JPH08164862A - Axle device - Google Patents

Abstract

PURPOSE: To prevent leakage of oil by providing knuckles to steer a wheel on both left and right ends of an axle main body, providing an interlocking body free to displace left and right between them, connecting the interlocking body and the knuckles repectively by tie rods and driving and controlling a motor to displace the interlocking body in accordance with a steering handle. CONSTITUTION: Knuckles 8a, 8b to steer both rear wheels 7a, 7b are provided free to revolve through a king pin 9 on both left and right end parts of an axle main body 3. A motor 15 is rotated in accordance with an angle of rotation of a steering handle, a rack 11 moves left and right by a worm gear 17, the left and right knuckles 8a, 8b are rotated through an arm 12 and tie rods 14a, 14b and the left and right rear wheels 7a, 7b are made to turn their direction. The motor 15 is controlled by a control device. Consequently, it is possible to minimize slippage of a steering angle of the left and right rear wheels 7a, 7b. Additionally, as both of the knuckles 8a, 8b are revolved by using the one motor 15, oil does not leak.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axle device used in industrial vehicles such as forklifts.

[0002]

2. Description of the Related Art Conventionally, an axle device of this type is shown in FIG. 9, for example. That is, 51 is a rear axle device provided at the rear of the forklift,
Knuckles 54 that turn both rear wheels 53 in the steering direction are rotatably provided at both left and right ends of the axle main body 52, and are horizontally rotatable via a center pin 55 at the center of the axle main body 52. A center arm 56 is provided.
The free end of the center arm 56 and the first arm 57 of the knuckle 54
And tie rods 58 are linked to each other.
Further, a pair of hydraulic left and right steering cylinders 59a and 59b are separately mounted on the axle body 52. The tip of the piston rod 60 of the left side steering cylinder 59a is connected to the second arm 61 of the left side knuckle 54, and the right side steering cylinder 59b.
The tip of the piston rod 60 is the second one of the knuckle 54 on the right side.
It is connected to the arm 61.

According to this, when the steering handle (not shown) is rotated counterclockwise, the piston rod 60 of the left steering cylinder 59a extends and the piston rod 60 of the right steering cylinder 59b shortens, so that both rear wheels 53 Turns to the right. As a result, the forklift turns to the left.

[0004]

However, in the above-mentioned conventional type, the hydraulic steering cylinders 59a and 59b are used.
Since both knuckles 54 are rotated by using, the oil leakage from the steering cylinders 59a and 59b becomes a problem.

The present invention solves the above problems, and an object of the present invention is to provide an axle device capable of solving oil leakage.

[0006]

In order to solve the above problems, in the axle device according to the first aspect of the present invention, knuckles for turning wheels in a steering direction are rotatably provided at both left and right ends of an axle body. An interlocking body that can be displaced in the left-right direction is provided between the knuckles, and this interlocking body and one side knuckle are connected by one tie rod,
The one in which the interlocking body and the knuckle on the other side are connected by the other tie rod, the axle body is provided with a motor for displacing the interlocking body, and a control device for driving and controlling the motor according to the rotation angle of the steering wheel is provided. Is.

In the axle device according to the second aspect of the present invention, knuckles for turning the wheels in the steering direction are rotatably provided at both left and right ends of the axle body, and the knuckle on one side is pivoted on the axle body. A motor and the other motor for rotating the knuckle on the other side are provided, and a control device for driving and controlling the both motors according to the rotation angle of the steering wheel is provided.

[0008]

According to the structure of the first invention, the motor is rotationally driven according to the rotation angle of the steering wheel to displace the interlocking body in the left-right direction. As a result, both knuckles rotate in the same direction via the tie rods, respectively, so that both wheels are turned in the same direction. As described above, since both the knuckles are rotated by using the motor instead of the conventional hydraulic steering cylinder, there is no fear of oil leakage.

According to the structure of the second aspect of the present invention, one motor is rotationally driven according to the rotation angle of the steering wheel to rotate the knuckle on one side and the other motor is rotationally driven on the other side. Rotate the knuckle in the same direction as the knuckle on one side. As a result, both wheels are turned in the same direction. As described above, since the two knuckles are rotated by using the two motors, there is no fear of oil leakage. Also,
Compared with the first aspect of the present invention, since the interlocking body and the tie rod are unnecessary, the axle device can be downsized.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment will be described below with reference to FIGS. A rear axle device 2 is provided at the rear of the forklift 1. The axle body 3 of the rear axle device 2 is formed by a pair of upper and lower axle plates 4 and 5 and a vertical plate 6 connecting the upper axle plate 4 and the lower axle plate 5. Knuckles 8a and 8b for directing both rear wheels 7a and 7b in the steering direction are rotatably provided at the left and right ends of the axle body 3 via kingpins 9, respectively.

A rack 11 (an example of an interlocking body) movable in the left-right direction is provided between the knuckles 8a and 8b. The left end of the rack 11 and the free end of the arm 12 of the left knuckle 8a are interlockingly connected by a left tie rod 14a via a connecting pin 13. Similarly, the right end of the rack 11 and the free end of the arm 12 of the right knuckle 8b are interlockingly connected by a right tie rod 14b via a connecting pin 13.

On the lower surface of the upper axle plate 4, an electric motor 15 for moving the rack 11 in the left-right direction is mounted on a bracket 16.
Is installed through. A worm gear 17 that meshes with the rack 11 is attached to the rotary drive shaft of the motor 15. Further, the forklift 1 is provided with a control device 19 that drives and controls the motor 15 according to the rotation angle of the steering handle 18.

On the left side and the right side of the upper axle plate 4, a pair of front and rear freely rotatable rollers 20 for restraining the rack 11 in the front-rear direction and guiding it in the left-right direction are mounted on the bracket 16.
It is provided through.

The operation of the above structure will be described below.
For example, when the steering handle 18 is rotated counterclockwise, the motor 15 is rotationally driven according to this rotation angle, and the worm gear 17 moves the rack 11 to the left while being guided by the rollers 20 as shown by the phantom line. . This allows
The left knuckle 8a rotates via the left tie rod 14a and the left rear wheel 7a turns to the right at the steering angle α, while the right knuckle 8b rotates via the right tie rod 14b and the right rear wheel 7b steers. Turn to the right at the angle β. As a result, the forklift 1 turns to the left.

At this time, the knuckle 8a on the left side and the rack 11 are interlockingly connected through the arm 12 and the tie rod 14a,
Moreover, since the right knuckle 8b and the rack 11 are interlockingly connected via the arm 12 and the tie rod 14b, the deviation between the steering angle α of the left rear wheel 7a and the steering angle β of the right rear wheel 7b is reduced as much as possible. be able to. When the steering handle 18 is rotated to the right to turn the forklift 1 to the right, the motor 15 is rotated in the reverse direction. As described above, since the two knuckles 8a and 8b are rotated by using one motor 15 instead of the conventional hydraulic steering cylinder, there is no risk of oil leakage.

Although the worm gear 17 is meshed with the rack 11 in the above embodiment, a pinion may be meshed with the rack 11. The second embodiment will be described below with reference to FIGS.

A center pin is provided between both knuckles 8a and 8b.
Center arm 32 that can be horizontally rotated in the horizontal direction via 31
(An example of an interlocking body) is provided. This center pin 31
Is inserted between the central portion of the upper axle plate 4 and the central portion of the lower axle plate 5, and is rotatably held via a bearing. Further, the center arm 32 has the center pin 31
Is externally fitted to and integrally mounted.

The free end of the center arm 32 and the free end of the arm 12 of the left knuckle 8a are interlocked by a left tie rod 14a via a connecting pin 13. Similarly, the free end of the center arm 32 and the arm 12 of the knuckle 8b on the right side
The free end of the tie rod 14b on the right side through the connecting pin 13.
Are linked together.

A gear 33 is externally fitted and integrally mounted on the center pin 31 together with the center arm 32. An electric motor 15 for horizontally rotating the center arm 32 in the left-right direction is attached to the upper surface of the lower axle plate 5. A worm gear 17 that meshes with the gear 33 is attached to the rotary drive shaft of the motor 15.

The operation of the above structure will be described below.
For example, when the steering handle 18 is rotated counterclockwise, the motor 15 is rotationally driven according to this rotation angle, and as shown by the phantom line in FIG. 4, the worm gear 17 causes the center pin 31 and the center arm 32 to be integrated together with the gear 33. Rotate to the left. As a result, the left knuckle 8a is rotated via the left tie rod 14a, the left rear wheel 7a is turned to the right at the steering angle α, and the right knuckle 8b is rotated via the right tie rod 14b. 7b turns to the right at the steering angle β. As a result, the forklift 1 turns to the left.

At this time, the left knuckle 8a and the center arm 32 are interlockingly connected via the arm 12 and the tie rod 14a, and the right knuckle 8b and center arm 32 are interlocking via the arm 12 and the tie rod 14b. Since they are connected, the deviation between the steering angle α and the steering angle β can be reduced as much as possible. Also steering wheel
When the forklift 1 is turned to the right by rotating 18 to the right, the motor 15 is rotated in the reverse direction and the same operation is performed. in this way,
Since both knuckles 8a and 8b are rotated by using one motor 15, there is no risk of oil leakage.

Further, in the second embodiment, the center pin 31 is provided with the gear 33, but as shown in FIGS. 6 and 7 as the third embodiment, the gears 33 are respectively provided to the king pins 9a and 9b.
Examples thereof include those provided with a and 33b. That is, the kingpins 9a and 9b are respectively inserted between both ends of the upper axle plate 4 and both ends of the lower axle plate 5, and are rotatably held via bearings. Also, knuckle 8
The a and 8b are externally fitted to the king pins 9a and 9b and integrally mounted.

The gears 33a and 33b are knuckles 8a and 8b.
At the same time, the king pins 9a and 9b are externally fitted and integrally mounted. Further, electric motors 15a and 15b for horizontally rotating the knuckles 8a and 8b horizontally are attached to both ends of the upper surface of the lower axle plate 5 via brackets 16, respectively. A worm gear that meshes with the gears 33a and 33b is provided on the rotary drive shafts of the motors 15a and 15b.
17 is installed.

According to this, each motor 15a, 15b
Is driven and the worm gear 17 rotates, so that
As shown by the phantom line, the king pins 9a, 9b and the knuckles 8a, 8b together with the gears 33a, 33b rotate in the same direction in association with the tie rods 14a, 14b and the center arm 32. Since the two knuckles 8a and 8b are rotated by using the two motors 15a and 15b in this manner, there is no risk of oil leakage.

As described above, the first to third embodiments are the embodiments corresponding to the first invention, and the motors 15, 15a, 15b are not limited to the electric type, and hydraulic motors may be used. An embodiment corresponding to the second invention will be described below as a fourth embodiment.

That is, as shown in FIG. 8, knuckles 8a and 8b are rotatably provided at the left and right ends of the axle body 3 via king pins 9a and 9b, respectively. Gears 33a and 33b are externally fitted and integrally mounted on the king pins 9a and 9b. Further, electric motors 15a, 15b for horizontally rotating the knuckles 8a, 8b horizontally are attached to both ends of the upper surface of the lower axle plate 5, respectively. Worm gears 17 meshing with the gears 33a and 33b are attached to the rotary drive shafts of the motors 15a and 15b.

The motors 15a and 15b are driven and controlled by the control device 41 in accordance with the rotation angle of the steering wheel 18. Further, a steering wheel rotation angle detector 42 for detecting the rotation angle of the steering handle 18, a left knuckle rotation angle detector 43a for detecting the rotation angle of the left knuckle 8a, and a right knuckle for detecting the rotation angle of the right knuckle 8b. A rotation angle detector 43b is provided, and the rotation angles of both knuckles 8a and 8b are always detected by these knuckle rotation angle detectors 43a and 43b. The detected rotation angles of both knuckles 8a and 8b are the above-mentioned control device. Feedback to 41.

The operation of the above configuration will be described below.
For example, when the steering wheel 18 is rotated counterclockwise, the rotation angle of the steering wheel 18 is detected by the steering wheel rotation angle detector 42. As a result, the control device 41
According to the detected rotation angle of the steering handle 18, both knuckles 8a, 8b are set to a preset angle.
Both motors 15a and 15b are electrically controlled to rotate.
As a result, both motors 15a and 15b are rotationally driven, and as shown by the phantom line in FIG.
Both kingpins 9a and 9b and both knuckles 8a and 8b rotate integrally with a and 33b. When the left rear wheel 7a is turned right at a predetermined steering angle α and the right rear wheel 7b is turned right at a predetermined steering angle β, the steering angle α of the left rear wheel 7a is rotated to the left knuckle. Angle detector 43
The steering angle β of the right rear wheel 7b is detected by a and the right knuckle rotation angle detector 43b detects it. As a result, the control device 41 stops both the motors 15a and 15b, so that the forklift 1 turns to the left at a turning radius corresponding to the turning angle of the steering wheel 18.

When the steering handle 18 is rotated clockwise to turn the forklift 1 to the right, the motor 15 is used.
Similarly, the a and 15b rotate in reverse. Since the two knuckles 8a and 8b are rotated by using the two motors 15a and 15b in this manner, there is no risk of oil leakage. Further, in the fourth embodiment, the rack device 11, the center arm 32, and the tie rods 14a and 14b are unnecessary as compared with the above-described first to third embodiments, so that the axle device 2 can be downsized.

In the first to fourth embodiments, the axle device 2 is used.
The forklift 1 is equipped with
However, it may be provided in other industrial vehicles such as a wheel loader.

[0031]

As described above, according to the first aspect of the present invention, the motor is rotationally driven according to the rotation angle of the steering wheel to displace the interlocking body in the left-right direction. As a result, both knuckles rotate in the same direction via the tie rods, respectively, so that both wheels are turned in the same direction. As described above, since both the knuckles are rotated by using the motor instead of the conventional hydraulic steering cylinder, there is no fear of oil leakage.

According to the second aspect of the present invention, one motor is rotationally driven according to the rotation angle of the steering wheel to rotate the knuckle on one side and the other motor is rotationally driven to drive the knuckle on the other side. Rotate in the same direction as the knuckle on one side. As a result, both wheels are turned in the same direction.
As described above, since both knuckles are rotated by using two motors instead of the conventional hydraulic steering cylinder, there is no risk of oil leakage. Further, as compared with the first aspect of the invention, since the interlocking body and the tie rod are unnecessary, the axle device can be downsized.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view of an axle device according to a first embodiment of the present invention.

FIG. 2 is a view on arrow AA in FIG.

FIG. 3 is a plan view of a forklift truck provided with an axle device.

FIG. 4 is a partially cutaway plan view of an axle device according to a second embodiment of the present invention.

FIG. 5 is a partially cutaway plan view of a main part of an axle device according to the second embodiment.

FIG. 6 is a partially cutaway plan view of an axle device according to a third embodiment of the present invention.

FIG. 7 is a partially cutaway plan view of a main part of an axle device according to the third embodiment.

FIG. 8 is a partially cutaway plan view of an axle device according to a fourth embodiment of the present invention.

FIG. 9 is a partially cutaway plan view of an axle device in a conventional example.

[Explanation of symbols]

 2 Axle device 3 Axle body 7a, 7b Rear wheel 8a, 8b Knuckle 11 Rack (interlocking body) 14a, 14b Tie rod 15, 15a, 15b Motor 18 Steering handle 19 Control device 32 Center arm (interlocking body) 41 Control device

Claims (2)

[Claims] 1. A knuckle for turning a wheel in a steering direction is rotatably provided at both left and right ends of an axle body, and an interlocking body displaceable in the left-right direction is provided between the both knuckles. Connect the side knuckle with one tie rod, connect the interlocking body and the other side knuckle with the other tie rod, provide a motor for displacing the interlocking body on the axle body, and change the steering wheel rotation angle. An axle device comprising a control device for driving and controlling the motor according to the above. 2. A knuckle for turning wheels in a steering direction is rotatably provided at both left and right ends of the axle body, and the axle body has one motor for rotating one side knuckle and the other side knuckle. An axle device comprising: a motor for rotating the knuckle, and a controller for controlling driving of each of the motors according to a rotation angle of a steering wheel.