JP5208558B2 - Steering device for small vehicles - Google Patents

Description

  The present invention relates to a steering apparatus for a small vehicle in which a steering shaft penetrates between upper arm attachment portions from the upper side to the lower side, and a wheel is steered by a tie rod connected to a center arm provided on the steering shaft.

Some small vehicles, such as ATV (All Terrain Vehicle), have their wheels suspended using a double wishbone suspension device composed of a pair of upper and lower arms. In this type of small vehicle, the steering shaft penetrates between the upper arm mounting parts from the upper side to the lower side, the lower part of the shaft is supported by a bearing, and the ball end of the tie rod is provided on the lower surface of the center arm provided on the steering shaft. Are connected and the direction of the wheel is steered by this tie rod (for example, see Patent Document 1).
Japanese Patent No. 3792851

  However, in the conventional configuration, when the frame, the suspension arm, and the center arm are close to each other as the frame is downsized, the layout space that can be allocated to the tie rod becomes narrow, so it may be difficult to lay out the tie rod. there were.

  Accordingly, an object of the present invention is to provide a steering device for a small vehicle that solves the above-described problems of the prior art and enables the tie rods to be appropriately laid out in a narrow layout space.

In order to solve the above-described problems, the present invention is provided with a double wishbone suspension (5) including a pair of upper arms (6) and a lower arm (7), and a steering shaft (21) serving as an upper arm (6). Tie rods (not shown ) extending from above to below and supporting the lower portion of the shaft (21) with bearings (75 ) and connected to a center arm (23) provided on the steering shaft (21). 24) In a steering device for a small vehicle that steers the direction of the wheel (2 ) by 24) , the center arm is disposed below the bearing holder (65) holding the bearing (75) that supports the lower portion of the steering shaft (21). (23) is provided, and the center arm (23) is curved downward, and the center arm (23) The ball end (24a ) of the tie rod (24) is fixed upward, the nut mounting portion (24c) connected to the ball end (24a) is directed downward, and the nut mounting portion (24c) side is directed to the vehicle body. The tie rod (24) is attached while being inclined inward .

  According to the present invention, the center arm is provided at the lower portion of the bearing holder that holds the bearing that supports the lower portion of the steering shaft, the center arm is curved downward, and the ball end of the tie rod is fixed to the center arm. The center arm is disposed at a lower position away from the lower portion of the bearing holder, and the center arm and the tie rod can be appropriately laid out by efficiently using the space under the bearing holder.

Also, the ball end by utilizing the space between the centers arm and bearing holder, can be laid while satisfying the installation conditions.

The small vehicle includes an upper front frame (42) that supports upper ends of a pair of left and right cushions (9), an upper beam portion (42a) that is disposed below the upper frame (42) and supports the upper arm ( 6) , and the lower arm ( 7) having a lower front frame (43) having a lower beam portion (43b ) for supporting the steering shaft (21) by supporting the steering shaft (21) with a front frame comprising these upper and lower front frames (42, 43). The upper part of the steering shaft (21) is supported by the upper front frame (42), and the lower part of the steering shaft (21 ) is provided in the upper beam part (42a) of the lower front frame (43). may be the be supported through a bearing (75) to said bearing holder (65) has.

According to this configuration, since the steering shaft is supported by the upper front frame that supports the upper ends of the pair of left and right cushions and the upper beam portion that supports the upper arm, the length of the front frame including the upper and lower front frames is shortened. However, the upper and lower sides of the steering shaft can be supported using an existing frame. Further, the steering shaft can be supported by the upper beam portion without supporting the steering shaft by the lower beam portion.
In this case, the center arm (23) may be disposed between the upper beam portion (42a) and the lower beam portion (43b) . According to this configuration, the space formed between the upper beam portion and the lower beam can be efficiently used as the arrangement space for the center arm.

In the present invention, a center arm is provided at the lower part of the bearing holder that holds the bearing that supports the lower part of the steering shaft, the center arm is curved downward, and the ball end of the tie rod is fixed to the center arm. The tie rod can be properly laid out in the layout space.
In addition, the tie rod is attached to the center arm with the ball end of the tie rod facing upward, the nut mounting portion connected to the ball end facing downward, and the nut mounting portion side inclined to the inside of the vehicle body. The ball end can be laid out while satisfying the mounting conditions by utilizing the space between the bearing holder and the bearing holder.
The small vehicle also includes an upper front frame that supports the upper ends of the pair of left and right cushions, and a lower front frame that is disposed below the upper front frame and supports the upper arm and the lower beam portion that supports the lower arm. The upper part of the steering shaft is supported by the upper front frame, and the lower part of the steering shaft is supported by the bearing holder provided in the upper beam part of the lower front frame via the bearing, so the steering shaft is supported by the lower beam part. Without this, the upper and lower parts of the steering shaft can be supported by the upper front frame and the upper beam portion.
In addition, since the center arm is arranged between the upper beam portion and the lower beam portion, the space formed between the upper beam portion and the lower beam is efficiently used as the arrangement space of the center arm. be able to.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
Note that the directions such as front, rear, left and right in the following description are the same as those in the vehicle unless otherwise specified. In the figure, the arrow FR indicates the front of the vehicle, the arrow LH indicates the left side of the vehicle, and the arrow UP indicates the upper side of the vehicle.
FIG. 1 shows a saddle-ride type vehicle 1. This saddle-ride type vehicle 1 includes a pair of left and right front wheels 2 and rear wheels 3 that are relatively large-diameter low-pressure balloon tires in front of and behind a compact and lightweight vehicle body, and mainly ensures a minimum ground clearance. It is a so-called ATV (All Terrain Vehicle) with improved running ability on rough terrain.
The saddle-ride type vehicle 1 has a body frame 4, which is an all-aluminum frame in which a plurality of types of aluminum alloy materials are joined together by welding or the like, and is located at the front part of the left and right central part of the vehicle body A box structure which is relatively long in the front and rear is formed. A front end portion of the seat frame 4a extending in the front-rear direction is integrally coupled to the upper rear end portion of the vehicle body frame 4 by bolt fastening or the like, and the saddle riding seat 31 is supported on the seat frame 4a.

  A double wishbone type (independent suspension type) front suspension (double wishbone type suspension device) 5 is supported at the front part of the vehicle body frame 4, and the left and right front wheels 2 are connected to the front part of the vehicle body via the front suspension 5. Suspended. The front suspension 5 includes a pair of left and right upper arms (suspension arms) 6 connected to the left and right sides of the lower front side of the body frame 4 so as to be swingable up and down, and on the left and right sides of the body frame 4 below the pair of left and right upper arms 6. A pair of left and right lower arms (suspension arms) 7 swingably connected to each other, a pair of left and right knuckles 8 supported by the upper arm 6 and the tip of the lower arm 7, and between the lower arm 7 and the vehicle body frame 4. The left and right front wheels 2 are rotatably supported by the pair of left and right knuckles 8.

  A swing arm type (axle suspension type) rear suspension (axle suspension device) 11 is supported at the rear part of the vehicle body frame 4, and the left and right rear wheels 3 are suspended from the rear part of the vehicle body via the rear suspension 11. The rear suspension 11 includes a swing arm 12 coupled to a pivot shaft 55 a supported by a pivot portion (swing arm pivot portion) 55 of the center frame 52 so as to be swingable up and down, and a rear end portion of the swing arm 12. And a single rear cushion 14 interposed between the swing arm 12 and the vehicle body frame 4, and the left and right rear wheels 3 are rotatable on both sides of the rear wheel axle 13. Supported by

An engine 15 as a prime mover of the saddle riding type vehicle 1 is mounted on the inner side of the rear part of the vehicle body frame 4. The engine 15 is a water-cooled single-cylinder engine having a crankshaft extending in the vehicle width direction (left-right direction), and a cylinder 17A is erected substantially vertically on a crankcase 16 constituting the lower part thereof. The exhaust pipe 28a of the engine exhaust system is connected to the front side of the cylinder head 17 above the cylinder 17A. The exhaust pipe 28a extends forward and bends, extends to the rear of the vehicle body through the right side of the cylinder 17A, and the seat frame 4a. The lower part is connected to the silencer 28b. An engine intake system throttle body 27 a and an air cleaner case 27 b are connected to the rear end side of the cylinder head 17.
A drive sprocket 18a is disposed on the left side of the rear portion of the crankcase 16, and an endless drive chain 18c is wound around the drive sprocket 18a and a driven sprocket 18b provided at the intermediate portion of the rear wheel axle 13. The power of the engine 15 is transmitted to the left and right rear wheels 3 via the mechanisms (18a to 18c).

  A steering shaft 21 that is inclined so that the upper part is located on the rear side is rotatably supported at the left and right central part of the front part of the body frame 4. A bar-type steering handle 22 is integrally attached to the upper end of the steering shaft 21, and a center arm (center-side steering arm) 23 of the steering mechanism (steering mechanism) is integrally attached to the lower end of the steering shaft 21. Attached. The center arm 23 is connected to the ball ends 24a on the proximal end side of the pair of left and right tie rods 24, and the ball ends 24b on the distal end side of the tie rods 24 are connected to the left and right knuckles 8, respectively. Therefore, when the steering shaft 21 rotates in accordance with the operation of the steering handle 22, this rotation is transmitted to the left and right front wheels 2 via the center arm 23 and the tie rod 24, and the direction of the front wheels 2 (that is, the traveling direction of the vehicle) is changed. Be changed.

  A fuel tank 25 is disposed at the front and rear intermediate portion of the vehicle body frame 4, a radiator 26 is disposed at the front lower side of the fuel tank 25, a radiator fan 26 a is disposed at the rear surface of the radiator 26, and a radiator is disposed at the front of the radiator 26. A grill 26b is provided. A radiator reserve tank 26 c is disposed at the lower rear portion of the radiator 26. In FIG. 1, reference numerals 29a and 29b denote front and rear fenders that cover the upper outer periphery of the front wheel 2 and rear wheel 3, reference numeral 32 denotes a vehicle body cover that mainly covers the front upper side of the vehicle body, and reference numerals 33a and 33b denote saddle riding seats. A battery and various electrical components housed in the vehicle body cover 32 between 31 and the steering shaft 21, a reference numeral 34 denotes a link mechanism for connecting the lower end of the rear cushion 14 to the swing arm 12 and the vehicle body frame 4, and reference numeral 35. Indicates left and right steps for passengers.

Next, the structure of the vehicle body frame 4 will be described.
The vehicle body frame 4 is formed by integrally bonding a plurality of types of aluminum alloy materials by welding or the like, and as shown in FIG. 2, a front frame assembly (front frame) 41 having a front suspension support portion 41A and a rear suspension support portion 51A. And a pair of left and right upper main frames 61 and a pair of left and right lower main frames 62 connecting the front frame assembly 41 and the center frame assembly 51. As shown in FIG. 3, the front frame assembly 41 has an upper front frame 42 that is formed wider toward the rear of the vehicle body in a top view, and is connected to a lower portion of the upper front frame 42 and is narrower than the upper front frame 42. And has a lower front frame 43 that extends rearward of the vehicle body, and has a configuration roughly divided into two.

  As shown in FIG. 4, the upper front frame 42 has openings 42 a that are substantially oblong and elliptical when viewed from the front, and has vertically extending portions 42 f that extend vertically on both side edges of the opening 42 a. Has a laterally extending portion 42c extending substantially horizontally, and is formed in an oblong shape when viewed from the front. As shown in FIG. 2, the upper front frame 42 is disposed so as to be inclined so that the upper part is located on the rear side in a side view. As shown in FIG. 4, a pair of left and right cushion upper end support portions 45 are provided at the widest portion of the vertically extending portion 42 f, and a reinforcing cross member is interposed between the pair of left and right cushion upper end support portions 45. 42g is handed over. The left and right cushion upper end support portions 45 have a pair of support portions which are front and rear walls parallel to each other (see FIG. 3), and the upper end portion of the front cushion 9 is interposed between the pair of support portions as shown in FIG. Is fixed by a fixing bolt 81 that penetrates substantially in the front-rear direction (slightly rearward downward direction) of the vehicle body and a nut 82 that is fastened to the fixing bolt 81, and is fixed to the front via a shaft portion (connection shaft) of the fixing bolt 81. The cushion 9 is pivotably connected.

  As shown in FIGS. 2 and 3, the lower front frame 43 has upper and lower beam portions 43 a and 43 b that extend rearward and rearwardly from the rear of the vehicle body with an interval in the vertical direction. The front half portions of the upper and lower beam portions 43a and 43b are arranged substantially in parallel with each other, while the rear half portion of the upper beam portion 43a extends at a lower slope than the front half portion and the rear end portion thereof is behind the lower beam portion 43b. It merges and integrates at an acute angle in side view on the upper end. And between the front-end parts of the up-and-down beam parts 43a and 43b and between the front-and-rear intermediate parts are connected via the front-and-rear columnar parts 43c and 43d. In this configuration, the front and rear end portions and the front and rear intermediate portions of the lower front frame 43 that are long in the front-rear direction are integrated to increase rigidity, and the lower front frame 43 is disposed between the front half portions and the rear half portions of the upper and lower beam portions 43a and 43b. The front and rear space portions K1, K2 penetrating left and right are formed, and the weight of the lower portion of the front frame assembly 41 can be reduced.

  The upper and lower beam portions 43a and 43b extend in the front-rear direction so as to have a flat shape having a width that is wider than the vertical thickness. Further, the front and rear columnar portions 43c and 43d extend in the vertical direction in a flat shape having a width that is wider than the front and rear thickness. The upper and lower end portions of the front and rear columnar portions 43c and 43d increase in the front and rear thickness toward the distal end side, thereby suppressing the stress concentration at the connecting portion with the upper and lower beam portions 43a and 43b. The left and right widths of the lower front frame 43 are provided so as to increase toward the rear side. A pair of left and right lower main frames 62 are connected to the rear end portion of the lower beam portion 43b. A pair of left and right gusset pipes 44 are provided between the rear portions of the upper and lower front frames 42 and 43.

  A front pedestal portion 49a protruding upward is integrally provided on the upper side of the front end portion of the upper beam portion 43a, and the lower end portion of the upper front frame 42 is welded to the front pedestal portion 49a. Further, a rear pedestal portion 49b that protrudes upward is formed on the upper side of the front and rear intermediate portion of the upper beam portion 43a, and the lower ends of the left and right gusset pipes 44 are welded to the rear pedestal portion 49b. The left and right gusset pipes 44 are made of an aluminum pipe having an elliptical cross section, and are inclined so that the upper part is located on the front side when viewed from the side, and are inclined so that the upper part opens to the left and right outside when viewed from the front. And are arranged in a substantially V shape with different widths. These left and right gusset pipes 44 are provided between the left and right lower extending portions 42 d extending downward from the cushion upper end support portion 45 and both sides of the rear base portion 49 b of the lower front frame 43. The left and right widths of the front portion of the vehicle body frame 4 are wider toward the upper side (see FIG. 4), and the vicinity of the left and right cushion upper end support portions 45 is the maximum width, and the upper side is slightly narrower than that.

  The front half portions of the gusset pipe 44, the upper front frame 42, and the upper beam portion 43a are arranged in a substantially triangular shape in a side view, and an upper space portion K3 penetrating the front frame assembly 41 to the left and right is formed inside thereof. Is done. As a result, the rigidity of the upper portion of the front frame assembly 41 is increased and the weight is reduced. Further, the upper front frame 42 and the front columnar portion 43c are connected in a substantially square shape in a side view, and the gusset pipe 44 and the rear columnar portion 43d are connected in a straight line in a side view, thereby causing a front frame assembly 41 that is long in the vertical direction. The front portion of the front frame and the lower portion of the front frame assembly 41 that is long in the front-rear direction (lower front frame 43) are firmly provided. Further, the upper front frame 42 and the front columnar portion 43c are connected in a substantially square shape in a side view, so that the overall length of the vehicle body frame 4 is shortened.

  A pair of left and right front engine support portions 49c that form a trapezoidal shape in a side view and project obliquely upward and rearward are integrally formed on the upper rear end portion of the upper beam portion 43a, and the front engine support portion 49c and the lower main frame 62 are A pair of left and right gusset pipes 43f are provided between them. The lower main frame 62 has an engine support bracket 63 that is reinforced by a cross member 43e that extends in the vehicle body width direction between the connecting portions of the left and right gusset pipes 43f, and protrudes upward at the reinforcing portion.

  A base end portion of a pair of left and right front engine support plates 49d (see FIG. 1) is coupled to the left and right sides of the front engine support portion 49c by bolt fastening or the like, and a front end portion of the front engine support plate 49d is a crankcase of the engine 15. 16 is coupled to the upper side of the front end by bolt fastening or the like. That is, the upper front end portion of the crankcase 16 of the engine 15 is supported by the front engine support portion 49c of the lower front frame 43 via the left and right front engine support plates. In addition to the upper side of the front end of the crankcase 16, the engine 15 is supported by the front side of the pair of left and right lower main frames 62 via the engine support bracket 63 on the lower side of the front end of the crankcase 16. Is supported by an upper cross member 53 provided between upper portions of the left and right center frames 52 via a rear engine support plate 52d constituting the rear engine support portion 52c, and the rear end portion of the crankcase 16 is supported by the left and right center frames 52. The lower swing arm pivot portion 55 is supported via a pivot shaft 55a (see FIG. 1).

  As shown in FIGS. 2 and 3, the pair of left and right upper main frames 61 includes a front frame assembly 41 having both sides of the upper end where the width of the front frame assembly 41 is widest (the rear end portion 42 b of the upper front frame 42), and a center frame assembly. 51 extends in the front-rear direction between both sides of the upper end 51b of the upper end 51b (the upper end of the left and right center frame 52). The front end 61a is the rear end 42b of the upper front frame 42, and the rear end 61b is the left and right. The front end portion 52b of the center frame 52 is welded to each other. The width between the pair of upper main frames 61 is widest at the front end portion 61a at the position where the fuel tank 25 is disposed, gradually becomes narrower toward the rear end portion 61b at the rear of the vehicle body, and becomes substantially parallel at the rear end portion 61b. . The fuel tank 25 has a lower half portion that fits in a space between the pair of left and right upper main frames 61 that is most widened, and an upper half portion that protrudes above the pair of left and right upper main frames 61 in a side view. The fuel tank 25 is positioned inside the pair of left and right upper main frames 61 in the top view and substantially in the center of the vehicle body width direction, and is arranged by center distribution.

  A support portion 61c is provided at substantially the upper end of the center of the pair of left and right upper main frames 61, and the fuel tank 25 mounts a fixing member 25c protruding from both sides of the fuel tank 25 on the support portion 61c. It is supported by connecting with bolts. In the figure, reference numeral 25a denotes a fuel cap that is attached to the fuel inlet at the upper end of the rear portion of the fuel tank 25, and reference numeral 25b denotes a fuel pump that is attached to the opening at the upper end of the front portion of the fuel tank 25 to Each supporting pump holder is shown. The radiator 26 has a plate shape extending in the left-right direction, has a posture slightly inclined forward from the upright state, and is disposed below the fuel tank 25 in a side view. The radiator 26 has an upper end portion 26d supported by the upper portion of the upper front frame 42 and a lower end portion 26e supported by the central portion of the upper beam portion 43a. The radiator grill 26 b is made of resin, and is disposed in a forward tilt posture with a slight inclination compared to the radiator 26, and is supported by the front frame assembly 41 by being provided between the pair of left and right gusset pipes 44.

  The pair of left and right lower main frames 62 are provided on both sides of the rear end portion of the lower beam portion 43b where the width of the lower portion of the front frame assembly 41 is narrow (on both sides of the rear end portion of the lower front frame 43) and on both sides of the lower end portion of the center frame assembly 51. (The lower end portion of the left and right center frame 52) extends forward and backward, and its front end is welded to the lower beam portion 43b and its rear end is welded to the left and right center frame 52, respectively. The width between the pair of lower main frames 62 is the narrowest at the front end portion 62a (see FIG. 3) connected to the rear end portion of the lower beam portion 43b, gradually becomes wider toward the rear of the vehicle body, and is substantially parallel at the rear end portion 62b. Become.

  As shown in FIGS. 2 and 5, the center frame assembly 51 includes a pair of left and right center frames 52 and upper and lower cross members 53 and 54 that connect them. The left and right center frames 52 extend vertically in the rear portion of the vehicle body front-rear intermediate portion, and are provided symmetrically with respect to each other. The rear end portions 61b of the pair of left and right upper main frames 61 are welded to the front side of the upper end portions of the left and right center frames 52. Further, a member support portion 58 projecting rearward is integrally formed on the rear side of the upper end portion of the left and right center frames 52, and the end portion of the upper cross member 53 is welded to the left and right inner sides of the member support portion 58. A cushion upper end support portion 56 protruding rearward is integrally formed on the rear side of the left and right intermediate portions of the upper cross member 53.

  The lower end portions of the left and right center frames 52 are curved forward and extend, and the rear end portions 62b of the pair of left and right lower main frames 62 are welded to the front end portions thereof. Further, the end of the lower cross member 54 (see FIG. 5) is welded to the left and right inner sides of the lower end of the left and right center frame 52. On the rear side of the left and right intermediate portions of the lower cross member 54, the link mechanism support portion 57 protruding rearward is integrally formed. A step support portion 52a for supporting the step 35 is provided on the left and right outer sides of the lower end portion of the left and right center frame 52, and a seat frame support for supporting the front end portion of the seat frame 4a on the upper rear side of the left and right center frame 52. A portion (not shown) is provided.

  A swing arm pivot portion 55 is provided at the lower portion of the left and right center frame 52. The front end portion of the swing arm 12 swings up and down via the pivot shaft 55a (see FIG. 1) along the left and right direction. Supported as possible. The center frame assembly 51 is formed so that the left and right widths are substantially equal and extend upward, and the upper left and right widths are slightly narrowed. The pair of left and right lower main frames 62 are provided to be inclined so as to be separated from each other in the rear view, and are provided to be substantially horizontal in the side view. The pair of left and right upper main frames 61 are widest on the front side when viewed from the top, gradually narrow toward the rear, and extend substantially parallel to each other at the rear end, and are inclined so as to be lowered rearward as viewed from the side. .

  The upper and lower front frames 42 and 43 are integrally cast aluminum parts, and the left and right center frame 52 and the upper and lower cross members 53 and 54 are integrally forged aluminum parts. The upper and lower front frames 42 and 43 may be integrated aluminum forged parts, and the left and right center frames 52 and the upper and lower cross members 53 and 54 may be aluminum cast parts. All of the upper and lower front frames 42 and 43, the left and right center frame 52, and the upper and lower cross members 53 and 54 may be integrated aluminum casting parts or forging parts. Each of the frames 61 and 62 and the gusset pipes 44 and 43f is a part formed by bending an integrally extruded aluminum material. Note that a part or all of the frames 61 and 62 and the gusset pipes 44 and 43f may be integrated aluminum casting parts or forging parts, respectively.

Next, the structure of the front suspension 5 will be described.
FIG. 6 is a side view showing the front portion of the vehicle body frame 4 together with the peripheral configuration (front suspension 5 and the like), and FIG. 7 is a view seen from the front of the vehicle body. FIG. 8 is a view of the upper arm 6 as viewed from above together with the peripheral configuration. As shown in FIGS. 6 and 7, front and rear upper arm support portions 46a and 46b are formed integrally on both sides of the front end portion and both front and rear intermediate portions of the upper beam portion 43a. Each of the upper arm support portions 46a and 46b has a pair of support portions 91 and 92 which are front and rear walls parallel to each other, and a cylindrical shape at the base end portion of the upper arm 6 between each pair of support portions 91 and 92. Each of the connecting portions 6a and 6b enters and is fixed by a fixing bolt 93 that penetrates in a substantially rearward and rearward direction of the vehicle body and a nut 94 fastened to the fixing bolt 93, and a shaft portion (connecting shaft) of each fixing bolt 93 is fixed. The upper arms 6 are connected to each other in a swingable manner.

  Front and rear lower arm support portions 47a and 47b are integrally provided on both sides of the front end portion and the rear portion of the lower beam portion 43b so as to project outward in the left and right directions. Each of the lower arm support portions 47a and 47b has a pair of support portions 101 and 102 which are front and rear walls parallel to each other, and a cylindrical connecting portion at the base end portion of the lower arm 7 between the pair of support portions 101 and 102. 7a and 7b enter each other and are fixed by a fixing bolt 103 that penetrates in a substantially rearward and rearward direction of the vehicle body and a nut 104 fastened to the fixing bolt 103, and via a shaft portion (connection shaft) of each fixing bolt 103. The lower arms 7 are swingably connected to each other.

In this case, the shaft centers of the fixing bolts 93 fastened to the pair of front and rear upper arm support portions 46a and 46b are coaxially arranged along the inclination of the front half of the upper beam portion 43a, and the pair of front and rear lower arm support portions 47a. , 47b, the shaft centers of the fixing bolts 103 are arranged coaxially along the rearward downward slope of the lower beam portion 43b parallel to the front half of the upper beam portion 43a. Therefore, the upper arm 6 and the lower arm 7 are supported by the vehicle body frame 4 so as to be swingable with their base ends parallel to each other.
As shown in FIGS. 7 and 8, the upper arm 6 whose base end portions are supported by the upper arm support portions 46a and 46b and the lower arm 7 whose base end portions are supported by the lower arm support portions 47a and 47b, respectively, It extends outward in the direction, and its tip is connected to the upper and lower portions of the knuckle 8 via ball joint portions 6c and 7c (see FIG. 7). A hub 71 is rotatably connected to the outer side (outside the vehicle body) of each knuckle 8, and the front wheel 2 is bolted to each hub 71. In FIG. 7, reference numeral 72 denotes a brake disc for front wheel braking.

  As described above, since the front upper arm support portion 46a is provided at the front end portion of the upper beam portion 43a and the front lower arm support portion 47a is provided at the front end portion of the lower beam portion 43b, the front arm support portions 46a and 47a are provided. The layout is vertically arranged close to the front end of the body frame 4 (see FIG. 6). According to this, as shown in FIG. 6, the shaft (front wheel shaft) 2a of the front wheel 2 supported by the upper arm 6 and the lower arm 7 can be laid out close to the front end of the vehicle body frame 4 in a side view of the vehicle body. Become. Therefore, even when the vehicle body frame 4 is shortened by shortening the longitudinal length of the vehicle body frame 4, it is possible to secure a desired wheel base without shortening the wheel base of the vehicle.

Further, as shown in FIG. 7, the lower arm 7 is formed as an arm component that is larger and heavier than the upper arm 6, and constitutes a heavy component among components laid out on the front side of the vehicle body. In the present embodiment, as shown in FIG. 6, since the rear lower arm support portion 47b is provided at the rear portion of the lower beam portion 43b, the rear base end portion (connecting portion 7b) of the lower arm 7 is located at the vehicle front-rear center. The position of the center of gravity of the lower arm 7 can be made closer to the front-rear center of the vehicle body. That is, it is possible to concentrate the mass of the vehicle 1 by setting the position of the center of gravity of the lower arm 7, which is a heavy component on the front side of the vehicle body, to the center of the vehicle body. In this case, since the span of the front and rear base ends (the connecting portions 7a and 7b) of the lower arm 7 is secured widely, the rigidity of the lower arm 7 can be easily secured.
Furthermore, since the rear upper arm support portion 46b is provided at the front and rear intermediate portion of the upper beam portion 43a, the front and rear length of the upper arm 6 is shortened. For this reason, the upper arm 6 can be reduced in size and weight, and this can also concentrate the mass of the vehicle 1.

  By the way, in this saddle-ride type vehicle 1, the upper front frame 42 and the front columnar portion 43c are connected in a substantially square shape with a relatively steep inclination in a side view, and the front and rear frame members of the front frame assembly 41 are connected to each other. The vehicle body frame 4 is reduced in size by shortening the front and rear length of the upper front frame 42 by making them approach each other. Therefore, the spaces K1 to K3 formed in the front frame assembly 41 are narrowed, and the front frame assembly 41 and the components of the front suspension 5 are arranged close to each other, and the direction of the left and right front wheels 2 is steered. The layout space of the steering mechanism (steering device) is restricted. In this embodiment, in order to arrange a steering mechanism (steering device) in such a narrow layout space, it is configured as follows.

  In the present embodiment, in order to arrange the steering shaft 21 in such a layout space, first, the upper steering support portion that supports the upper portion of the steering shaft 21 to the laterally extending portion 42c that extends substantially horizontally at the upper edge of the upper front frame 42. 64, and a lower steering support portion (bearing holder) 65 that supports the lower end portion of the steering shaft 21 is provided in the front half of the upper beam portion 43 a of the lower front frame 43. In this case, the steering shaft 21 is relatively in side view so that the steering shaft 21 is disposed in the upper space K3 of the front frame assembly 41 through the opening 42a (see FIG. 7) of the upper front frame 42. It is supported at a steep back tilt angle.

The upper steering support portion 64 is provided with an arc-shaped recess 42e at the center in the width direction of the laterally extending portion 42c, and a front / rear split body 64a (see FIG. 6) is attached to the recess 42e. A steering shaft 21 is rotatably supported on a cylindrical inner peripheral surface to be formed via a cylindrical collar (not shown).
The lower steering support portion 65 is provided in the front half of the upper beam portion 43a of the front frame assembly 41. The lower steering support portion 65 has a shaft insertion hole 65a that vertically penetrates the upper beam portion 43a, and a bearing 75 is held in the shaft insertion hole 65a. The steering shaft 21 is inserted into the shaft insertion hole 65 a so as to penetrate from the upper side to the lower side, and the lower end portion of the steering shaft 21 is rotatably supported via a bearing 75. That is, the lower steering support portion 65 also functions as a bearing holder that holds a bearing that rotatably supports the steering shaft 21. An oil seal (not shown) is provided above and below the bearing 75 in the shaft insertion hole 65a of the lower steering support portion 65.

  Therefore, even when the front and rear length of the front frame assembly (front frame) 41 including the upper and lower front frames 42 and 43 is shortened, the upper and lower portions of the steering shaft 21 can be supported using the existing frame. Further, the steering shaft 21 can be supported by the upper beam portion 43a without supporting the steering shaft 21 by the lower beam portion 43b.

  The lower end portion 21 a of the steering shaft 21 is formed with a smaller diameter than the upper portion of the lower end portion 21 a, and the lower end portion 21 a with a small diameter passes through the bearing 75, so that the lower steering support portion (bearing holder) 65 As shown in FIG. 6, the center arm 23 of the steering mechanism (steering device) is attached to the lower end 21a. That is, the front space K1 is used as an arrangement space for the steering mechanism (steering device). In FIG. 6, reference numeral 65b is provided below the upper beam portion 43a so as to abut against the center arm 23 when the steering shaft 21 is rotated, and the maximum rotation angle of the steering shaft 21 (the maximum rotation of the steering handle 22). (Steering angle) is a handle stopper.

  9A is a side view of the center arm 23, FIG. 9B is a top view, and FIG. 9C is a rear view. The center arm 23 is a cast part integrally including a base end portion 23a through which the lower end portion 21a of the steering shaft 21 is inserted and an arm portion 23b extending from the base end portion 23a. The base end portion 23a is formed in a cylindrical shape having a through hole penetrating vertically. Inside the through hole of the base end portion 23a, a groove portion 23c that engages with a plurality of protrusions (not shown) formed at the lower end portion of the steering shaft 21 is provided. The center arm 23 engages with the center arm 23 in a rotatable manner. A pair of left and right projecting portions 23d projecting left and right are provided on the left and right sides of the base end portion 23a, and the projecting portions 23d of the center arm 23 are provided on the vehicle body frame 4 when the steering shaft 21 rotates. The maximum rotation angle of the steering shaft 21 (the maximum steering angle of the steering handle 22) is defined by contacting each of the handle stoppers 65b.

The arm portion 23b is formed in a shape that has a flattened shape that is smaller than the vertical thickness of the base end portion and wider in the left-right width than the vertical thickness, and is curved downward from the base end portion 23a. The A pair of left and right ball end fixing portions 23e to which a ball end 24a (see FIG. 7) provided on the base end side of the pair of left and right tie rods 24 is fixed is formed at the distal end portion of the arm portion 23b.
Each of the pair of left and right ball end fixing portions 23e includes a screw hole 23f penetrating in a substantially vertical direction and a base portion 23g constituting a peripheral member of each screw hole 23f. As shown in FIG. 9C, the center axes LL and LR of each screw hole 23f are symmetric with respect to the center axis L0 of the through hole (coincident with the axis of the steering shaft 21) in rear view, It is set to an inclined axis that is inclined at the same angle so as to have a reverse C-shaped relationship with each other, and is further away from the central axis L0 in the horizontal direction as it goes upward. Each of the central axes LL and LR is an axis extending in the vertical direction substantially parallel to the central axis L0 in a side view of the center arm 23.
The pedestal portion 23g provided with the screw holes 23f constitutes the mounting surface of the ball end 24a, and the upper and lower surfaces thereof are in relation to the central axes LL and LR of the screw holes 23f penetrating the pedestal portions 23g. Each is formed on a vertical surface, and the bottom surfaces are substantially inward and the top surfaces are substantially outward in rear view.

  The inclination angles and positions of the central axes LL and LR are uniquely determined when the layout (length, position, shape, etc.) of the tie rod 24 is determined. Since the center arm 23 has the arm portion 23b bent downward from the base end portion 23a, as shown in FIG. 9C, the pair of left and right ball end fixing portions 23e provided at the distal end of the arm portion 23b The axes LL and LR can be positioned on the lower side close to each other. For this reason, compared with the case where the left and right ball end fixing portions 23e are provided on the upper side where the central axes LL and LR are separated from each other, the screw holes 23f formed in the left and right ball end fixing portions 23e can be brought closer to each other. That is, the left and right ball end fixing portions 23e can be arranged close to each other to form the arm portion 23b with a small width.

  When the center arm 23 is attached to the lower end portion 21a of the steering shaft 21 with the nut 77, the steering shaft 21 is tilted backward, so that the center arm 23 has the arm portion 23b at the base end as shown in FIG. It arrange | positions below the part 23a. For this reason, the ball end fixing portion 23e formed at the tip of the arm portion 23b is disposed at a lower position away from the upper beam portion 43a and at a front position of the front cushion 9 in a side view of the vehicle body, that is, in the front space portion K1. The front cushion 9 can be laid out on the front side.

As shown in FIG. 6, the left and right ball end fixing portions 23e of the center arm 23 have nut mounting portions 24c extending downward from the ball end 24a provided on the proximal end side of the tie rod 24 from the upper side to the lower side. The screw holes 23f of the pedestals 23g are inserted into the screw holes 23f, positioned on the pedestals 23g, and fixed by fastening nuts 78 to the nut mounting portions 24c protruding below the pedestals 23g.
That is, the tie rod 24 has a posture in which the ball end 24a provided at the base end portion thereof is directed upward, the nut mounting portion 24c connected to the ball end 24a is directed downward, and the nut mounting portion 24c is inclined to the inside of the vehicle body. To be fixed to the center arm 23 (see FIGS. 6 and 7).

  For this reason, as shown in FIG. 6, the ball end 24a attached to the center arm 23 is laid out so as to fit in the space on the front side of the front cushion 9 in the front space K1 in a side view of the vehicle body. Therefore, the tie rod 24 can be provided between the center arm 23 and the knuckle 8 without contacting the front cushion 9 and the upper beam portion 43a and the lower beam portion 43b of the front frame assembly 41 (FIG. 7). reference). As shown in FIG. 7, the ball end 24b on the tip side of the tie rod 24 is attached to the knuckle 8 with the ball end 24b facing downward. Depending on the shape of the knuckle 8 and the like, the ball end 24b on the tip side of the tie rod 24 is not limited to being downward and may be attached upward.

As described above, in this embodiment, the center arm 23 is provided at the lower portion of the lower steering support portion 65 that supports the lower portion of the steering shaft 21, and the center arm 23 is curved downward. Since the ball end 24a of the tie rod 24 is fixed, the ball end fixing portion 23e formed at the tip of the center arm 23 is positioned at a lower position away from the upper beam portion 43a and at a front position of the front cushion 9 in a side view of the vehicle body. The center arm 23 can be laid out by efficiently using the space K1 below the lower steering support portion 65.
In addition, the center arm 23 has the ball end 24a of the tie rod 24 facing upward, the nut mounting portion 24c connected to the ball end 24a facing downward, and the nut mounting portion 24c side inclined to the inside of the vehicle body so that the tie rod 24 is tilted. because the installed can properly position the ball end 24 a by utilizing the space between the center arm 23 and the upper beam part 43a. The layout of the ball end 24a corresponds to a layout that satisfies the mounting condition of the ball end 24a that is uniquely determined when the tie rod 24 is determined, and the tie rod 24 is appropriately laid out in a narrow layout space while satisfying the mounting condition. It becomes possible to do.

  The upper portion of the steering shaft 21 is supported by an upper front frame 42 that supports the upper ends of the pair of left and right front cushions 9, and the lower portion of the steering shaft 21 is a lower steering support portion provided on the upper beam portion 42 a of the lower front frame 43. (Bearing holder) 65 is supported by bearing 75 through bearing 75, so that steering shaft 21 is supported by upper and lower steering shafts 21 using existing upper front frame 42 and upper beam portion 43a without lower beam portion 43b supporting steering shaft 21. Can be supported. In this case, since the center arm 23 is disposed between the upper beam portion 43a and the lower beam portion 43b, the front space portion K1 formed between the upper beam portion 43a and the lower beam 43b is disposed on the center arm 23. It can be used efficiently in the space.

As mentioned above, although this invention was demonstrated based on one embodiment, the said embodiment is an example of this invention and is not limited to this.
For example, the present invention can be applied to a vehicle having more than three wheels or four wheels, a vehicle that is not a saddle-ride type, or the like, and it goes without saying that various modifications can be made without departing from the gist of the invention. .

1 is a left side view of a saddle-ride type vehicle according to an embodiment of the present invention. It is a left view of a vehicle body frame. It is the same top view. It is the same front view. It is the same rear view. It is a left view which shows a vehicle body frame front part with a periphery structure. It is the same front view. It is the figure which looked at the upper arm from upper direction with the periphery structure. (A) is a side view of the center arm, (B) is a top view, and FIG. 9 (C) is a rear view.

Explanation of symbols

1 Saddle-type vehicle (small vehicle)
2 Front wheels
3 Rear wheels
4 Body frame 5 Front suspension (double wishbone suspension)
6 Upper arm (suspension arm)
7 Lower arm (suspension arm)
11 Rear suspension (axle suspension)
21 Steering shaft 23 Center arm 24 Tie rod 24a, 24b Ball end 24c Nut mounting part 41 Front frame assembly (front frame)
65 Lower steering support (bearing holder)
75 Bearing

Claims (3)

A double wishbone suspension (5) comprising a pair of upper arms (6) and a lower arm (7) is provided, and the steering shaft (21) extends from the upper side to the lower side between the mounting portions of the upper arm (6). The lower part of the shaft (21) is supported by a bearing (75) , and the direction of the wheel (2) is steered by a tie rod (24) connected to a center arm (23) provided on the steering shaft (21). In a steering device for a small vehicle,
The center arm (23) is provided at a lower portion of a bearing holder (65) holding the bearing (75) supporting the lower portion of the steering shaft (21) , and the center arm (23) is curved downward. The ball end (24a ) of the tie rod (24) is fixed upward on the center arm (23) , the nut mounting portion (24c) connected to the ball end (24a) is directed downward, and the nut mounting portion (24c) A steering device for a small vehicle, wherein the tie rod (24) is attached with the side inclined toward the inside of the vehicle body . The small vehicle includes an upper front frame (42) that supports upper ends of a pair of left and right cushions (9), an upper beam portion (42a) that is disposed below and supports the upper arm (6), and the lower arm (7). A lower front frame (43) having a lower beam portion (43b) for supporting the steering shaft (21), and the steering shaft (21) is supported by a front frame comprising these upper and lower front frames (42, 43), The upper part of the steering shaft (21) is supported by the upper front frame (42), and the lower part of the steering shaft (21) is provided in the upper beam part (42a) of the lower front frame (43). The small bearing according to claim 1, wherein the bearing holder (65) is supported via the bearing (75). Steering system of the vehicle. The steering device for a small vehicle according to claim 2, wherein the center arm (23) is disposed between the upper beam portion (42a) and the lower beam portion (43b).

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