Title of Invention

"FRAME STRUCTURE OF SCOOTER TYPE VEHICLE"

Abstract

In the scooter type vehicle 1 in which the down frame 6 extending back-downward from the head pipe 5 extends backward horizontally under the floor 29, the rear frame 7 rising back-upward is integrally combined with the rear end of the down frame 6, and the power unit 21 is swingably supported under the rear frame 7, the front bottom 7a of the rear frame 7 is curved back-downward and extended backward so as to cover under the power unit 21, and the main stand 11 is attached to the rear end of the lower rear extending^portion 7d of the rear frame

Full Text

[DETAILED DESCRIPTION OF THE INVENTION] [0001] [Field of Utilization in Industry] This invention relates to a frame structure involving the configuration of a rear frame and attaching mechanism of main stand of a scooter type vehicle. [0002] [Prior Art] In the conventional scooter type vehicle, as shown in Japanese Utility Model Publication Sho No. 60-20546, a hole for inserting a down frame is formed at the bottom end of a rear frame in the after-process, a rear end of the down frame is inserted to the bottom end hole of the rear frame, and the inserted portion is then welded. [0003] [Problem to be Solved by the Invention] In the above-mentioned scooter type vehicle, because the down frame and rear frame are orthogonally fixed each other, the stress is apt to concentrate to the joint, and to reinforce the joint, a gusset is integrally combined with the rear frame, the rear end of the down frame is inserted to a hole of the gusset and the gusset and down frame are integrally combined each other by welding. [0004] In the scooter type vehicle, because a rear wheel is engaged with the output shaft of a heavy power unit comprising an integrated structure containing an internal combustion engine, clutch, and transmission, the location of the center of gravity of the body deviates to the rear of the body, so the position to which a stand is attached should be positioned backward beyond the joint between the down frame and rear frame to lift up the wheel from the ground when the main frame stand is stood, as the result, because a heavy bending load is exerted on the reinforcing bracket if the reinforcing bracket of the joint between the down frame and rear frame is served as a stand attaching member, the use of a large-sized heavy-weight high-cost reinforcing bracket has been inevitable. [0005] [Means for Solving the Problem and Effects] The present invention involves the improvement of the frame structure of a scooter type vehicle form which such problem is eliminated, and the present invention provides a frame structure of a scooter type vehicle, in which a down frame extending back-downward from a head pipe and horizontally extending backward under a floor is integrally combined at the rear end of the down frame to a rear frame rising back-upward, and a power unit is swingably supported under the rear frame, wherein the front bottom of the rear frame is curved back-downward and is extended backward so as to cover under the power unit, and a main stand is attached to the rear end of the rear extending portion of the rear frame. [0006] In the scooter type vehicle of the present invention, because the front bottom of the rear frame rising back-upward is curved back-downward, and extended backward, and a main stand is attached to the rear end of the rear extending portion of the rear frame, a large-sized heavy-weight main stand for supporting heavy load is not required and the number of required parts and man-hour for assembling are reduced and the weight and cost are reduced. [0007] Because the lower rear extending portion of the rear frame extends backward so as to cover the front rear of the power unit, the front bottom of the power unit is protected from scattering rocks and curbs. [0008] A scooter type motorcycle of the present invention is structured as described in the claim 2, the expansive space for accommodating the power unit in rear of the rear frame is thereby afforded. [0009] A scooter type motorcycle of the present invention is structured as described in the claim 3, the rear end and the 'curved bottom of the rear frame are easily and strongly combined each other. [BRIEF DESCRIPTION OF THE DRAWINGS] Fig .lisa side view of a scooter type motorcycle to which one embodiment of the frame structure in accordance with the present invention is applied. Fig. 2 is a side view of the down frame and rear frame of the frame structure shown in Fig. 1. Fig. 3 is a partial plan view of Fig. 2. Fig. 4 is a cross-sectional view of the main stand in standing configuration along the line IV-IV in Fig. 1. Fig. 5 is an enlarged view of V-portion in Fig. 2. Fig. 6 is a cross-sectional view along the line V-V in Fig. 2. Fig. 7 is a cross-sectional view along the line VII-VII in Fig. 2. Fig. 8 is an enlarged view from the arrow VIII in Fig. 2. Fig. 9 is a view from the arrow IX in Fig. 5. Fig. 10 is a view from the arrow X in Fig. 5. Fig. 11 is a partial perspective view of another embodiment. Fig. 12 is a cross-sectional view of Fig. 11. [Preferred Embodiments] An embodiment of the present invention will be described hereinafter referring to Fig. 1 to Fig. 10. A scooter type motorcycle 1 is provided with a front wheel 3 and rear wheel 4 on the front and rear of the body frame 2 as shown in Fig. 1, the body frame 2 comprises a head pipe 5, a tubular down frame 5 extending back-downward from the head pipe 5 and extending horizontally backward under the step floor 29, and a rear frame 7 having a hollow rectangular cross-section integrally combined with the rear end 6a of the down frame 6 and rising back-upward (size in the body width direction is larger), the front bottom la of the rear frame 7 is curved back-downward and extended backward to cover under the rear of the power unit 21. [0011] The rear end 6a of the down frame 6 is slightly curved downward, the upper face is formed flat so as to fit to the curved bottom face of the rear frame 7, and both edges of the joint between the down frame 6 and rear frame 7 are integrally combined by welding as shown in Fig. 2. [0012] A front gusset 8 is joined to the upper face of the horizontal rear 6b of the down frame 6 positioned in front of the joint between the down frame and rear frame 7 and to the front face of the rising portion 7b of the rear frame 7 positioned above the joint between the down frame 6 and rear frame 7 as shown in Fig. 2, both edges of the joint are integrally combined by welding as shown in Fig. 6, and the joint between the down frame 6 and rear frame 7 is rigidly reinforced by the front gusset 8. [0013] A portion 7c above the rising portion 7b of the rear frame 7 is gradually curved backward as shown in Fig. 2, a rear gusset 9 is placed on the rear face and both sides of the curved portion 7c, both edges of the joint are integrally combined by welding as shown in Fig. 7, and the curved portion 7c of the rear frame 7 is rigidly reinforced by the rear gusset 9. [0014] Amain stand bracket 10 having Z-shaped form in the side view is integrally combined by welding to the rear end of the lower rear extending portion 7d extending backward from the front bottom 7a of the rear frame 7, right and left stand attaching pieces lOc are integrally combined by welding to both right and left sides of a center vertical piece lOa and backward extending piece lOb of the main stand bracket 10, and a spring hook lOd is integrally combined with the upper face of the backward extending piece lOb facing onto the left side of the body. [0015] As shown in Fig. 4, a main stand 11 swingably joined to the main stand bracket 10 comprises a steel rod leg la having a inverse V-shaped configuration having the both ends extending horizontally to the right and left outward, a steel body lib integrally combined with the top of the leg lla, right and left pivots lie projecting upward from both sides of the body 11, and a spring hook lid projecting leftward from the left pivot lie, the right and left pivots lie of the main stand 11 are placed adjacent to the inside of the right and left stand attaching pieces lOc, and the main stand 11 is swingably joined to the main stand bracket 10 bv a Divot shaft 12 which is inserted through the right and left pivots lie and right and left stand attaching pieces lOc. A tension coil spring 13 is stretched between the spring hook lOd of the main stand bracket 10 and the spring hook lid of the main stand 11. [0016] As shown in Fig. 6, a hanger sleeve 14 is inserted through right and left both sides of the rising portion 7b of the rear frame 7 and right and left both sides of the front gusset 8, the engaging portion between both right and left sides of the rising portion 7b of the rear frame 7 and the hanger sleeve 14 is welded to integrally fix the hanger sleeve 14 to the rear frame 7, and as shown in Fig. 1, the ends of a pair of right and left hanger links 16 are integrally combined with both ends of a hanger pin- 15 engaged with the hanger sleeve 14, the front end of the power unit 21 is attached to the rear end of the hanger link 16 with interposition of an attaching pin 17, thus the power unit 21 is swingable upward and downward. [0017] A snubber supporting shaft 19 is integrally combined by welding with the left side of the upper rear end 7e above the curved portion 7c of the rear frame 7 with interposition of a bracket 18 as shown in Fig. 5, Fig. 9, and Fig. 10, and a spark coil attaching stay 20 is integrally combined by welding with the right side of the upper rear end 7e above the curved portion 7c of the rear frame 7, and the joint between the base end of the snubber supporting shaft 19 and the spark coil attaching stay 20 is welded to combine. [0018] The power unit 21 comprises an internal engine 22, a V-belt non-stage transmission 23, and a mechanical reduction gear 24, the rear wheel 4 is integrally attached to the output shaft of the mechanical reduction gear 24, both top and bottom ends of the snubber 26 are joined to the snubber supporting shaft 19 of the upper rear end 7e of the rear frame 7 and the attaching shaft 25 of the power unit 21, the weight of the rear portion of the scooter type motorcycle 1 is supported by the rear wheel 4 with interposition of the snubber 26 and power unit 21. [0019] Floor pipes 27 directed to the body width direction are integrally combined by welding through the rear frame 7 at the middle position in the vertical direction of the horizontal central portion 6c and horizontal rear 6b of the down frame 6, a step floor 29 is provided on the floor bracket 28. [0020] As shown in Fig. 1, a steering shaft 30 is engaged rotatably in the right-left direction to the head pipe 5, a steering handle 31 is integrally attached to the top end of the steering shaft 30, a pair of right and left front forks 32 is integrally attached to the bottom end of the steering shaft 30, and a front wheel 3 is rotatably joined to the bottom end of the front forks 32. [0021] An air cleaner 33 is provided above the V-belt non-stage transmission 23 on the left, a carburetor 34 is proved in front of the V-belt non-stage transmission 23, and a muffler 35 is provided on the right side of the body opposite to the V-belt non-stage transmission 23 with respect to the rear wheel 4. [0022] One end of an aluminum rear frame 36 is inserted to the upper rear end 7e of the hollow rear frame 7, and the rear frame 36 is integrally combined with the upper rear end 7e, a fuel tank 37, oil tank 38, and battery 39 are successively provided from the front to the rear above the rear frame 7 and rear frame 36, and these are sealed by a seat 40 joined swingably in the upward-downward direction to the front end of the fuel tank 37, which will be described hereinafter. [0023] A front fender 41 is integrally attached to the front fork 32 at the position above the front wheel 3, and a leg shield 42 extending from the position in front of the step floor 29 and rising up along the front of the down frame 6 is provided. [0024] The rear of the step floor 29 rises upward and the rear cover 29a is formed, a body cover 43 is provided to the upper edge 29b of the rear cover 29a, and a center cover 44 is provided to the front upper edge 43a of the body cover 43. [0025] As shown in Fig. 2 and Fig. 3, a burglar preventing U-shaped locking hook 48 is integrally fixed to the one side of the lower rear extending portion 7d of the rear frame 7. [0026] In the embodiment shown in Fig. 1 to Fig. 10, the front lower portion 7a of the rear frame 7 is curved back-downward, and subsequently extended backward, and the main stand bracket 10 is integrally combined with the rear end of the lower rear extending portion 7d, the main stand 11 is swingably joined to the main stand bracket 10, so the heavy bending load is loaded on the lower rear extending portion 7d of the rear frame 7 when the main stand 11 is swung to stand and the scooter type motorcycle 1 is supported by the main stand 11 differently from the conventional stand attaching member in which the heavy bending load is loaded on the main stand bracket 10, thus the main stand bracket 10 can be minimized and made light weight. [0027] The lower rear extending portion 7d of the rear frame 7 is integrally combined with the rear frame 7, the possibility of reduction of strength due to welding is eliminated, the structure is strong, the process for fabrication is simplified, and the cost can be saved. [0028] Because the lower rear extending portion 7d of the rear frame 7 extends backward so as to cover the front rear of the power unit 21, the bottom of the crank case of the internal combustion engine 22 is protected from scattering rocks and curb. [0029] Because the rear frame 7 has a hollow rectangular cross-section with a longer size in the body width direction than the vertical direction, the space in the front-rear direction near the rising portion 7b of the rear frame 7 and the space in the vertical direction near the upper rear end 7e of the frame 7 become small to afford the free space, thus the length in the front-rear direction and height of the scooter type motorcycle 1 can be reduced, and the scooter type motorcycle can be made small sized. [0030J Further, because the rear end 6a of the down frame 6 having a circular cross-section, is slightly curved and the upper face thereof is formed flat so as to fit to the curved lower face of the rear frame 7, the down frame 6 and rear frame 7 are combined securely. [0031] Because the gusset 8 is placed on the upper face of 'the horizontal rear 6b of the down frame 6 positioned in front of the contact between the down frame 6 and rear frame 7 and on the front face of the rising portion 7b of the rear frame 7 positioned above the contact between the down frame 6 and rear frame 7, and the rear gusset 9 is placed on the rear face and both sides of the curved portion 7c gradually curved backward above the rising portion 7b of the rear frame 7, both edges of both contacts are integrally combined by welding, the joint portion between the down frame 6 and rear frame 7 on which the heavy load is loaded is significantly reinforced rigidly, as the result, the plate thickness and overall size can be reduced, and the body frame 2 can be made small sized and light weight. [0032] In the embodiment shown in Fig. 1 to Fig. 10, the main stand 11 is joined to the main stand bracket 10, however alternately as shown in Fig. 11 and Fig. 12, a sleeve 45 directed to the body width direction is inserted through the lower rear extending portion 7d of the rear frame 7 and the engaging portion is welded, and a spring hook shaft 46 is integrally projected, the pivots lie of the main stand 11 is engaged with the both ends of the sleeve 45, then a collar 47 is engaged with the space between the one side of the lower rear extending portion 7d of the rear frame 7 on the side provided with the spring hook shaft 46 and the pivot lie, and a pivot shaft 12 is inserted to the pivots lie of the main stand 11 and the sleeve 45, thus in this embodiment, the main stand bracket 10 is not necessary, the structure is therefore more simplified. [DESCRIPTION OF REVERENCE NUMERALS] 1...scooter type motorcycle 2...body frame 3... front wheel 4... rear wheel 5...head pipe 6...down frame 7...rear frame 8...front gusset 9...rear gusset 10...main stand bracket 11...main stand 12...pivot shaft 13...tensile coil spring 14...hanger sleeve 15...hanger pin 16...hanger link 17...attaching pin 18...bracket 19...snubber supporting shaft 20...spark coil attaching stay 21...power unit 22...internal combustion engine 23...V belt 24...mechanical reduction gear 25...attaching shaft 26...snubber 27...floor pipe 28...floor bracket 29...step floor 30... steering shaft 31...steering handle 32. . .front fork 33...air cleaner 34...carburetor 35...muffler 36.. .rear frame 37...fuel tank 38...oil tank 39...battery 40. . .seat 41...front fender 42...leg shield 43...body cover 44...center cover 45...sleeve 46...spring hook shaft 47... collar 48...burglar preventing U-shaped locking hook [Claim 1] A frame structure of a scooter type vehicle, in which a down frame extending back-downward from a head pipe and horizontally extending backward under a floor is integrally combined at the rear end of said down frame to a rear frame rising back-upward, and a power unit is swingably supported under said rear frame, the front bottom of said rear frame being curved back-downward and being extended backward so as to cover under the power unit, and a main stand being attached to the rear end of the rear extending portion of said rear frame. [Claim 2] The frame structure of a scooter type vehicle as claimed in claim 1, wherein said rear frame has a rectangular cross-section. [Claim 3] The frame structure of a scooter type vehicle as claimed in claim 2, wherein the rear end of the down frame is deformed flat and integrally combined with the curved bottom of said rear frame, said down frame and rear frame are integrally combined each other with interposition of a reinforcing member. 4. A frame structure of a scooter type vehicle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Documents:

73-del-1997-abstract.pdf

73-del-1997-claims.pdf

73-del-1997-correspondence-others.pdf

73-del-1997-correspondence-po.pdf

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

73-del-1997-drawings.pdf

73-del-1997-form-1.pdf

73-del-1997-form-13.pdf

73-del-1997-form-19.pdf

73-del-1997-form-2.pdf

73-del-1997-form-3.pdf

73-del-1997-form-4.pdf

73-del-1997-form-6.pdf

73-del-1997-gpa.pdf

73-del-1997-petition-137.pdf

73-del-1997-petition-138.pdf