JP4088537B2 - Power steering device for rough terrain vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power steering device for a rough terrain vehicle.
[0002]
[Prior art]
In rough terrain vehicles, an auxiliary rotational force corresponding to the driver's operating force is applied to the steering shaft by the drive motor in order to reduce the operating force required for the driver to steer the steering wheel. In some cases, the power steering device is provided.
[0003]
By the way, in this kind of rough terrain vehicle, the width of the vehicle is relatively narrow and the distance between the left and right wheels is accordingly narrow, so that the shock absorber of the front wheel suspension device is easily located near the steering shaft. It has a structure. For this reason, when arranging the drive motor, it is necessary to avoid interference with the shock absorber.
[0004]
In order to avoid such interference with the shock absorber, conventionally, a structure has been proposed in which the drive motor is directed parallel to the steering shaft and disposed behind the steering shaft.
[0005]
[Problems to be solved by the invention]
However, when the drive motor is arranged parallel to the steering shaft and behind the steering shaft as in the conventional structure, there is a problem that the drive motor is easily affected by the exhaust heat of the engine, and the road surface. There is concern that it will be damaged by bouncing stones.
[0006]
The present invention has been made in view of the above-described conventional situation, and when a drive motor is arranged, the rough terrain that can prevent the influence of exhaust heat and damage from the rock surface while avoiding interference with the shock absorber. An object of the present invention is to provide a power steering device for a steering vehicle.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, a steering shaft for transmitting the rotational movement of the steering handle to the tie rod is disposed in front of the engine mounted substantially at the center in the front-rear direction of the vehicle body frame, and an auxiliary rotational force is applied to the steering shaft. In the power steering device for a rough terrain vehicle, the drive motor is oriented in a direction perpendicular to the axis of the steering shaft, and the upper side of the frame member extending in the vehicle front-rear direction is directed outward in the vehicle width direction. It is characterized by being placed across.
[0008]
According to a second aspect of the present invention, in the first aspect, the drive motor is arranged to be positioned on the rear side of a shock absorber of a front wheel suspension device that supports the front wheel so as to swing up and down.
[0009]
A third aspect of the present invention is characterized in that, in the first aspect, the drive motor is disposed on the front side of a shock absorber of a front wheel suspension device that supports the front wheel so as to be swingable up and down.
[0010]
According to a fourth aspect of the present invention, in any one of the first to third aspects, a base portion of an arm member of a front wheel suspension device that supports the front wheel so as to swing up and down is pivotally supported on the frame member. It is said.
[0011]
According to a fifth aspect of the present invention, there is provided a water supply hose according to any one of the first to fourth aspects, wherein a water supply hose for supplying cooling water cooled by a radiator disposed on the front side of the drive motor to the engine is disposed above the drive motor. It is characterized by being arranged.
[0012]
[Effects of the invention]
According to the power steering device of the first aspect of the present invention, the drive motor is disposed so as to be directed in a direction perpendicular to the axis of the steering shaft and across the upper side of the frame member extending in the vehicle longitudinal direction outward in the vehicle width direction. Compared with the case where the conventional drive motor is arranged on the rear side of the steering shaft, it can be moved away from the engine, and the influence of exhaust heat can be suppressed while avoiding interference with the shock absorber. In addition, the frame member functions as a protective member that catches the rock from the road surface, and as a result, the drive motor can be prevented from being damaged by the rock.
[0013]
According to the second aspect of the present invention, since the drive motor is disposed on the rear side of the shock absorber, it is possible to prevent damage from the jumping stone while avoiding interference with the shock absorber.
[0014]
In the invention of claim 3, since the drive motor is disposed on the front side of the shock absorber, it is possible to prevent the influence of the exhaust heat and the damage due to the jumping stone while avoiding the interference with the shock absorber.
[0015]
In the invention of claim 4, since the drive motor is arranged above the frame member that pivotally supports the arm member of the front wheel suspension device, the drive motor can be protected by the arm member and the frame member having high strength and rigidity. Damage caused by stones can be prevented more reliably.
[0016]
In the fifth aspect of the present invention, since the water supply hose for supplying the cooling water to the engine is disposed on the upper side of the drive motor, the temperature rise around the drive motor can be suppressed, and the influence of the exhaust heat can be prevented more reliably.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0018]
1 to 6 are views for explaining a power steering device for a rough terrain vehicle according to an embodiment of the present invention. FIG. 1 is a side view of the rough terrain vehicle, and FIG. 2 is a power steering device. FIG. 3 is a plan view showing the positional relationship of the drive motors (cross-sectional view taken along the line III-III in FIG. 2), FIG. 4 is a sectional side view of the power steering device, and FIG. FIG. 6 is a plan view of the drive motor of the power steering apparatus, and FIG. 6 is a front view of the drive motor (viewed in the direction of arrow VI in FIG. 5).
[0019]
In the figure, reference numeral 1 denotes a small-sized four-wheel vehicle for running on rough terrain, which is equipped with an engine unit 3 in the center of the vehicle frame 2 in the front-rear direction of the vehicle, and is bar-shaped in order from the front at the top of the vehicle body frame 2. The steering handle 4, the fuel tank 5, and the straddle-type seat 6 are generally structured.
[0020]
Left and right front wheels 8 and 8 are disposed at the front of the vehicle body frame 2 via a front wheel suspension device 7, and left and right rear wheels 10 and 10 are disposed at a rear portion via a rear wheel suspension device (not shown). Each is arranged so as to be swingable up and down. Each front wheel 8 and rear wheel 10 is equipped with low-pressure wide balloon tires 8a, 10a.
[0021]
A front fender 11 and a rear fender 12 are disposed at the front upper part and the rear upper part of the vehicle body frame 2 so as to cover the upper part of the front wheel 8 and the rear wheel 10, respectively. A supporting footboard 15 is provided. Carriers 13 and 14 are provided on the upper surfaces of the front fender 11 and the rear ferender 12, respectively. Reference numeral 16 denotes a front bumper.
[0022]
The vehicle body frame 2 has a structure in which a pair of left and right steel pipe side frames 17 and 17 that are formed in a substantially rectangular shape extending in the longitudinal direction of the vehicle are welded together by a number of cross members (not shown) extending in the vehicle width direction. It is. The left and right side frames 17 are formed by connecting rear end portions of the upper pipe 18 and the lower pipe 19 with a rear pipe 20 extending in the vertical direction, and forming a front pipe portion formed by bending the front end portion of the upper pipe 18 downward. The lower end of 18 a is connected to the front end of the lower pipe 19.
[0023]
A rear cross pipe 21 extending obliquely forward and downward is bridged between the rear portions of the upper pipe 18 and the lower pipe 19, and is coupled to the lower pipe 19 between the cross pipe 21 and the rear pipe 20. A rear suspension support pipe 22 is bridged and joined.
[0024]
The rear wheel suspension device supports a rear suspension arm member (not shown) that supports the rear wheel 10 on suspension brackets 22a and 19a joined to the rear suspension pipe 22 and the lower pipe 19, and the rear suspension arm member and the rear cross pipe are supported. A shock absorber (not shown) is disposed between 21.
[0025]
A front cross pipe 23 is bridged between the front pipe portion 18 a and the front portion of the lower pipe 19. The front cross pipe 23 has a rising portion 23a that extends obliquely forward and upward from the lower pipe 19 and a front suspension support portion (frame member) 23b that extends slightly upward from the upper end of the rising portion 23a. A reinforcing pipe 24 is bridged between the front suspension support portion 23 b and the front end portion of the upper pipe 18.
[0026]
The front wheel suspension device 7 supports the left and right front wheels 8 independently so as to be swingable up and down, a lower front suspension arm member (the lower front suspension arm member is not shown) 25, and the upper front suspension arm. A shock absorber 26 is provided between the member 25 and the upper pipe 18. The upper end of the shock absorber 26 is pivotally supported by a bracket 27 joined to the upper pipe 18, and the lower end is pivotally supported by a bracket 28 joined to the upper front suspension arm member 25.
[0027]
The front wheel suspension device 7 is of a double wishbone type, and the upper front suspension arm member 25 is composed of a pair of front and rear suspension brackets 30 and 30 in which front and rear arm portions 25a and 25b are joined to the front suspension support portion 23b. The upper and lower front suspension arm members 25 are supported so that they can swing up and down, and the outer ends 25c of the upper and lower front suspension arm members 25 are connected to each other by a wheel support member (not shown) that rotatably supports the front wheel 8 so as to be able to swing up and down. Yes. The lower front suspension arm member is pivotally supported on the lower pipe 19 via a suspension bracket, and the basic structure is the same as that of the upper front suspension arm member.
[0028]
The engine unit 3 includes a water-cooled four-cycle parallel two-cylinder engine main body 35 and a transmission case 36 integrally coupled to the rear portion of the engine main body 35. Although not shown, a carburetor is connected to the rear wall 37a of the cylinder head 37 of the engine main body 35 via an intake pipe, and the carburetor is disposed below the seat 6 via an intake duct. Connected air cleaner is connected. An exhaust pipe 38 for each cylinder is connected to the front wall 37 b of the cylinder head 37. Each exhaust pipe 38 is once drawn forward of the vehicle, then bent rearward and connected to a common merging pipe 39 through the side of the cylinder head 37, and a muffler is connected to the downstream end of the merging pipe 39. 40 is connected.
[0029]
A radiator 41 is disposed in front of the left and right front pipe portions 18a, and a cooling fan 42 is disposed on the rear side of the radiator 41. A water supply hose 43 for supplying cooling water to the engine body 35 and a return hose (not shown) for returning the cooling water from the engine body 35 are connected to the radiator 41.
[0030]
Next, the steering apparatus of this embodiment will be described.
[0031]
A steering shaft 50 is connected to the steering handle 4. The steering shaft 50 is disposed so as to be inclined obliquely forward and downward on the front side of the engine unit 3 and located on the vehicle body centerline A. As shown in FIG. 4, the steering shaft 50 is formed by connecting an upper shaft 50a and a lower shaft 50b with a universal joint 51. The upper shaft 50a can be rotated by a shaft support member 52 via a bearing. It is supported. The shaft support member 52 is fixedly attached to an upper bracket 53 that is connected to the left and right upper pipes 18. The lower shaft 50b is rotatably supported via a gear case 55 described later on a lower bracket 54 that is connected between the left and right front suspension support portions 23b.
[0032]
A pitman arm 57 connected to left and right tie rods 56 and 56 is fastened and fixed to the lower end of the lower shaft 50b, and the outer ends of the left and right tie rods 56 and 56 are interposed via the wheel support members. And connected to the front wheel 8. As a result, the rotational movement of the steering handle 4 is converted from the steering shaft 50 through the pitman arm 57 into movement in the vehicle width direction of the left and right tie rods 56 and transmitted to the left and right front wheels 8.
[0033]
The steering device according to the present embodiment includes an auxiliary rotational force control device (power steering device) that applies an auxiliary rotational force according to the operating force applied to the steering handle 4. This auxiliary rotational force control device includes a drive motor 60 connected to the steering shaft 50 via a worm gear 62, a potentiometer 61 for detecting the rotational angle and rotational speed of the steering shaft 50, and a detection value from the potentiometer 61. And a controller (not shown) that drives and controls the drive motor 60 based on the above.
[0034]
The worm gear 62 is housed in the gear case 55, and includes a worm 62a fixed to the lower shaft 50b and a pinion 62b meshing with the worm 62a. The potentiometer 61 is fixedly mounted on the upper side of the worm gear 62 of the gear case 55 and on the front side of the vehicle.
[0035]
The drive motor 60 has a structure in which an output shaft 60b protrudes from a motor body 60a, and the pinion 62b is fixed to the output shaft 60b.
[0036]
The drive motor 60 is disposed such that its output shaft 60b is oriented in a direction perpendicular to the axis of the steering shaft 50, and the output shaft 60b is positioned on the front side of the steering shaft 50. Further, as shown in FIG. 3, the drive motor 60 is disposed so as to cross the upper side of the right front suspension support portion 23 b outward in the vehicle width direction in a plan view, and is located on the rear side of the shock absorber 26. Is arranged.
[0037]
Further, as shown in FIG. 2, the drive motor 60 is disposed in a triangular space surrounded by the front pipe portion 18a, the front suspension support portion 23b, and the reinforcing pipe 24 when viewed from the side of the vehicle, and is buffered. It arrange | positions so that the part may overlap with the container 26. FIG. Since the drive motor 60 is disposed in the triangular space, the drive motor 60 can be protected from spearstones, obstacles, and the like without hindering work when the drive motor 60 is maintained.
[0038]
Above the drive motor 60, a water supply hose 43 for supplying cooling water to the engine body 35 is routed. Further, the drive motor 60 is disposed so as to be deviated to one side in the vehicle width direction from the cooling fan 42 and located below. This prevents the cooling air from the cooling fan 42 from being blocked by the drive motor 60.
[0039]
Next, the effect of this embodiment is demonstrated.
[0040]
According to the steering device provided with the power steering device of the present embodiment, the drive motor 60 is oriented in a direction perpendicular to the axis of the steering shaft 50 and is arranged so as to cross the upper side of the front suspension support portion 23b outward in the vehicle width direction. Therefore, the drive motor 60 can be moved away from the exhaust pipe 38 of the engine main body 35 as compared with the case where the drive motor is disposed behind the conventional steering shaft, and the exhaust heat is generated while avoiding interference with the shock absorber 26. The influence can be suppressed.
[0041]
Further, since the front suspension support portion 23b and the upper and lower front suspension arm members 25 function as protective members that receive the rocks from the road surface, it is possible to prevent the drive motor 60 from being damaged by the rocks.
[0042]
In the present embodiment, the drive motor 60 is disposed such that its output shaft 60b is located on the front side of the steering shaft 50 and its rear end is located on the rear side of the shock absorber 26. The influence of exhaust heat and the damage caused by flint can be prevented while avoiding the interference.
[0043]
In the above embodiment, the output shaft 60b of the drive motor 60 is positioned on the front side of the steering shaft 50. However, in the present invention, as shown in FIG. The rear end portion may be located on the rear side of the shock absorber 26.
[0044]
Further, the drive motor 60 ″ may be arranged so as to be positioned on the front side of the shock absorber 26, and this is the invention of claim 3. In this case, interference with the shock absorber 26 is avoided. While being further away from the exhaust pipe 38, it is possible to prevent the influence of the exhaust heat and the damage by the flint.
[0045]
In the present embodiment, the drive motor 60 is disposed so as to cross the vehicle width direction outer side on the upper side of the front suspension support portion 23b that pivotally supports the upper front suspension arm member 25, so that the front suspension support portion 23b having high strength and rigidity is used. The drive motor 60 can be protected from the rock.
[0046]
In the present embodiment, the water supply hose 43 for supplying the cooling water to the engine body 35 is disposed on the upper side of the drive motor 60, so that the temperature rise around the drive motor can be suppressed and the influence of exhaust heat can be avoided more effectively. it can.
[Brief description of the drawings]
FIG. 1 is a side view of a rough terrain vehicle provided with a power steering device according to an embodiment of the present invention.
FIG. 2 is a side view showing an arrangement positional relationship of drive motors of the power steering device.
FIG. 3 is a plan view (sectional view taken along line III-III in FIG. 2) showing the positional relationship of the drive motors.
FIG. 4 is a cross-sectional side view of the power steering device.
FIG. 5 is a plan view of the drive motor.
6 is a front view of the drive motor (viewed in the direction of arrow VI in FIG. 5). FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Four-wheeled vehicle for rough terrain 2 Body frame 4 Steering handle 7 Front wheel suspension device 8 Front wheel 23b Front suspension support part (frame member)
25 Front suspension arm member 26 Shock absorber 35 Engine 41 Radiator 43 Water supply hose 50 Steering shaft 56 Tie rod 60 Drive motor

Claims (5)

A steering shaft that transmits the rotational movement of the steering handle to the tie rod is disposed in front of the engine mounted approximately in the center in the front-rear direction of the body frame, and an auxiliary rotational force is applied to the steering shaft by a drive motor. In the power steering device for leveling vehicle, the drive motor is disposed so as to cross the upper side of the frame member extending in the vehicle front-rear direction in a direction perpendicular to the axis of the steering shaft and outward in the vehicle width direction. A power steering device for a rough terrain vehicle. 2. The power steering for a rough terrain vehicle according to claim 1, wherein the drive motor is disposed on the rear side of a shock absorber of a front wheel suspension device that supports the front wheel so as to swing up and down. apparatus. 2. The power steering device for a rough terrain vehicle according to claim 1, wherein the drive motor is disposed on the front side of a shock absorber of a front wheel suspension device that supports the front wheel so as to be swingable up and down. . 4. The rough terrain vehicle according to claim 1, wherein a base portion of an arm member of a front wheel suspension device that supports the front wheel so as to swing up and down is supported on the frame member. Power steering device. 5. The water supply hose according to claim 1, wherein a water supply hose for supplying cooling water cooled by a radiator disposed on the front side of the drive motor to the engine is disposed above the drive motor. A power steering device for a rough terrain vehicle.

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