Front fork arrangement of a saddle-seat vehicle

Abstract

Front fork assembly of a saddle-seat vehicle, wherein a front fork (12) comprises a pair of left and right fork tubes (61), a bridge element (68), and a steering stem (64), the fork tubes (61) supporting a front wheel (2), the bridge element (68) connecting the left and right fork tubes (61) to each other, the steering stem (64) being attached to the bridge element (68), the front fork (12) being rotatably held by a steering head tube (15) of a body frame (10) through the steering stem (64), a stem retaining area (62y, 63y) and a pair of left and right fork retaining areas (62x, 63x) being connected to each other by a base area (62z, 63z), the stem retaining area (62y, 63y) supporting the steering stem (64), and the fork retaining areas (62x, 63x) supporting the left and right fork tubes. (61) hold, the bridge element (68) is designed from an upper bridge element (62) and a lower bridge element (63),wherein the upper bridge element (62) connects the upper parts of the left and right fork tubes (61) to each other, the lower bridge element (63) is arranged below the upper bridge element (62) and connects the upper parts of the left and right fork tubes (61) to each other, wherein each of the upper bridge element (62) and the lower bridge element (63) has a front wall region (62b, 63b) and a rear wall region (62c, 63c) at the front and rear edges of each of the upper bridge element (62) and the lower bridge element (63), wherein the front wall region (62b, 63b) and the rear wall region (62c, 63c) connect the left and right fork retaining areas (62x, 63x) to each other, characterized in that a reinforcing rib (62d) is provided at the rear of the base region (62z) of the upper bridge element (62), wherein the reinforcing rib (62d) is not attached to the shaft holding area (62y) is attached,runs around the shaft holding area (62y) and connects the left and right fork holding areas (62x).

Description

[0001] The present invention relates to a front fork arrangement of a saddle seat vehicle.

[0002] A motorcycle has a front fork that allows the front wheel to be steered. The front fork comprises fork tubes, a bridge element, and a steering stem. The fork tubes are a pair of left and right shock absorbers that hold the front wheel via an axle. The bridge element connects the left and right fork tubes. The steering stem is attached to the bridge element and is rotatably held by a steering head tube of a body frame. The bridge element consists of an upper bridge and a lower bridge, which are arranged separately from each other in the vertical direction.

[0003] The lower bridge features a stem holding area, a pair of left and right fork holding areas, and a base area, with the stem holding area holding the handlebar stem, the fork holding areas holding the left and right fork tubes, and the base area connecting the handlebar stem and the left and right fork holding areas.

[0004] A conventional arrangement is known in which a front end rib and a rear end rib are arranged at the front and rear edges of the base region, respectively, the rear end rib being connected to the shaft holding region, reinforcing ribs being formed at the rear of the base region, the reinforcing ribs connecting the front wall region and the shaft holding region, and the reinforcing ribs extending radially from the shaft holding region to the front end rib (see, for example, JP 2007 - 302 109 A).

[0005] Although the reinforcing ribs in the bridge element are provided to improve the stiffness of the bridge element in JP 2007 - 302 109 A, with the reinforcing ribs connecting the front end rib and the shaft holding area, and the shaft holding area and the fork holding area being connected to each other in the bridge element, it is desirable to allow flexibility when the vehicle goes into a curve, while ensuring strength and stiffness.

[0006] DE 79 13 184 U1 discloses a telescopic fork for the front wheel of motorcycles or the like, in which the two upper fork legs, which engage in the fork tubes, are connected to each other in the area of ​​the fork crown by two spaced-apart cross members that support the central fork steerer tube. The lower cross member has two inclined legs that extend obliquely upwards on both sides from the hub-shaped central section of the cross member, which is connected to the steerer tube, towards the fork legs. The two inclined legs of the lower cross member have a smooth upper surface and are provided with stiffening ribs on their underside.

[0007] JP 2012 - 176 701 A shows a steering device for a motorcycle in which an adjustment of the asymmetry of a rib located on top of an arm results in the expression of a stiffness difference between a right leg and a left leg with respect to the right-left bending moment of a fork bridge.

[0008] The objective of the present invention is to provide a front fork arrangement of a saddle seat vehicle which allows it to be bent when the vehicle goes into a curve, while ensuring strength and stiffness.

[0009] In a front fork structure of a saddle-seat vehicle, wherein a front fork (12) comprises a pair of left and right fork tubes (61), a bridge element (68), and a steering stem (64), the fork tubes (61) supporting a front wheel (2), the bridge element (68) connecting the left and right fork tubes (61), and the steering stem (64) being attached to the bridge element (68), the front fork (12) being rotatably held by a steering head tube (15) of a body frame (10) through the steering stem (64), wherein a stem retaining area (62y, 63y) and a pair of left and right fork retaining areas (62x, 63x) being connected to each other by a base area (62z, 63z), the stem retaining area (62y, 63y) supporting the steering stem (64), and the fork retaining areas (62x, 63x) supporting the left and right fork legs. The fork tubes (61) hold the bridge element (68), which is designed from an upper bridge element (62) and a lower bridge element (63),wherein the upper bridge element (62) connects the upper parts of the left and right fork tubes (61) to each other, the lower bridge element (63) is arranged below the upper bridge element (62) and connects the upper parts of the left and right fork tubes (61) to each other, wherein each of the upper bridge element (62) and the lower bridge element (63) has a front wall region (62b, 63b) and a rear wall region (62c, 63c) at the front and rear edges of each of the upper bridge element (62) and the lower bridge element (63), wherein the front wall region (62b, 63b) and the rear wall region (62c, 63c) connect the left and right fork retaining areas (62x, 63x) to each other, it is characterized in that a reinforcing rib (62d) is provided at the rear of the base region (62z) of the upper bridge element (62),wherein the reinforcing rib (62d) runs around the shaft holding area (62y) - i.e. the reinforcing rib (62d) is not connected to the shaft holding area (62y) - and connects the left and right fork holding areas (62x) to each other.

[0010] In the design described above, it can also be designed such that the rear wall area (62c, 63c) is connected to the shaft holding area (62y, 63y) of each of the upper bridge element (62) and the lower bridge element (63).

[0011] Furthermore, in the design described above, it can also be designed such that the reinforcing rib (62d) of the upper bridge element (62) runs in a curved shape and both end parts of the reinforcing rib (62d) are connected to the side of the rear part of the left and right fork holding areas (62x).

[0012] Furthermore, in the design described above, it can also be designed such that a vertical dimension of the reinforcing rib (62d) of the upper bridge element (62) is larger than a vertical dimension of the rear wall area (62c).

[0013] Furthermore, in the above design it can also be configured such that a vertical dimension of the front wall area (62b) of the upper bridge element (62) is larger than a vertical dimension of the reinforcing rib (62d).

[0014] Furthermore, in the design described above, it can also be designed such that the fork holding areas (62x, 63x) are formed in a C-shape, which has separating areas (62v, 63v) in which an annular part is cut out, and which have a slot fastening structure to which the separating areas (62v, 63v) are attached by screws (71) to fix the fork tubes (61), and the separating area (62v) of the upper bridge element (62) is arranged on the side of the front wall area (62b).

[0015] Furthermore, in the design described above, it can also be designed such that the reinforcing rib (63d) of the lower bridge element (63) runs linearly from intermediate parts in the direction from front to rear of the left and right fork holding areas (63x), connects the left and right fork holding areas (63x) to each other and is connected to the shaft holding area (63y) on the middle part in the vehicle width direction.

[0016] Furthermore, in the design described above, it can also be designed such that a vertical dimension of the rear wall area (63c) of the lower bridge element (63) is larger than a vertical dimension of the reinforcing rib (63d), and a vertical dimension of the front wall area (63b) is larger than a vertical dimension of the rear wall area (63c).

[0017] Furthermore, in the design described above, it can also be designed such that a vertical dimension of the reinforcing rib (63d) of the lower bridge element (63) is larger than a vertical dimension of the front wall area (62b) of the upper bridge element (62).

[0018] Since the front fork assembly of the saddle-seat vehicle features a reinforcing rib on the rear of the base area of ​​the upper bridge element, and this reinforcing rib extends around the stem retaining area and connects the left and right front fork retaining areas, the stiffness and strength between the left and right fork retaining areas can be improved by connecting them via the reinforcing rib. This allows the stiffness and strength of the stem retaining area and the fork retaining areas to be separated, and flexibility is easily accommodated between the stem retaining area and the fork retaining areas, as there is no reinforcing rib connecting them. Consequently, the upper bridge element can flex easily when the vehicle turns.

[0019] In the design described above, since the back wall area of ​​each of the upper bridge element and the lower bridge element is connected to the shaft holding area, the strength and stiffness of the shaft holding area can be ensured by the back wall areas.

[0020] Furthermore, since in the design described above the reinforcing rib of the upper bridge element runs in a curved shape and both end parts of the reinforcing rib are connected to the side of the rear part of the left and right fork holding areas, the strength and stiffness can be improved by arranging the front wall area and the reinforcing rib between the front and rear ends of the fork holding area separately from the rear wall area.

[0021] Furthermore, since in the design described above a vertical dimension of the reinforcing rib of the upper bridge element is larger than a vertical dimension of the back wall area, a difference in strength and stiffness is created between the shaft holding area and the fork holding area, and the upper bridge element can easily be bent.

[0022] Furthermore, since in the design described above a vertical dimension of the front wall area of ​​the upper bridge element is larger than a vertical dimension of the reinforcing rib, a difference in strength and stiffness is created between the shaft holding area and the fork holding area, and the upper bridge element can easily be bent.

[0023] Since, in the design described above, the fork retaining areas are formed in a C-shape, have separating areas in which an annular part is cut out, and have a slot fastening structure in which the separating areas are fastened by screws to fix the fork tubes, and the separating area of ​​the upper bridge element is located on the side of the front wall area, when the reinforcing rib is bent and connected to the side of the rear part of the fork retaining area, a space at the front of the reinforcing rib can be easily ensured, the stiffness of the upper bridge element can be increased by the slot fastening, and therefore the reinforcing rib and the slot fastening structure can be designed effectively.

[0024] Furthermore, since in the design described above the reinforcing rib of the lower bridge element runs linearly from the intermediate parts in the direction from front to rear of the left and right fork holding areas, connects the left and right fork holding areas to each other and is connected to the shaft holding area on the middle part in the vehicle width direction, it is not easily possible for the lower bridge element to be bent between the left and right fork holding areas and the shaft holding area, and if the stiffness and strength of the lower bridge element are greater than that of the upper bridge element, the upper bridge element can be bent, with the lower bridge element becoming a pivot point.

[0025] Furthermore, since in the design described above a vertical dimension of the rear wall area of ​​the lower bridge element is larger than a vertical dimension of the reinforcing rib and a vertical dimension of the front wall area is larger than a vertical dimension of the rear wall area, the strength and stiffness of the lower bridge element can be ensured by the front wall area and the rear wall area, and an increase in the strength and stiffness of the reinforcing rib, which has a compact shape, is also possible.

[0026] Furthermore, since in the design described above a vertical dimension of the reinforcing rib of the lower bridge element is larger than a vertical dimension of the front wall area of ​​the upper bridge element, the strength and stiffness of the lower bridge element can be greater compared to the upper bridge element. Fig. Figure 1 is a left-side view showing a motorcycle with respect to an embodiment of the present invention. Fig. Figure 2 is a side view from the left, showing a front fork and handlebar grips. Fig. Figure 3 is a front view showing the front fork and handlebar grips. Fig. Figure 4 is a top view from below, showing the front fork and handlebar grips. Fig. Figure 5 is a drawing that represents the top of an upper bridge. Fig. Figure 6 is a drawing that shows the underside of the upper bridge. Fig. Figure 7 is a drawing depicting the front of the upper bridge. Fig. Figure 8 is a drawing that depicts the back side of the upper bridge. Fig. 9 (A) is a cross-sectional view extending along line IXA-IXA from Fig. 8 was created, and Fig. 9 (B) is a cross-sectional view taken along line IXB-IXB from Fig. 8 was created. Fig. Figure 10 is a drawing that depicts the top of a lower bridge. Fig. Figure 11 is a drawing that depicts the underside of the lower bridge. Fig. Figure 12 is a drawing depicting the front of the lower bridge. Fig. Figure 13 is a drawing depicting the back of the lower bridge. Fig. 14 (A) is a cross-sectional view extending along line XIVA-XIVA from Fig. 13 was created, and Fig. 14 (B) is a cross-sectional view taken along line XIVB-XIVB from Fig. 13 was created. Fig. Figure 15 (A) is a cross-sectional view of the upper bridge, and Fig. Figure 15 (B) is a cross-sectional view of the lower bridge. Fig. Figure 16 is a right-hand side view showing a rear wheel and its surroundings. Fig. Figure 17 is a side view from the left, showing a rear component of a swing arm, a brake caliper bracket and a brake caliper. Fig. 18 is a cross-sectional view taken along line XVIII-XVIII of Fig. 16 was created. Fig. 19 is a cross-sectional view taken along the XIX-XIX line from Fig. 16 was created. Fig. Figure 20 is a side view from the left, showing the front part of the vehicle body. Fig. Figure 21 is a top view from below, showing the front part of the vehicle body. Fig. Figure 22 is a top view showing a lower panel. Fig. Figure 23 is a cross-sectional view obtained by cutting in the vertical direction along an axis of the rear wheel. Fig. Figure 24 is the first cross-sectional view, showing a gear guard, a flange mounting element and its surroundings. Fig. Figure 25 is the second cross-sectional view, showing the gear guard, the collar receiving element and its surroundings.

[0027] One embodiment of the present invention is described below with reference to the drawings. In the explanation, a directional designation such as front, rear, left, right, top, and bottom is the same as the direction with respect to the vehicle body, unless a different specific description is given. Likewise, the symbol FR shown in each drawing represents the vehicle direction forward, a symbol UP represents a vehicle direction upward, and a symbol LH represents a left side of the vehicle body.

[0028] Fig. Figure 1 is a left-side view showing a motorcycle with respect to an embodiment of the present invention.

[0029] The motorcycle 1 is a vehicle in which an engine 11 as a drive unit is held by a body frame 10, a front fork 12 which holds a front wheel 2 is steerably held by the front end of the body frame 10, and a swing arm 13 which holds a rear wheel 3 is arranged on the rear part of the body frame 10.

[0030] The motorcycle 1 is a saddle-seat vehicle on which a rider sits astride a seat 14, and the seat 14 is arranged over the rear part of the vehicle body frame 10.

[0031] The body frame 10 comprises a steering head tube 15, a pair of left and right main frames 16, a pair of left and right pivot frames 17, a pair of left and right seat frames 18, wherein the head tube 15 is located at the front end of the body frame 10, the main frames 16 extend rearward and downward from the head tube 15, the pivot frames 17 extend downward from the rear ends of the main frames 16, and the seat frames 18 extend upward and rearward from the upper parts of the pivot frames 17.

[0032] Likewise, the body frame 10 has a transverse element (not shown) that connects the lower parts of the left and right pivot frames 17 in the vehicle width direction.

[0033] The main frames 16 have an engine mounting area (not shown) that extends downwards from the front parts of the main frames 16 and holds the engine 11.

[0034] The front fork 12 is pivotally mounted on the steering head tube 15, allowing it to be steered left and right. A pair of left and right handlebar grips 21 is arranged in the upper part of the front fork 12. The handlebar grips 21 have a throttle grip (not shown) at the end of one of them, which adjusts the throttle opening and is rotatable.

[0035] The front wheel 2 is pivotably held by an axle 2a, which is located at the lower end part of the front fork 12.

[0036] The swing arm 13 is pivotally held by a pivot shaft 22, which is itself held by the left and right pivot frames 17. The pivot shaft 22 runs horizontally in the direction of the vehicle's width. The swing arm 13 is pivotally held by the pivot shaft 22 through its front end section and pivots vertically around the pivot shaft 22.

[0037] The rear wheel 3 is pivotably held by an axle 3a, which is located at the rear end part of the swing arm 13.

[0038] The engine 11 is located below the main frame 16 and in front of the pivot frame 17 and is attached to the body frame 10.

[0039] The engine 11 comprises a crankcase 28 and a cylinder section 29, the crankcase 28 holding a crankshaft 27 which extends horizontally in the vehicle width direction (from left to right), the cylinder section 29 extending forward and upward toward the front part of the crankcase 28. A piston (not shown) is accommodated in the cylinder section 29, the piston performing a reciprocating motion within the cylinder section 29. A cylinder axis 29a of the cylinder section 29 is inclined forward with respect to the vertical direction.

[0040] The rear section of the crankcase 28 is a gearbox housing section that accommodates a gearbox (not shown). An output of the engine 11 is transmitted to the rear wheel 3 via a drive chain 30, which connects an output shaft of the gearbox and the rear wheel 3.

[0041] An air filter box 31 is arranged at the rear above the cylinder area 29. The air filter box 31 is connected to an inlet opening at the rear of the cylinder area 29 via a throttle body (not shown).

[0042] An exhaust pipe 32 of the engine 11 extends outwards from an exhaust opening at the front of the cylinder area 29, passes under the engine 11 and runs to the rear. The rear end of the exhaust pipe 32 is connected to an exhaust muffler 33, which is located in the side of the rear wheel 3.

[0043] A fuel tank 35 is arranged above the main frame 16 and between the seat 14 and the air filter box 31.

[0044] A radiator 36 is arranged in front of the engine 11, with the cooling water for the engine 11 passing through the radiator 36.

[0045] As a body fairing that covers the vehicle body, such as the body frame 10 and the engine 11, the motorcycle 1 has a front fairing 40, a side fairing 41, a lower fairing 42, a tank fairing 43 and a rear fairing 44, wherein the front fairing 40 covers the upper part of the front fork 12 and the steering head tube 15 from the front, the side fairing 41 covers the front part of the vehicle body from the side, the lower fairing 42 covers the engine 11 from below, the tank fairing 43 covers the air filter box 31 and part of the fuel tank 35, and the rear fairing 44 covers the rear part of the vehicle body.

[0046] A front fender 45, covering the front wheel 2 from above, is attached to the front fork 12. An inner fender 46, covering the front part of the rear wheel 3 from above, is attached to the swing arm 13. A rear fender 47, covering the rear part of the rear wheel 3 from above, extends downwards towards the rear from the rear end parts of the seat frame 18.

[0047] A footrest 48 is held by the pivot frames 17 and is arranged behind the pivot frames 17, with a driver on the seat 14 resting his feet on the footrest 48.

[0048] A headlight 49 is provided on the front end part of the front fairing 40.

[0049] A pair of left and right side mirrors 51 and a windshield 52 are mounted on the front fairing 40, the side mirrors 51 being arranged in the left and right side panels, and the windshield 52 being arranged in the central part of the upper section. The windshield 52 covers a gauge 53 from above, the gauge 53 being arranged below the windshield 52.

[0050] Fig. Figure 2 is a view from the left, showing the front fork 12 and the handlebar grips 21. Fig. Figure 3 is a front view showing the front fork 12 and the handlebar grips 21, and Fig. Figure 4 is a top view from below, showing the front fork 12 and the handlebar grips 21.

[0051] As in Fig. 2 and Fig. As shown in Figure 3, the front fork 12 has a pair of left and right fork tubes 61, an upper bridge 62, a lower bridge 63 and a handlebar stem 64.

[0052] Each of the left and right fork tubes 61 is a telescopic type damper having an outer tube 66 having a tubular shape and an inner tube 67 having a tubular shape, wherein the inner tube 67 is slidably inserted into the outer tube 66 from below and fits into the outer tube 66.

[0053] The handlebar grips 21 are attached to the left and right outer tubes 66 in areas near the upper bridge 62, which will be described in detail later.

[0054] The lower end parts of the left and right inner tubes 67 support the front wheel 2 (see Fig. 1) through axis 2a ( Fig. 1) held.

[0055] The upper bridge 62 connects the upper end sections of the left and right fork tubes 61 (more precisely, the outer tubes 66) to each other, and the lower bridge 63 connects the intermediate sections of the left and right fork tubes 61 (more precisely, the outer tubes 66) to each other in the longitudinal direction. The upper bridge 62 and the lower bridge 63 form a bridge element 68.

[0056] The steering shaft 64 is attached to the central section in the vehicle width direction from each of the upper bridge 62 and the lower bridge 63, in order to run between the upper bridge 62 and the lower bridge 63, and is rotatably mounted by the head tube 15 (see Fig. 1) of the body frame 10 (see Fig. 2) held.

[0057] As in Fig. As shown in Figure 4, a front wall area 62b, a rear wall area 62c and a reinforcing rib 62d are formed on a bottom side 62a of the upper bridge 62 to ensure strength and stiffness.

[0058] Likewise, a front wall area 63b, a rear wall area 63c and a reinforcing rib 63d are formed on a bottom side 63a of the lower bridge 63 to ensure strength and stiffness.

[0059] According to the front fork 12 of the present embodiment, by taking into account the shape of the front wall area 62b, the rear wall area 62c and the reinforcing rib 62d of the upper bridge 62 described above and the shape of the front wall area 63b, the rear wall area 63c and the reinforcing rib 63d of the lower bridge 63, the improvement of steering stability and the improvement of steering feel is made possible by the flexibility of the front fork 12 at a time when the vehicle enters a curve, while ensuring the strength and stiffness of the front fork.

[0060] Fig. Figure 5 is a drawing that represents an upper surface 62e of the upper bridge 62, Fig. Figure 6 is a drawing that represents the lower surface 62a of the upper bridge 62, Fig. Figure 7 is a drawing that represents a front surface 62f of the upper bridge 62, and Fig. Figure 8 is a drawing that represents a rear surface 62g of the upper bridge 62.

[0061] As in Fig. As shown in Figure 5, the upper bridge 62 has an integral pair of left and right fork retaining areas 62x, a stem retaining area 62y and a base area 62z, wherein the fork retaining areas 62x hold the left and right fork tubes 61, the stem retaining area 62y holds the longitudinal stem 64, and the base area 62z connects the left and right fork retaining areas 62x and the stem retaining area 62y.

[0062] Each of the left and right fork retaining areas 62x is configured to have a slotted fastening structure having a tube fitting area 62h and a separating area 62v, wherein the tube fitting area 62h is configured in a C-shape with part of a ring shape cut out, the separating area 62v is arranged at the end part of the letter C and is fastened by a screw 71.

[0063] The pipe fitting area 62h is an area into which the outer pipe 66 fits.

[0064] The separating area 62v is formed from a slot 62j and edge areas 62m, 62n, wherein the edge areas 62m, 62n are arranged on both sides of the slot 62j and opposite each other. The screw 71 (see Fig. 3) continues between the edge areas 62m, 62n, and the outer tube 66, which fits into the tube fitting area 62h, is fastened and fixed by the screw 71.

[0065] The shaft retention area 62y forms a projection area that has a ring-shaped form, which has a shaft fitting opening 62k and extends downwards over the lower surface 62a (see Fig. 6) of the base area 62z protrudes, wherein the handlebar stem 64 is pressed into the stem fitting opening 62k and attached to it.

[0066] As in Fig. As shown in Figure 6, with respect to the upper bridge 62, the front wall area 62b and the rear wall area 62c are formed at the front edge and the rear edge, the front wall area 62b and the rear wall area 62c each connect the left and right fork holding areas 62x to each other, and the reinforcing rib 62d is formed between the front wall area 62b and the rear wall area 62c, wherein the reinforcing rib 62d connects the left and right fork holding areas 62x to each other.

[0067] The front wall area 62b, the rear wall area 62c and the reinforcing rib 62d extend downwards beyond the lower surface 62a of the base area 61z.

[0068] The front wall area 62b extends linearly in the vehicle width direction and the rear wall area 62c is designed such that the middle section is connected to the shaft holding area 62y in the vehicle width direction in order to extend around the rear part of the shaft holding area 62y in order to allow the width from front to rear of the middle section in the vehicle width direction to be wider than the width from front to rear of the other areas.

[0069] The reinforcing rib 62d is formed between the front wall area 62b and the rear wall area 62c in order to run around (bypass) the shaft holding area 62y and bends to project forward. That is, with respect to the reinforcing rib 62d, both ends are connected to the positions of the left and right fork holding areas 62x closer to the rear wall area 62c compared to the front wall area 62b, and the central part of the reinforcing rib 62d in the vehicle width direction is arranged closer to the front wall area 62b compared to the rear wall area 62c.

[0070] As in Fig. As shown in Figure 7, in the front wall area 62b of the upper bridge 62, in the edge areas 62m, 62n, which are designed to be opposite both sides of the slot 62j, a threaded opening 62p and a screw insertion opening 62q are each formed in order to be directed towards the slot 62j.

[0071] The screw 71 (see Fig. 3) is designed to pass through the screw insertion opening 62q of the edge region 62n, and the distal end part of the screw 71 is screwed into the threaded opening 62p of the edge region 62m.

[0072] As in Fig. As shown in Figure 8, the rear wall area 62c of the upper bridge 62 gradually increases in terms of vertical width in the direction of vehicle width from the left and right fork holding areas 62x inwards, gradually increases further in the direction of the middle section in the direction of vehicle width and is largest in terms of vertical width at the middle section in the direction of vehicle width.

[0073] In this rear view, part of each of the front wall area 62b and the reinforcing rib 62d, which extends downwards beyond the rear wall area 62c, can be perceived.

[0074] Fig. 9 (A), (B) are cross-sectional views of the upper bridge 62, Fig. 9 (A) is a cross-sectional view extending along line IXA-IXA from Fig. 8 was created, and Fig. 9 (B) is a cross-sectional view taken along line IXB-IXB from Fig. 8 was created.

[0075] In Fig. 9 (A) is compared to a thickness A and a vertical width (a vertical dimension) WA (a vertical dimension between a reference line drawn from the top surface 62e and a dimension line 62b1 drawn from the front wall area 62b) of the front wall area 62b, a thickness B and a vertical width (a vertical dimension) WB (a vertical dimension between the reference line drawn from the top surface 62e and a dimension line 62c1 drawn from the rear wall area 62c) of the rear wall area 62c and a thickness C and a vertical width (a vertical dimension from the top surface 62e,(a reference surface SA) of the base area 62z) WC (a vertical dimension between the reference line drawn from the upper surface 62e and a dimension line 62d1 drawn from the reinforcing rib 62b) of the reinforcing rib 62d the front wall area 62b is thickest with respect to thickness and the thickness C of the reinforcing rib 62d lies between that of the front wall area 62b and that of the rear wall area 62c (B< C < A).,

[0076] Regarding the vertical width, the front wall area 62b is the widest and the vertical width WC of the reinforcement rib 62d lies between that of the front wall area 62b and that of the rear wall area 62c (WB < WC < WA).

[0077] Thus, in the front wall region 62b, the rear wall region 62c and the reinforcing rib 62d become larger in both thickness and vertical width when positioned towards the front of the upper bridge 62. This means that the strength and stiffness are increased when positioned towards the front of the upper bridge 62.

[0078] As in Fig. As shown in Figure 9 (B), the shaft holding area 62y is formed in a cylindrical shape and a vertical width WS of the shaft holding area 62y is formed to be equal to or generally equal to the vertical width of the reinforcing rib 62d.

[0079] Fig. 10 is a drawing that represents a surface 63e of the lower bridge 63, Fig. 11 is a drawing that represents the lower surface 63a of the lower bridge 63, Fig. 12 is a drawing that represents a front surface 63f of the lower bridge 63 and Fig. Figure 13 is a drawing that represents a rear surface 63g of the lower bridge 63.

[0080] As in Fig. As shown in Figure 10, the lower bridge 63 has a pair of left and right fork retaining areas 63x, a stem retaining area 62y and a base area 63z integrated in a manner, wherein the fork retaining areas 63x hold the left and right fork tubes 61, the stem retaining area 63y holds the handlebar stem 64, and the base area 63z connects the left and right fork retaining areas 63x and the stem retaining area 63y.

[0081] Each of the left and right fork retaining areas 63x is designed to have a slotted fastening structure having a tube insertion area 63h and a separating area 63v, wherein the tube insertion area 63h is formed in a C-shape with an annular part cut out, the separating area 63v is arranged at the end area of ​​the letter C and is fastened by a screw 71.

[0082] The pipe fitting area 63h is an area into which the outer pipe 66 fits.

[0083] The separating area 63v is formed from a slot 63j and the edge areas 63m, 63n, wherein the edge areas 63m, 63n are arranged on both sides of the slot 63j and opposite each other. The screw 71 (see Fig. 3) runs between the edge areas 63m, 63n, and the outer tube 66, which fits into the tube fitting area 63h, is fastened and fixed by the screw 71.

[0084] The shaft retention area 63y forms a projection area that has a ring-shaped form, which has a shaft fitting opening 63k and extends downwards over the lower surface 63a (see Fig. 11) of the base area 63z protrudes, wherein the longitudinal shaft 64 is pressed into the shaft fitting opening 63k and attached to it.

[0085] As in Fig. As shown in Figure 11, with respect to the lower bridge 63, the front wall area 63b and the rear wall area 63c are formed at the front edge and the rear edge, the front wall area 63b and the rear wall area 63c each connect the left and right fork holding areas 63x to each other, and the reinforcing rib 63d is formed between the front wall area 63b and the rear wall area 63c, wherein the reinforcing rib 63d connects the left and right fork holding areas 63x to each other.

[0086] The front wall area 63b, the rear wall area 63c and the reinforcing rib 63d extend downwards beyond the lower surface 63a of the base area 63z.

[0087] The front wall area 63b extends linearly in the direction of the vehicle's width. The rear wall area 63c is designed such that the central section is connected to the shaft holding area 63y in the direction of the vehicle's width, in order to extend around the rear part of the shaft holding area 63y, thus allowing the width of the central section from front to rear in the direction of the vehicle's width to be wider than the width of the other areas.

[0088] The reinforcing rib 63d runs linearly between the front wall region 63b and the rear wall region 63c, connects the left and right fork retaining regions 63x, and is connected to the front part of the shaft retaining region 63y. That is, the shaft retaining region 63y is connected to the rear wall region 63c and the reinforcing rib 63d. Thus, since both the rear wall region 63c and the reinforcing rib 63d are connected to the shaft retaining region 63y, the strength and stiffness of the lower bridge 63 can be further increased.

[0089] As seen in the front view of Fig. As shown in Figure 12, a damping retaining area 63w is arranged on one side (the left side) of the lower bridge 63 in order to protrude forward, with the damping retaining area 63w holding one end of the steering damper 111 (see Figure 12). Fig. 20). The other end of the steering damper 111 is routed over the side of the body frame 10 (see Fig. 2) held.

[0090] The front wall area 63b is narrower in terms of vertical width compared to the left and right fork holding areas 63x. More precisely, the front wall area 63b gradually decreases in vertical width as it extends inwards in the direction of the vehicle width from the side of the left and right fork holding areas 63x, and is designed such that the vertical width in the vehicle width direction is constant in the central section.

[0091] As in Fig. As shown in Figure 13, in the left and right fork holding areas 63x of the lower bridge 63, in the edge areas 63m, 63n, which are designed to be opposite both sides of the slot 63j, a threaded opening 63p and a screw insertion opening 63q are each formed in order to be oriented towards the slot 63j.

[0092] The screw 71 (see Fig. 3) is inserted to pass through the screw insertion opening 63q of the edge region 63n, and the distal end part of the screw 71 is screwed into the threaded opening 63p of the edge region 63m.

[0093] In a similar manner to the front wall area 62b (see Fig. 12) the rear wall area 63c gradually decreases in vertical width as it extends inwards in the vehicle width direction from the side of the left and right fork holding areas 63x and is designed to have a constant vertical width at the middle section in the vehicle width direction.

[0094] Fig. 14 (A), (B) are cross-sectional views of the lower bridge 63, Fig. 14 (A) is a cross-sectional view extending along line XIVA-XIVA from Fig. 13 was created, and Fig. 14 (B) is a cross-sectional view taken along line XIVB-XIVB from Fig. 13 was created.

[0095] As in Fig. Figure 14 (A) shows that, compared to a thickness D and a vertical width (a vertical dimension) WD (a vertical dimension between a reference line bs drawn from the upper surface 63e and a dimension line 63b1 drawn from the front wall area 63b) of the front wall area 63b, a thickness E and a vertical width (a vertical dimension) WE (a vertical dimension between the reference line bs drawn from the upper surface 63e and a dimension line 63c1 drawn from the rear wall area 63c), and a thickness F and a vertical width (a vertical dimension from the upper surface 63e (a reference surface SB) of the base area 63z) WF (a vertical dimension between the reference line bs drawn from the upper surface 63e and a dimension line 63d1 drawn from the reinforcing rib 63d), the thickness in in the order D < E ≤ F, the thickness of the front wall region 63b is the smallest,However, the difference in thicknesses D, E, F is small, and it can be concluded that thicknesses D, E, F are of a similar thickness. Likewise, the vertical width in the order WF < WE < WD of the front wall area 63b is the widest, and the reinforcing rib 63d is the narrowest.

[0096] As in Fig. As shown in Figure 14(B), the shaft retaining area 63y is cylindrical, and a solid area 63r is formed in front of the shaft retaining area 63y. The solid area 63r is connected to the shaft retaining area 63y and to the front wall area 63b and the reinforcing rib 63d. The solid area 63r projects downwards from the central section in the vehicle width direction of the lower surface 63a of the base area 63z.

[0097] Fig. 15 (A), B) are drawings for comparing the shape of the upper bridge 62 and the lower bridge 63, Fig. 15 (A) is a cross-sectional view of the upper bridge 62 and Fig. Figure 15 (B) is a cross-sectional view of the lower bridge 63. Likewise, Fig. 15 (A) and Fig. 15 (B) obtained by each Fig. 9 (A) and Fig. 14 (A) each be reprinted with the addition of a dimension line and the upper bridge 62 and the lower bridge 63 at the same reduction scale in Fig. 15 (A) and in Fig. 15 (B) will be drawn.

[0098] Likewise, each of the vertical width WA, WB, WC of the front wall area 62b, the rear wall area 62c and the reinforcing rib 62d of the upper bridge 62 is narrower than any of the vertical width WD, WE, WF of the front wall area 63b, the rear wall area 63c and the reinforcing rib 63d of the lower bridge 63, and the height of the reinforcing rib 63d, which is lowest in the lower bridge 63, is greater than the height of the front wall area 62b, which is highest in the upper bridge 62.

[0099] Furthermore, the width W1 from front to back from the front wall area 62b to the rear wall area 62c of the upper bridge 62 is narrower than the width W2 from front to back from the front wall area 63b to the rear wall area 63c of the lower bridge 63, and the thickness T1 of the base area 62z of the upper bridge 62 is thinner than the thickness T2, T3 of the base area 63z of the lower bridge 63.

[0100] Accordingly, based on the difference in shape of the upper bridge 62 and lower bridge 63 described above, the strength and stiffness of the lower bridge 63 will be higher than that of the upper bridge 62, and the side of the upper bridge 62 will be easily bendable based on the difference in stiffness.

[0101] Fig. Figure 16 is a right-hand side view showing the rear wheel 3 and its surroundings.

[0102] Motorcycle 1 (see Fig. 1) has a rear wheel disc brake device 80 which brakes the rear wheel 3.

[0103] The rear wheel disc brake assembly 80 comprises a brake disc 81, a brake caliper bracket 82 and a brake caliper 83.

[0104] The brake disc 81 is a circular plate having a circular ring shape, wherein the circular plate is attached to a hub 85a by several screws 86, wherein the hub 85a is arranged in the central part of a wheel 85 which forms the rear wheel 3.

[0105] The brake caliper 82 fits into the axle 3a of the rear wheel 3 and is prevented from rotating by an arm section 13A on one side (the right side) of the swing arm 13 (more precisely, a pair of left and right arm sections 13A, 13B that define the swing arm 13 (see Fig. 23 regarding 13B)).

[0106] The brake caliper 83 is attached to the brake caliper bracket 82 by several screws 87 and brakes the brake disc 81 by means of hydraulic oil pressure. More precisely, the brake caliper 83 has a piston and a pair of brake pads, the piston being movably inserted into a cylinder located inside, with the brake pads arranged to engage the brake disc 81 between them. When the piston is driven by the hydraulic pressure, the brake disc 81 is engaged by a pressure force of the piston via the pair of brake pads between them, and thus the rear wheel 3 is braked.

[0107] The brake caliper bracket 82 integrally incorporates an axle fitting area 82a (see Fig. 17) and an extension area (82b), wherein the axis fitting area 82a is fitted into the axis 3a, and the extension area 82b extends downwards and forwards from the axis fitting area 82a.

[0108] The extension area 82b integrally includes a front extension area 82c, a first brake caliper holding area 82d and a second brake caliper holding area 82e, which extend radially clockwise from the axle fitting area 82a.

[0109] The front extension area 82c is formed on the upper edge part of the extension area 82b and extends forward from the axis fitting area 82a.

[0110] At the distal end part of the front extension area 82c, a brake caliper mounting engagement area 82f is provided to position the brake caliper 82 at a specific angle with respect to the axis 3a, the brake caliper engagement area 82f engaging in the inner surface side of the swing arm 13.

[0111] The first caliper retaining area 82d and the second caliper retaining area 82e secure the caliper 83 to the distal end of each by means of screws 87.

[0112] The second brake caliper holding area 82e has an integral projection area 82g close to the axle fitting area 82a, the projection area 82g being located on the rear end part of the swing arm 13 to be guided.

[0113] Fig. Figure 17 is a left-side view showing the rear part of the swing arm 13, the brake caliper bracket 82, and the brake caliper 83. A mounting procedure for a rear wheel assembly 3B on the swing arm 13 is also described by this drawing, wherein the rear wheel assembly 3B is obtained by mounting the brake caliper bracket 82 and the brake caliper 83 together with the rear wheel 3 (see Figure 17). Fig. 1).

[0114] The swing arm 13 (more precisely, the arm section 13A on the right side of the pair of left and right arm sections) has an axle insertion opening 13b, a positioning area 13d and a projecting guide area 13e, wherein the axle insertion opening 13b allows the axle 3a to pass through to the rear end part in order to be movable in the front-to-back direction and has an elongated circular shape that is laterally long, wherein the positioning area 13d is arranged on an inner surface 13c in front of the axle insertion opening 13b, the projecting guide area 13e is formed on the inner surface of the lower end edge part of the rear end part and has a chamfered shape.

[0115] The brake caliper bracket 82 fits into the axle 3a through the axle fitting area 82a and is mounted to engage in the positioning area 13d through the brake caliper bracket engagement area 82f.

[0116] A method for mounting the rear wheel assembly 3B described above on the swing arm 13 is explained below.

[0117] First, the rear wheel assembly 3B is positioned behind the swing arm 13, so that the front extension area 82c of the brake caliper bracket 82 of the rear wheel assembly 3B is aligned with the rear end part of the swing arm 13.

[0118] Next, as shown in the white arrow, the rear wheel assembly 3B is moved forward, and the projection area 82g of the brake caliper bracket 82 of the rear wheel assembly 3B, the contour of which is shown in a bold dashed line with two dots, is brought to rest on the rear end portion of the projection area guide area 13e of the swing arm 13.

[0119] Likewise, when the rear wheel assembly 3B is moved further forward while a state of the projection area 82b is formed to rest on the projection area guide area 13e, the brake caliper mounting engagement area 82f of the brake caliper mounting 82 of the rear wheel assembly 3B engages in the positioning area 13d of the swing arm 13.

[0120] In this state, the axle 3a is caused to pass through the swing arm 13 and the rear wheel assembly 3B, the position of the rear wheel assembly 3B is adjusted in the front-to-back direction, and then a nut 91 (see Fig. 16) screwed onto the distal end of axle 3a. This completes the assembly of the rear wheel assembly 3B.

[0121] As described above, by arranging the projecting guide area 13e in the swing arm 13 and the projecting area 82g in the brake caliper bracket 82, the front extension area 82c of the brake caliper bracket 82 can be configured to engage in the positioning area 13d of the swing arm 13, with the positioning area 13b not being easily visible from the front. This improves the feasibility of the assembly work for the rear wheel assembly 3B.

[0122] Fig. 18 is a cross-sectional view taken along line XVIII-XVIII of Fig. 16 was created, and Fig. 19 is a cross-sectional view taken along the XIX-XIX line from Fig. 16 was created.

[0123] As in Fig. As shown in Figure 18, the brake caliper bracket engagement area 82f of the front extension area 82c engages in the brake caliper bracket 82 in the positioning area 13d of the swing arm 13, or, more precisely, an engagement groove 13f is formed in the positioning area 13d. Thus, the brake caliper bracket 82 is positioned and prevented from rotating relative to the swing arm 13.

[0124] As in Fig. As shown in Figure 19, a bearing 93 and a sealing element 94 for fitting into an inner circumferential surface 85b are formed in the hub 85a of the wheel 85 in the rear wheel 3, a flange element 95 is formed for fitting into an inner circumferential surface 94a of the sealing element 94 and an end surface of the flange element 95 is formed to rest on the side surface of the bearing 93.

[0125] The axle 3a of the rear wheel 3 passes through an intermediate collar element 97, the left and right bearings 93, the sealing element 94, and the collar element 95, the intermediate collar element 97 being arranged between the pair of left and right bearings 93 (only one bearing 93 is shown) and having a tubular shape. Furthermore, the axle 3a passes through an axle insertion opening 82h and the axle insertion opening 13b, the axle insertion opening 82h being formed in the axle insertion area 82a of the brake caliper 82, the axle insertion opening 13b being located at the rear end part of the swing arm 13.

[0126] In the rear end part of the swing arm 13, a recess area 13h and the axle insertion opening 13b are provided, wherein the recess area 13h is formed in an outer surface 13g, and the axle insertion opening 13b is formed in a bottom surface 13j of the recess area 13h.

[0127] The recess area 13h is designed to be long in the front-to-back direction, with its rear end opening to the rear. A sliding element 101 is arranged in the recess area 13h, and an axle fitting opening 101a is drilled into the sliding element 101, with the axle 3a passing through the axle fitting opening 101a.

[0128] The sliding element 101 is arranged to be movable in the direction from front to back in the recess area 13h and can be forcibly moved backwards in the recess area 13h by a movement mechanism not shown, which consists, for example, of a screw and a nut for tensioning the drive chain 30 (see Fig. 16) is designed to be located between the transmission of the motorcycle 1 and the rear wheel. That is, by moving the sliding element 101, the rear wheel 3 can be moved backwards by the axle 3a.

[0129] A washer 103 is appropriately formed on the end part of the axle 3a and a nut 104 is screwed together and the axle 3a is attached to the swing arm 13.

[0130] The projection area 82g of the brake caliper bracket 82 has an inclined surface 82j that slopes gradually downwards as it extends from the inside to the outside in the vehicle width direction, and the inclined surface 82j is designed to bear against the projection area guide area 13e, which is located at the rear part of the swing arm 13. Thus, since the inclined surface 82j of the projection area 82g is designed to bear against the projection area guide area 13e of the swing arm 13, rotation of the brake caliper bracket 82 and the brake caliper bracket 82 can be prevented.

[0131] Fig. Figure 20 is a left-side view showing the front of the vehicle body and a state of the side panel 41 being detached from the state of Fig. 1 represents.

[0132] A steering damper 111 is arranged between the steering head tube 15 of the body frame 10 and the lower bridge 63 of the front fork 12.

[0133] The steering damper 111 is arranged in front of the lower bridge 63 and an end part of the steering damper 111 is oscillatively connected to the damper holding area 63w of the lower bridge 63.

[0134] A lower fairing 112 is arranged below the steering damper 111, the lower fairing 112 being attached to the lower bridge 63 from below. The lower fairing 112 rotates integrally with the front fork 12 as a result of steering the left and right handlebar grips 21.

[0135] Fig. Figure 21 is a top view from below, showing the front of the vehicle body. Likewise, in Fig. 21 the left and right inner tubes 67 (see Fig. 4) under the left and right outer tubes 66 of the front fork 12 as well as the axle 2a, the front wheel 2, the front fender 45 and similar parts in Fig. 1. Figures shown have been omitted.

[0136] As in Fig. As shown in Figure 21, the lower fairing 112 is formed in a shape that extends around (recesses) the left and right outer tubes 66 of the front fork 12 and a lower end region 64a of the handlebar stem 64, and has a space for arranging a horn 114. The handlebar stem 64 passes through the lower fairing 112 and protrudes downwards from a lower surface 112a of the lower fairing 112.

[0137] Fig. Figure 22 is a top view showing the lower panel 112.

[0138] The lower fairing 112 has a front rib 112b, a rear rib 112c, a pair of left and right notch areas 112d, 112e, a shaft opening 112f, a pair of left and right bridge attachment projection areas 112g, a pair of left and right guide ribs 112h, a pair of left and right drainage openings 112j and a hupan attachment opening 112k.

[0139] The front rib 112b projects upwards from the leading edge of the lower fairing 112 and is curved to protrude forwards. The leading edge of the lower fairing 112 is reinforced by the front rib 112b.

[0140] The rear rib 112c projects upwards from the trailing edge of the lower fairing 112 and is curved to project rearwards. The trailing edge of the lower fairing 112 is reinforced by the rear rib 112c. The rear rib 112c is designed to be lower than the front rib 112c.

[0141] The left and right notch areas 112d, 112e are areas for rotation around the left and right outer tubes 66 ( Fig. 21) the front fork 12 (see Fig. 21) and are designed such that they extend inwards in the vehicle width direction from both end sections of each, from the front edge and the rear edge of the lower fairing 112. On the edge section of each of the left and right notch areas 112d, 112e, upwardly projecting notch area ribs 112m, 112n are formed.

[0142] The shaft opening 112f is an area to accommodate the handlebar shaft 64 (see Fig. 21) to allow it to pass through, and a circular rib 112p is formed on the circumferential edge of the shaft opening 112f, wherein the circular rib 112p projects upwards and has a circular shape.

[0143] Each of the left and right bridge mounting projection areas 112g projects from a surface 112q of the lower panels 112 and has a screw insertion opening 112r which allows a screw (not shown) to be inserted, the screw being attached to the lower surface of the lower bridge 63 (see Fig. 20).

[0144] The left and right guide ribs 112h each run linearly to connect the circular rib 112p of the shaft opening 112f and the left and right bridge mounting projection areas 112g, and project upwards from the surface 112q. The left and right guide ribs 112h are designed in a shape that widens towards the end, so that they gradually extend outwards in the direction of the vehicle's width from the circular rib 112p forwards.

[0145] The left and right drainage openings 112j are drilled in the corners of the circular rib 112p and the left and right guide ribs 112h and are designed to pass through the lower cladding 112 in the vertical direction.

[0146] In surface 112q, since a front surface 112s is inclined upwards towards the front in front of the circular rib 112p and the left and right guide ribs 112h, rainwater and similar substances that have fallen onto the front surface 112s flow from the front surface 112s to the rear, collect at the corners of the circular rib 112p and the left and right guide ribs 112h, and fall from the left and right drainage openings 112j onto the front fender 45 below (see Fig. 20) (the position and direction of the falling water are indicated by an arrow of a dashed line in Fig. 20 shown).

[0147] The horn assembly opening 112k is formed in a shape along a contour of the horn 114 (see Fig. 21) and a horn opening rib 112t is formed on the edge part of the horn assembly opening 112k, with the horn opening rib 112t projecting upwards. And as described above, the anti-vibration properties of the lower panels 112 can be improved in addition to their strength and stiffness when the ribs are formed in the respective parts of the lower panels 112.

[0148] Fig. Figure 23 is a cross-sectional view obtained by cutting it in the vertical direction along an axis 3a of the rear wheel 3.

[0149] The swing arm 13 has the pair of left and right arm sections 13A, 13B.

[0150] A wheel damper 122 is arranged on one side (the left side) of the hub 85a of the wheel 85, the wheel damper 122 holding a driven gear 121.

[0151] The wheel damper 122 has a gear holding area 124, a bearing 125, several damper chambers 85c and several elastic bodies 126.

[0152] The gear holding area 124 is rotatably held by a cylinder area 85d of the end area, which is formed in an end part of the hub 85a, and the driven gear 121 is attached to the outer circumferential part of the gear holding area 124.

[0153] The bearing 125 holds the gear holding area 124 so that it can rotate with respect to the axis 3a.

[0154] The damping chambers 85c are formed in several in an end part of the hub 85a in order to open outwards in the direction of the vehicle width.

[0155] The elastic bodies 126 are each arranged in several of the damper chambers 85c.

[0156] The gear holding area 124 has pressure areas (not shown) which are each used in several of the damper chambers 85c.

[0157] On an output shaft of the gearbox that is integrally arranged in the motor 11 (see Fig. 1) A drive gear (not shown) is arranged and the drive chain 30 (see Fig. 16) extends between the drive gear and the driven gear 121.

[0158] When the power is transmitted via the drive chain 30 from the gearbox to the driven gear 121, the power is transmitted to the driven gear 121, the gear holding area 124 (more precisely, the pressure area of ​​the drive gear 124), several of the elastic bodies 126, several of the damper chambers 85c and the hub 85a in this order.

[0159] Since the pressure area of ​​the gear retaining area 124 transmits the force to the hub 85a while pressing the elastic bodies 126 in the damper chambers 85c and allowing the elastic bodies 126 to be elastically deformed, the power fluctuation on the side of the driven gear 121 at the hub 85a is reduced.

[0160] A sealing element 128 is located adjacent to the bearing 125 and a wheel flange 131 fits into the inner circumferential surface of the sealing element 128.

[0161] The axle 3a passes through the arm area 13b on one side, the wheel flange 131, the bearing 125, a flange 132 and the bearings 93 and is finally screwed to the nut 104.

[0162] At the lower part of the rear end part of the arm section 13B on one side of the swing arm 13, a gear guard 134 and a collar mounting element 135 are fastened together by a pair of screws 137.

[0163] The gear guard 134 covers the driven gear 121 from the side. The flange receiving element 135 is arranged under the wheel flange 131 (more precisely, a flange area 131a, which is arranged on the end part on the outside in the vehicle width direction of the wheel flange 131).

[0164] The flange mounting element 135 is an element that receives a wheel assembly 140 (including the wheel 85, the driven gear 121, the wheel damper 122, the bearings 93, 93, the sealing elements 94, 128, the flange element 95, the flange 132, the intermediate flange element 97 and the wheel flange 131) so that the wheel assembly 140 does not fall off when the axle 3a is removed. Likewise, WW is the width of the wheel assembly 140 in the vehicle width direction.

[0165] Fig. Figure 24 is the first cross-sectional view, which represents the gear guard 134, the collar receiving element 135 and the surrounding area thereof, and shows a cross-section obtained by being cut by a plane passing through the pair of front and rear screws 137 in the longitudinal direction and in the vertical direction and in the front-to-back direction. Fig. 25 is the second cross-sectional view showing the gear guard 134, the collar receiving element 135 and the surrounding area, and showing a cross-section obtained by being cut by a plane passing through a screw 137 in the longitudinal direction and extending in the vertical direction and the vehicle width direction.

[0166] As in Fig. As shown in Figure 24, a rear section 134a of the gear guard 134 and the collar mounting element 135 are fastened together by the pair of front and rear screws 137 at the lower end part of a rear end section 13X in the arm section 13B of the swing arm 13.

[0167] In the rear area 134a of the gear guard 134, a pair of front and rear vertically extending openings 134b are formed to accommodate collar elements 142, which have a tubular shape, designed to fit into the pair of vertical openings 134b.

[0168] The flange mounting element 135 is designed from a vertical plate area 135a and a lateral plate area 135b, wherein the vertical plate area 135a is arranged under the wheel flange 131 in order to run in the vertical direction and in the direction from front to rear, wherein the lateral plate area 135b is bent outwards in the vehicle width direction from the lower edge of the vertical plate area of ​​135a.

[0169] The vertical plate section 135a is designed such that the width of its upper part, from front to back, is wider than that of its lower part, and an inclined section 135c is arranged at the upper edge of the front part of the vertical plate section 135a, the inclined section 135c being inclined forward and upward. By arranging such an inclined section 135c, it is possible to prevent the wheel flange 131, which is received by the vertical plate section 135a, from moving forward. A pair of screw insertion holes 135d are drilled in the lateral plate section 135b to be spaced apart from each other in the front-to-back direction.

[0170] A plate element 144 is arranged below the lateral plate area 135b. A pair of screw insertion holes 144a are drilled into the plate element 144 to be spaced apart from each other in the front-to-back direction.

[0171] The pair of screws 137 are inserted into the pair of screw insertion openings 144a of the plate element 144, the pair of screw insertion openings 135d of the lateral plate region 135b of the collar receiving element 135 and the pair of collar elements 142 in this order, and respective distal parts of the pairs of screws 137 are screwed together with the threaded openings (not shown) formed in the lower surface of the posterior end region 13X in the arm region 13B.

[0172] As in Fig. 24 and Fig. As shown in Figure 25, the vertical plate area 135a of the collar receiving element 135 lies on or is adjacent to the flange area 131a of the wheel collar 131.

[0173] In Fig. 25 the vertical plate area 135a runs in the vertical direction, the lateral plate area 135b is fastened in the vertical direction by the pair of screws 137, and therefore a load exerted by the wheel flange 131 can be effectively absorbed by the flange receiving element 135.

[0174] As described above Fig. 1, Fig. 3, Fig. 6 and Fig. Figure 11 shows that in the motorcycle 1, as a saddle seat vehicle, the front fork 12 comprises the pair of left and right fork tubes 61, the bridge element 68 and the handlebar stem 64, wherein the fork tubes 61 hold the front wheel 2, the bridge element 68 connects the left and right fork tubes 61 together, and the handlebar stem 64 is attached to the bridge element 68.

[0175] The front fork 12 is rotatably held by the steering head tube 15 of the body frame 10 through the steering stem 64.

[0176] The stem retaining area 62y, 63y and the pair of left and right fork retaining areas 62x, 63x are connected to each other via the base area 62z, 63z, with the stem retaining area 62y, 63y holding the handlebar stem 64, the fork retaining areas 62x, 63x holding the left and right fork tubes 61.

[0177] The bridge element 68 is formed from the upper bridge 62 as an upper bridge element and the lower bridge 63 as a lower bridge element, wherein the upper bridge 62 connects the upper parts of the left and right fork tubes 61 together, the lower bridge 63 is arranged under the upper bridge 62 and connects the left and right fork tubes 61 together.

[0178] The front wall area 62b, 63b and the rear wall area 62c, 63c are provided at the front edge and rear edge of each of the upper bridge and the lower bridge 63, the front wall area 62b, 63b and the rear wall area 62c, 63c, which connect the left and right fork holding areas 62x, 63x.

[0179] The reinforcing rib 62d is provided on the rear of the base area 62z of the upper bridge 62, with the reinforcing rib 62d extending around the shaft retaining area 62y and connecting the left and right fork retaining areas 62x.

[0180] According to this design, the stiffness and strength between the left and right fork retaining areas 62x can be improved by connecting them to each other via the reinforcing rib 62d. The stiffness and strength of the shaft retaining area 62y and the fork retaining areas 62x can be designed independently, and flexibility between the shaft retaining area 62y and the fork retaining areas 62x is easily achieved because no reinforcing rib is required to connect them. Consequently, the upper bridge element 62 can easily bend when the vehicle turns.

[0181] Likewise, as in Fig. 6 and Fig. As shown in Figure 11, the rear wall area 62c, 63c of each of the upper bridge element 62 and the lower bridge element 63 are connected to the shaft holding area 62y, 63y.

[0182] According to this design, the strength and stiffness of the shaft holding area 62y, 63y can be ensured by the back wall area 62c, 63c.

[0183] The process continues as in Fig. Figure 6 shows the reinforcing rib 62d of the upper bridge element 62 in a curved shape and both end parts of the reinforcing rib 62d are connected to the side of the rear part of the left and right fork holding areas 62x.

[0184] According to this design, by arranging the front wall area 62b and the reinforcing rib 62d between the front and rear ends of the fork holding area 62x, separate from the rear wall area 62c, the strength and stiffness can be further improved.

[0185] Likewise, as in Fig. As shown in Figure 9 (A), a vertical dimension of the reinforcing rib 62d of the upper bridge 62 is larger than a vertical dimension of the rear wall area 62c.

[0186] According to this design, a difference in strength and stiffness is created between the shaft holding area 62y and the fork holding area 62x, and bending of the upper bridge 62 can be easily enabled.

[0187] As in Fig. As shown in Figure 15, a vertical dimension of the front wall area 62b of the upper bridge 62 is larger than a vertical dimension of the reinforcing rib 62d.

[0188] According to this design, a difference in strength and stiffness is created between the shaft holding area 62y, 63y and the fork holding areas 62x, 63x, and bending of the upper bridge 62 can be easily enabled.

[0189] As in Fig. 3, Fig. 6 and Fig. As shown in Figure 11, the fork retaining areas 62x, 63x are formed in a C-shape, which has separating areas 62v, 63v in which part of a ring shape is cut out, and which have a slot fastening structure to which the separating areas 62v, 63v are fastened by screws 71 to fasten the fork tubes 61, and the separating area 62v of the upper bridge element 62 is arranged on the side of the front wall area 62b.

[0190] According to this design, when the reinforcing rib 62d of the upper bridge 62 bends and is connected to the side of the rear part of the fork retaining area 62x, a space at the front of the reinforcing rib 62d can be easily ensured, the stiffness of the upper bridge 62 can be increased by the slot fastening, and therefore the reinforcing rib 62d and the slot fastening structure can be designed in an effective manner.

[0191] Likewise, as in Fig. As shown in Figure 11, the reinforcing rib 63d of the lower bridge element 63 extends linearly from the intermediate parts in the direction from front to rear of the left and right fork holding areas 63x, connects the left and right fork holding areas 63x together and is connected to the shaft holding area 63y on the middle part in the vehicle width direction.

[0192] According to this design, it is not easily possible for the lower bridge 63 to be bent between the left and right fork holding areas 63x and the shaft holding area 63y, and if the stiffness and strength of the lower bridge 63 are greater than that of the upper bridge 62, the upper bridge 62 can be bent, with the lower bridge 63 becoming a pivot point.

[0193] Likewise, as in Fig. As shown in Figure 14 (A), a vertical dimension of the rear wall area 63c of the lower bridge 63 is larger than a vertical dimension of the reinforcing rib 63d and a vertical dimension of the front wall area 63b is larger than a vertical dimension of the rear wall area 63c.

[0194] According to this design, the strength and stiffness of the lower bridge 63 can be ensured by the front wall area 63b and the rear wall area 63c, and an increase in strength and stiffness by the reinforcing rib 63d, which has a compact shape, is also possible.

[0195] Likewise, as in Fig. 15 (A) and (B) shown, a vertical dimension of the reinforcing rib 63d of the lower bridges 63 is larger than a vertical dimension of the front wall area 62b of the upper bridge 62.

[0196] According to this design, the strength and stiffness of the lower bridge 63 can be greater compared to the upper bridge 62.

[0197] Without limiting its application to a motorcycle 1, the present invention can also be applied to articulated vehicles, including those different from the motorcycle 1. Likewise, the articulated vehicle includes all vehicles on which a rider sits astride the body 70 and is a vehicle that includes not only the motorcycle 1 (including a motorized bicycle) but also three-wheeled vehicles and four-wheeled vehicles classified as all-terrain vehicles (ATVs). List of reference symbols: 1 Motorcycle (saddle seat vehicle) 2 front wheel 10 body frames 12 Front fork 15 Steering head tube 61 Fork tube 62 Upper bridge (upper bridge element) 62b, 63b Front wall area 62c, 63c rear wall area 62d, 63d Reinforcing rib 62V, 63V separation range 62x, 63x fork holding area 62y, 63y shaft holding area 62z, 63z base range 63 Lower bridge (lower bridge element) 64 handlebar stem 68 bridge element 71 screw

Claims

[1] A front fork assembly of a saddle seat vehicle, wherein a front fork (12) comprises a pair of left and right fork tubes (61), a bridge member (68) and a handlebar stem (64), the fork tubes (61) holding a front wheel (2), the bridge member (68) connecting the left and right fork tubes (61) to each other, the handlebar stem (64) is fixed to the bridge member (68), the front fork (12) is rotatably supported by a steering head tube (15) of a body frame (10) through the handlebar stem (64), a stem holding portion (62y, 63y) and a pair of left and right fork holding portions (62x, 63x) are connected to each other by a base portion (62z, 63z), the stem holding portion (62y, 63y) holds the handlebar stem (64), the fork holding portions (62x, 63x) support the left and right fork tubes (61), the bridge element (68) is designed from an upper bridge element (62) and a lower bridge element (63),wherein the upper bridge member (62) connects the upper parts of the left and right fork tubes (61) to each other, the lower bridge member (63) is arranged below the upper bridge member (62) and connects the upper parts of the left and right fork tubes (61) to each other, wherein each of the upper bridge member (62) and the lower bridge member (63) has a front wall portion (62b, 63b) and a rear wall portion (62c, 63c) at the front edge and the rear edge of each of the upper bridge member (62) and the lower bridge member (63), wherein the front wall portion (62b, 63b) and the rear wall portion (62c, 63c) connect the left and right fork holding portions (62x, 63x) to each other, , characterized bythat a reinforcing rib (62d) is provided on the back of the base portion (62z) of the upper bridge member (62), wherein the reinforcing rib (62d) is not connected to the shaft holding portion (62y), extends around the shaft holding portion (62y) and connects the left and right fork holding portions (62x) to each other. [2] The front fork assembly of the saddle seat vehicle according to claim 1, wherein the rear wall portion (62c, 63c) of each of the upper bridge member (62) and the lower bridge member (63) is connected to the shaft holding portion (62y, 63y). [3] Front fork assembly of the saddle seat vehicle according to claim 1 or 2, wherein the reinforcing rib (62d) of the upper bridge element (62) is curved, and both parts of the reinforcing rib (62d) are connected to the side of the rear part of the left and right fork holding sections (62x). [4] The front fork assembly of the saddle seat vehicle according to any one of claims 1 to 3, wherein a vertical dimension of the reinforcing rib (62d) of the upper bridge member (62) is larger than a vertical dimension of the rear wall portion (62c). [5] The front fork assembly of the saddle seat vehicle according to any one of claims 1 to 4, wherein a vertical dimension of the front wall portion (62b) of the upper bridge member (62) is larger than a vertical dimension of the reinforcing rib (62d). [6] Front fork assembly of the saddle seat vehicle according to one of claims 1 to 5, wherein the fork holding portions (62x, 63x) are formed in a C-shape, the separating portions (62v, 63v) have an annular part cut out therein, and the fork holding portions (62x, 63x) have a slotted fastening structure in which the separating portions (62v, 63v) are fastened by screws (71) to fix the fork tubes (61), and the separating region (62v) of the upper bridge element (62) is arranged on the side of the front wall region (62b). [7] The front fork assembly of the saddle seat vehicle according to any one of claims 1 to 6, wherein a reinforcing rib (63b) of the lower bridge member (63) extends linearly from intermediate parts in the front-rear direction of the left and right fork support portions (63), connects the left and right fork support portions (63x) to each other, and is connected to the shaft support portion (63y) at the center part in the vehicle width direction. [8] Front fork assembly of the saddle seat vehicle according to one of claims 1 to 7, wherein a vertical dimension of the rear wall region (63c) of the lower bridge element (63) is greater than a vertical dimension of the reinforcing rib (63d), and a vertical dimension of the front wall region (63b) is greater than a vertical dimension of the rear wall region (63c). [9] The front fork assembly of the saddle seat vehicle according to any one of claims 1 to 7, wherein a vertical dimension of the reinforcing rib (63d) of the lower bridge member (63) is larger than a vertical dimension of the front wall portion (62b) of the upper bridge member (62).

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