JP2584747Y2 - Work vehicle steering mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering mechanism for a vehicle, such as an aerial work vehicle, which works while turning sharply in a narrow place.

[0002]

2. Description of the Related Art Conventionally, a technique for driving four wheels and rotating the four wheels for steering in an aerial work vehicle is known. For example, the technique is described in Japanese Utility Model Laid-Open No. 33730/1990.

[0003]

Conventionally, in a high-altitude work vehicle, each of the drive steerable wheels can be steered and turned separately, and a "front wheel mode" in which the steer operation is performed only by two front wheels, 2
"Skew mode" in which the wheel and the rear two wheels are steered and rotated in the same phase direction
It was possible. According to the present invention, in the "front wheel mode", only the front wheels are steered and turned in response to the turning operation of the steering lever. If the steering wheel is turned over a certain angle, for example, 37 degrees or more, there is a possibility that the vehicle will roll over. Therefore, even if the steering lever is turned beyond a certain angle, the steering rotation angle of the front two wheels does not become larger. It was composed. Therefore, in the case of the "front wheel mode", there is a problem that a sharp turn cannot be performed. According to the present invention, in the case of the "front wheel mode", if the steering lever is tilted more than a fixed angle of 37 degrees, a steeper turn is required, so that the rear two wheels are steered in opposite phase directions. By turning in the opposite direction, a sharp turn is enabled.

[0004]

Next, means for solving the problem will be described. The four wheels of the four-wheel work vehicle can be driven,
In a configuration in which the body advances in the tilting direction of the steering lever 7 by operating the steering lever 7 in the forward / backward / left / right directions of 360 degrees, only the front two wheels are used while the steering lever 7 is tilted from the straight traveling direction to a certain angle. When the steering lever 7 is turned by a certain angle or more, the rear two wheels are turned to the front two.
The steering wheel is turned in the opposite phase to the wheels, and the steering lever
-7 by tilting 90 degrees left and right, the front two wheels
Both directions are the same as the direction in which the steering lever 7 is tilted.
Is driven and rotated 90 degrees from the straight running direction,
Both wheels have the opposite direction of the tilting of the steering lever 7
The direction of rotation is 90 degrees from the straight direction.
The front two wheels and the rear two wheels are configured to rotate in a centering position of the traveling vehicle 12 by being driven and rotated in a direction opposite to the right and left by exactly 180 degrees.

[0005]

Next, the operation will be described. As shown in FIGS. 5 and 6, in the “front wheel mode”, when the tilt angle of the steering lever 7 is within 37 degrees left and right with respect to the straight traveling direction, the front of the steering drive wheels 2 and 3 Only the two wheels steer and turn left and right. When the steering lever 7 is rotated beyond the range of 37 degrees left and right, as the steering drive wheels 2 and 3 are rotated 37 degrees or more, the rear 2
The wheels are tilted in the opposite phase direction at an angle of 37 degrees or more. This allows the working vehicle to turn with a smaller turning radius.

[0006]

Next, an embodiment will be described. 1 is a side view showing an aerial work vehicle of the work vehicle, FIG. 2 is a plan view showing a part of a traveling vehicle 12 of the aerial work vehicle, and FIG. 3 is a plan view showing an operation mechanism of a four-wheel drive steering wheel. FIG. 4 is a plan view of the operation box B, FIG. 5 is a plan view of a state in which the front two wheels and the rear two wheels are steered and rotated in opposite phases, and FIG. 6 is a plan view showing a tilting direction of the steering lever 7. is there.

[0007] The high work vehicle has an upper work platform 11 and a lower traveling vehicle 12 connected by a scissor link 13. The scissor link 13 is configured to move up and down by expansion and contraction of a lifting cylinder 14. An operation box B and a foot switch 5 are provided on the workbench 11. The steering mode changeover switch 6 provided on the operation box B is switched, and the foot switch 5 is depressed. 2, 2, 3 and 3 are set and rotated to the initial setting positions of the "front wheel mode" and the "skew mode". Thereafter, by rotating the steering lever 7 in a desired direction by 360 degrees, the aircraft is steered in that direction in various steering modes.

Referring to FIG. The traveling vehicle 12 includes a lower operation box C, a battery, a DC motor driven by the battery, and a hydraulic pump driven by the DC motor. Hydraulic motors disposed on the respective steering drive wheels 2, 2, 3, 3 are driven by the hydraulic oil from the hydraulic pump, and the steering drive wheels 2, 2, 3,.
3 is driven and rotated. The front two wheels 2, 2 and the rear two wheels 3, 3 are steered and rotated as a pair.

That is, the front two wheels 2 are steered and rotated by the steering cylinder 15 via the tie rod 1, and the rear two wheels 3.
3 are steered and turned in the same direction. And the front two wheels 2.2
Is detected by the steering position sensor 16, and the steering rotation position of the rear two wheels 3 is detected by the steering position sensor 18. In FIG. 4, a plan view of the surface of the operation boxes B and C is disclosed. In the operation box B, a workbench elevating operation lever 8, a steering lever 7, and a steering mode changeover switch 6 are arranged. And
When the steering mode is changed by the steering mode switch 6, the steering mode is displayed on the steering mode display device 30.

As shown in FIG. 6, when the steering lever 7 is tilted within a range of 37 degrees left and right with respect to the straight traveling direction due to the normal tilting of the steering lever 7,
From the state of FIG. 2, only the front two wheels 2
It rotates within the range of 7 degrees. And conventionally, 3
If the steering lever 7 is turned by 7 degrees or more, it is dangerous. Therefore, the steering rotation angle of the front two wheels 2 is configured to be no larger. However, in the present invention, the front two wheels 2.2 also rotate with respect to the rotation of the steering lever 7 of 37 degrees or more. 3 is configured to rotate in the opposite phase direction. When the steering lever 7, which is the maximum limit, is rotated in the right and left directions by 90 degrees, the front two wheels are both tilted.
Direction of 90 degrees from the straight running direction in the same direction as the movement
The rear two wheels are both driven by the steering lever 7
90 ° from the straight running direction in the direction opposite to the direction in which
The front two wheels and the rear two wheels are completely
By driving and rotating in a direction opposite to the direction of 80 degrees, an interlining turn is performed at the center position of the traveling vehicle 12.

[0011]

[Effect of the Invention] The present invention is constructed as described above, and has the following effects. First, in the case of steering in the "front wheel mode", if the vehicle is tilted more than 37 degrees left and right with respect to the straight traveling direction which is a fixed angle, the rear two wheels are steered and rotated in the opposite phase direction. By doing so, it is possible to make a sharp turn without overturning the body. Second, by tilting the steering lever 7 in the right and left directions by 90 degrees, the front two wheels
90 degrees from the straight running direction in the same direction as the tilted direction of 7
The rear two wheels are steering levers
90 degrees from the straight running direction in the direction opposite to the tilted direction of 7
The front two wheels 2.2 and the rear two wheels 3.3
Travels in the opposite direction 180 degrees,
Since the interlining turning can be performed at the center position of No. 2, no switching operation tool for interlining turning is required at all, and the interlining turning operation can be performed only by the tilting operation of one steering lever 7. You can do it.

[Brief description of the drawings]

FIG. 1 is a side view showing an aerial work vehicle among work vehicles.

FIG. 2 is a plan view showing a traveling carriage 12 of the aerial work vehicle.

FIG. 3 is a plan view showing an operation mechanism of a four-wheel drive steering wheel.

FIG. 4 is a plan view of an operation box B.

FIG. 5 is a plan view showing a state in which two front wheels and two rear wheels are steered and rotated in opposite phases.

FIG. 6 is a plan view showing a tilting direction of a steering lever 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tie rod 2 Front two wheels 3 Rear two wheels 4 Tie rod 5 Foot switch 6 Steering mode switch 7 Steering lever 8 Platform lifting operation lever

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-146777 (JP, A) JP-A-63-49589 (JP, A) JP-A-4-109682 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) B62D 7/14

Claims (1)

(57) [Scope of request for utility model registration] 1. A four-wheel working vehicle that can drive four wheels,
In a configuration in which the body advances in the tilting direction of the steering lever 7 by operating the steering lever 7 in the forward / backward / left / right directions of 360 degrees, only the front two wheels are used while the steering lever 7 is tilted from the straight traveling direction to a certain angle. When the steering lever 7 is turned by a certain angle or more, the rear two wheels are turned to the front two.
The steering wheel is turned in the opposite phase to the wheels, and the steering lever
-7 by tilting 90 degrees left and right, the front two wheels
Both directions are the same as the direction in which the steering lever 7 is tilted.
Is driven and rotated 90 degrees from the straight running direction,
Both wheels have the opposite direction of the tilting of the steering lever 7
The direction of rotation is 90 degrees from the straight direction.
The working vehicle is characterized in that the front two wheels and the rear two wheels are driven and rotated in a direction completely opposite to each other by 180 degrees to the right and left so as to make an interlining turn at the center position of the traveling vehicle 12. Steering mechanism.