Title of Invention

VEHICLE FRAME OF SADDLE-TYPE VEHICLE

Abstract

A vehicle frame of a saddle-type vehicle (10) of a closed-section structure formed by jointing flange portions of a pair of stampings having the profile including bottom, wall portions raised from both ends of said bottom, and flange portions (51c, 52c, 81c, 91d, 92d) extended to the right and left from the upper end of said wall portions (51b, 52b, 81b, 91c, 92c) , characterized in that a vibration-damping block (46, 47, 84, 85) for the suppression of vibrations of said vehicle frame is attached at one end to one of said stampings and is compressed at the other end by the other stamping, thereby jointing said flange portions of both' stampings and attaching said vibration-damping block to said vehicle frame.

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] PROVISIONAL/ COMPLETE SPECIFICATION [See Section 10] VEHICLE FRAME OF SADDLE- TYPE VEHICLE" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan The following specification particularly describes the nature of the invention and the manner in which it is to be performed :- 5-1-2007 791/MUM/2000 3 0 AUG 2000 [DETALED DESCRIPTION OF THE INVENTION] [Industrial Field of Utilization] This invention relates to a vibration-damping structure of a vehicle frame capable of easy fabrication, prevention of resonance despite a narrow clearance between a pair of stampings to be jointed, and further, use of a large-sized vibration-damping block like a rubber block having a great damping effect. [Prior Art] As a vehicle frame with flanges formed at the end portion by stamping a plate material and by mutually jointing a pair of stamped members at the flanges, there have been disclosed vehicle frames in for example (1) Japanese Patent Laid-Open No. Hei 7=285483 "Vehicle Frame of Motorcycle" and (2) Japanese Method of Fabricating Frame of Motorcycle. " In the prior art (1) stated above, as shown in Fig. 6 of the patent, a vehicle frame with plates 31 and 32 welded to both sides of a main frame 8 and a down tube 21 has been described. In the prior art (2) stated above, as shown in Fig. 5 of the patent, there has been described a main frame 6 which is formed by welding the plates 6i, 6i, by welding plates. 6o, 6o, and further by welding the welded plates 6i, 6i to the welded plates 6o, 6o. [Problem to Be Solved by the Invention] In the prior art (1) stated above, the plates 31 and 32 attached between the main frame 8 and the down tube 21 are long and accordingly are considered to resonate at the central part with vibrations of the engine. Similarly, in the prior art (2) stated above, it is considered that the wide plates 60, 60 also resonate. As a vehicle frame capable of preventing resonance, a vehicle frame disclosed in for example (3) Japanese Patent Laid-open No. Hei 10-316 074 "Main Frame Structure of Motorcycle" is known. In the prior art (3) stated above, as shown in Fig. 5 of the patent, there is described such a main frame 5 having a fish-shaped cross section that an outer split frame 50 having a U-shaped cross section and an inner split frame 51 similarly having a U-shaped cross section are oppositely placed, and are compressed with a rubber member 71 for suppression of vibrations inserted between a flat portion 50c of the outer split frame 50 and a flat portion 50c of the inner split frame 51. The upper end portion 50a of the outer split frame 50 and the upper end portion 51a of the inner split frame 51 are welded, and furthermore the lower end portion 50b of the outer split frame 50 and the lower end portion 51b of the inner split frame 51 are welded. In the prior art (3), the outer split frame 50 and the inner split frame 51 are of a U-shaped cross section. Therefore, when the main frame 5 is fabricated, it is necessary to joint the frames by spot-welding in a direction nearly orthogonal to the direction of compression while compressing the rubber 71 with a specific load. There is, therefore, such disadvantage that complicated equipment is needed for fabricating the main frame 5. When the clearance present between the flat portion 50c of the outer split frame 50 and the flat portion 51c of the inner split frame 51 is narrow, a rubber having a great vibration damping effect cannot be inserted. Therefore, it is necessary to change the position of the rubber 71 and to take such a measure for resonance prevention that the natural frequency of the main frame 5 will not agree with the frequency of engine vibration. [Object of the Invention] It is an object of this invention to provide a vehicle frame vibration-damping structure of a saddle-type vehicle which can readily be fabricated by simple fabricating equipment (1) , prevent resonance despite a narrow clearance between a pair of stampings jointed (2), and can use a large-sized vibration-damping block having a great damping effect despite a narrow clearance between the pair of stampings jointed. [0010]— [Means for Solving the Problem] To accomplish the above-described object, according to a first aspect, the vehicle frame of a saddle-type vehicle of a closed-section structure is formed by jointing flange portions of a pair of stampings of the profile including a bottom, wall portions raised from both ends of the bottom, and flange portions extended to the right and left from the upper end of the wall portions. In this vehicle frame, a vibration-damping block for the suppression of vibration of the vehicle frame is attached at one end to one of the stampings and is compressed at the other end by the other stamping, thereby jointing the flange portions of both stampings and attaching the vibration-damping block to the vehicle frame. The vibration-damping block for suppression of vehicle frame vibrations is attached at one end to one of the stampings; and the flange portion of the other stamping is pressed with a spot-welding electrode for example, to thereby compress the other end of the vibration-damping block with the other stamping. Then the flanges of both stampings are spot-welded. Consequently, in the case of spot-welding, it is possible to weld the flanges while compressing the vibration-damping block by the electrode through the other stamping. Therefore, in the prior art vehicle frame, the direction of rubber compression differs from the direction of jointing of a pair of stampings. In the present invention, however, since the direction of compression of the vibration-damping block is the same as the direction of welding pressure application in spot-welding, welding pressure application for spot-welding is usable for the compression of the vibration-damping block, and accordingly no special device is needed for compression of the vibration-damping block, and in addition it is possible to simplify the equipment for fabricating the vehicle frame provided with the vibration-damping structure and also to easily fabricate the vehicle frame equipped with the vibration-damping structure. The vehicle frame of a saddle-type vehicle of a closed-section structure according to a second aspect is formed by jointing flange portions of a pair of stampings of the profile including a bottom, wall portions raised from both ends of the bottom, and flange portions extended to the right and left from the upper end of the wall portions. The vehicle frame is characterized in that convex sections are formed by pressing so that the bottoms of the pair of stampings will approach each other, and by jointing the convex sections to thereby suppress vibrations occurring at the bottom. The stamped convex sections are jointed in such a manner that the bottom portions of the pair of stampings will approach each other, changing the natural frequency of the vehicle frame to thereby suppress vibrations occurring at the bottoms. When it is difficult to interpose a vibration-damping member, such as a vibration-damping block, between a pair of stampings because of a narrow clearance at the bottoms of the pair of stampings, vibrations at the bottom can be suppressed. The vibration-damping structure, therefore, is applicable regardless of the clearance at the bottoms. When the stampings are jointed by spot-welding for example, the flange portion and the convex section can be welded simultaneously while applying a welding pressure by the spot-welding electrode. It is, therefore, possible to easily fabricate a vehicle frame having a vibration-damping structure and also to simplify equipment for fabricating the vehicle frame having the vibration-damping structure. [Preferred Embodiments] Referring to the accompanying drawings, the present embodiment of a vehicle frame vibration-damping structure according to this invention will be explained. The drawings should be viewed in the direction of reference numerals. Accordingly, the present invention relates to a vehicle frame of a saddle-type vehicle of a closed-section structure formed by jointing flange portions of a pair of stampings having the profile including bottom, wall portions raised from both ends of said bottom, and flange portions extended to the right and left from the upper end of said wall portions, characterized in that a vibration-damping block for the suppression of vibrations of said vehicle frame is attached at one end to one of said stampings and is compressed at the other end by the other stamping, thereby jointing said flange portions of both stampings and attaching said vibration-damping block to said vehicle frame. [BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a side view of a saddle-type vehicle equipped with a vehicle frame vibration-damping structure of this invention; Fig. 2 is a side view of a vehicle frame having the vibration-damping structure according to this invention; Fig. 3 is an exploded perspective view of the vehicle frame having the vibration-damping structure according to this invention; Fig. 4(a) and Fig. 4(b) are first explanatory views explaining the vehicle frame vibration-damping structure according to this invention; Fig. 5 is a sectional view taken along line 5-5 of Fig. 2; Fig. 6 is a sectional view taken along line 6-6 of Fig. 2; Fig. 7(a) and Fig. 7(b) are secondary explanatory views explaining the vehicle frame vibration-damping structure according to this invention; Fig. 8(a) to Fig. 8(c) are first operation views explaining the procedure for assembling the vehicle frame vibration-damping structure according to this invention; Fig. 9(a) and Fig. 9(b) are secondary operation views explaining the procedure for assembling the vehicle frame vibration-damping structure according to this invention; Fig. 10 is a sectional view showing another embodiment of the vehicle frame vibration-damping structure according to this invention; Fig. 11 is a sectional view showing further another embodiment of the vehicle frame vibration-damping structure according to this invention; Fig. 12(a) and Fig. 12(b) are operation views explaining the procedure for assembling further another embodiment of the vehicle frame vibration-damping structure according to this invention. Fig. 1 is a side view of a saddle-type vehicle using a vehicle frame vibration-damping structure of this invention, in which a motorcycle 10 as the saddle-type vehicle comprises a vehicle frame 11, a head pipe 12 mounted at the front end portion of the vehicle frame 11, a front fork 13 steerably attached on the head pipe 12, a front wheel 14 mounted on the lower end of the front fork 13, a handlebar 15 mounted on the upper part of the front fork 13, a fuel tank 16 mounted in the front upper part of the vehicle frame 11, and a power unit 21 including an engine 17 and a transmission 18 located beneath the fuel tank 16. [0018]— The motorcycle 10 comprises a seat 22 mounted in the upper rear part of the vehicle frame 11, a swing arm 23 swingably attached in the lower part of the vehicle frame 11, a rear wheel 24 mounted on the rear end of the swing arm 23, and a rear cushion unit 25 mounted between the rear part of the swing arm 23 and the rear part of the vehicle frame 11. Reference numeral 27 refers to a headlamp; 28, a front fender; 31, a carburetor; 32, a taillamp; and 33, a rear fender. Fig. 2 is a side view of the vehicle frame having the vibration-damping structure according to this invention, in which the vehicle frame 11 comprises the head pipe 12, a main frame 41 extended nearly horizontally to the rear from the head pipe 12, a down frame 42 extended downwardly from the head pipe 12 and attached on the front part of the main frame 41, a center frame 43 extended downwardly from the central part of the main frame 41, and a rear frame 44 mounted between the rear part of the main frame 41 and the lower part of the center frame 43. Here, 46 ... denotes a vibration-damping block ("..." means a plural number, which applies to the following description), and 47 ... is a vibration-damping block for suppression of vibrations of the vehicle frame 11. Fig. 3 is an exploded perspective view of the vehicle frame having the vibration-damping structure according to this invention. The main frame 41 of the vehicle frame 11 is comprised of the upper member 51 and a lower member 52 jointed to the lower part of the upper member 51, and is a member for jointing the front ends of the upper member 51 and the lower member 52 to the head pipe 12. Numeral 53 is a seat mounting stay, and 54 is a cross member which serves also as a mounting portion for attaching the upper end portion of the rear cushion unit 25 (see Fig. 1). The upper member 51 is a stamping of the profile including a bottom 51a, wall portions 51b, 51b (the wall portion 51b located on the far side is not shown) raised from both ends of the bottom 51a, and flange portions 51c, 51c (the flange portion 51c located on the far side is not shown) extended to the right and left from the upper end of the wall portions 51b, 51b, and is provided with a convex section 51d ... on which one end of the vibration-damping block 46 ..., 47 is positioned. The lower member 52 is a stamping of the profile including a bottom 52a, wall portions 52b, 52b raised from both ends of the bottom 52a, and flange portions 52c, 52c extended to the right and left from the upper end of the wall portions 52b, 52b; on the bottom 52b the vibration-damping blocks 46 ..., 47 are attached. The down frame 42 is a member including a left member 55 and a right member 56 jointed to the left member 55. The left and right members 55 and 56 are jointed at the upper part to the wall portions 52b, 52b of the lower member 52, and at the front end to the head pipe 12 . Numeral 57 denotes a tank mounting stay for mounting the fuel tank 16 (shown in Fig. 1); numerals 55a and 56a denote stay mounting portions for mounting the tank mounting stay 57; and numerals 58, 58 are collars forming an attaching portion for attaching the front part of the power unit 21 (shown in Fig. 1). The center frame 43 is a member including a main member 61 and a sub member 62 to be jointed to the main member 61; the main member 61 being jointed at the upper part to the wall portions 52b, 52b of the lower member 52. Numerals 63 and 64 are a reinforcing member and a support pipe which form a swing arm attaching portion for attaching the swing arm 23 (shown in Fig. 1) . The main member 61 is a stamping of a U- shaped cross section including a bottom 61a, and wall portions 61b, 61b raised from both ends of the bottom 61a . The vibration-damping blocks 46 ... and 47 are attached on the bottom 61a. The sub member 62 is a stamping having a U-shaped cross section including a bottom 62a, and wall portions 62b, 62b (the wall portion 62b on the far side is not shown) raised from both ends of the bottom 62a. The bottom 62a has convex sections 62d . . . positioning one end of the vibration-damping blocks 46 . . . and 47, and the wall portions 62b, 62b are jointed to the wall portions 61b, 61b of the main member 61 respectively. The rear frame 44 is a member including a rear main member 65 and a rear sub member 66 jointed to the rear main member 65; the rear main member 65 being jointed at the upper part to the wall portions 52b, 52b of the lower member 52. The rear main member 65 is a stamping having a U-shaped cross section including a bottom 65a, and wall portions 65b, 65b raised from both ends of the bottom 65a, on which a convex section 65c is formed. The rear sub member 66 is also a stamping having a U-shaped cross section including a bottom 65b, and wall portions 66b, 66b raised from both ends of the bottom 66a; the bottom 66a being jointed to a convex section 65c of the rear main member 65, and the wall portions 66b, 66b being jointed to the wall portions 65b, 65b of the rear main member 65 respectively. Fig. 4 (a) and Fig. 4 (b) are explanatory views showing the vehicle frame vibration-damping structure of this invention. Fig. 4(a) is an enlarged side view, partly in cross section, of A portion of Fig. 2. Fig. 4(b) is a sectional view taken along line b-b of Fig. 4(a). In Fig. 4(a), the vibration-damping block 46 is a rubber vibration-damping member comprising a body portion 46a, and a projecting portion 46b projecting from the body portion 46a. A height adjusting member 68 is attached on the lower member 52 of the main frame 41. On the height adjusting member 68 the projecting portion 46b is attached. The vibration-damping block 46 is interposed in a compressed state between the height adjusting member 68 and the upper member 51 with the bottom surface 46c placed on the projecting portion 51d provided on the upper member 51 of the main frame 41. Since the height adjusting member 68 is provided, the same vibration-damping block 46 is usable in any position by adjusting the height of the height adjusting member 68 despite a difference in the amount of clearance between the bottoms of the pair of stampings at each part of the vehicle frame (shown in Fig. 1). In Fig . 4(b), the vibration- damping block 46 is interposed between the height adjusting member 68 mounted on the lower member 52 which comprises the bottom 52a, the wall portions 52b, 52b and the flange portions 52c, 52c, and the projecting portion 51d of the upper member 51 which comprises the bottom. 51a, the wall portions 51b, 51b, and the flange portions 51c, 51c. Numeral 46c is an annular groove formed in the projecting portion 46b of the vibration-damping block 46 for fitting in a through hole 68b formed in the height adjusting member 68. Numeral 46e is a hole formed in the bottom 46c for the adjustment of the spring constant of the vibration-damping block 46. Interposing the vibration-damping block 46 between the height adjusting member 68 and the upper member 51, as previously stated, can suppress vibrations occurring in the bottom 51a of the upper member 51 and the bottom 52a of the lower member 52. Fig. 5 is a sectional view taken along line 5-5 of Fig. 2, in which the vibration-damping block 47 is a rubber vibration-damping member comprising a body portion 47a and a projecting portion 47b projecting from the body portion 47a. The lower member 52 is provided with a convex section 52d raised to the inside; a through hole 52e is formed in the convex section 52d; the projecting portion 47b is attached to the through hole 52e; and the bottom surface 47c is set on the convex section 51d of the upper member 51, thereby suppressing vibration occurring at the bottoms 51a and 52a of the main frame 41. Numeral 47d denotes an annular groove formed in the projecting portion 47b of the vibration-damping, block 47 to fit in the through hole 52e of the lower member 52 . Numeral 47e is a hole formed in the bottom 47c for adjusting the spring constant of the vibration-damping block 47. Attaching the vibration-damping block 47 on the wide area of the bottoms 51a and 52a of the main frame 41 can further improve the vibration-damping effect of the vehicle frame 11 (shown in Fig. 1). Fig. 6 is a sectional view taken along line 6-6 of Fig. 2, showing that the height adjusting member 71 is attached to the left member 55 of the down frame 42; the projecting portion 46b of the vibration-damping block 46 is attached to the height adjusting member 71; and the bottom 46c of the vibration-damping block 46 is set on the convex section 56d of the right member 56. Numeral 71a refers to a through hole made in the height adjusting member 71 in which the annular groove 46d of the vibration-damping block 46 fits. Thus interposing the vibration-damping block 46 between the left member 55 and the right member 56 can suppress vibrations occurring in the left member 55 and the right member 56. Fig. 7(a) and Fig. 7(b) are the second explanatory views explaining the vehicle frame vibration-damping structure according to this invention. Fig. 7 (a) is an enlarged side view of B portion of Fig. 2, and Fig. 7(b) is a sectional view taken along line b-b of Fig. 7(a). Fig. 7(a) shows the jointed state of the convex section 65c formed in the rear main member 65 of the rear frame 44 and the bottom 66a of the rear sub member 66. In the rear main member 65 shown in Fig. 7 (b) , the convex section 65c is comprised of the first convex section 65d formed by protruding the bottom 65a inwardly and the second convex section 65e formed by protruding the first convex section 65d further inwardly. Then the second convex section 65e is jointed to the bottom 66a. Thus jointing the convex section 65c of the rear main member 65 to the bottom 66a of the rear sub member 66 can improve the rigidity of the rear frame 44 to substantially increase the natural frequency, thereby preventing resonance of the rear frame 44 with engine vibrations. Next, a procedure for assembling the vehicle frame vibration-damping structure stated above will be explained. Fig. 8(a) and Fig. 8(b) are the first operation views explaining the vehicle frame vibration-damping structure assembling procedure according to this invention. As the jointing process a spot-welding process will be explained. In Fig. 8(a), the projecting portion 46b of the vibration-damping block 46 is inserted into a through hole 68a formed in the height adjusting member 68 of the lower member 52, and then fitted at the annular groove 64d in the through hole 68a, thereby mounting the vibration-damping block 46 to the height adjusting member 68. In Fig. 8(b), the upper member 51 is placed on the vibration-damping block 46 in such a manner that the convex section 51d of the upper member 51 will contact the bottom 46c of the vibration-damping block 46. In Fig. 8(c), the flange portions 51c, 51c of the upper member 51 are pressed with a specific load by means of the upper electrodes UE, UE against the flange portions 52c, 52c of the lower member 52 with the lower electrodes LE, LE for spot-welding pressed against the lower part, then the electric current is supplied across the upper electrodes UE, . UE and the lower electrodes LE, LE to thereby perform spot-weldirig. At this time, let L1 be the overall length before compression of the vibration-damping block 46 and L2 be the overall length after the compression, and the amount of compression of the vibration-damping block 46 will be As has been explained by referring to Fig. 4(a) and Fig. 4(b) and Fig. 8(a) to Fig. 8(c), the vehicle frame vibration-damping structure of this invention is characterized in that the upper member 51 of the profile including the bottom portion 51a, the wall portions 51b, 51b raised from both ends of the bottom portion 51a, and the flange portions 51c, 51c extended to the right and left from the upper end of these wall portions 51b, 51b respectively is superposed on the lower member 52 of the profile including the bottom portion 52a, the wall portions 52b, 52b raised from both ends of the bottom portion 52a, and flange portions 52c, 52c extended to the right and left from the upper end of the wall portions 52b, 52b; then the flange portions 51c, 51c and the flange portions 52c, 52c are jointed to form the vehicle frame 11 of a motorcycle (shown in Fig. 1) of a closed-section structure. In this vehicle frame 11, the projecting portion 46b of the vibration-damping block 46 for suppression of vibrations of the vehicle frame 11 is attached on the lower member 52; the bottom surface 46c of the vibration-damping block 46 is compressed with the upper member 51, and the flange portions 51c, 51c and the flange portions 52c, 52c of these members 51 and 52 are jointed, thus completing the mounting of the vibration-damping block 46 to the vehicle frame 11. According to the above constitution, spot-welding, when adopted for example to joint the upper and lower members, can be performed while compressing the vibration-damping block with the upper electrodes UE, UE via the upper member 51. Therefore, unlike the prior art in which the direction of compression of the rubber differs from the direction of jointing a pair of stampings, the compression of the vibration-damping block 46 and the application of spot-welding pressure are performed in the same direction. The spot-welding pressure, therefore, can be utilized also for the compression of the vibration-damping block, and accordingly no special device is needed for compressing the vibration-damping block. Consequently it is possible to use equipment of simplified structure for fabricating the vehicle frame 11 and to facilitate the fabrication of the main frame 41 having the vibration-damping structure, that is, the vehicle frame 11 through one process. Therefore, it is possible to reduce the manufacturing cost of the vehicle frame 11 having the vibration-damping structure. Fig. 9(a) and Fig. 9(b) are the second operation views explaining the vehicle frame vibration-damping structure assembling procedure according to this invention. In Fig. 9 (a) the bottom portion 66a of the rear sub member 66 is applied to the convex section 65c of the rear main member 65 of the rear frame 44. In Fig. 9 (b) the convex section 65c and the bottom portion 66a are sandwiched with the upper electrodes UE, UE and the lower electrodes LE, LE and spot-welded by applying a welding pressure and supplying the electric current. Then in Fig. 3, the wall portions 66b, 66b of the rear sub member 66 are spot-welded to the wall portions 65b, 65b of the rear main member 65. Fig. 10 is a sectional view of another embodiment of the vehicle frame vibration-damping structure according to this invention, showing the state of suppression of vibrations occurring in the bottom portions 81a and 82a: by forming a frame 83, which is a closed-section structure; superposing the upper member 81 of a stamping of the profile including the bottom portion 81a, the wall portions 81b, 81b, and the flange portions 81c, 81c on the lower member 82 of a stamping of the profile including the bottom portion 82a, the wall portions 82b, 82b, and flange portions 82c, 82c; opening through holes 81d and 82d in the bottom portion 81a of the upper member 81 and in the bottom portion 82a of the lower member 82 respectively; placing rubber vibration-damping blocks 84 and 85 on the outside of the bottom portions 81a and 82a; further installing washers 86 and 87 as vibration-damping block support members for supporting the vibration-damping blocks 84 and 85 on the outside of the vibration-damping blocks 84 and 85; compressing the vibration-damping blocks 84 and 85 with the washers 86 and 87; connecting the washers 86 and 87 to each other by a bolt 88, that is, by inserting the bolt 88 through into the washer 86, the vibration-damping block 84, the through hole 81d, the through hole 82d, the vibration-damping block 85, and the washer 87 in order of mention; and then by screwing a nut 89 onto the bolt 88, thereby suppressing vibrations produced in the bottom portions 81a and 82a. The vehicle frame vibration-damping structure is effective specially when there is a small clearance between the bottom portion 81a of the upper member 81 and the bottom portion 82b of the lower member 82, and therefore a vibration absorbing member such as the vibration-damping block thick enough to suppress vibrations can not be interposed between the bottom portions 81a and 82a. The vehicle frame vibration-damping structure, as heretofore explained, is characterized in that the upper member 81 of the profile including the bottom portion 81a, the wall portions 81b, 81b raised from both ends of the bottom portion 81a, and the flange portions 81c, 81c extended to the right and left from the upper end of the wall portions 81b, 81b is superposed on the lower member 82 of the profile including the bottom portion 82a, the wall portions 82b, 82b raised from both ends of the bottom portion 82a, and the flange portions 82c, 82c extended to the right and left from the upper end of the wall portions 82b, 82b; and the flange portions 81c, 81c and the flange portions 82c, 82c are jointed to form the frame 83 of the motorcycle 10 of a closed-section structure. In the frame 83, the vibration-damping blocks 84 and 85 which function to suppress vibrations of the frame 83 are placed on the outside of the bottom portions 81a and 82a respectively, and furthermore the washers 86 and 87 for supporting the vibration-damping blocks 84 and 85 are installed on the outer side of these vibration-damping blocks 84 and 85 . Then the vibration-damping blocks 84 and 85 are compressed with the washers 86 and 87; and the washers 86 and 87 are connected by the bolt 88 and the nut 89, thereby suppressing vibrations occurring in the bottom portions 81a and 82a. Because of the above-described constitution, vibrations of the bottom portions 81a and 82a can be suppressed despite a narrow clearance between the bottom portion 81a of the upper member 81 and the bottom portion 82a of the lower member 82. It is, therefore, possible to' apply the vibration-damping structure regardless of the amount of clearance provided between the bottom portions 81a and 82a of the vehicle frame 11. Fig. 11 is a sectional view showing further another embodiment of the vehicle frame vibration-damping structure according to this invention, in which an upper member 91 formed by stamping and having the profile including a convex section 91b formed by stamping in the bottom portion 91a, wall portions 91c, 91c, and flange portions 91d, 91d, is superposed on a lower member 92 formed by stamping and having the profile including a convex section 92b formed by stamping in the bottom portion 92a, wall portions 92c, 92c, and flange portions 92d, 92d. The flange portions 91d, 91d are jointed to the flange portions 92d, 92d to thereby form a frame 93 which is a closed-section structure, thus suppressing vibrations occurring in the bottom portions 91a and 92a. The vehicle frame vibration-damping structure is effective especially when a vibration absorbing member such as the vibration-damping block thick enough to suppress vibrations can not be interposed between the bottom portions 91a and 92a because of a small clearance between the bottom portion 91a of the upper member 91 and the bottom portion 92a of the lower member 92. Next, a procedure for assembling further another embodiment of the vehicle frame vibration-damping structure heretofore stated will be explained. Fig. 12(a) and Fig. 12(b) are operation views explaining a procedure for assembling further another embodiment of the vehicle frame vibration-damping structure according to this invention. Spot-welding for jointing the flange portions is as follows. In Fig. 12 (a) , set the upper member 91 on the lower member 92 with the lower electrodes LE ... placed under the lower surface of the flange portions 92d, 92d and the convex portion 92b. In Fig. 12(b), set the upper electrodes UE ... on, and the lower electrodes LE . . . under, the flange portions 91d, 91d, flange portions 92d, 92d, and the convex sections 91b and 92b, and then while applying a welding pressure, supply the electric current to perform spot-welding. It should be understood that the vehicle frame jointing process of this invention is not limited to spot-welding; and projection-welding may be adopted. It also should be understood that the vibration-damping member (vibration absorbing member) of this invention is not limited to rubber and may be such a damping force generating mechanism as an air damper, a hydraulic damper, etc. Furthermore, the saddle-type vehicle to be mounted with the vehicle frame vibration-damping structure of this invention is not limited to the motorcycle and may be an off-road vehicle such as a buggy, a saddle-type three-wheeled vehicle, or a saddle-type four-wheeled vehicle. [Effect of the Invention] This invention has the following advantage because of the above-described constitution. According to the vehicle frame vibration-damping structure of a saddle-type vehicle according to the first aspect, the vibration-damping block functioning to suppress vibrations of the vehicle frame is attached at one end to one stamping, and compressed at the other end by the other stamping. Then the flange portions of these stampings are jointed to each other and the vibration-damping block is attached to the vehicle frame. Therefore, in the case of the spot-welding for example, welding can be performed with the spot-welding electrode while compressing the vibration-damping block through the other stamping. Unlike the prior art in which the direction of compression of the rubber differs from the direction of jointing a pair of stampings, the compression of the vibration-damping block and the application of spot-welding pressure are performed in the same direction. The spot-welding pressure, therefore, can be utilized also for the compression of the vibration-damping block, and accordingly no special device is needed for compressing the vibration-damping block. Consequently it is possible to use equipment of simplified structure for fabricating the vehicle frame having the vibration-damping structure and to facilitate the fabrication of the vehicle frame having the vibration-damping structure. The vehicle frame having the vibration-damping structure can be fabricated at a lower cost. According to the vehicle frame vibration-damping structure of a saddle-type vehicle according to the second aspect, a convex section is formed by stamping at the bottom portion of either of a pair of stampings so that the bottom portions of the stampings will approach each other, and by jointing the convex sections to thereby suppress vibrations occurring at the bottom portion. It is therefore possible to suppress vibrations at the bottoms even when it is hard to interpose a vibration absorbing member such as the vibration-damping block between the pair of stampings because of a narrow clearance between the bottoms of the pair of stampings. The vibration-damping structure of this invention, therefore, is usable irrespective of the amount of clearance between the bottom portions of the vehicle frames. Furthermore, when the spot-welding process for example is adopted for jointing the stampings, the flange portions and the convex sections can be welded at a time while applying a welding pressure with the spot-welding electrodes. It is therefore possible to readily fabricate the vehicle frame having the vibration-damping structure and to facilitate the equipment for fabricating the vehicle frame having the vibration-damping structure. [Explanation of Reference Numerals] 10... saddle-type vehicle (motorcycle); 11 ... vehicle frame; 41 . . . main frame; 46, 47, 84, 85 ... vibration-damping blocks; 46b, 47b . . . one ends (convex sections) ; 46c, 47c . . . the other ends (bottoms); 51a, 52a, 81a, 82a, 91a, 92a .... bottom portions; 51b, 52b, 81b, 82b, 91c, 92c ... wall portions; 51c, 52c, 81c, 82c, 91d, 92d . . . flange portions; 83, 93 .... vehicle frames (frames); 86, 87 ... vibration-damping block support members (washers); 88, 89 . . . connecting members (bolts, nuts) ; 91b, 92b ... convex sections. WE CLAIM: 1. A vehicle frame of a saddle-type vehicle (10) of a closed-section structure formed by jointing flange portions of a pair of stampings having the profile including bottom, wall portions raised from both ends of said bottom, and flange portions (51c, 52c, 81c, 91d, 92d) extended to the right and left from the upper end of said wall portions (51b, 52b, 81b, 91c, 92c) , characterized in that a vibration-damping block (46, 47, 84, 85) for the suppression of vibrations of said vehicle frame is attached at one end to one of said stampings and is compressed at the other end by the other stamping, thereby jointing said flange portions of both' stampings and attaching said vibration-damping block to said vehicle frame. 2. A vehicle frame of a saddle-type vehicle of a closed-section structure formed by jointing flange portions of a pair of stampings of the profile including a bottom, wall portions raised from both ends of said bottom, and flange portions extended to the right and left from the upper end of said wall portions, characterized in that convex sections (46b, 47b) are formed by stamping so that said bottoms of said pair of stampings will approach each other, and by jointing said convex sections to thereby suppress vibrations occurring at said bottom. 3. A vehicle frame of a saddle-type vehicle substantially as hereinbefore described with reference to the accompanying drawing Dated this 30th day of August, 2000. (RANJNA MEHTA-DUTT) OF REMFRY & SAGAR ATTORNEY FOR THE APPLICANTS

Documents:

791-mum-2000--form 2(granted)-(5-1-2007)).pdf

791-mum-2000--form 2(granted)-(5-1-2007).doc

791-mum-2000-cancelled page(5-1-2007).pdf

791-mum-2000-claim (granted)-(5-1-2007)).pdf

791-mum-2000-claim(granted)-(5-1-2007)).doc

791-mum-2000-correspondence(22-3-2006).pdf

791-mum-2000-correspondence(ipo)-(15-7-2004).pdf

791-mum-2000-drawing(12-10-2000).pdf

791-mum-2000-form 1(30-8-2000).pdf

791-mum-2000-form 19(15-4-2004).pdf

791-mum-2000-form 2(granted)-(5-1-2007)).pdf

791-mum-2000-form 3(30-8-2000).pdf

791-mum-2000-form 3(7-6-2005).pdf

791-mum-2000-form 3(9-3-2001).pdf

791-mum-2000-form 5(30-8-2000).pdf

791-mum-2000-petition under rule 137(7-6-2005).pdf

791-mum-2000-petition under rule 138(7-6-2005).pdf

791-mum-2000-power of aouthority(28-11-2000).pdf

791-mum-2000-power of aouthority(7-6-2005).pdf

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