JP3948819B2 - Scooter type motorcycle body frame - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a body frame of a scooter type motorcycle having a low floor footrest between a steering handle and a seat.
[0002]
[Prior art]
Conventionally, as a body frame of a scooter type motorcycle, one main frame is directly welded to a head pipe, the main frame is extended obliquely rearward and downward, and further extended rearward substantially horizontally. In some cases, a footrest portion with a low floor is formed.
[0003]
By the way, in the body frame of the scooter type motorcycle, since a large bending moment acts on the connection portion between the head pipe and the main frame, it is necessary to increase the rigidity of the connection portion.
[0004]
In the conventional vehicle body frame, in order to increase the rigidity of the connection portion, the main frame is directly connected to the head pipe by welding, and the connection portion has a left and right size extending over both the head pipe and the main frame. A structure is adopted in which a pair of reinforcing plates, or a pair of upper and lower reinforcing plates, are arranged and the reinforcing plates are welded to the head pipe and the main frame.
[0005]
[Problems to be solved by the invention]
By the way, recently, in order to improve fuel consumption, there is an increasing demand for weight reduction of vehicles, not limited to starter type motorcycles. However, in order to ensure rigidity, the above-described conventional vehicle body frame employs a structure in which not only the head pipe but also the main frame employs a considerably thick pipe member, and a structure in which both connecting portions are covered with a reinforcing plate. The weight of the connecting portion increases, and this point becomes a bottleneck in reducing the weight of the body frame.
[0006]
Further, since the above-described conventional vehicle body frame is premised on the main frame being directly welded to the head pipe, there is a problem that the degree of freedom in design is low with respect to the inclination angle of the main frame. That is, if the inclination angle of the main frame is too steep, it becomes difficult to weld the main frame and the head pipe. In order to ensure weldability while steeply tilting the main frame, it is necessary to bend the upper end of the main frame so that it is close to the head pipe, but the thick main frame is bent with a small curvature. As a result, the degree of freedom in design is low.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and can provide a vehicle body for a scooter type motorcycle that can reduce the weight of the vehicle body frame and can increase the degree of design freedom such as the inclination angle of the main frame. The challenge is to provide a frame.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, in a vehicle body frame of a scooter type motorcycle having a low-floor footrest between a steering handle and a seat, the main frame is extended obliquely downward rearward of the vehicle, and further substantially horizontally rearward. Extend the left and right sub-frames located on the left and right of the main frame obliquely downward and rearward of the vehicle, and extend substantially horizontally rearward. The rear end of the main frame and the left and right The rear end of the sub-frame is positioned at substantially the same height, and the left and right of the left and right sub-frames have different diameters through the cylindrical left and right side gussets at the rear end of the left and right sub-frame. The left and right side gussets and the rear end of the main frame are connected via a cross pipe that extends substantially linearly in the vehicle width direction. Side gusset connection The bracket engine suspension is characterized in that connected to span in both the above cross pipe and the side gussets.
[0009]
According to a second aspect of the present invention, in the first aspect, the side gusset is generally L-shaped in a side view, the subframe and the side frame are connected to one end and the other end of the side gusset, and the side gusset is in the vicinity of a bent portion. A cross pipe is connected. The invention according to claim 3 is the rectangular tube body according to claim 1, wherein the side gusset is formed by abutting and joining an outer plate and an inner plate pressed to have a U-shaped cross section. The rear end portion of the sub-frame is fitted and inserted into the front end opening, and the front end portion of the side frame is fitted and inserted into the rear end opening.
[0015]
[Effects of the invention]
According to the first aspect of the present invention, since the front ends of the left and right side frames are welded to the rear ends of the left and right subframes via the side gussets, the diameters of the front and rear end openings of the side gussets are appropriately set. By setting, there is an effect that the sub-frame and the side frame having different diameters can be easily and securely connected.
[0016]
Also, the left and right side gussets are welded together via a cross pipe, the rear end of the main frame is welded to the cross pipe, and the engine suspension bracket is connected to the connection portion between the cross pipe and the side gusset . And since it connected so that it might cross over both this cross pipe and a side gusset, there exists an effect which can improve the support rigidity of an engine unit.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 8 are views for explaining a body frame of a scooter type motorcycle according to a first embodiment of the present invention, and FIG. 1 is a left side view of the scooter type motorcycle provided with the body frame of the embodiment. 2 and 3 are a left side view and a plan view of the body frame, FIG. 4 is a left side view around the head gusset, FIG. 5 is a cross-sectional view taken along line VV in FIG. 4, and FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 6, and FIG. 8 is a plan view of the connecting portion of the main, sub, side frame, and cross pipe.
[0018]
In the figure, reference numeral 1 denotes a scooter type motorcycle, which pivotally supports a front fork 4 so as to be steerable left and right by a head pipe 3 at the front end of a body frame 2, and pivotally supports a front wheel 5 at the lower end of the front fork 4. At the same time, a steering handle 6 is fixed to the upper end, the engine unit 7 is pivotally supported at a substantially central portion in the front-rear direction of the body frame 2, and the rear wheel 8 is pivotally supported at the rear end of the engine unit 7. And, it has a schematic structure in which a seat 9 is mounted on the upper part of the body frame 2. The front fork 4 and the vehicle body frame 2 are surrounded by a vehicle body cover 22, and a low floor footrest F is formed between the seat 9 and the steering handle 6. The backrest of the front seat occupant 9a, 9b is the backrest of the rear seat occupant, and 9c is a gripping member for stabilizing the riding posture of the rear seat occupant.
[0019]
The vehicle body frame 2 includes one main frame 11 welded to the head pipe 3 via a head gusset 10 and two left and right subframes 12 and 12, and the left and right subframes 12 and 12. 12 are provided with left and right side frames 14 and 14 which are welded and connected to the rear end portions of 12 via side gussets 13 and 13.
[0020]
The head gusset 10 has a so-called monocoque-like shape in which the left and right plates 10a and 10a press-molded in a U-shaped cross section are butted and connected to each other, and the front and rear end openings 10b and 10c are in a vertically long rectangular cross section. Is. The left and right side plates 10a, 10a are connected to each other through a reinforcing plate 23 disposed inside. The reinforcing plate 23 has a U-shaped cross section, and one side 23a is welded to the inner surface of the right side plate 10a, and the other side 23b is welded from the outside to the peripheral edge of the slit 10e of the left side plate 10a.
[0021]
The front end opening 10b of the head gusset 10 has a shape along the outer peripheral shape of the head pipe 3, and the periphery of the front end opening 10b is fitted to the outer peripheral surface of the head pipe 3 and welded.
[0022]
The rear end opening 10c of the head gusset 10 has a shape corresponding to the shape of the front end portion 11a of the main frame 11, and the front end portion 11a is fitted and inserted into the rear end opening 10c and welded. . The main frame 11 is composed of a lower inclined portion 11b extending obliquely downward and rearward from the rear end opening 10c of the head gusset 10, and a horizontal portion (rear extension portion) 11c extending rearward substantially horizontally from the lower end of the lower inclined portion 11b. Has been.
[0023]
The upper end portion of the sub-frame 12 is crushed and the front end portion 12a is welded to a portion of the outer surface of the side plate 10a of the head gusset 10 facing the reinforcing plate 23 in a flange shape. The sub-frame 12 includes an inclined portion 12b extending obliquely rearward and downward from the side plate 10a of the head gusset 10, and a horizontal portion (rear extension portion) 12c extending substantially horizontally rearward from the lower end of the inclined portion 12b.
[0024]
The inclined portions 12b and 12b of the left and right sub-frames 12 are steeper than the inclined portion 11b of the main frame 11, and one center between the left and right inclined portions 12b and 12b. A radiator 24 is disposed in a space in front of the downward inclined portion 11b of the main frame 11. Reference numeral 24a denotes a blower fan, which is located in a triangular space formed by the inclined portions 12b and 11b when viewed from the side.
[0025]
Further, the left and right side gussets 13 and 13 are so-called monocoque-shaped square cylinders in which an outer plate 13a and an inner plate 13b press-molded to have a substantially U-shaped cross section and are substantially L-shaped in side view are welded and joined. It is. The rear end portion 12d of the sub-frame 12 is fitted and inserted into the front end opening 13c of the side gusset 13, and the front end portion 14a of the side frame 14 is fitted and inserted into the rear end opening 13d. Welded connected.
[0026]
The left and right side frames 14 have a rising portion (upward inclined portion) 14b extending obliquely rearward and upward from the rear end opening 13d of the side gusset 13, and rearward substantially horizontally from the upper end of the rising portion 14b. It is comprised from the horizontal part 14c extended.
[0027]
The left and right side gussets 13, 13 are welded together by a cross pipe 15. This cross pipe 15 has a circular cross-sectional shape, and its left and right end portions 15b are fitted and inserted into connection holes in the inner plate 13a of the side gusset 13 and fixed by welding. The left and right end portions 15b of the cross pipe 15 are fixed by welding via a reinforcing member 15a. Reference numeral 25 denotes a bracket for attaching the side stand.
[0028]
Further, the horizontal portions 12c, 12c of the left and right subframes 12 and the horizontal portion 11c of the central main frame 11 are set so that the bottom surfaces thereof substantially coincide with each other, and the rear end portion of the main frame 11 11d is formed in accordance with the size of the cross pipe 15, and is welded to the center portion of the cross pipe 15 in the vehicle width direction.
[0029]
The left and right engine suspension brackets 16 and 16 are fixed by welding so as to extend over the lower surfaces of the left and right side gussets 13 and 13 and the left and right ends 15b of the cross pipe 15. The pivot portion 7a of the engine unit 7 is pivotally supported by the engine suspension brackets 16,16.
[0030]
The downward inclined portion 11b of the one main frame 11 and the left and right rising portions 14b, 14b of the left and right two side frames 14, 14 are welded together by tension pipes 17, 17. The front end portions 17a and 17a of the tension pipes 17 and 17 are fixed to the common front bracket 18 by welding, and the front bracket 18 is fixed to the middle portion of the inclined portion 11b of the main frame 11 by welding. The rear end portions 17b and 17b of the left and right tension pipes 17 and 17 are fixed by welding to the rear brackets 19 and 19, respectively, and the rear bracket 19 is fixed by welding to the rising portion 14b.
[0031]
The left and right tension pipes 17 and 17 are joined in a portal shape by sheet metal seat stays 20 and welded together. A hinge bracket 21 is provided on the upper surface of the seat stay 20 in the center in the vehicle width direction, and a hinge fixed to the front end of the seat 9 is pivotally supported by the hinge bracket 21.
[0032]
A foot bracket 12e is fixed to the inclined portion 12b and the horizontal portion 12c of the left and right subframes 12 by welding, and the footboard portion 22b of the vehicle body cover 22 is supported by the foot bracket 12e.
[0033]
Further, the front and rear center portions of the left and right side frames 14 and 14 are welded together by a cross pipe 29, and the rear ends of the horizontal portions 14c and 14c are While supporting the rear-end part of the said sheet | seat 9, it is welded and joined by the gate-shaped sheet | seat receiving bracket 30 by which the locking mechanism was arrange | positioned.
[0034]
Furthermore, a standing handle 31 is disposed substantially in parallel with the horizontal portion 14c in plan view at the rear of the left and right horizontal portions 14c, 14c. The standing handle 31 is grasped by inserting a hand from a hole formed in the side cover portion 22a that covers the lower part of the seat of the vehicle body cover 22, and lifted upward so that the vehicle stands on the main stand.
[0035]
A fuel tank 26 is mounted from between the rising portions 14b, 14b of the left and right side frames 14, 14 to between the horizontal portions 14c, 14c, and a storage capable of storing a helmet H or the like at the rear portion between the horizontal portions 14c, 14c. A box 27 is mounted, and a battery 28 is mounted between the storage box 27 and the fuel tank 26. The storage box 27 is fixed to the vehicle body frame using a bolt hole 31b formed in the vehicle body mounting flange portion 31a of the standing handle 31 and a bolt hole 30b formed in the upper side portion 30a of the seat receiving bracket 30. Yes.
[0036]
In the vehicle body frame 2 of this embodiment, a front end opening 10d of a monocoque head gusset 10 made of sheet metal is welded and fixed to the head pipe 3, and a front end portion 11a of the main frame is fixed to the rear end opening 10e of the head gusset 10 by welding. Since the front ends 12a and 12a of the left and right subframes 12 and 12 are welded and fixed to the left and right plates 10a and 10b of the head gusset 10, generally the thick and heavy main frame 11 is substantially the head gusset 10. It can be shortened by the length of, so that the weight can be reduced.
[0037]
The head gusset 10 is vertically long when viewed in cross section, that is, vertically long with respect to the direction of the bending moment (vertical direction) acting on the connection between the head pipe 3 and the main frame 11, and the cross section in this direction. The coefficient increases, so that it is possible to easily and surely secure the necessary rigidity at the connection portion between the head pipe and the main frame where the largest bending moment acts on the body frame 2. In this embodiment, since the reinforcing plate 23 is disposed and fixed by welding in the head gusset 10, the left and right plates 10a and 10a are not deformed inward, and rigidity can be secured from this point.
[0038]
In this embodiment, since the main frame 11 and the sub frame 12 are joined to the head pipe 3 via the head gusset 10, compared to the conventional structure in which the main frame and the sub frame are joined directly to the head pipe, The degree of freedom of the inclination angle of the main frame and sub frame is high. In other words, in the case of a structure in which a main frame or the like is directly joined to a conventional head pipe, the steep inclination angle becomes difficult to join with the head pipe or the problem of interference with a radiator or the like is likely to occur. . In the case of this embodiment, making the inclination angle of the main frame steeper can be realized without any trouble by appropriately setting the shape of the head gusset.
[0039]
Further, since the main frame 11 and the sub frame 12 are joined to the head pipe 3 via the head gusset 10, the necessary welding length can be shortened, and the productivity is improved. That is, when the main frame and the sub frame are directly joined to the head pipe, the reinforcing plate is essential from the viewpoint of securing rigidity, and as a result, the required weld length is increased.
[0040]
Furthermore, in this embodiment, since the front ends 14a of the left and right side frames 14 are welded to the rear end portions 12d of the left and right subframes 12 via the side gussets 13, the front and rear ends of the side gussets 13 are connected. By appropriately setting the diameters of the openings 13b and 13c, the subframe 12 and the side frame 14 having different diameters can be easily welded together.
[0041]
Further, the left and right side gussets 13 and 13 are welded to each other via a cross pipe 15, and the rear end 11 d of the main frame 11 is welded to the cross pipe 15, so that the cross pipe 15 and the side gusset 13 are connected to each other. Since the engine suspension bracket is welded to the connecting portion, the support rigidity of the engine unit 7 can be increased.
[0042]
The middle of the lower inclined portion 11b of the main frame 11 and the middle of the rising portions 14b and 14b of the left and right side frames 14 and 14 are welded and joined with a pair of left and right tension pipes 17 and 17, and the left and right Since the tension pipes 17 and 17 are joined by the seat stay 20, the rigidity of the entire vehicle body frame 2 can be greatly increased, and the twisting feeling of the vehicle body can be reduced.
[Brief description of the drawings]
FIG. 1 is a left side view of a scooter type motorcycle including a body frame according to an embodiment of the present invention.
FIG. 2 is a left side view of the vehicle body frame.
FIG. 3 is a plan view of the body frame.
FIG. 4 is a left side view of a head gusset portion of the vehicle body frame.
FIG. 5 is a cross-sectional rear view (cross-sectional view taken along the line VV in FIG. 4) of the head gusset portion of the vehicle body frame.
FIG. 6 is a left side view of a side gusset portion of the vehicle body frame.
7 is a sectional rear view (sectional view taken along line VII-VII in FIG. 6) of a side gusset and a cross pipe portion of the vehicle body frame.
FIG. 8 is a plan view of a connection portion between the main, sub, side frame, and cross pipe of the body frame.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Scooter type motorcycle 2 Body frame 3 Head pipe 6 Steering handle 9 Seat 10 Head gussets 10a, 10a Left, right side plate (left, right side)
10b Front end opening 10c Rear end opening 11 Main frame 11a Main frame front end 12 Subframe 12a Subframe front end 13 Side gusset 14 Side frame 15 Cross pipe 16 Engine suspension bracket

Claims (3)

In a vehicle body frame of a scooter type motorcycle having a low floor footrest between a steering handle and a seat, the main frame is extended obliquely downward rearward of the vehicle, and further extended substantially horizontally rearward . The left and right sub-frames arranged on the left and right are extended obliquely downward rearward of the vehicle, and further extended substantially horizontally rearward. The rear end of the main frame and the rear end of the left and right sub-frames Are positioned at substantially the same height, and the left and right side frames having a diameter different from that of the sub frame are connected to the rear ends of the left and right sub frames via cylindrical left and right side gussets, The left and right side gussets and the rear end of the main frame are connected via a cross pipe extending substantially linearly in the vehicle width direction, and the connection portion between the cross pipe and the left and right side gussets Engine suspension bracket A body frame of a scooter type motorcycle, wherein a socket is connected to span in both the above cross pipe and the side gussets. 2. The side gusset according to claim 1, wherein the side gusset has a substantially L shape in a side view, the sub frame and the side frame are connected to one end and the other end of the side gusset, and the cross pipe is connected to the vicinity of the bent portion. Scooter type motorcycle body frame characterized by this. 2. The side gusset according to claim 1, wherein the side gusset is a rectangular tube body obtained by abutting and joining an outer plate and an inner plate press-formed in a U-shaped cross section, and the subframe is formed at a front end opening of the rectangular tube member. A body frame of a scooter type motorcycle, wherein a rear end portion is fitted and inserted and connected, and a front end portion of the side frame is fitted and inserted into a rear end opening.

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