JP2000211899A - Vehicle for high lift work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the operator from accident to fall off in the water bleeding works of a working table. SOLUTION: A vehicle for high lift work is equipped with a mode changeover switch 33 to make selective changing-over between the leveling mode to maintain horizontal the floor surface of a working table (bucket) and an angular mode to perform water bleeding, etc., by tilting the bucket, an over-part works sensing means 23 to sense that operator(s) is in the bucket, and a bucket tilt restricting device 31b to restrict the tilt of the bucket, whereby the angle varying motion of the bucket is restricted when any operator is in the bucket. Also an operation device changeover switch 34 is installed to make changing-over between an upper operation device 22 and a lower operation device 32, and the mode changeover switch 33 is made valid only when the lower operation device is solely selected while the switch 34 is made valid only when the leveling mode is selected by the changeover switch 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aerial work vehicle having a work table at the tip of a boom and moving to an arbitrary height to perform work. The present invention relates to a safety device for performing a work by releasing a leveling operation for always maintaining a horizontal position.

[0002]

2. Description of the Related Art A work provided with a boom provided on a vehicle body for freely rotating, raising, lowering, expanding and contracting, bending and extending, and a worktable on which a worker is mounted at a tip thereof, is mounted on the worktable. An aerial worker operating the upper operating device provided on the workbench to operate the boom, such as turning and raising / lowering, and moving the workbench to a desired height to perform construction work, such as a power distribution work. It is used for construction work, maintenance work for aircraft and ships, and the like. And, in such an aerial work vehicle, the workbench on which the worker rides does not tilt with the raising and lowering movement of the boom,
A leveling mechanism is provided to keep the floor of the worktable horizontal regardless of the boom undulation angle.

In this leveling mechanism, a supporting portion is provided at an upper end portion of a work table, and a gravity type which takes the work table horizontally by gravity,
A mechanical link system that balances by constructing a mechanical link between the vehicle body and the boom and the work table, hydraulic cylinders are arranged on the work table side and the vehicle body side with the boom interposed, and these are connected in a closed circuit There are used a hydraulic method for balancing the work table by hydraulic pressure, an electric method for leveling the work table by controlling various actuators using an inclination angle sensor disposed on the work table, and the like.

In each of these leveling mechanisms except for the gravity type, an operating mechanism of this leveling function (balancing function), that is, an operating mechanism for relatively changing the angle between the worktable and the boom is used. In addition, the work platform can be configured with a function of intentionally tilting the work table.

For example, a high work vehicle used for electric work such as a power distribution work employs the hydraulic or electric leveling mechanism, and one stage of a telescopic boom between a vehicle body and a worktable is electrically insulated. The workbench is formed integrally with the insulating boom from an electrically insulating material such as GFRP, so that the workbench (bucket) can be contacted with the high-voltage line at a high place through the workbench. It is configured so that electric current does not flow to the vehicle body and that an operator does not suffer an electric shock accident. For this reason, in such an aerial work platform, it is necessary to secure an insulation distance (creepage distance), so that a drain hole cannot be provided in the bucket. Therefore, when water accumulates inside the bucket due to rainfall or the like, this water is removed. A function for discharging is required.

Therefore, when water accumulates inside the bucket due to rainfall or the like, the boom is fully retracted, and after confirming that no worker is on board, the leveling inside the lower operating device provided on the vehicle body side is performed. By operating the initial balance angle adjustment device and driving the hydraulic device or electric device for leveling operation and tilting the bucket slightly,
It is easy to remove the water accumulated inside, or a drain switch using the above function is provided inside the lower operation device, and by operating this switch, the bucket is tilted greatly and the accumulated water is forcibly discharged. A device having a water draining function has been devised.

[0007]

However, the work of adjusting the initial balancing angle and the draining operation performed as described above are performed as a balancing operation or a leveling operation of the worktable (both are referred to as a balancing operation. The same is temporarily released and the workbench is forcibly tilted, which may cause danger when this function is easily operated.

[0008] For example, when an operator is on a work table and is working at a high place, another operator on the ground operates the drain switch by mistake, or when the switch is broken, If the drainage function is activated and the workbench suddenly tilts without any restrictions, workers at high places may be at risk of collision with surrounding structures or falling off the workbench.

For this reason, the above-mentioned water draining function, initial balancing angle adjusting function, and the like are configured so as not to operate unless the boom is fully retracted so that the above-mentioned dangerous state does not occur. There are many.

However, even when the boom is fully retracted and stored, for example, when the operator is performing preparation work inside the bucket or performing maintenance work on the workbench internal device in this state, If the drain switch is operated without noticing the above, there is a problem that the workbench may be inclined and the worker inside may fall.

In addition, when the boom is tilted and the work table is tilted, water inside the work table is wiped out, or when a work such as a maintenance check is performed, the work table is suddenly moved due to an erroneous operation or malfunction by another operator. When the operation returns to the balancing operation, there is a problem that a worker working near the work table may collide with the work table or fall off the working scaffold.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is intended to prevent an accident such as a fall of a worktable occupant or a collision of surrounding workers, and a work for intentionally tilting the workbench. It is an object of the present invention to provide an aerial work vehicle with further improved safety.

[0013]

In order to solve the above problems, according to the present invention, a floor surface angle of a workbench (for example, a bucket 20 in the embodiment) disposed on a vehicle body of an aerial work vehicle is set to be substantially horizontal. Mode switching means (e.g., mode switch 33 in the embodiment) for selectively switching between a leveling mode for maintaining the operation at a predetermined angle and an angle mode for changing the floor surface angle of the worktable to a predetermined angle. Leveling means (for example, the lower leveling cylinder 41 and the upper leveling cylinder 42 in the embodiment) for maintaining the floor of the worktable substantially horizontal regardless of the undulation angle.
And an oil passage connecting these oil chambers to each other, and angle changing means (for example, the hydraulic pump P, the inclined solenoid valve 43 in the embodiment) for changing the floor surface angle of the worktable to a predetermined angle in the angle mode. Etc.) and that an operator is present on the workbench, or that an upper operating device (for example, the upper operating device 22 in the embodiment) disposed on the worktable and operating the boom is in an activated state. Upper work detecting means (for example, upper work detecting means 2 in the embodiment)
3) and angle change restricting means for restricting the operation of the angle changing means (for example, the bucket inclination restricting device 31 in the embodiment).
b) to constitute an aerial work vehicle.

When the upper work detecting means detects that a worker is present on the workbench or that the upper operating device is in the activated state, the angle change restricting means is selected by the mode switching means. Acts to regulate the operation of the angle changing means regardless of the mode.

With such a configuration and operation, when it is detected that the worker is on the work table, or when the worker is going to work on a high place while riding on the work table, Or, when performing maintenance work on the worktable, etc., the operation of changing the angle of the worktable is restricted by the angle change restricting means, for example, the worktable tilts or returns to the original leveling angle Never do.

Therefore, not only when the worker is actually working at a high place, but also when the worker is preparing for work inside the workbench or performing maintenance work, the other workers are in the mode. Even when the switching means is accidentally switched to the angle mode, or conversely, when the mode is returned from the angle mode to the leveling mode, the workbench does not perform the tilting operation or the returning operation, so that a fall accident, a collision accident, etc. It can be prevented beforehand.

[0017] Further, an upper operation device provided on the work table so that a worker who is on the work table can perform operations such as raising and lowering and expanding and contracting the boom, and a worker can operate the boom from the ground side. A lower operating device (for example, the lower operating device 32 in the embodiment) disposed on the vehicle body as described above, and an operating device switching means (for example, an operating device) for selectively switching between a boom operation by the upper operating device and a boom operation by the lower operating device. And an operation device changeover switch 24, 34) according to the embodiment, to constitute an aerial work vehicle. The mode switching by the mode switching unit is enabled only when only the lower operating device is selected by the operating device switching unit, and the operating device switching unit is enabled only when the leveling mode is selected by the mode switching unit. Valid.

With this configuration, it is assumed that the operation device of the boom is switched to only the lower part when draining work or the like of the work table. In order to perform the boom operation, it is assumed that the workbench is in the leveling mode. Therefore, to double-lock accidents caused by erroneous operations and to establish that the equilibrium function will be activated when the worker gets on board and performs work at heights, to further enhance the safety of work vehicles at height. Can be.

The aerial work vehicle constructed as described above has a boom operation restricting means (for example, a boom operation restricting device 31c in the embodiment) for restricting the operation of the boom. It is preferable that the restricting means restricts the operation of the boom when the angle mode is selected by the mode switching means.

By restricting the operation of the boom as described above, it is possible to restrict the operation of the boom when the workbench is tilted. Therefore, for example, when the power of the upper operation device is completely turned off, Even if wiping work is performed after the discharge operation of the boom, or if maintenance work is performed in the same state, there is a danger that the boom will operate due to erroneous operation of the boom and the worker will fall over. Absent. In addition, by performing such a regulation, it is requested to return to the leveling mode when the boom is operated. Therefore, work safety and reliability can be improved.

Further, in these aerial work vehicles, a boom position detecting means (for example, a boom position detector 35 in the embodiment) for detecting a tip position of the boom and a boom capable of operating in an angle mode are provided. Storage means (for example, a working range memory 31a in the embodiment) for storing an angle mode area set in advance as the tip position area, and the angle change restricting means comprises a boom tip position detected by the position detecting means. It is desirable to restrict the operation of the angle changing means when the angle is outside the range of the angle mode area stored in the storage means.

By setting the usable area of the angle mode in advance as described above, the work area which should be originally performed using this function is limited, and unsafe work outside this area is prevented. can do. Therefore, work safety can be further improved.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 shows an embodiment of an aerial work vehicle 1 according to the present invention. A turning table 3 is provided on a vehicle body 2 so as to be able to turn freely by a turning motor (not shown). A boom 5 is pivotally mounted on the upper part of the revolving base 3 so as to be able to move up and down with respect to the vehicle body 2 by operation of an up / down cylinder 4. Boom 5
Is a base boom 5a pivotally supported by the swivel 3 and an intermediate boom 5
b and a distal end boom 5c, which are telescopically arranged in the proximal end boom and are configured to be able to expand and contract by operating a telescopic cylinder (not shown).

A vertical post 6 is provided at the tip of the boom 5 by a leveling mechanism, which will be described later, and is always maintained vertically regardless of the elevation angle of the boom 5. The vertical post 6 projects horizontally from the vertical post and pivots around the vertical post (neck). A worktable (bucket) 20 is attached via an arm that is freely swingable. Therefore, the operator gets on the work table 20 which is always horizontally maintained by the leveling mechanism, and operates the upper operating device 221 provided on the work table 20 to operate the boom 5 such as turning, undulating, expanding and contracting. In addition, by swinging the bucket around the vertical post 6, the bucket can be moved to an arbitrary altitude to perform altitude work such as power distribution work.

In order to stably support the vehicle body 2 against the overturning moment acting on the vehicle body 2 due to the turning movement, the up-and-down movement, and the expansion and contraction movement of the boom 5 on the front, rear, left and right sides of the vehicle body 2, the vehicle body 2 is extended and expanded. Outrigger jack 8 to support the vehicle body
Is provided.

A hydraulic unit 40 is provided on the vehicle body for generating a hydraulic pressure used as an operation source such as a boom swinging motion, a hoisting motion, a telescopic motion, and a swinging motion of a bucket. The hydraulic unit 40 includes a hydraulic pump P as a hydraulic pressure generating source, a solenoid valve for distributing and switching the generated hydraulic pressure to oil passages connected to the actuators, and the like. Upper operating device 22 or lower operating device 3 provided on the vehicle body
By controlling a solenoid valve or the like based on a control signal from the control unit 2, a hydraulic motor or a hydraulic cylinder as an actuator is driven and operated.

In the aerial work vehicle 1 shown in the embodiment, the tip boom 5c, the main members of the bucket 20 on which the operator rides, the cover member around the worktable, etc. are formed of an electrically insulating material such as GFRP. Also, even in the case of high-voltage line maintenance work at a high place or work such as transformer replacement, current does not flow through the boom to the vehicle body even if it comes into contact with live wires, or the bucket 20 is used as a transmission path between live wires. It is configured so as not to cause a short circuit and to prevent an electric shock accident of a boarding operator, a breakage of a vehicle, and the like. Such an aerial work vehicle is referred to as an insulated aerial work vehicle.

In an insulated aerial work vehicle, a hole for draining water may be provided at the bottom of the bucket 20 in order to protect the occupant from an electric shock accident even in the case of contact with a high-voltage live line as described above. Can not. In addition, the upper operating device 2 is mounted on the bucket 20.
In order to operate the boom by operating the operation lever 2 or the like, it is necessary to transmit a control signal from the upper operation device 22 to the hydraulic unit on the vehicle body side.

However, in the case of an insulated aerial work vehicle, this control signal cannot be transmitted to the vehicle body via electric wires because electrical insulation between the bucket 20 and the vehicle body 2 is required.
Also, power cannot be supplied to the upper operation device 22 via electric wires.

For this reason, the insulated aerial work vehicle has an upper battery 27 mounted on the bucket side as a driving power source for the upper operating device 22 and the upper controller, and the operating signal of the upper operating device 22 is once an optical signal. The optical signal is transmitted to the vehicle body via an optical fiber, and the optical signal is converted back into an electric signal by the vehicle body to operate each device.

Next, the aerial work vehicle shown in FIG. 1 shows an example of a configuration provided with a hydraulic leveling mechanism. The schematic configuration of the hydraulic circuit is as shown in FIG. The rod-side oil chambers 41a, 42a and the tube-side oil of the lower leveling cylinder 41 pivotally supported at both ends by the base end boom 5a and the upper leveling cylinder 42 pivotally supported at both ends by the distal boom 5c and the vertical post 6 are provided. Rooms 41b, 42
b are connected in series in a closed circuit via an oil passage. Therefore, for example, when the boom 5 is started by the operation of the up-and-down cylinder 4, the lower leveling cylinder 41 is extended, the hydraulic oil in the rod-side oil chamber 41a of the lower leveling cylinder 41 is discharged, and the discharged hydraulic oil is It is supplied to the rod side oil chamber 42a of the upper leveling cylinder 42 connected by a hose, and presses the cylinder piston to the bottom side to contract the cylinder.

In this manner, the vertical post 6 becomes larger as the boom undulation angle increases (the upper leveling cylinder 42 contracts as the lower leveling cylinder 41 extends).
The relative angle with the boom is reduced as the relative angle with the boom is reduced, and conversely, as the elevation angle of the boom is reduced (as the lower leveling cylinder 41 is contracted, the upper leveling cylinder 42 is extended). ,As a result,
The vertical post 6 always maintains a constant angle, that is, vertical regardless of the boom angle, and the bucket 20 is operated so that its floor surface is always horizontal.

A hydraulic circuit composed of a hydraulic pump P, a tilt solenoid valve 43 and the like shown in the figure constitutes an angle changing means in the claims, and a spool of the tilt solenoid valve 43 shown in the figure. Moves the spool to the right or left in response to the operation of the mode changeover switch 33 disposed on the lower operation device 31 (the operation of which will be described later in detail). Operation and return operation.

FIG. 3 shows another embodiment in which an aerial work vehicle is constructed by using an electric leveling mechanism. In this mechanism, a lower leveling cylinder 41 shown in FIG. 2 is provided. Instead, the bucket 20 is provided with a tilt angle sensor 45 for detecting the tilt state of the bucket, and the upper controller 21 is provided with a correction value of the tilt angle of the bucket according to the tilt angle of the bucket detected by the tilt angle sensor 45. There is provided a workbench horizontal holding circuit for calculating and operating the tilt solenoid valve 43 to hold the bucket horizontally.

In such an electric leveling mechanism, the workbench horizontal holding circuit corresponds to the tilt angle detected in accordance with the boom up / down operation, and always controls the tilt solenoid valve 43 to a closed loop in the leveling mode. Then, the upper leveling cylinder 42 is operated to perform the horizontal maintenance operation of the work table.

When the leveling mode is switched to the angle mode by the operation of the mode changeover switch 33 provided in the lower operation device 32, the bucket 20 is tilted by moving the spool of the tilt solenoid valve 43 rightward or leftward. Movement or return movement.

Next, the construction of the aerial work vehicle according to the present invention will be described with reference to FIGS. 4 shows a configuration of the aerial work vehicle having the hydraulic leveling mechanism, and FIG. 5 is a block diagram showing a configuration of the aerial work vehicle having the electric leveling mechanism.

First, an aerial work vehicle is provided with an upper controller 21 provided on the bucket 20 side for converting a boom operation or the like of an on-board worker into a control signal, and for controlling equipment provided on the bucket; Body 2
, A lower controller 31 for controlling each device, an upper controller 21 and a lower controller 3
1 and an optical cable for transmitting control signals to each other.

The upper controller 21 includes a bucket 20
The upper operating device 22 in which a worker who rides on the boom 5 operates an operation such as raising / lowering, turning, expanding / contracting movement of the boom 5 and swinging of the bucket, and the presence of the occupant in the bucket 20 or the upper operating device 22 An upper operation detecting means 23 for detecting the activation state, and an operation device changeover switch 24 for switching between the upper operation device 22 and the lower operation device 32 are connected.

The lower controller 31 includes a lower operating device 32 for operating the boom 5 and the bucket 6 on the vehicle body (ground side), and a bucket 2 disposed near the lower operating device.
A mode changeover switch 33 for selectively switching between a leveling mode in which the floor surface angle of 0 is kept horizontal and an angle mode in which the floor surface angle of the bucket 20 is changed to a predetermined angle, the boom turning angle, the undulation angle, the extension amount, and the like. A boom position detector 35 for calculating a boom tip position, an operation device changeover switch 34 for switching between the upper operation device 22 and the lower operation device 32, and the like are connected, and based on an operation command signal from the upper operation device 22 or the lower operation device 32. Hydraulic unit 4
Outputs a control signal for controlling a solenoid valve or the like inside 0.

Among these, in the aerial work vehicle equipped with the hydraulic leveling mechanism, as described with reference to FIG. 2, the lower leveling cylinder 41 provided on the base boom side and the lower leveling cylinder 41 provided on the bucket side. The oil chamber of the upper leveling cylinder 42 is connected to each other to form a hydraulic leveling mechanism, and by controlling the operation of the tilt solenoid valve 43 of the hydraulic unit 40 connected to the oil passage connecting these oil chambers. The tilt operation and the return operation of the bucket 20 are performed.

Also, in an aerial work vehicle equipped with an electric leveling mechanism, as already described with reference to FIG.
A tilt angle sensor 45 is provided on the bucket, and the upper controller 21 calculates a tilt angle correction amount of the bucket according to the detected tilt angle of the bucket, and controls the operation of the tilt solenoid valve 43 to perform leveling operation.
Perform tilt operation and return operation.

Inside the lower controller 31, a work range memory 31a pre-stored as an operable area in the angle mode and an upper work detecting means, an upper operation device, an operation device changeover switch, a mode changeover switch, and other devices are provided. A bucket inclination restricting device 31b for restricting a switching operation of a hydraulic circuit serving as an angle changing means according to a detection state and a switching state of a switch, and a boom operation restricting device 31c for restricting an operation of a boom are provided.

Hereinafter, the operation of the aerial vehicle constructed as described above will be described. First, the bucket 20 of the aerial work vehicle is provided with an upper work detecting means 23. As the upper work detecting means 23, it is preferable to provide a worker detector for detecting a worker in the bucket. Examples of the worker detector include a sheet-like or mat-like pressure-sensitive switch that detects that the worker has boarded the bucket 20, a load detector that detects an additional load on the bucket 20, and a safety belt for the worker. A safety belt mooring detector that detects a mooring state, an infrared detector that detects a person in a bucket, or the like can be used. In particular, when using an infrared detector, the worker can be detected regardless of the posture of the bucket. Therefore, even when the work is performed with the bucket tilted for maintenance or the like, the detection can be performed. There is an advantage that you can.

The upper work detecting means 23 can also be achieved by detecting the activation state of the upper operation device 22 instead of the worker detector for detecting the presence of a worker. That is, the insulated aerial work vehicle has an upper battery 27 for driving each device on the bucket because of the need for electrical insulation between the vehicle body 2 and the bucket 20, and a control device including an upper operating device. Is started / stopped (on / off) by a key switch or the like provided on the upper operation device 22. Then, when the operator gets on board and performs high-altitude work, the upper operating device 21 is turned on, and then the operating lever of the upper operating device is operated to move the boom 5 up and down to operate at an altitude. Moving. Therefore, by detecting the activation signal of the upper operation device 22, it is possible to determine that the worker is on the bucket or is in a ready state for boarding.

Then, as described above, the upper work detecting means 23 detects the boarding of the worker on the bucket 20, and
Or, in the work preparation state, the lower controller 3
1 restricts the operation of the tilt solenoid valve 43 in the hydraulic unit 40 regardless of the mode selected by the mode changeover switch 33,
The tilt movement and the return movement of the bucket 20 are not performed.

Therefore, not only when working at a high place, but also when the worker crouches inside the bucket while the boom 5 is stored, or when the bucket 20 is inclined, Even if another operator operates the mode changeover switch 33 by mistake while performing maintenance work from the beginning, the bucket 20 does not start moving from that state, and thus a fall accident, a collision accident, etc. are prevented beforehand. be able to.

The upper operating device 22 and the lower operating device 3
2 is provided with operating device changeover switches 24 and 34 for switching the operating device. This switch may be either a switch that enables only one of the upper operating device and the lower operating device, or a switch that has a position that enables both the upper operating device and the lower operating device. It is preferable that the switch be selectable from both the upper operation device 22 and the lower operation device 32 in consideration of emergency response.

The above-mentioned switches include, for example, a rotary switch which sequentially switches in the order of an upper operating device → lower operating device → both → upper operating device each time the switch is pressed, and an upper operating device ← → lower operating device which is pressed in the order of a lower operating device. Each time the operation switch is switched to one of them, an individual selection switch which is provided with its own selection switch to enable the operating device in which the switch is turned on, and the like.

The bucket inclination restricting device 31b operates only when the lower operation device 32 is selected by the operation device changeover switch 34.
And the operation device changeover switches 24 and 34 are made effective only when the leveling mode is selected by the mode changeover switch 33.

With this configuration, the bucket 2
When tilting or returning 0 (when performing the switching operation of the mode switch), the lower operating device 32
It is assumed that only the state of the upper operation device 22 is selected, and the operation of the mode change switch is invalidated when the upper operation device 22 is selected. Further, in order to get on the bucket 20 and select the upper operation device 22 by the operation device changeover switch 24 and perform the boom operation, it is assumed that the mode changeover switch 33 is in the leveling mode. The boom cannot be operated while riding on the bucket 20 in the angle mode.

For example, one worker A leaves the site in the middle of draining work, and another worker B enters preparations for work at a high place (for example, loads goods in a bucket), and puts the upper working device 22 in the meantime. When the activation is enabled, the bucket 20 does not tilt as long as the upper operation device 22 is selected, even if the original worker A switches the mode switch 33 again to tilt the bucket. Another worker B who enters the high place after the worker A leaves the work site during the draining operation is provided with a mode changeover switch 3 provided on the vehicle body side.
Only after switching the bucket 3 to the leveling mode to make the bucket 20 in the horizontal state, the upper operation device 22 cannot be selected to perform work at a high place. Therefore, for example, in the case of the above example, the situation in which the worker A who has performed the original drainage work has the mode changeover switch 33 switched by another worker (B) and the upper operating device 22 is selected. And recognize that it is necessary to reconfirm the inside of the bucket.

In this way, it is established that the worker can double-lock accidents due to erroneous operations, and that when the worker gets on board and performs high-altitude work, the balancing function is surely activated. The safety of the aerial work vehicle can be further enhanced.

In the aerial work vehicle 1 according to the present invention, the boom operation restricting device 31c in the lower controller 31 regulates the operation of the boom 5 when the angle mode is selected by the mode switch 33. The operation control of the boom includes, for example, a direction-specific operation restriction (partial operation restriction) for restricting the operation of a specific operation direction such as an up-down operation and an extension operation of the boom 5, and a full operation restriction for prohibiting the entire boom operation. Various restricting methods, such as a permissible operating restriction that allows only the swing of the bucket 20, can be appropriately adopted according to, for example, a vehicle type, a boom form, a type of a work table, and the like. Here, the case where the full-surface operation restriction system is adopted will be described.

By restricting the operation of the boom as described above, the boom 5 does not operate even if the operation device of the boom is operated when the angle mode is selected. Therefore, for example, the power of the upper operation device 22 is turned off in an aerial work vehicle that uses the upper operation detection means for detecting the activation state of the upper operation device 22, and only the lower operation device 32 is selected as the operation device. Worker C
Selects the angle mode, tilts the bucket 20 to drain the water accumulated inside the bucket, and performs wiping and maintenance work inside the bucket, even if the other worker D does not notice this. Even when the lower operation device 32 is operated, the boom 5 does not operate.

Therefore, in the above example, the worker C is the worker D
There is no fear of collision with the bucket by the boom operation, falling down from the work scaffold, or swinging in the bucket.

Further, the aerial work vehicle 1 of the present invention uses the boom 5 based on the detected values of the turning angle detector, the undulation angle detector, and the extension amount detector (all not shown) provided on the boom 5.
A boom position detector 35 for calculating the tip position of the camera, and a work range memory 31a provided inside the lower controller 31 and stored in advance as an angle mode operable area are provided.

The bucket inclination restricting device 31b in the lower controller 31 determines whether or not the boom tip position detected by the boom position detector 35 is within the angle mode operation area set in the work range memory 31a. When it is determined that it is out of the angle mode operation range, the operation of the tilt solenoid valve 43 as the angle changing means is restricted.

The angle mode operation area can be appropriately set in a suitable range in accordance with the vehicle type, the boom form, the type of the work table, and the like, as in the case of the boom operation restriction. For example, the mode shown in FIG. In the aerial work vehicle 1, the boom undulation angle is 5 degrees or less above the stow angle, the boom is fully retracted, the turning angle is within ± 30 degrees in front of and behind the vehicle, and the swing angle of the bucket , 90 ° ± 5 ° on the left and right.

By setting the usable area of the angle mode within the safe area in advance as described above, it is possible to prevent unsafe work outside this area and to enhance the safety of the work. Can be.

Now, a description will be given of a draining operation in a case where water accumulates inside the bucket 20 due to, for example, nighttime rainfall in the aerial work vehicle 1 described above. First, the worker moves the vehicle to a location suitable for draining the vehicle, checks the safety inside the bucket 20, and checks if the upper operating device 22
If the power supply is activated, it is turned off. After descending to the vehicle body side, only the lower operation device 32 is selected by the operation device changeover switch 34, and when necessary, the lower operation device 32 causes the bucket 20 to pivot, raise and lower, swing the bucket, etc. to drain water, Move to a position suitable for wiping work after draining.

After confirming the safety around the bucket, the mode switch 33 is operated to select the angle mode. Here, the mode changeover switch 33 is, for example, a toggle switch that switches between two positions of a leveling mode and an angle mode by a snap action or an alternate switch that switches each time the switch is pressed, and a leveling maintaining operation by switching from the leveling mode to the angle mode. Operate the bucket inclining, and conversely, switch from the angle mode to the leveling mode, and the bucket inclining state → bucket returning operation →
A method of performing the leveling maintaining operation, or a three-position rotary that sequentially switches to a leveling mode (leveling maintaining operation) → an angle mode (bucket tilting operation) → an angle mode (bucket returning operation) → a leveling mode (same) by pressing. A method using a switch or the like can be employed.

When the angle mode is selected as described above, when there is no obstacle in all the interlocks described above, the bucket inclination restricting device 3
1b permits the operation of the angle changing means, and energizes the tilt solenoid valve 43 in the hydraulic unit to move the internal spool to the left (see FIGS. 2 and 3).

The hydraulic pressure generated by the hydraulic pump P is supplied to the rod-side oil chamber 42a of the upper leveling cylinder 42 through the oil path switched by the inclined solenoid valve 43, and as shown in FIG.
To tilt the bucket 20 to a predetermined tilt angle. Here, in the aerial work vehicle of the embodiment illustrated in FIG. 1, the predetermined inclination angle is, for example, an angle of about 90 ° to 120 ° when the bucket floor surface angle is 0 ° in a horizontal state. Proximity switch provided, dog and limit switch provided between vertical post 6 and tip boom 5c,
It can be set and detected using a known method such as a photo interrupter or a rotary encoder. In the case of an electric leveling mechanism, the inclination angle sensor 45 can be used.

In this manner, the bucket 20 is tilted as exemplified in FIG. 6, and the worker performs the draining operation and the wiping operation. When these operations are completed and the work table is returned to the leveling state, the mode changeover switch 33 is operated to switch to the leveling mode or the angle mode. At this time, the bucket inclination regulating device 31
b confirms the presence or absence of a failure in all of the interlocks described above, and when it is determined that there is no failure, moves the spool of the inclined solenoid valve 43 to the right to return the bucket 20 to the return position.

The predetermined angle of the worktable floor surface when the bucket 20 is returned is set to be the same as the floor surface angle in the leveling maintaining operation state (for example, within a range of horizontal ± 2 degrees). It can be set and detected by the same setting means as the setting of the tilt angle in the state (for example, the detection angle of a rotary encoder or a tilt angle sensor).

When the return operation of the bucket 20 is detected, the two-position mode changeover switch shifts to the leveling operation, and the three-position mode changeover switch selects the leveling mode. Later, the mode shifts to the leveling mode (the mode at the time of ordinary high-place work), and the leveling maintaining operation for maintaining the bucket 20 horizontally by each leveling mechanism is performed.

Although only the operation of each operation restriction has been described above, a display device, an alarm device, and the like for displaying the operation restriction state are provided at the operation positions of the upper operation device, the lower operation device, and the mode switch. It is provided appropriately. By providing such a display device or the like, each operation restriction state can be visually and uniquely transmitted to the operator, and erroneous operation can be prevented, and the safety of the aerial work vehicle can be further improved. .

In the above description, in the embodiment of the electric leveling mechanism, as the angle changing means for performing the leveling operation, the tilting operation, and the returning operation of the work table,
A method has been described in which the hydraulic pressure generated by the hydraulic pump is used, and this is controlled by switching the supply oil path to the leveling cylinder by a solenoid valve.However, these means are not limited to this method. The same effect can be obtained by a method using a combination of gears or a method using a ball screw.

Further, in this description, the insulated type aerial work vehicle having the insulating boom has been described. However, even for a general aerial work vehicle having no insulating boom, for example, adjustment of the leveling initial floor angle of the workbench can be performed. The present invention can be applied to a device, a large tilt device for work in maintenance work and the like.

[0071]

As described above, according to the present invention,
Mode switching means for switching between a leveling mode in which the floor surface angle of the work table is maintained substantially horizontal and an angle mode in which the floor surface angle of the work table is changed to a predetermined angle, and a floor surface of the work table regardless of the boom undulation angle Leveling means for maintaining the work table substantially horizontal, angle changing means for changing the floor angle of the worktable to a predetermined angle, and the presence of an operator on the worktable or activation of an upper operation device disposed on the worktable An aerial work vehicle is provided with upper work detecting means for detecting that the vehicle is in a state, and angle change restricting means for restricting the operation of the angle changing means. When it is detected that the operating device is in the activated state, the angle change restricting means restricts the operation of the angle changing means regardless of the mode selected by the mode switching means.

For this reason, when the worker is going to work on a high place on the work table or performing maintenance work or the like on the work table, the angle change restricting means changes the angle of the work table. Is restricted, and the work table does not tilt or return to the leveling angle. Therefore, not only when the worker is actually performing high-altitude work, but also in the retracted state, the workbench does not tilt or return due to erroneous operation of another worker, etc.
Therefore, a fall accident, a collision accident, and the like can be prevented.

Further, an upper operating device for operating the boom by an operator on the work table, a lower operating device for operating the boom by the operator from the ground, a boom operation by the upper operating device, and a lower operating device. An aerial work vehicle further comprising operating device switching means for selectively switching the boom operation, wherein mode switching by the mode switching means is performed only when only the lower operating device is selected by the operating device switching means. Is enabled, and only when the leveling mode is selected by the mode switching means, the operating device switching means is enabled.

With such a configuration, it is assumed that the operating device is switched only to the lower portion when the work table is tilted or returned, and the boom operation is performed by the upper operating device while riding on the work table. To do so, it is assumed that the leveling mode is set. Therefore, to double-lock accidents caused by erroneous operations and to establish that the equilibrium function will be activated when the worker gets on board and performs work at heights, to further enhance the safety of work vehicles at height. Can be.

The aerial work vehicle constructed as described above has a boom operation restricting means for restricting the operation of the boom. The angle mode is selected by the mode switching means. It is preferable to control the operation of the boom when the boom is operating.

By restricting the operation of the boom,
The operation of the boom in a state where the workbench is tilted can be restricted, and there is no danger that the boom operates due to an erroneous operation of the boom and the worker falls down. In addition, by performing this restriction, the operator is requested to return to the leveling mode when operating the boom. Therefore, work safety and reliability can be improved.

Further, in these aerial work vehicles, a boom position detecting means for detecting a boom tip position, and an angle mode area preset as a boom tip position area in which an angle mode can be operated are stored. The angle change restricting means restricts the operation of the angle changing means when the boom tip position detected by the position detecting means is out of the range of the angle mode area stored in the storing means. It is desirable.

By setting the usable area of the angle mode in the safe area in advance, the work area to be originally performed by using this function is limited, and unsafe work outside the area is prevented. Can be. Therefore, work safety can be further improved.

[Brief description of the drawings]

FIG. 1 is a side view showing an aerial work vehicle according to the present invention.

FIG. 2 is an explanatory diagram showing a configuration example of a hydraulic leveling mechanism and an angle changing means of the aerial work vehicle.

FIG. 3 is an explanatory view showing a configuration example of an electric leveling mechanism and an angle changing means of the work platform at a high place according to the present invention.

FIG. 4 is a block diagram illustrating a configuration of an aerial work vehicle equipped with the hydraulic leveling mechanism.

FIG. 5 is a block diagram illustrating a configuration of an aerial work vehicle equipped with the electric leveling mechanism.

FIG. 6 is a side view showing a state where the workbench of the aerial work vehicle according to the present invention is inclined.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Height work vehicle) 2 Body 5 Boom (5a base end boom, 5b middle boom, 5c end boom) 20 Workbench (bucket) 22 Upper operation device 23 Upper operation detection means 24 Operation device changeover switch (operation device switching device) 31 Lower controller 31a Working range memory (storage means) 31b Bucket tilt regulating device (angle regulating device) 31c Boom operation regulating device (boom operation regulating device) 32 Lower operating device 33 Mode switch (mode switching device) 34 Operating device switch (Operation device switching means) 35 Boom position detector (Boom position detecting means) 40 Hydraulic unit (Angle changing means) 41 Lower leveling cylinder (Leveling means) 42 Upper leveling cylinder (Leveling means, angle changing means) 43 Inclined solenoid valve ( angle Change means, leveling means)

Claims (4)

[Claims] A work table is provided at the end of a boom which is disposed at least on a vehicle body so as to be able to move up and down freely, and the work table is moved to an arbitrary height by operating the boom to perform a work. In the work vehicle, a leveling mode, which is disposed on the vehicle body and operates to maintain the floor surface angle of the worktable substantially horizontal, and an angle mode in which the floor surface angle of the worktable is changed to a predetermined angle, are selected. Mode switching means for freely switching; leveling means for operating the floor of the worktable to be substantially horizontal regardless of the elevation angle of the boom in the leveling mode; and floor angle of the worktable in the angle mode Angle changing means for changing the angle to the predetermined angle, and that an operator is present on the work table, or that the upper operation device that is disposed on the work table and operates the boom is in an activated state. An upper work detecting means for outputting the light, and an angle change restricting means for restricting an operation of the angle changing means. An operator is present on the work table by the upper work detecting means, or the upper operating device is activated. When a state is detected, the angle change restricting means restricts the operation of the angle changing means irrespective of the mode selected by the mode switching means. 2. An upper operation device disposed on the work table and operable by a worker who is mounted on the work table to operate the boom; and an upper operation device disposed on the vehicle body to control the boom from a ground side. A lower operating device operably disposed; and operating device switching means for selectively switching between a boom operation by the upper operating device and a boom operation by the lower operating device, wherein the lower operating device is operated by the operating device switching device. The mode switching means is enabled only when only the device is selected, and the operating device switching means is enabled only when the leveling mode is selected by the mode switching means. 2. The aerial work vehicle according to 1. 3. The aerial work vehicle has a boom operation restricting means for restricting the operation of the boom, wherein the boom operation restricting means is provided when the angle mode is selected by the mode switching means. 3. The operation of the boom is regulated.
Aerial work vehicles as described in. 4. A boom position detecting means for detecting a tip position of the boom, and a storage means for storing an angle mode area preset as a tip position area of the boom capable of operating in the angle mode, The angle change restricting unit restricts the operation of the angle changing unit when the boom tip position detected by the position detecting unit is out of the range of the angle mode area stored in the storage unit. The aerial work vehicle according to any one of claims 1 to 3, wherein