Title of Invention

"FRAME STRUCTURE FOR SCOOTER"

Abstract

A frame structure for a scooter, equipped with one main pipe (3) that extends in the longitudinal direction of the chassis under the foot panel Ps on which the rider"s feet are placed and that rises in front toward a head pipe H, and a pair of left and right rear frames (41) and (42) that are arranged in parallel to the left and right under a seat S and whose front ends incline forward and downward, and are connected to the rear end (3a) of the said main pipe (3), allowing the seat S to be supported on these rear frames (4i) and (4a); characterized in that the rear end (3a) of the said main pipe (3) and a cross pipe (10) made of a steel tube extending in the lateral direction of the chassis are integrally joined together by passing the one through the other, and the front ends of the pair of the left and right rear frames (41) and (42) are joined to the left and right ends of the said cross pipe (10) and the front frame (15s) of a hanger (15) that swingably supports the front of a power unit (2) for driving the rear wheel is supported by being fitted via a damper rubber part (20) into an opening in the rear end (3a) of the said main pipe (3).

Full Text

The present invention relates to a frame structure for a scooter. [0001] [ Technical Field of the Invention ] The present invention relates to a small vehicle, and in particular to a frame structure for a scooter, equipped with one main pipe that extends in the longitudinal direction of the chassis under the foot panel on which the rider's feet are placed and that rises in front toward a head pipe, and a pair of left and right rear frames .that are arranged in parallel to the left and right under a seat and whose front ends incline forward and downward, and are connected to the .rear end of. the aforementioned main pipe, wherein the seat can be supported-.on these rear frames. « [0002] [Prior Art] In conventional scooters, a bracket is fixed to the rear end of a main pipe extending in the longitudinal direction under the foot panel, and the front ends of a pair of left and right rear frames are connected to and supported by this bracket (see, for example, Utility Model Publication 7-14146). [0003] A scooter in which the hollow part of the rear frames can be used as a conduit through which cool air passes to the transmission mechanism in the power unit has already been proposed (see, for example japense Utility Model Publication 1-8478). [0004] [ Problems Which the Invention Is Intended to Solve ] However, in the conventional structure disclosed in the former publication, the bracket to which the front ends of the left and right rear frames are connected is relatively small in the widthwise direction of the vehicle, so the distance between the front ends of the left and right rear frames (and, accordingly, the rear frame support span) is relatively short, and the rear frames have correspondingly lower support rigidity for the seat or the like. [ 0005 ] ' Because the front ends of the left and right rear frames are so close to each other, it is difficult to insert the front end of the power unit for driving the rear wheel between them, making it impossible to bring the power unit near the front of the rear frames (that is, bring it to the front side of the chassis) so as to reduce the longitudinal scale of the vehicle. In particular, when an intake duct protruding from the outside surface of the transmission case for the power unit is connected to the front of the rear frames\ a relatively long duct is required. [0006] In view of the foregoing, an object of the present invention is to provide a frame structure for a scooter capable of remedying the aforementioned conventional structural problems. [ 0007 ] [ Means Used to Solve the Above-Mentioned Problems ] To achieve the aforementioned objective, the invention in Claim 1 is a frame structure for a scooter, equipped with one main pipe that extends in the longitudinal direction of the chassis under the foot panel on which the rider's feet are placed and that rises in front toward a head pipe, and a pair of left and right rear frames that are arranged in parallel to the left and right under a seat and whose front ends incline forward and downward, and are connected to the rear end of the aforementioned main pipe, allowing the seat to be supported on these rear frames; wherein said frame structure for a scooter is characterized by the fact that: the rear end of the aforementioned main pipe and a cross pipe made of a steel tube extending in the lateral direction of the chassis are integrally joined together by passing the one through the other, and the front ends of the pair of left and right rear frames are joined to the left and right ends of the aforementioned cross pipe. In addition to the features in Claim 1, the invention in Claim 2 is characterized by the fact that the front end of a hanger that swingably supports the front of a power unit for driving the rear wheel is supported by being fitted via a damper rubber part into an opening in the rear end of the aforementioned main pipe. In addition to the features of Claims 1 and 2, the invention in Claim 3 is characterized by the fact that the aforementioned pair of left and right rear frames are constructed of hollow pipes, the front end of the power unit for driving the rear wheel is inserted between the two rear frames, an intake duct protruding from the outside surface of the front of the transmission case of the power unit is connected to the bottom of at least one of the aforementioned rear frames so as to introduce cool air into said transmission case, and the tops of the aforementioned rear frames are provided with intake ports through which outside air can be introduced. Accordingly the present invention relates to a frame structure for a scooter, equipped with one main pipe (3) that extends in the longitudinal direction of the chassis under the foot panel Ps on which the rider's feet are placed and that rises in front toward a head pipe H, and a pair of left and right rear frames (4i) and (4a) that are arranged in parallel to the left and right under a seat S and whose front ends incline forward and downward, and are connected to the rear end (3a) of the said main pipe (3), allowing the seat S to be supported on these rear frames (4i) and (4a); characterized in that the rear end (3a) of the said main pipe (3) and a cross pipe (10) made of a steel tube extending in the lateral direction of the chassis are integrally joined together by passing the one through the other, and the front ends of the pair of the left and right rear frames (4i) and (42) are joined to the left and right ends of the said cross pipe (10) and the front frame (15s) of a hanger (15) that swingably supports the front of a power unit (2) for driving the rear wheel is supported by being fitted via a damper rubber part (20) into an opening in the rear end (3a) of the said main pipe (3). [ Brief Description of the Figures ] [ Figure 1 ] Figure 1 is a comprehensive side view schematically depicting a practical example of a scooter of the present invention. [ Figure 2 ] Figure 2 is a schematic plant (viewed from arrow 2 in Figure 1) of the aforementioned practical example. [ Figure 3 ] Figure 3 is an enlarged cross section viewed from arrow 3-3 in Figure 2. [ Figure 4 ] Figure 4 is an enlarged cross section viewed from arrow 4-4 in Figure 3. [ Figure 5 ] Figure 5 is an enlarged cross section viewed from arrow 5-5 in Figure 3. [ Figure 6 ] Figure 6 is an enlarged cross section viewed from arrow 6-6 in Figure 4. [0008] [ Preferred Embodiments of the Invention ] An embodiment of the present invention is described in detail below with reference to a practical example of the present invention depicted in the attached drawings. [0009] Among the attached drawings, Figure 1 is a comprehensive side view schematically depicting a practical example of a scooter of the present invention. Figure 2 is a schematic plan (viewed from arrow 2 in Figure 1) of the aforementioned practical example. Figure 3 is an enlarged cross section viewed from arrow 3-3 in Figure 2. Figure 4 is an enlarged cross section viewed from arrow 4-4 in Figure 3. Figure 5 is an enlarged cross section viewed from arrow 5-5 in Figure 3. Figure 6 is an enlarged cross section viewed from arrow 6-6 in Figure 4. [ 0010 ] In Figures 1 and 2, the outer panel P of the scooter-type two-wheel vehicle V comprises: a foot panel Ps on which the rider's feet are placed; a front outer panel Pf having an integral leg shield 1 rising from the front end of the foot panel Ps; and a rear outer panel Pr that is connected to the rear end of the foot panel Ps and that covers (from above) the rear wheel Wr and rear wheel driving power unit 2. A seat S is situated in an opening in the top end of the rear outer panel Pr, and the bottom front end of the seat S is openably and closably hinged at the rear outer panel Pr. [0011] A metal chassis frame F that supports the aforementioned outer panel P integrally comprises: a head pipe H inside the front outer panel Pf that steerably supports the front wheel Wf; one main pipe 3 that extends in the longitudinal direction of the chassis under the foot panel Ps and that rises in front toward the head pipe H; and a pair of left and right rear frames 4! and 42 in the rear outer panel Pr under the seat S that are arranged in parallel at a distance to the left and right and whose front halves incline forward and downward, and are connected to the rear end of the main pipe 3. [ 0012 ] The pair of left and right rear frames 4l and 42 are constructed of hollow pipes. The tops, that is, the rear halves 4rj and 4r2, extend roughly linearly in the longitudinal direction of the chassis directly under the seat S and are integrally connected to each other via a top cross pipe 5, and the rear ends are bent inward toward each other. As may be seen in Figure 5, an upward facing intake port 5a for taking air into said pipe 5 (and thus the rear frame 4j) is provided in the upper face in the lateral center of the top cross pipe 5, a channel-shaped support panel 6 is fixed straddling the intake port 5a, and a seat catch stay 7 attachably and detachably contact supporting the longitudinal center of the bottom panel of the seat S is screwed to the support panel 6. [ 0013 ] A bracket 8 is fixed facing backward and downward adjacent to the support panel 6 on the top cross pipe 5, and the top end of a rear cushion 9 elastically supporting the power unit 2 is pivotally connected to the bracket 8. A rear fender Rf placed over the rear wheel Wr is situated under the rear halves 4^ and 4r2 of the rear frames 4j and 42, so as to prevent mud and the like flung up by the rear wheel Wr from penetrating into the chassis space surrounded by the rear outer panel Pr above said fender Rf and below the seats. [0014] As shown in Figures 3 and 4, the rear end 3a of the main pipe 3 and the bottom cross pipe 10 made of a steel tube extending in the lateral direction of the chassis are integrally joined together by passing the one (the main pipe rear end 3a in the example in the figure) through the other (the cross pipe 10 in the example in the figure), and the front ends of the pair of left and right rear frames 4] and 42 are butt-welded to the left and right ends of the bottom cross pipe 10. The bottom cross pipe 10 constitutes the cross pipe in-the present invention. The rear end 3a of the main pipe 3 is formed into an oblong shape having a vertically flat side cross section, with the flat tube component welded to said pipe 10 while passing through the bottom cross pipe 10 in the longitudinal direction. Between the left and right ends of the bottom cross pipe 10 and the front ends of the pair of left and right rear frames 4j and 42, a pair of left and right brackets B! and B2 which are intended to enhance the bonding strength between the above is welded between them so as to straddle the space therebetween. The rear ends of left and right stays St^ and St2 supporting the foot panel Ps are connected to the brackets B! and B2. [ 0015 ] The front end 2a of the power unit 2 (the head cover part of the engine E in the example in the figure) protrudes between the front of the pair of left and right rear frames 4! and 42 near the bottom cross pipe 10, thereby allowing the power unit 2 as a whole to be moved toward the front, that is, near the main pipe 3, without interfering with the rear frames 4l and 42, so that the longitudinal scale of the vehicle can be reduced. [0016] The power unit 2, which is constructed by making a unit of the engine E and the gears for shifting and transmitting power to the rear wheel Wr, functions as a swing arm on which the rear wheel Wr swingably pivots. The front of the power unit 2 is vertically swingably connected to and supported by the bottom cross pipe 10 via a hanger 15. That is, the back frame 15 b of the hanger 15 in the form of a roughly square-shaped frame is rotatably connected, via a rubber bushing 16 and a spindle 17 passing through it, to a support arm 2b protruding at the bottom near the front end of the power unit 2. The front frame 15a of the hanger 15 is rotatably connected, via a rubber bushing 18 and a spindle 19 passing through it, to the pair of left and right brackets lOb and 1 Ob .which straddle and are welded between the rear face of the left and right ends of the bottom cross pipe 10 and the fronts of the left and right rear frames 41 and 42. [0017] A channel-shaped stopper piece 15s fixing a block-shaped damper rubber part 20 to the front end protrudes integrally from the center of the front face of the front frame 15a of the hanger 15. This stopper piece 15s, as may be seen in Figure 6, is fitted into and supported in an opening in the rear end 3a of the main pipe 3 via the damper rubber part 20, so that the vertical swinging of the hanger 15 around the spindle 19 is elastically suppressed by means of the damper rubber part 20. In this way, the damper rubber part 20 and the stopper piece 15 serving as the front end of the hanger 15 are housed in the opening of the rear end 3a of the main pipe 3, allowing said rear end 3a to be used as a swinging stopper means for the hanger 15, and allowing the hanger support structure to be simplified and made more compact. As shown in the example in the figures, the main pipe rear end 3a is in the form of a vertically flat (and thus relatively long, laterally speaking) tube, so that not only is the support strength reinforced for the bottom cross pipe 10, but left and right positional shifting between the hanger 15 and the main pipe rear end 3a can also be readily absorbed, and the vibration proofing properties of the damper rubber part 20 can also be enhanced. [0018] The transmission case 11 of the wrapping mechanism M by which the engine E power is transmitted to the rear wheel Wr is integrally provided on either side of the power unit 2. A tube-shaped intake port lla for cool air is provided in the outer face of the front end of the transmission case 11. Between the intake port lla and an air outlet 43^ provided in the bottom surrounding wall of the rear frame 4j (left side in example in figure) facing the intake port, a flexible intake duct 12 is inserted to connect them. The interior of the transmission case 11 is provided with a suction means 13 (suction fan fixed to the drive pulley side face of the transmission mechanism M in the example in figures) that forcibly suctions cool air from the aforementioned intake duct 12 into the transmission case 11. [0019] The action of the aforementioned practical example is described below. When the rear wheel Wr bounces because of depressions and protrusions or the like on the ground while the vehicle V is running, the power unit 2 swings vertically in response around the spindle 17 of the rear end of the hanger 15 while dampened by the rear cushion 9. At this tune, the hanger 15 itself also tends to swing somewhat (see double-dot dashed line in Figure 3) around the spindle 19 on the bottom cross pipe 10 side because of shock force exerted on the hanger 15, but the motion is buffered since the stopper piece 15s at the hanger 15 front end is elastically engaged in the opening of the main pipe rear end 3a via the damper rubber part 20. [0020] The suction means 13 inside the transmission case 11 acts according to the operation of the engine E in the power unit 2. The transmission mechanism M is cooled by air introduced by the suction action of the suction means 13 from the chassis space directly under the seat through the intake port 5a, the top cross pipe 5, the one rear frame 41, the air outlet 4a.1, and the intake duct 12 into the transmission case 11. The air is then released to the outside through an exhaust outlet (not shown in figure) in a suitable location in the power unit 2. [ 0021 ] The fronts of the left and right rear frames 4l and 42 are supported by the rear end 3a of the main pipe 3 via the bottom cross pipe 10 made of a steel tube intersecting said pipe 3, and the gap between the left and right rear frames 4l and 42 in the support component (and thus the rear frame support span) is kept relatively ••>, long, so the support rigidity provided by the left and right rear frames 4! and 42 for the seat S, rear outer panel Pr, rear cushion 9, and the like can be effectively increased while reducing the weight and cost of the frame structure, and the gap between the fronts of the left and right rear frames 41 and 42 is also widened, so that the front end 2a of the rear wheel-driving power unit 2 can be inserted there without difficulty, allowing the power unit 2 to be brought closer to the extreme front side overall without interfering with the rear frames 4, and 42. [ 0022 ] As shown in the example in the figures, the front end 2a of the power unit 2 is inserted between the front ends of the left and right rear frames 4! and 42, allowing the intake duct 12 protruding from the outer face of the transmission case 11 of the power unit 2 to be brought closer by means of the bottoms of the rear frames 4j and 42, so the duct length can be shortened by that much, and the clean outside air passing from the top of the rear frames 4j and 42 through the interior of the rear frames 4j and 42 into the duct 12 can be efficiently introduced into the transmission case 11. [ 0023 ] A practical example of the present invention was described above, but the present invention is not limited to the aforementioned practical example. Various practical examples are possible within the scope of the present invention. For example, the practical example above was of a scooter two-wheel vehicle, but the present invention may also be realized with scooter three-wheel vehicles. In the practical example above, the intake port 5a that is supposed to be provided in the top of the rear frames 4j and 42 was open on the top face of the upper cross pipe 5 connecting the left and right rear frames 4j and 42 underneath the support panel 6 for the seat catch stay, but the location of the intake port in the present invention is not limited to the aforementioned practical example. For example, the intake port can be open directly in the top of either of the rear frames 41 and 42. It is also desirable to provide it facing upward in.-the chassis space directly under the seat S surrounded by the rear outer panel Pr in order to take in only clean air from the intake port while keeping out mud, rain, or the like flung up by the rear wheel. [0024] In the practical example above, the rear end 3a of the main pipe passed longitudinally through the cross pipe 10, but the cross pipe 10 may in contrast be passed laterally through the rear end 3a of the main pipe. [0025] [ Merits of the Invention ] As described above, the invention in the claims is such that the front ends of left and right rear frames are supported by the rear end of the main pipe via a cross pipe made of a steel pipe that is relatively light weight, is inexpensive, and has considerable bending strength, so the gap between the left and right rear frames (and thus the rear frame support span) in the support component can be made sufficiently long, allowing the support rigidity for the seat or the like by the left and right rear frames to be effectively enhanced while lowering the weight and cost of the frame structure. The gap between the fronts of the left and right frames is also wider, allowing the rear wheel-driving power unit whose front end faces said fronts to be brought closer to the extreme front side without interfering with the rear frames, so the vehicle can be made smaller in the longitudinal direction. [0026] In the invention in Claim 2 in particular, a damper rubber part and the front end of the power unit hanger are housed in the opening of the rear end of the main pipe, allowing the main pipe itself to be used as a stopper means for said hanger, so the hanger support structure can be simplified and made smaller. [ 0027 ] In the invention in Claim 3, the front end of the rear wheel-driving power unit is inserted between the front ends of the left and right rear frames, allowing the power unit to be brought even closer to the front side of the chassis, and allowing the intake duct protruding on the outer surface of the power unit transmission case to be brought closer by means of the bottoms of the rear frames, so the duct length can be shortened, thereby allowing clean air passing from the top of the rear frames through the interior of the rear frames and into the duct to be efficiently introduced iaside the transmission case. [ Key to Symbols ] H: head pipe; Ps: foot panel; S: seat; 2: power unit; 3: main pipe; 3a: rear end; 41, and 42: rear frames; 5a: intake port; 10: bottom cross pipe serving as cross pipe; 11: transmission case; 12: intake duct; 15: hanger; 15s: stopper piece serving as front end; 20: damper rubber WE CLAIM: 1. A frame structure for a scooter, equipped with one main pipe (3) that extends in the longitudinal direction of the chassis under the foot panel Ps on which the rider's feet are placed and that rises in front toward a head pipe H, and a pair of left and right rear frames (41) and (42) that are arranged in parallel to the left and right under a seat S and whose front ends incline forward and downward, and are connected to the rear end (3a) of the said main pipe (3), allowing the seat S to be supported on these rear frames (41) arid (4a); Characterized in that the rear end (3a) of the said main pipe (3) and a cross pipe (10) made of a steel tube extending in the lateral direction of the chassis are integrally joined together by passing the one through the other, and the front ends of the pair of the left and right rear frames (4i) and (42) are joined to the left and right ends of the said cross pipe (10) and the front frame (15s) of a hanger (15) that swingably supports the front of a power unit (2) for driving the rear wheel is supported by being fitted via a damper rubber part (20) into an opening in the rear end (3a) of the said main pipe (3). 2. A frame structure for a scooter as claimed in claim 1, wherein the said pair of left and right rear frames (4i) and (4z) are constructed of hollow pipes, the front end (2a) of the power unit (2) for driving the rear wheel is inserted between the two rear frames (41) and (4a) an intake duct (12) protruding from the outside surface of the front of the transmission case (11) of the power unit (2) is connected to the bottom of at least the one said rear frame (41) so as to introduce cool air into said transmission case (11), and the tops of the said rear frames (41) and (42) are provided with intake ports (5a) through which outside air is introduced. 3. A frame structure for a scooter substantially as herein before described with reference to the accompanying drawings.

Documents:

1242-del-1997-abstract.pdf

1242-del-1997-claims.pdf

1242-del-1997-correspondence-others.pdf

1242-del-1997-correspondence-po.pdf

1242-del-1997-description (complete).pdf

1242-del-1997-drawings.pdf

1242-del-1997-form-1.pdf

1242-del-1997-form-13.pdf

1242-del-1997-form-19.pdf

1242-del-1997-form-2.pdf

1242-del-1997-form-3.pdf

1242-del-1997-form-4.pdf

1242-del-1997-form-6.pdf

1242-del-1997-gpa.pdf

1242-del-1997-petition-137.pdf

1242-del-1997-petition-138.pdf