JP2001180899A - Safety device vehicle for high lift work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety device of a vehicle high lift work which can safely achieve the turn-traveling at a large steering angle, and keep the peripheral speed of a working platform constant in the turn-traveling mode. SOLUTION: A traveling motor control valve 56 to feed and control the working fluid to a traveling motor 15 is driven by tilting a traveling lever L4 via a controller 50. The relationship between the tiltation of the traveling lever L4 stored in the controller 50 and the drive of the traveling motor control valve 56 is controlled according to the steering angle of a front wheel 11 detected by a steering angle detector 64. The maximum drive of the traveling motor control valve 56 in each relationship is set to be a value corresponding to the traveling speed (the allowable traveling speed) at which a vehicle body 10 can be safely turn-traveled even when the traveling lever L4 is operated with the maximum tiltation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aerial work vehicle,
More specifically, the present invention relates to a safety device for an aerial work vehicle capable of safely turning even when the steering angle is large.

[0002]

2. Description of the Related Art There has been known an aerial work vehicle in which a boom is attached to a vehicle body that can travel by wheels, and a work table is provided at a tip end of the boom. Such an aerial work vehicle is advantageous in that it can travel with a small turning radius and has a small turning radius because the working range is widened. For this reason, recently, a vehicle body with a large steering angle and a steering system capable of steering all four wheels have been developed.
In some cases, the aerial work vehicle is configured using a WS-equipped vehicle body.

[0003]

However, although an aerial work vehicle capable of providing a large steering angle as described above is advantageous in terms of the working range, when turning at a large steering angle, the speed is sufficiently reduced. Care must be taken, and if neglected, a lateral load may be generated due to centrifugal force and the stability of the vehicle body may be reduced.

[0004] The present invention has been made in view of such a problem, and it is possible to safely perform turning at a large steering angle and to keep the circumferential speed of a worktable constant during turning. It is an object of the present invention to provide a safety device for an aerial work vehicle that is capable of operating at a height.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a safety device for an aerial work vehicle comprising a boom mounted on a vehicle body capable of traveling from wheels and a work table provided at a tip end of the boom. (For example, the travel lever L in the embodiment
4) (for example, the drive motor 15, the drive motor control valve 56, and the controller 50 in the embodiment) for driving wheels (for example, the rear wheel 12 in the embodiment) in response to an external input ( For example,
A steering unit (for example, a steering motor 14, a steering motor control valve 55, and a controller 5 in the embodiment) for steering a wheel (for example, the front wheel 11 in the embodiment) in accordance with the input by the steering lever L3 in the embodiment.
0), steering angle detecting means for detecting the steering angle of the wheel (for example, the steering angle detector 64 in the embodiment), and the traveling speed of the vehicle body is set according to the steering angle of the wheel detected by the steering angle detecting means. And a restricting means (for example, the controller 50 in the embodiment) for restricting the driving of the wheel by the wheel driving means so as to be equal to or less than the allowable traveling speed. In such a configuration, the traveling speed of the vehicle body is suppressed below the allowable traveling speed set in accordance with the steering angle, and it is impossible to increase the speed beyond the allowable traveling speed. A situation that lowers the stability of the vehicle can be prevented, and the safety can be improved. In addition, it is also possible to keep the circumferential speed of the worktable constant during turning traveling.

When the allowable traveling speed is set according to only the steering angle as described above, the allowable traveling speed needs to be based on the case where the workbench is at the highest position. If the height is low, unnecessary traveling speed restrictions are imposed. For this reason, a position detecting means (for example, the up-and-down angle detector 61, the length detector 62, the turning angle detector 63, and the controller 50 in the embodiment) for detecting the position of the worktable with respect to the vehicle body is provided, and the allowable traveling speed is: Preferably, it is set in accordance with both the steering angle of the wheel detected by the steering angle detecting means and the position of the worktable with respect to the vehicle body detected by the position detecting means. If it is, the allowable traveling speed can be set not only according to the steering angle but also according to the height of the work platform. When the running speed is low, adjustment can be made to increase the allowable running speed, and the adverse effect that the running speed is unnecessarily limited to a low speed can be avoided.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows an example of an aerial work vehicle equipped with the safety device according to the present invention. The aerial work vehicle 1 is capable of traveling with a pair of left and right front wheels 11 and a rear wheel 12, a swivel 20 provided on the body 10, and swings by a foot pin 21 above the swivel 20. It has a boom 30 that is freely attached, and a work table 40 that is attached to the tip of the boom 30.

The swivel table 20 is attached to the vehicle body 10 so as to be rotatable about a vertical axis by 360 degrees, and can be swiveled in a horizontal plane by hydraulically operating a swing motor 13 built in the vehicle body 10. is there. The boom 30 has a plurality of boom members assembled in a nested manner. The boom 30 can be extended and contracted in the longitudinal direction by hydraulically operating a built-in telescopic cylinder 31, and is provided between the swivel 20 and the boom 30. By operating the undulating cylinder 22 with hydraulic pressure, undulating movement in the upper and lower surfaces is possible.

The work table 40 is attached to a vertical post 32 attached to the tip of the boom 30 so as to be rotatable 360 degrees, and the built-in oscillating motor 41 is hydraulically actuated to move the head around the vertical post 32. Swing is possible. The vertical post 32 is always kept vertical by a leveling device (not shown).
As a result, the floor surface of the worktable 40 is always kept horizontal.

The front wheels 11 are wheels for steering (steering), and a gear mechanism and a link mechanism are operated by hydraulically operating a steering motor 14 (not shown in FIG. 2) built in the vehicle body 10. It can be driven to change its direction. The rear wheels 12 are wheels for driving the vehicle, and the rear wheels 12 are driven to rotate via a gear mechanism or the like by hydraulically operating a driving motor 15 (not shown in FIG. 2) built in the vehicle body 10. Is available.

As shown in FIG. 3, at a predetermined position of the work table 40, a boom operation lever L1, a work table swing operation lever L2, a steering lever L3, and a traveling lever L4 are provided. The boom operation lever L1 can perform a tilting operation in the front-rear and left-right directions and a twisting operation around an axis, and the worktable swing operation lever L2 can perform a tilting operation in the left-right direction. Further, the steering lever L3 can be tilted in the left-right direction, and the traveling lever L4 can be tilted in the front-rear direction.

FIG. 1 shows an undulating cylinder 22 and a telescopic cylinder 3.
1 is a block diagram showing an operation system of a turning motor 13, a swinging motor 41, a steering motor 14, and a traveling motor 15. As can be seen from this figure, the up-and-down cylinder 22, the telescopic cylinder 31, the turning motor 13, the oscillating motor 41, the steering motor 14, and the traveling motor 15 operate by receiving hydraulic oil from the hydraulic pump P driven by the engine E. A control cylinder 51 for controlling the supply of hydraulic oil, a control valve for telescopic cylinder 52, a control valve for swing motor 53, a control valve for swinging motor 54, a motor control valve for steering 55, and a motor for traveling. The control valve 56 is electromagnetically driven by the controller 50.

Here, the controller 50 includes a front-rear tilting, a left-right tilting and a twisting around the axis of the boom operating lever L1, a left-right tilting of the worktable swinging operating lever L2, and a steering lever L3.
The control valves 51 to 56 are driven in accordance with left and right tilting of the traveling lever L4 and forward and backward tilting of the traveling lever L4. Therefore, the operation of the levers L1 to L4 allows the raising and lowering cylinder 22, the telescopic cylinder 31, the turning motor 13 to rotate. Operating the swing motor 41, the steering motor 14, and the traveling motor 15 to raise and lower, extend, and turn the boom 30;
, The front wheels 11 can be steered, the forward / backward switching of the vehicle body 10 and the traveling speed can be adjusted.

The controller 50 also includes detection information from an elevation angle detector 61 for detecting the elevation angle of the boom 30, detection information from a length detector 62 for detecting the length of the boom 30, and the turning table 20. Swing angle (ie, boom 3
The detection information from the turning angle detector 63 for detecting the turning angle of “0” is input, and the position of the work table 40 (the height of the work table 40) with respect to the vehicle body 10 is constantly determined based on the information. It has become required. Note that FIG.
As shown in the figure, the undulation angle detector 61 and the length detector 62 are provided in the boom 30, and the turning angle detector 63 is provided in the vehicle body 10.

Further, a steering angle detector 64 for detecting the steering angle of the front wheel 11 from the amount of tilt of the steering lever L3 is provided in the workbench 40.
0 is input.

As shown in FIG. 4, the storage device of the controller 50 stores the relationship between the tilt amount of the steering lever L3 and the driving amount of the steering motor control valve 55, and receives the operation input of the steering lever L3. Then, the operation motor control valve 55 is driven according to this relationship. Here, the horizontal axis in FIG. 4 indicates the tilt amount σ of the steering lever L3, and the vertical axis indicates the drive amount p of the steering motor control valve 55. Here, σ ₊₀ indicates the maximum value of the positive direction tilt amount of the steering lever L3, σ ₋₀ indicates the maximum value of the negative direction tilt amount,
p ₊₀ is the driving amount of the steering motor control valve 55 corresponding to the tilt amount σ ₊₀ of the steering lever L3, and p- ₀ is the driving amount of the steering motor control valve 55 corresponding to the tilt amount σ _-0 of the steering lever L3. Is shown.

As shown in FIG. 5, the storage device of the controller 50 stores the relationship between the amount of tilt of the traveling lever L4 and the amount of driving of the traveling motor control valve 56.
When there is an operation input of the travel lever L4, the travel motor control valve 56 is driven according to this relationship. However, the relationship between the amount of tilt of the traveling lever L4 and the amount of driving of the traveling motor control valve 56 is in accordance with the steering angle of the front wheels 11 detected by the steering angle detector 64. Motor control valve 5 in Japan
The maximum drive amount of 6 is a traveling speed at which the vehicle body 10 can safely turn (for example, without the vehicle body 10 falling over) even when the traveling lever L4 is operated with the maximum amount of tilt (hereinafter, this is the allowable speed). This value is determined according to the steering angle.

FIG. 5 shows a specific example of the relationship between the amount of tilt of the travel lever L4 and the amount of drive of the travel motor control valve 56. The horizontal axis represents the tilt amount δ of the travel lever L4.
The vertical axis indicates the driving amount q of the traveling motor control valve 56. Here, (A) is a case where the vehicle is running straight with the steering angle being almost zero, (B) is a case where the steering angle is small and the vehicle is running gently, and (C) is a case where the steering angle is large and the vehicle is running sharply. , Respectively. As can be seen from these figures, when the steering lever L3 is tilted (corresponding to FIGS. 5B and 5C), the drive amount of the traveling motor control valve 56 depends on the steering angle. The maximum drive amount (which is indicated by q _{+ 1} , q- ₁ or q _{+ 2} , q- ₂ in FIG. 5) is limited to a maximum, and the travel lever L4 is moved by a certain amount (this Even if it is larger than δ ₊₁ , δ _-1 or δ ₊₂ , δ _-2 in FIG. 5), it does not become larger than the maximum drive amount.

As described above, the maximum drive amount of the traveling motor control valve 56 is set according to the steering angle.
Since the maximum drive amount of the traveling motor control valve 56 and the permissible traveling speed are in one-to-one correspondence, the permissible traveling speed eventually depends on the steering angle. The allowable traveling speed is determined as the maximum traveling speed at which the vehicle can safely turn at the steering angle. Therefore, the allowable traveling speed decreases as the steering angle increases (the maximum driving amount of the traveling motor control valve 56 also increases as the steering angle increases). Smaller). In FIG. 5, for simplicity, the maximum drive amounts of the traveling motor control valve 56 are three cases: a case where the steering angle is almost zero; a case where the steering angle is small; and a case where the steering angle is large. However, in practice, it is not necessary to provide three types as described above, and it is preferable that the setting is made so as to change further in multiple steps (for example, five steps) or continuously according to the steering angle. So that the traveling speed of the rear wheels 12 is equal to or less than the allowable traveling speed set in accordance with the steering angle.
Is limited to an amount that can regulate the driving of the motor.

As described above, according to the safety device of the present invention, the traveling speed of the vehicle body 10 can be suppressed below the allowable traveling speed set in accordance with the steering angle, and can be increased beyond the allowable traveling speed. Since it is no longer possible, it is possible to prevent a situation in which the stability of the vehicle body is degraded due to excessive turning travel, and safety is enhanced.

For example, when the vehicle is traveling straight with the steering angle substantially zero, and the relationship between the amount of tilt of the traveling lever L4 and the amount of driving of the traveling motor control valve 56 is as shown in FIG. And the current operation amount of the traveling lever L4 is δ
₊₃ (where δ _{+ 1} <δ _{+ 3} <δ _{+ 0} ), the steering is suddenly performed, and the relationship between the tilt amount of the traveling lever L4 and the driving amount of the traveling motor control valve 56 is as shown in FIG. 5B. In such a case, the driving amount of the traveling motor control valve 56 is reduced to q _{+ 1} .

When the allowable traveling speed is set according to only the steering angle as described above, the allowable traveling speed needs to be based on the case where the work table 40 is at the highest position. If the height of 40 is low, unnecessary traveling speed restrictions are imposed. For this reason, as described above, the workbench 40 obtained based on the detection information from the undulation angle detector 61, the length detector 62, and the turning angle detector 63.
Using the position information, the allowable traveling speed is set in consideration of not only the steering angle of the front wheels 11 detected by the steering angle detector 64 but also the height of the worktable 40. Is preferred. With such a configuration, the allowable traveling speed can be set not only according to the steering angle but also according to the height of the worktable 40. Therefore, when the height of the worktable 40 is high, the allowable travel speed is reduced. When the height of the workbench 40 is low, it is possible to make an adjustment to increase the allowable traveling speed, thereby avoiding the disadvantage that the traveling speed is unnecessarily limited. This also makes it possible to make the circumferential speed of the worktable 40 constant during the turning travel.

Although the safety device of the aerial work vehicle according to the present invention has been described above, the scope of the present invention is not limited to the above. For example, in the above embodiment, the steering angle detector 64 is configured to detect the amount of tilt of the steering lever L3 to determine the steering angle. However, the steering angle detector 64 is configured to detect the rotation angle of the steering motor 14 to determine the steering angle. And so on. Further, in the above-described embodiment, the configuration for switching the forward / backward movement of the vehicle body 10 and adjusting the traveling speed is performed by a combination of the traveling motor 15 and the traveling motor control valve 56. For example, a hydraulic motor of a swash plate type variable displacement type is configured to change the rotation direction and rotation speed of the hydraulic motor by changing the tilt direction and the tilt amount of the swash plate to switch the forward / backward movement of the vehicle body 10 and adjust the traveling speed. It may be. Alternatively, an electric motor may be used instead of these hydraulic motors. In the above embodiment, the aerial work vehicle configured to perform the traveling operation of the vehicle body from the work table 40 is described as an example. However, the aerial work vehicle configured to perform the traveling operation from the driver's seat of the vehicle body 10 may be used. The present invention is applicable.

[0024]

As described above, according to the present invention, the traveling speed of the vehicle body is suppressed below the allowable traveling speed set in accordance with the steering angle and the position of the worktable, and the speed is increased beyond the allowable traveling speed. Therefore, it is possible to prevent a situation in which the stability of the vehicle body is degraded due to excessive turning travel, and safety is enhanced. In addition, it is also possible to keep the circumferential speed of the worktable constant during turning traveling.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a safety device according to the present invention.

FIG. 2 is a side view of an aerial work vehicle provided with the safety device.

FIG. 3 is a perspective view of a work bench of the aerial work vehicle.

FIG. 4 is a graph showing a relationship between a tilt amount of a steering lever and a drive amount of a steering motor control valve.

5A and 5B are graphs showing the relationship between the amount of tilt of the traveling lever and the amount of driving of the traveling motor control valve. FIG. 5A shows a case where the vehicle travels straight ahead with the steering angle substantially zero, and FIG. (C) is a case where the steering angle is large and the vehicle is making a sharp turn.

[Explanation of symbols]

Reference Signs List 1 aerial work vehicle 10 body 14 steering motor (steering means) 15 traveling motor (wheel driving means) 30 boom 40 work table 50 controller (steering means, wheel driving means, regulating means) 55 steering motor control valve (steering Means 56 Traveling motor control valve (wheel driving means) 61 Undulating angle detector (position detecting means) 62 Length detector (position detecting means) 63 Turning angle detector (position detecting means) 64 Steering angle detector (steering Angle detecting means) L3 Steering lever L4 Traveling lever

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F333 AA08 AB04 FA20 FA29 FD02 FD07 FD08 FD09 FE04 FE09

Claims (2)

[Claims] 1. A safety device for an aerial work vehicle comprising a boom mounted on a vehicle body capable of traveling by wheels and a work table provided at a tip end of the boom, wherein the wheels are driven according to an external input. Wheel driving means, steering means for steering the wheels in response to an external input, steering angle detection means for detecting a steering angle of the wheels, and the traveling speed of the vehicle body detected by the steering angle detection means A high-altitude working vehicle, comprising: a restricting means for restricting driving of the wheel by the wheel driving means so as to be equal to or less than an allowable traveling speed set according to a steering angle of the wheel. Safety equipment. 2. The vehicle according to claim 1, further comprising a position detection unit configured to detect a position of the worktable with respect to the vehicle body, wherein the allowable traveling speed is detected by the steering angle of the wheel detected by the steering angle detection unit and the position detection unit. 2. The safety device for an aerial work vehicle according to claim 1, wherein the safety device is set according to both values of the position of the work table with respect to the vehicle body.