output shaft of the transmission and the rear wheel 3.

The air cleaner case 31 is disposed at the rear upper side of the cylinder portion 29. The air cleaner case 31 is connected to an intake port on the rear surface of the cylinder portion 29 via a throttle body (not shown).

The exhaust pipe 32 of the engine 11 is drawn downward from an exhaust port in the front surface of the cylinder portion 29, and extends rearward through the engine 11. The rear end of the exhaust pipe 32 is connected to a muffler 33 disposed on the side of the rear wheel 3.

The fuel tank 35 is disposed above the main frame 16 between the seat 14 and the air cleaner case 31.

The radiator 36 of the engine 11 is disposed in front of the engine 11.

The motorcycle 1 has the following parts as a body cover for covering a vehicle body such as a frame 10 and an engine 11: a front cover 40 that covers the upper portion of the front fork 12 and the front seat tube 15 from the front; a front cover 41 for laterally covering the front portion of the vehicle body; a bottom cover 42 that covers the engine 11 from below; a tank cover 43 covering a part of the air cleaner tank 31 and the fuel tank 35; and a rear cover 44 covering the rear of the vehicle body.

A front fender 45 that covers the front wheel 2 from above is attached to the front fork 12.

An inner fender 46 that covers the front of the rear wheel 3 from above is mounted on the swing arm 13.

A rear fender 47 that covers the rear portion of the rear wheel 3 from above extends rearward and downward from the rear end portion of the seat frame 18.

The step 48 for placing the foot of the occupant of the seat 14 is supported by the pivot frame 17 and is disposed rearward of the pivot frame 17.

Next, the swing arm 13 will be described in detail.

Fig. 3 is a perspective view of the swing arm 13 portion as viewed from the left side. Fig. 4 is a perspective view of the swing arm 13 portion as viewed from the right side. Fig. 5 is a side view of the swing arm 13. Fig. 6 is a plan view of the swing arm 13. Fig. 7 is a bottom view of the swing arm 13. Fig. 8 is a front view of the swing arm 13. Fig. 9 is a rear view of the swing arm 13. Fig. 10 is a perspective view of the swing arm 13 as viewed from obliquely above. Fig. 11 is a perspective view of the swing arm 13 as viewed obliquely from below. Fig. 12 is a perspective view showing a state where the outer member of the swing arm 13 is detached. Fig. 13 is an exploded perspective view of the swing arm 13.

As shown in fig. 3 and 4, as described above, the front end portion of the swing arm 13 is pivotally supported on the pivot shaft 22 so as to be swingable up and down.

As shown in fig. 5 to 13, the swing arm 13 includes a left arm portion 51 positioned on the left side in the vehicle width direction of the motorcycle 1 and a right arm portion 61 positioned on the right side. The left arm 51 has a left outer member 52 and a left inner member 53. The right arm portion 61 has a right outer member 62 and a right inner member 63. The left outer member 52, the left inner member 53, the right outer member 62, and the right inner member 63 are each formed by a stamping.

The left outer member 52 has an upper left outer surface portion 54 and a lower left outer surface portion 55 formed by bending an upper edge portion and a lower edge portion thereof inward toward the rear wheel 3. The left inner member 53 has an upper edge portion and a lower edge portion bent inward in the vehicle width direction, and thus has a left inner upper surface portion 56 and a left inner lower surface portion 57.

The left arm 51 is formed by integrally welding the left outer upper surface 54 and the left outer lower surface 55 of the left outer member 52 and the left inner upper surface 56 and the left inner lower surface 57 of the left inner member 53.

Similarly, the right outer 62 is formed with a right outer upper surface portion 64 and a right outer lower surface portion 65 by bending the upper edge portion and the lower edge portion inward toward the rear wheel 3. The right inner member 63 has its upper and lower edges bent inward in the vehicle width direction, thereby forming a right inner upper surface portion 66 and a right inner lower surface portion 67.

The right arm portion 61 is configured by integrally welding the right outer upper surface portion 64 and the right outer lower surface portion 65 of the right outer member 62 and the right inner upper surface portion 66 and the right inner lower surface portion 67 of the right inner member 63, respectively.

A substantially triangular opening 58 is formed in the left outer member 52 and the left inner member 53 in the rear direction. A cylindrical member 75 formed in a substantially same shape as the opening 58 is provided inside the left outer member 52 and the left inner member 53 at a position corresponding to the opening 58. The cylindrical member 75 is fixed to the edges of the openings 58 of the left outer member 52 and the left inner member 53 by welding.

As shown in fig. 12, the cylindrical member 75 is first welded to the edge of the opening 58 of the left inner member 53 and then welded to the opening 58 of the left outer member 52, and therefore, has no influence on the appearance.

Further, a drive member opening 70 directed in the vehicle body longitudinal direction of the motorcycle 1 is formed in the front of the left outer member 52 and the left inner member 53.

The left outer member 52 and the left inner member 53 are formed to be bent halfway so that the front side is located on the inner side in the vehicle width direction of the motorcycle 1 and the rear side is located on the outer side in the vehicle width direction of the motorcycle 1 in a plan view. The opening 70 for the driving member is formed at a bent position of the left outer member 52 and the left inner member 53, and the opening 70 for the driving member is formed to penetrate from the inside to the outside of the left outer member 52 and the left inner member 53 toward the front of the vehicle body of the motorcycle 1.

A tubular member 71 is provided between the drive member opening 70 of the left outer member 52 and the drive member opening 70 of the left inner member 53. The cylindrical member 71 is fixed to the edge of the opening 70 for the driving member by welding.

A chain 30 of the motorcycle 1 as a driving member is inserted through the driving member opening 70.

A substantially triangular opening 68 is formed in the right outer member 62 and the right inner member 63 at a rear portion thereof. A cylindrical tubular member 75 having substantially the same shape as the opening 68 is provided inside the right outer member 62 and the right inner member 63 at a position corresponding to the opening 68. The cylindrical member 75 is fixed to the edges of the openings 68 of the right outer member 62 and the right inner member 63 by welding.

Similarly, the cylindrical member 75 is first welded to the edge of the opening 68 of the right inner member 63 and then welded to the opening 68 of the right outer member 62, and therefore, has no effect on the appearance.

A reinforcing member 76 formed in a wave shape continuously from a substantially trapezoidal shape in plan view is provided on the inner front side of the right outer member 62 and the right inner member 63. The reinforcement member 76 is first welded to the surface of the inner side of the right outer member 62, and then welded from the inner side of the right inner member 63. Thus, although the trace of welding is exposed from the inside of the right inner member 63, the trace of welding is not exposed from the outside of the right outer member 62, and therefore, the appearance is not affected.

A lateral portion 80 connecting the left arm portion 51 and the right arm portion 61 is provided at the front side portions of the left arm portion 51 and the right arm portion 61. The lateral portion 80 has a front surface portion 81, a rear surface portion 82, an upper surface portion 83, and a lower surface portion 84, and the front surface portion 81, the rear surface portion 82, and the upper surface portion 83 are each formed by a press-formed member. The lateral portion 80 is fixed to the left and right

inner members

53, 63 by welding.

The lower surface portion 84 is formed of a casting, and as shown in fig. 7 and 11, a suspension support portion 85 for supporting the rear suspension 24 is provided on the lower surface side of the lower surface portion 84. The suspension support portion 85 is configured as a tube portion 86 extending in the vehicle body width direction of the motorcycle 1, and a support arm 87 for supporting the lower end portion of the rear suspension 24 is attached to the tube portion 86. The upper end of the rear suspension 24 is supported by the pivot frame 17.

By forming the front surface portion 81, the rear surface portion 82, and the upper surface portion 83 of the lateral portion 80 by the pressing member in this manner, a smooth appearance shape can be obtained, and the appearance shape is somewhat rough because the lower surface portion 84 is formed by the casting, but exposure to the outside can be suppressed because it is located on the lower surface.

A pivot portion 88 through which the pivot shaft 22 is inserted is welded to the distal end portions of the left arm portion 51 and the right arm portion 61, and the pivot portion 88 is supported by the left and right pivot frames 17 via the pivot shaft 22, whereby the swing arm 13 is pivotally supported to be free to swing.

A rear wheel support portion 89 for supporting the rear wheel 3 is attached to the rear end portions of the left arm portion 51 and the right arm portion 61 by welding. The rear wheel support portion 89 has a support hole 90 for inserting and holding an axle of the rear wheel 3.

Next, the operation of the present embodiment will be explained.

In the present embodiment, the swing arm 13 is supported to be swingable by supporting the pivot shaft 22 on the pivot frame 17, and the rear suspension 24 is disposed between the swing arm 13 and the pivot frame 17, so that the rear suspension 24 can absorb the shock applied to the rear wheel 3, and the running stability of the motorcycle 1 can be improved.

In the present embodiment, the left outer member 52 of the left arm portion 51 of the swing arm 13 is formed by 1 piece of the pressing member, and the drive member opening 70 through which the chain 30 is inserted is provided in the left arm portion 51, so that the appearance can be fashionable even with the pressing member, and the arrangement of the chain 30 can be ensured.

Further, the left arm section 51 is configured by forming a left outer upper surface portion 54 and a left outer lower surface portion 55 on the left outer member 52, forming a left inner upper surface portion 56 and a left inner lower surface portion 57 on the left inner member 53, and integrally welding the left outer upper surface portion 54 and the left outer lower surface portion 55 of the left outer member 52 and the left inner upper surface portion 56 and the left inner lower surface portion 57 of the left inner member 53, respectively, whereby the rigidity of the left arm section 51 can be secured.

Further, the right arm section 61 is configured by forming a right outer upper surface portion 64 and a right outer lower surface portion 65 on the right outer member 62, forming a right inner upper surface portion 66 and a right inner lower surface portion 67 on the right inner member 63, and integrally welding the right outer upper surface portion 64 and the right outer lower surface portion 65 of the right outer member 62 and the right inner upper surface portion 66 and the right inner lower surface portion 67 of the right inner member 63, respectively, whereby the rigidity of the right arm section 61 can be ensured.

Further, since the reinforcing member 76 is provided between the right inner member 63 and the right outer member 62, the rigidity of the left arm portion 51 and the right arm portion 61 can be ensured, and the appearance is not spoiled even if the reinforcing member 76 is disposed inside the right arm portion 61. Further, the vibration of the right arm portion 61 can be suppressed and the generation of vibration sound can be prevented by the reinforcing member 76.

Further, by providing the suspension support portion 85 in the lateral portion 80 connecting the left arm portion 51 and the right arm portion 61, the suspension support portion 85 using the lateral portion 80 can be provided.

Even if the front surface portion 81, the rear surface portion 82, and the upper surface portion 83 of the lateral portion 80 are a combination of pressed parts, a smooth appearance shape can be formed, and since the cast portion forming the lower surface portion 84 is located on the lower surface, exposure to the outside can be suppressed.

Further, the pivot portion 88 formed separately is provided at the front end portion of the left arm portion 51 and the right arm portion 61, the drive wheel support portion formed separately is provided at the rear end portion of the left arm portion 51 and the right arm portion 61, and the swing arm 13 formed of a press member can be formed by welding the pivot portion 88 and the rear wheel support portion 89 formed separately to the left arm portion 51 and the right arm portion 61.

As described above, in the present embodiment, the present embodiment includes the left arm 51 and the right arm 61 (arms), the left arm 51 and the right arm 61 include the left inner member 53, the left outer member 52, the right inner member 63, and the right outer member 62 (inner and outer members) formed by pressing, at least the left outer member 52 and the right outer member 62 (outer member) are formed by 1 pressing, the left inner member 53 and the left outer member 52 include the driving member opening 70 directed in the vehicle body longitudinal direction, the tubular member 71 communicating the left outer member 52 and the left inner member 53 is disposed in a part (partial) of the driving member opening 70, and the chain 30 (driving member) for driving the rear wheel 3 (driving wheel) is inserted through the driving member opening 70.

Thus, the left outer member 52 of the left arm portion 51 of the swing arm 13 is formed of 1 piece of the pressing material, and the drive member opening 70 through which the chain 30 is inserted is provided in the left arm portion 51, so that the appearance can be fashionable even with the pressing material, and the arrangement of the chain 30 can be ensured.

In the present embodiment, the left outer side member 52 and the right outer side member 62 (outer members) are formed with a left outer side upper surface portion 54, a left outer side lower surface portion 55, a right outer side upper surface portion 64, and a right outer side lower surface portion 65 (upper surface portion and lower surface portion) by bending the upper edge portion and the lower edge portion in the vehicle body inner direction.

Thus, the rigidity of the left arm 51 and the right arm 61 can be ensured by forming the left outer upper surface 54, the left outer lower surface 55, the right outer upper surface 64, and the right outer lower surface 65.

In the present embodiment, the left inner member 53 and the right inner member 63 (inner member) are formed of 1 piece of pressing, the left and right

inner members

53, 63 are formed with left and right inner

upper surfaces

56, 57, 66 and 67 (upper and lower surfaces) by bending the upper and lower edges in the vehicle body outer direction, and the left and right arm sections 51, 61 (arm sections) are formed by welding the left and right inner

upper surfaces

56, 57, 66 and 67 of the left and right

inner members

53, 63 to the left and right outer

upper surfaces

54, 55, 64 and 65 of the left and right outer members 52, 62 (outer members), respectively.

Thus, the left arm section 51 and the right arm section 61 are configured by welding the left inner upper surface portion 56, the left inner lower surface portion 57, the right inner upper surface portion 66, and the right inner lower surface portion 67 of the left inner member 53 and the right inner member 63, and the left outer upper surface portion 54, the left outer lower surface portion 55, the right outer upper surface portion 64, and the right outer lower surface portion 65 of the left outer member 52 and the right outer member 62, respectively, and higher rigidity of the left arm section 51 and the right arm section 61 can be secured.

In the present embodiment, a reinforcing member 76 is provided between the right inner member 63 (inner member) and the right outer member 62 (outer member).

This allows the reinforcing member 76 to be disposed in the space between the right inner member 63 and the right outer member 62. Further, the reinforcing member 76 suppresses the vibration of the right arm portion 61, thereby preventing the generation of vibration sound. The reinforcing member 76 is disposed inside the right arm portion 61, and therefore, the appearance is not spoiled.

In the present embodiment, the lateral portion 80 connecting the left arm portion 51 and the right arm portion 61 is provided, and the suspension support portion 85 is provided in the lateral portion 80.

Thus, the suspension support portion 85 can be provided by the lateral portion 80 connecting the left arm portion 51 and the right arm portion 61.

In the present embodiment, the lateral portion 80 includes a front surface portion 81, a rear surface portion 82, an upper surface portion 83, and a lower surface portion 84, the front surface portion 81, the rear surface portion 82, and the upper surface portion 83 are formed by pressing, the lower surface portion 84 is formed by casting, and the suspension support portion 85 is provided on the lower surface portion 84.

Accordingly, the front surface portion 81, the rear surface portion 82, and the upper surface portion 83 can be configured to have a smooth appearance even when they are a combination of pressed parts, and the cast portion configuring the lower surface portion 84 is positioned on the lower surface, so that exposure to the outside can be suppressed.

In the present embodiment, the pivot portion 88 is formed separately at the front end portions of the left arm portion 51 and the right arm portion 61 (arm portions), and the rear wheel support portion 89 is formed separately at the rear end portions of the left arm portion 51 and the right arm portion 61.

Thus, the swing arm 13 formed of a stamped component can be formed by welding the separate pivot portion 88 and rear wheel support portion 89 to the left arm portion 51 and the right arm portion 61.

The present invention is described in terms of embodiments, but the present invention is not limited to the embodiments. Since only one embodiment of the present invention is illustrated, any modification and application can be made without departing from the scope of the present invention.

Claims

1. A swing arm of a motorcycle, having a pivot part (88) at a front end part thereof for supporting the swing arm on a frame (10) in a swingable manner, and having a driving wheel supporting part (89) at a rear end part thereof for supporting a driving wheel (3),

the swing arm of the motorcycle has arm parts (51, 61), the arm parts (51, 61) have inner members (53, 63) and outer members (52, 62) formed by pressing, at least the outer members (52, 62) are formed by 1 pressing,

the outer members (52, 62) and the inner members (53, 63) have openings (70) for driving members directed in the front-rear direction of the vehicle body, and a tubular member (71) communicating the outer members (52, 62) and the inner members (53, 63) is disposed in the opening (70) for driving members,

a drive member (30) for driving the drive wheel (3) is inserted into the drive member opening (70).

2. Swing arm of a motorcycle according to claim 1,

the outer members (52, 62) are formed with upper surface portions (54, 64) and lower surface portions (55, 65) by bending upper and lower edge portions in the vehicle body inner direction.

3. Swing arm of a motorcycle according to claim 2,

the inner member (53, 63) is formed of 1 piece of stamping, an upper surface portion (56, 66) and a lower surface portion (57, 67) are formed on the inner member (53, 63) by bending an upper edge portion and a lower edge portion in the vehicle body outer direction,

the arm sections (51, 61) are formed by welding the upper surface sections (56, 66) and the lower surface sections (57, 67) of the inner members (53, 63) to the upper surface sections (54, 64) and the lower surface sections (55, 65) of the outer members (52, 62), respectively.

4. Swing arm of a motorcycle according to any one of claims 1 to 3,

a reinforcing member (76) is provided between the inner member (53, 63) and the outer member (52, 62).

5. Swing arm of a motorcycle according to any one of claims 1 to 4,

the arm sections (51, 61) have a pair of left and right arm sections (51, 61), and have a lateral section (80) that connects the left and right arm sections (51, 61), and the suspension support section (85) is provided on the lateral section (80).

6. Swing arm of a motorcycle according to claim 5,

the lateral portion (80) has a front surface portion (81), a rear surface portion (82), an upper surface portion (83), and a lower surface portion (84), the front surface portion (81), the rear surface portion (82), and the upper surface portion (83) are constituted by stamping, the lower surface portion (84) is constituted by casting, and the suspension support portion (85) is provided at the lower surface portion (84).

7. Swing arm of a motorcycle according to any one of claims 1 to 6,

the arm sections (51, 61) have pivot sections (88) formed separately at the front end sections thereof, and the arm sections (51, 61) have drive wheel support sections (89) formed separately at the rear end sections thereof.