JP2013095250A - Vehicle body frame of motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle body frame which includes a press-molded article capable of enhancing its stiffness while achieving weight saving.SOLUTION: In the vehicle body frame 11 of a motorcycle, a main frame 22 includes a linear portion 27, and a curved portion 28 which is elongated downward while being curved from a back end of the linear portion 27. A rear frame 23 is a member which has tips joined to right and left vehicle-width-direction surfaces of the curved portion 28 and which is elongated backward. Approximately rectangular reinforcing members 77 and 78 are laid across the curved portion 28 and a front inner surface of the rear frame 23 in a plan view. Front edges of the reinforcing members 77 and 78 are joined to a rear surface of the curved portion 28 and a pivot frame 24, respectively.

Description

  The present invention relates to an improvement in a body frame of a motorcycle.

  2. Description of the Related Art In recent years, a body frame of a motorcycle having a plate structure in which press-molded plate materials are joined to form a skeleton is known (see, for example, Patent Document 1 (FIG. 5)).

  FIG. 5 of Patent Document 1 shows an exploded view of a vehicle body frame, and a motorcycle frame (21) (numbers in parentheses indicate reference numerals described in Patent Document 1. The same applies hereinafter) extends in the front-rear direction of the vehicle. The main frame (30) is the main element. The main frame (30) has a closed cross-section structure (also referred to as a closed structure) in which a concave cross-section upper member (31) opening downward and a concave cross-section lower member (32) opening upward are joined from above and below. .)

  A middle member (50) having a pivot portion is suspended from an intermediate portion of the main frame (30), and a rear member (70) is passed between a lower end of the middle member (50) and a rear end of the main frame (30). .

By the way, the main frame (30) of Patent Document 1 adopts a closed structure that satisfies a predetermined rigidity at the connecting portion with the middle member (50) that requires high rigidity and the support point at the upper end of the rear cushion unit. The In addition, a rigid closed structure is adopted for the intermediate portion and the rear portion of the seat rail that supports the seat other than the connecting portion and the support point, and the body frame (21) of Patent Document 1 tends to be heavy overall. .
In recent years, there has been a demand for a body frame that can increase the rigidity of the vehicle while reducing the weight of the vehicle while reducing the weight of the vehicle.

Japanese Patent No. 4153104

  This invention makes it a subject to provide the vehicle body frame comprised with the press-formed product which can raise the rigidity, aiming at weight reduction.

The invention according to claim 1 is a vehicle body frame of a motorcycle comprising a main frame extending rearward from the head pipe and a rear frame extending rearward from the main frame.
The main frame is composed of a straight portion that extends linearly from the head pipe toward the rear of the vehicle and a curved portion that extends downward while curving from the rear end of the straight portion, and the rear frame has a tip on the left side in the vehicle width direction of the curved portion. It consists of a left rear frame that is joined and extends rearward, and a right rear frame that has a tip joined to the right side in the vehicle width direction of the curved portion and extends rearward, and in plan view, the rear surface of the main frame, the inner surface of the left rear frame front portion, and the right A substantially rectangular reinforcing member is passed to the inner surface of the front portion of the rear frame, the front edge of the reinforcing member is joined to the rear surface of the curved portion, and the left and right edges of the reinforcing member are joined to the inner surfaces of the left and right rear frames. It is characterized by.

  In the invention according to claim 2, the reinforcing member is characterized in that at least three sides of the front edge and the left and right edges are bent into a flange portion, and the flange portion is used for joining.

  In the invention according to claim 3, the pair of left and right rear frames includes a frame rear portion, a frame front upper portion extending forward from the front end of the frame rear portion, and a frame extending obliquely downward from the front end of the frame rear portion in the vehicle body side view. The main frame includes a pivot frame part at the lower end of the curved part, and the upper part of the front part of the frame is joined to the curved part. The frame front falling part is joined to the part.

  The invention according to claim 4 is characterized in that the reinforcing member includes an upper reinforcing member attached to the front portion of the upper front portion of the frame and a lower reinforcing member attached to the front portion of the lower portion of the front portion of the frame.

  In the invention according to claim 5, the main frame has a left vertical wall portion, a ceiling portion and a bottom portion extending from the upper and lower ends of the left vertical wall portion toward the vehicle width direction center side, and a flange-like shape extending upward from the ceiling portion. A left member comprising a left upper overhang and a flange-like lower left overhang extending downward from the bottom, a right vertical wall, a ceiling extending from the upper and lower ends of the right vertical wall to the vehicle width direction center side, and The upper left overhanging portion and the upper right overhanging portion include a bottom member and a right member including a flange-like upper right overhanging portion extending upward from the ceiling portion and a flange-like lower right overhanging portion extending downward from the bottom surface portion. Is a hollow frame formed by joining the lower left overhanging portion and the lower right overhanging portion, and the reinforcing member is provided with a notch-shaped recess for storing the upper left overhanging portion and the upper right overhanging portion. It is characterized by.

  The invention according to claim 6 is characterized in that a cross member extending in the vehicle width direction is passed to a vehicle rearward position relative to the lower reinforcing member in the frame front lowering portion.

  In the invention according to claim 1, the substantially rectangular reinforcing member is passed and joined to the rear surface of the main frame and the inner surfaces of the front portions of the left and right rear frames. In the main frame and its curved portion, the torsional force on the left and right rear frame sides is concentrated at the junction with the rear frame. Therefore, in the present invention, the rigidity to withstand the torsional force is secured by welding the reinforcing member to this portion.

The reinforcing members do not need to be provided over the entire length of the left and right rear frames, but need only be provided at the front portions of the left and right rear frames. As a result, it is possible to reduce the size of the reinforcing member and further reduce the weight of the body frame.
That is, according to the present invention, there is provided a vehicle body frame formed of a press-molded product that can increase the rigidity while reducing the weight.

  In the invention according to claim 2, the reinforcing member has a flange portion formed by bending at least three sides of the front edge and the left and right edges. Since the flange portion is formed on the reinforcing member, the rigidity of the reinforcing member is remarkably increased as compared with the case where the reinforcing member is only the flat plate portion. In addition, the reinforcing members are less likely to be displaced during the joining work by applying the flange portions of the three sides to the rear surface of the curved portion and the inner surfaces of the left and right rear frames. As a result, work related to joining becomes easy.

  In the invention according to claim 3, the front portion of the rear frame includes a frame front upper portion joined to the bending portion and a frame front lowering portion joined to the pivot frame portion. The torsional force from the rear frame toward the main frame is distributed to the upper front part of the frame and the lower part of the front frame. As a result, the influence on the main frame is mitigated, and the main frame can be made thinner and lighter. In addition, since the rear portion of the vehicle body frame is composed of only the left and right rear frames, the vehicle body frame can be made thinner and lighter.

  In the invention according to claim 4, the rear frame is reinforced by the upper reinforcing member and the lower reinforcing member. Since it is reinforced by the upper reinforcing member and the lower reinforcing member provided at the upper and lower portions, the reinforcing action at the joint portion between the rear frame and the main frame is further enhanced.

  In the invention which concerns on Claim 5, the recessed part which accommodates a flange-shaped upper left overhang | projection part and an upper right overhang | projection part is provided in the reinforcement member. By this recess, interference between the reinforcing member, the upper left overhanging portion, and the upper right overhanging portion can be avoided. In addition, the reinforcing member can be joined to the upper left overhanging portion and the upper right overhanging portion, and the joining strength can be increased.

  In the invention which concerns on Claim 6, the cross member was passed between the left-right frame front falling part. This cross member can prevent the left and right rear frames from being deformed in the vehicle width direction.

1 is a left side view of a motorcycle. 1 is a left side view of a body frame of a motorcycle according to the present invention. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is a disassembled perspective view of a left rear frame. It is a disassembled perspective view of the rear part of a vehicle body frame. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. FIG. 8 is a view taken in the direction of arrow 8 in FIG. 2. FIG. 9 is a sectional view taken along line 9-9 in FIG. 8. FIG. 10 is a sectional view taken along line 10-10 in FIG. 8. It is a perspective view explaining the recessed part which accommodates the overhang | projection part of a main frame. It is a perspective view when FIG. 2 is seen by 12 arrows. FIG. 13 is a sectional view taken along line 13-13 of FIG. FIG. 14 is a cross-sectional view taken along line 14-14 of FIG.

  Hereinafter, embodiments of the present invention will be described in detail. In the drawings and examples, “up”, “down”, “front”, “rear”, “left”, and “right” respectively indicate directions viewed from the driver who rides the motorcycle. The drawings are viewed in the direction of the reference numerals.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a motorcycle 10 includes a body frame 11 extending in the longitudinal direction of the vehicle, an engine 12 suspended on the body frame 11, and a front portion of the body frame 11. The main elements are a front-wheel steering device 15 that is supported by the rear wheel and a rear-wheel suspension device 16 that is provided at the lower part of the rear portion of the vehicle body frame 11 and supports the rear wheel 14 in a swingable manner.

  The front wheel steering device 15 includes a front fork 31 that is rotatably attached to the head pipe 21, a front wheel 13 that is rotatably attached to the lower end of the front fork 31, and an upper end of the front fork 31. And a handle 32 for performing A front fender 33 and a headlight 34 are attached to the front fork 31.

  The rear-wheel suspension device 16 is attached to the vehicle body frame 11 via a pivot shaft 25 extending in the vehicle width direction, extends to the rear of the vehicle and swings up and down, and a rear end of the swing arm 36 and the vehicle body frame 11. The cushion unit 37 is passed between the two. A rear wheel 14 driven by the engine 12 is rotatably attached to the rear end of the swing arm 36.

The engine 12 is suspended from the vehicle body frame 11 via an engine hanger 19.
A fuel tank 41 is disposed above the engine 12, and a seat 42 on which a passenger sits is disposed behind the fuel tank 41. A rear fender 43 is provided below the rear portion of the seat 42, and a taillight 44 is disposed above the rear end of the vehicle.

Next, the configuration of the body frame will be described.
As shown in FIG. 2, the vehicle body frame 11 includes a head pipe 21, a main frame 22 that extends rearward from the head pipe 21, and an engine (FIG. 1, reference sign) that extends diagonally downward and rearward from the front end of the main frame 22. 12) and a rear frame 23 that extends rearward from the main frame 22.

  The main frame 22 is attached to a straight portion 27 that extends linearly from the head pipe 21 toward the rear of the vehicle, a curved portion 28 that extends downward from the rear end 29 of the straight portion 27, and a lower end 28b of the curved member. It consists of a pivot frame portion 24 extending downward. A pivot shaft 25 is provided on the pivot frame portion 24. That is, the pivot frame portion 24, which is a separate member, is attached to the lower end 28b of the bending portion.

  Reinforcing members 51 and 52 are passed inside the bending portion 28. That is, the upper reinforcing member 51 is passed inside the curved portion 28, and the lower reinforcing member 52 is passed inside the curved portion 28 below the upper reinforcing member 51.

  In the present embodiment, the upper and lower two reinforcing members 51 and 52 are provided in the main frame, but the number of reinforcing members may be one or three or more. That is, if necessary, a reinforcing member can be appropriately provided at a necessary location inside the main frame.

Next, a typical cross section of the main frame will be described.
As shown in FIG. 3, the main frame 22 is a rectangular tube-shaped hollow frame formed by combining a left member 71L press-molded so as to have a substantially U-shaped cross section and a press-molded right member 71R. is there.

  The left member 71L includes a left vertical wall portion 61L, a ceiling portion 65L and a bottom surface portion 66L extending from the upper and lower ends 63L and 64L of the left vertical wall portion toward the vehicle width direction center side, and a flange-like shape extending upward from the ceiling portion 65L. It consists of an upper left overhanging portion 67L and a flange-like lower left overhanging portion 68L extending downward from the bottom surface portion 66L.

  Similarly, the right member 71R extends upward from the right vertical wall portion 61R, the ceiling portion 65R and the bottom surface portion 66R extending from the upper and lower ends 63R and 64R of the right vertical wall portion toward the vehicle width direction center side, and the ceiling portion 65R. It consists of a flange-like upper right overhang portion 67R and a flange-like lower right overhang portion 68R extending downward from the bottom surface portion 66R.

  In the integration, the upper left overhanging portion 67L and the upper right overhanging portion 67R may be joined by the welding portion 69, and the lower left overhanging portion 68L and the lower right overhanging portion 68R may be joined by the welding portion 70. The welds 69 and 70 can be formed by spot welding or other welding.

  As shown in FIG. 2, the rear frame 23 is a frame that exhibits a Y shape in a vehicle side view. The structure of the rear frame 23 and the like will be described in detail next.

As shown in FIG. 4, the front lowering portion 90L and the front upper portion 89L of the left outer 88L are joined to the front lowering portion 84L and the front upper portion 83L of the left inner 85L, respectively. For this joining, welding is suitable, but joining with an adhesive or other joining methods may be used.
The rear frame 23L is manufactured by aligning the left outer 88L from the vehicle outer side with the left inner 85L located on the vehicle inner side. Then, the rear frame 23L shown in FIG. 5 is obtained.

As shown in FIG. 6 which is a cross-sectional view taken along line 6-6 of FIG. 5, the front upper portion 83L of the rear frame 23L has a channel-shaped left outer 88L that opens on the vehicle center side, and the left upper 88L that closes the opening. This is a hollow frame comprising a flat left inner 85L fitted to the outer 88L, and welded portions 91 and 92 that join the left inner 85L and the left outer 88L.
Preferably, the left outer 88L has a bead 87 recessed toward the center of the vehicle body. By this bead 87, the rigidity of the front upper portion 83L of the rear frame 23L can be improved.

  Although the structure of the front upper portion 83L of the rear frame 23L has been described above, the structure of the front upper portion 83R of the rear frame 23R is symmetrical with respect to the center line in the vehicle width direction with respect to the structure of the front upper portion 83L of the rear frame 23L. Is different. Since others are the same, description is abbreviate | omitted.

  The structure of the right rear frame 23R is the same as that of the left rear frame 23L described with reference to FIGS. 4 to 6 with respect to the center line in the vehicle width direction, except that the left and right are different. Therefore, the description is omitted.

Next, the front lowering portion of the rear frame and the joint structure to the pivot frame will be described.
As shown in FIG. 7, the front lowering portion 84L of the rear frame 23L, like the above-described front upper portion (FIG. 6, reference numeral 83L), closes the opening with a channel-shaped left outer 88L that opens on the vehicle center side. In this way, it is a hollow frame composed of a flat left inner 85L fitted to the left outer 88L, and welded portions 97 and 98 that join the left inner 85L and the left outer 88L.

  Similarly, the front lowering portion 84R of the rear frame 23R includes a channel-shaped left outer 88R that is open on the vehicle center side, a flat-plate-shaped right inner 85R that is fitted to the right outer 88R so as to close the opening, This is a hollow frame including welded portions 97 and 98 that join the right inner 85R and the right outer 88R.

Front end portions (lower side joint portions 96L, 96R) of the front lower portions of the left and right rear frames 23L, 23R are joined to the pivot frame portion 24 of the main frame 22, respectively. That is,
Lower side joint portions 96L and 96R are provided at the front end portions of the frame front lower portions 84L and 84R, and these lower side joint portions 96L and 96R are joined to the pivot frame portion 24.

  In FIG. 5, a pair of left and right rear frames 23L and 23R are respectively frame rear portions 82L and 82R, and frame front upper portions 83L and 83R extending forward from front ends 81L and 81R of the frame rear portions, respectively, in a side view of the vehicle body. It consists of front frame lowering portions 84L and 84R that extend diagonally downward from the front ends 81L and 81R of the rear portion of the frame, and has a substantially Y shape with the front portion opened in a side view of the vehicle.

  The front end 94L of the left rear frame 23L is joined to the left surface 93L in the vehicle width direction of the curved portion 28 of the main frame 22, and the front end 94R of the right rear frame 23R is joined to the right side 93R in the vehicle width direction of the curved portion 28. Specifically, upper side joint portions 95L and 95R provided at the front end portions of the frame front upper portions 83L and 83R are joined to the main frame 22, and a lower portion provided at the front end portions of the front frame lower portions 84L and 84R is joined to the pivot frame portion 24. Side joints 96L and 96R are joined together.

  Referring also to FIG. 2, in addition to the reinforcing members 51 and 52, an upper reinforcement is provided between the main frame 22 and the rear frame 23 </ b> L at the joint portions 73 and 74 between the main frame 22 and the rear frames 23 </ b> L and 23 </ b> R. A member 77 is handed over and a lower reinforcing member 78 is handed over.

The upper reinforcing member 77 is a member provided at the front part of the frame front upper parts 83L and 83R. The lower reinforcing member 78 is a member provided at the front part of the front frame lowering parts 84L and 84R.
By passing the reinforcing members 77 and 78 to the joint portions 73 and 74 between the main frame 22 and the rear frame 23L, the joint portions 73 and 74 to which a large load is applied can be reinforced.

Next, FIGS. 8 to 11 will be described with respect to the joining structure of the upper reinforcing member passed between the front upper part of the rear frame and the main frame.
As shown in FIG. 8, the upper reinforcing member 77 is joined to the curved portion 28 of the main frame and the left and right rear frames 23L, 23R. The upper reinforcing member 77 includes a flat surface portion 101, a front flange portion 102 obtained by bending the front portion of the flat surface portion 101, and left and right flange portions 103L and 103R obtained by bending left and right portions of the flat surface portion 101 in the vehicle width direction. .

  The flat portion 101 of the upper reinforcing member 77 is provided with a notch-shaped recess 100 at the front so as to avoid the flange-shaped left and right upper projecting portions 67L and 67R projecting from the ceiling portions 65L and 65R of the main frame. .

As shown in FIG. 9, the front upper parts 83L and 83R of the left and right rear frames are joined to the left and right surfaces 93L and 93R of the curved portion.
The upper reinforcing member 77 is disposed at a position where the lower end 83Lb of the front upper portion of the left rear frame and the lower end 103Lb of the left flange portion are substantially the same in the height direction. Similarly, the upper reinforcing member 77 is disposed at a position where the lower end 83Rb of the front upper portion of the right rear frame and the lower end 103Rb of the right flange portion are substantially the same in the height direction. The upper reinforcing member 77 is joined to the rear surface 35 of the main frame and the front upper portions 83L and 83R of the left and right rear frames. In the left and right flange portions, the strength of the joint portion 73 can be increased by passing the upper reinforcing member 77 to the lower ends 83Lb and 83Rb in the front upper portion where a larger load is applied than in the upper upper portion of the front upper portion of the rear frame.

As shown in FIG. 10, the front flange portion 102 extends obliquely upward from the front edge of the flat portion 101 along the rear surface 38 of the curved portion, and the front flange portion 102 is joined to the rear surface 38 of the curved portion. .
In FIG. 9, the left and right flange portions 103L, 103R bent downward are joined to the left and right rear frames 23L, 23R.

In FIG. 8, a substantially rectangular upper reinforcing member 77 is passed to the rear surface 38 of the curved portion, the inner surface 105L of the front upper portion of the left rear frame, and the inner surface 105R of the upper front portion of the right rear frame in plan view. 77 leading edges 106 are joined to the rear surface 38 of the curved portion.
The left and right edges 107L and 107R of the upper reinforcing member 77 are joined to the inner surfaces 105L and 105R of the left and right rear frames.

  As shown in FIG. 11, the left and right rear frames 23L and 23R are welded to the left and right vertical wall portions 61L and 61R of the main frame, respectively, and the upper reinforcing member 77 is attached to the rear surface 38 of the curved portion 28 constituting the main frame 22. The front flange portion 102 of the upper reinforcement member 77 is in contact with the front flange portion 102 of the upper reinforcing member 77, and a notch-shaped recess portion 100 that houses the upper left overhang portion 67L and the upper right overhang portion 67R of the main frame 22 is formed. Is provided.

  The upper reinforcing member 77 is provided with a recess 100 for accommodating the flange-like upper left overhanging portion 67L and the upper right overhanging portion 67R. The concave portion 100 can avoid interference between the upper reinforcing member 77 and the upper left overhanging portion 67L and the upper right overhanging portion 67R. In addition, the joining strength can be increased by joining the upper reinforcing member 77 to the upper left overhanging portion 67L and the upper right overhanging portion 67R.

In FIG. 8, the upper reinforcing member 76 is bent at three sides of the front edge 106 and the left and right edges 107L and 107R to form a flange portion 108, which is used for joining.
With such a structure, the rigidity of the upper reinforcing member 76 is remarkably increased as compared with the case where the upper reinforcing member 77 has only a flat plate portion. In addition, the reinforcing member 76 is difficult to be displaced during the joining work by applying the flange portions 108 of these three sides to the rear surface 38 of the curved portion and the inner surfaces 105L and 105R of the left and right rear frames. As a result, work related to joining becomes easy.

  In this embodiment, the flange portion is not provided at the rear edge of the reinforcing member. However, in addition to the flange portions 108 on the three sides, the rear edge of the reinforcing member may be a bent flange portion.

Next, a description will be given of a joining structure and the like of the lower reinforcing member passed between the front lowering portions of the left and right frames and the main frame.
As shown in FIG. 12, the lower reinforcing member 78 among the reinforcing members includes a flat surface portion 111 and a front flange portion 112 that extends obliquely upward along the rear surface 39 of the pivot frame portion 24 at the front edge of the flat surface portion 111. And left and right flange portions 113L and 113R extending downward from the left and right edges of the plane portion 101 in the vehicle width direction, and a rear flange portion 114 extending downward from the rear edge of the plane portion 101.
The flat surface portion 111, the front flange portion 112, the left and right flange portions 113L and 113R, and the rear flange portion 114 can be manufactured by bending a single metal plate with a press.
In addition to the lower reinforcing member 76, the cross member 121 is passed to the left and right frame front lowering portions 84L and 84R at the vehicle rearward position from the lower reinforcing member 76.

Next, the structure of the lower reinforcing member will be described.
As shown in FIG. 13, the left and right flange portions 113L and 113R are welded to the inner surfaces of the left and right rear frames 23L and 23R, respectively. A plurality of convex beads 122 (four in this example) are formed on the flat portion 111 so as to be convex upward. These convex beads 122 extend in the front-back direction of the figure, that is, in the vehicle front-rear direction.
By forming the plurality of convex beads 122 on the flat portion 111, a predetermined rigidity can be obtained without increasing the plate thickness. As a result, it contributes to weight reduction of the body frame.

In FIG. 12, the lower reinforcing member 78 has a front edge 116, left and right edges 117L, 117R, and a rear edge 119 that are bent downward to form a flange 118, and this flange 118 is used for joining.
With such a structure, the rigidity of the lower reinforcing member 78 is significantly increased as compared with the case where the lower reinforcing member 78 is only a flat plate portion. In addition, the reinforcing member 76 is hardly displaced during the joining work by applying these flange portions 118 to the rear surface 39 of the pivot frame portion and the inner surfaces 115L and 115R of the left and right rear frames. As a result, work related to joining becomes easy.

Next, the structure of the cross member will be described.
As shown in FIG. 14, cross members 121 extending in the vehicle width direction are passed to the front lowering portions 84L and 84R of the left and right frames. In the front lowering portions 84L and 84R of the left and right frames, the left and right outer 88L and 88R have channel portions 86 and 86 that protrude outward in the vehicle width direction. The left and right inner parts 85L and 85R joined to the left and right outer parts 88L and 88R from the inside in the vehicle width direction are channel parts that protrude inward in the vehicle width direction except for the part joined to the outer surface of the cross member 121. 186, 186.

The cross member 121 is disposed between the left and right front frame lowering portions 84L and 84R so as to pass to the channel portions 186 and 186 of the left and right inner 85L and 85R. The cross member 121 can prevent the left and right rear frames 23 from being deformed (bent) in the vehicle width direction.
Since the cross member 121 is provided so as to be passed to the upper surfaces 186a and 186a of the channel portions 186 and 186 of the left and right inner 85L and 85R, positioning work in the vehicle width direction when the cross member 121 is set becomes easy.

The operation of the body frame of the motorcycle described above will be described next.
In FIG. 2, a substantially rectangular upper reinforcing member 77 and a lower reinforcing member 78 are passed to the rear surface of the main frame 22 and the front portion of the rear frame 23.
At the joint point between the main frame 22 and the rear frame 23, the torsional force on the rear frame 23 side is concentrated. In view of this, the upper reinforcing member 77 is welded to this portion to ensure the rigidity to withstand the torsional force.

  A similar twisting force is also applied to the pivot frame portion 24 of the main frame 22. In view of this, the lower reinforcing member 78 is welded to this portion to ensure the rigidity to withstand the torsional force.

The upper and lower reinforcing members 77, 78 do not have to be provided over the entire length of the left and right rear frames 23, but need only be provided at the front portions of the left and right rear frames 23. As a result, the reinforcing members 77 and 78 can be reduced in size, and the body frame 11 can be further reduced in weight.
That is, according to the present invention, there is provided a vehicle body frame 11 constituted by a press-formed product that can increase the rigidity while reducing the weight.

  Referring also to FIG. 5, the rear frames 23L and 23R are reinforced by an upper reinforcing member 77 and a lower reinforcing member 78. Since the upper and lower reinforcing members 77 and 78 provided at the upper and lower portions are reinforced, the reinforcing action at the joint portion between the rear frame 23 and the main frame 22 is further enhanced.

  The front portions of the rear frames 23L and 23R include frame front upper portions 83L and 83R joined to the bending portion 28 and frame front lower portions 84L and 84R joined to the pivot frame portion 24. The torsional force from the rear frame 23 toward the main frame 22 is distributed to the frame front upper parts 83L and 83R and the frame front lower parts 84L and 84R.

  As a result, the influence on the main frame 22 is alleviated, and the main frame 22 can be made thinner and lighter. In addition, since the rear portion of the vehicle body frame 11 is composed only of the left and right rear frames 23, the vehicle body frame 11 can be reduced in thickness and weight. Further, such a Y-shaped rear frame as seen from the side of the vehicle has higher rigidity at the front portion than the I-shaped rear frame as seen from the side of the vehicle, and the rear frame 23 can be made thinner and lighter. Become.

In FIG. 2, the upper reinforcing member 51 provided inside the main frame is disposed at a joint 73 between the main frame 22 and the left and right rear frames 23L and 23R.
Further, in addition to the upper reinforcing member 51, the lower reinforcing member 52 provided in the main frame includes upper side joints 95L and 95R and a lower side joint 96L where the rear frame 23 is joined to the main frame 22. , 96R. That is, the reinforcing member 50 is disposed at the upper side joint portions 95L and 95R of the frame front upper portions 83L and 83R, and the upper side joint portions 95L and 95R and the frame front lower portions 84L and 84R lower side joint portions 96L, It is arranged between 96R.

  The joint portions 73 and 74 between the main frame 22 and the left and right rear frames 23 are one of the most concentrated portions of the load. By reinforcing these portions with the reinforcing members 51 and 52, a limited number of reinforcements are provided. The members 51 and 52 can be utilized most effectively. As a result, the number of reinforcing members can be reduced, and an increase in the weight of the body frame 11 can be suppressed.

  The reinforcing member 51 is disposed at the upper joint portion 73, and the reinforcing member 52 is disposed between the upper joint portion 73 and the lower joint portion 74. The body frame 11 can be efficiently reinforced by the two upper and lower reinforcing members 51 and 52.

  Although the present invention is applied to a motorcycle in the embodiment, it can also be applied to a tricycle and can be applied to a general vehicle.

  The present invention is suitable for motorcycles.

  DESCRIPTION OF SYMBOLS 10 ... Motorcycle, 11 ... Body frame, 21 ... Head pipe, 22 ... Main frame, 23L, 23R ... Rear frame, 24 ... Pivot frame part, 61L, 61R ... Left and right vertical wall part, 65L, 65R ... Left and right ceiling Part, 66L, 66R: left and right bottom surface part, 67L, 67R ... left and right upper projecting part, 68L, 68R ... left and right lower projecting part, 71L, 71R ... left and right member, 77 ... upper reinforcing member, 78 ... lower Reinforcing member, 82L, 82R ... frame rear, 83L, 83R ... upper front of frame, 84L, 84R ... lower front of frame, 87 ... bead, 100 ... recess, 108 ... flange, 121 ... cross member.

Claims (6)

In a body frame of a motorcycle including a main frame (22) extending rearward from the head pipe (21) and a rear frame (23) extending rearward from the main frame (22),
The main frame (22) includes a straight portion (27) extending linearly from the head pipe (21) toward the rear of the vehicle, and a curved portion (28) extending downward while curving from the rear end of the straight portion (27). And consist of
The rear frame (23) has a front end joined to the left surface in the vehicle width direction of the curved portion (28) and extends rearward, and a front end joined to the right surface in the vehicle width direction of the curved portion (28). And a rear rear frame (23R) extending rearward,
In plan view, a substantially rectangular reinforcing member (76) is passed to the rear surface of the main frame (22), the inner surface of the front portion of the left rear frame (23L), and the inner surface of the front portion of the right rear frame (23R). The front edge of the reinforcing member (76) is joined to the rear surface of the curved portion (28), and the left and right edges of the reinforcing member (76) are joined to the inner surfaces of the left and right rear frames (23L, 23R). Motorcycle body frame characterized by   The reinforcing member (76) is formed into a flange portion (108) by bending at least three sides of the front edge and the left and right edges, and the flange portion (108) is used for the joining. The body frame of the motorcycle according to claim 1. The pair of left and right rear frames (23L, 23R) includes a frame rear portion (82L, 82R) and a frame front upper portion (83L, 83R) extending forward from the front end of the frame rear portion (82L, 82R) in a side view of the vehicle body. The frame rear part (84L, 84R) extending obliquely downward from the front end of the frame rear part (82L, 82R), and has a substantially Y shape with the front part open in a side view,
The main frame (22) further includes a pivot frame portion (24) at a lower end of the curved portion (28),
The frame front part (83L, 83R) is joined to the curved part (28), and the frame front lower part (84L, 84R) is joined to the pivot frame part (24). A body frame of a motorcycle according to claim 2.   The reinforcing member (76) includes an upper reinforcing member (77) attached to the front part of the frame front upper part (83L, 83R) and a lower part attached to the front part of the frame front lowering part (84L, 84R). The body frame of the motorcycle according to any one of claims 1 to 3, characterized by comprising a reinforcing member (78). The main frame (22) includes a left vertical wall portion (61L), a ceiling portion (65L) and a bottom surface portion (66L) extending from the upper and lower ends of the left vertical wall portion (61L) to the vehicle width direction center side, A left member (71L) comprising a flange-like upper left overhanging portion (67L) extending upward from the ceiling portion (65L) and a flange-like lower left overhanging portion (68L) extending downward from the bottom surface portion (66L); A right vertical wall portion (61R), a ceiling portion (65R) and a bottom surface portion (66R) extending from the upper and lower ends of the right vertical wall portion (61R) to the center side in the vehicle width direction, and above the ceiling portion (65R) The upper left overhanging portion includes a right member (71R) including a flanged upper right overhanging portion (67R) and a flanged lower right overhanging portion (68R) extending downward from the bottom surface portion (66R). (67L) and the upper right overhang (67R) Joined, a hollow frame formed by bonding the lower left protruding section (68L) and said right lower extended portion (68R),
The notch-shaped recessed part (100) which accommodates the said upper left overhang | projection part (67L) and the said upper right overhang | projection part (67R) in the said reinforcement member (76) is provided. The body frame of the motorcycle according to claim 4.   A cross member (121) extending in a vehicle width direction is passed to the left and right front frame lowering portions (84L, 84R) at a vehicle rearward position from the lower reinforcing member (76). The body frame of the motorcycle according to 3.

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