JP2001099107A - Hydraulic controller of vehicle for high lift work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently drive a boom and a generator by limited engine output. SOLUTION: In a vehicle for high lift work, having a hydraulic driving source 41 on the body and for lifting a workbench 8 by oil pressure of a hydraulic pump 43 to be driven by power on the basis of an operation command from an operating device 20 is provided with a generator 50 for generating electric power by oil pressure of the hydraulic pump 42 to be driven by the hydraulic driving source 41, a passage selector valve 45 for feeding generated oil pressure to the generator 50, and a foot switch 25 for making the boom operation by the operating device 20 available by being depressed. When depressing of the foot switch 25 is released and the operation by the operating device 20 is switched to invalid, the passage selector valve 45 is switched, and the generator 50 is driven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work place which is provided on a vehicle body with a boom device or a scissors link device and is configured to be able to move up and down, and the work table is moved to a desired height to perform work. The present invention relates to a work vehicle, and more particularly, to a hydraulic control device for the aerial work vehicle.

[0002]

2. Description of the Related Art The aerial work vehicles as described above are widely used for electrical construction work, construction work, shipbuilding work and the like. In such an aerial work vehicle, there are various types of lifting devices for raising and lowering the work table, including a boom type, and the drive thereof is generally performed by hydraulic pressure. For example, a boom type aerial work vehicle having a boom configured to be capable of turning, raising and lowering, expanding and contracting freely on a vehicle body is provided with a hydraulic unit having an engine drive or an electric motor as a drive source on the vehicle body and a hydraulic unit. The hydraulic pressure generated by the pump is switched by a proportional control valve based on a command signal from a boom operating device disposed on the workbench, and a hydraulic actuator such as a swing motor, an up-and-down cylinder, and a telescopic cylinder is actuated. Is raised and lowered. For this reason, the operator operates the boom operating device while riding on the workbench, thereby moving the boom to a desired height by operating the boom, such as raising and lowering and turning.
The intended work can be performed.

In an aerial work vehicle, an operator on a workbench is required to carry out work at a height, such as a power tool such as a drill, a sander, an impact wrench, a welding tool, or a paint tool. In some cases, a workbench is provided with an extraction terminal for a work power supply on the worktable. In such an aerial work vehicle,
When the above-described boom operation is performed, a hydraulic pressure is generated using power from the same drive source, and the generated hydraulic pressure drives a hydraulic motor driven generator arranged near the worktable to generate required electric power. , And the power supply terminal.

[0004]

By the way, in the aerial work vehicle produced by generating the working power as described above, the operation of the boom is hindered by supplying the working oil to the hydraulic motor driving the generator. Distribute the discharged hydraulic oil using a large hydraulic pump that matches the hydraulic oil capacity required for boom operation and the hydraulic oil capacity required for power generation, or use the same drive source to prevent A hydraulic pump for operating a boom and a hydraulic pump for a generator are directly connected in parallel and supplied to each other, or one of hydraulic control methods has been adopted.

However, in such a conventional hydraulic control method, a manual tool is used even when the boom is operated in which the power tool is not used or when the boom is stationary at a high place. Even in such cases, the generator is constantly driven, and the drive source is operated at a rotational speed that ensures a predetermined power. For this reason, the size of the hydraulic pump or the pump drive source has been increased, the energy consumption of the pump drive source has been ineffective, and the oil temperature of the working oil has increased due to this.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and efficiently provides boom driving and generator driving with limited power of a driving source and reduces ineffective energy consumption. It is an object of the present invention to provide a hydraulic control device capable of reducing an increase in oil temperature.

[0007]

In order to achieve the above object, according to the present invention, a hydraulic drive source and a hydraulic pressure generated by power from the hydraulic drive source are provided on a vehicle body so as to be movable up and down. In an aerial work vehicle equipped with a workbench and an operation device arranged on the worktable and operated to raise and lower the workbench, the validity / invalidity of the operation operation by the operation device provided on the workbench is selected. Operating device selecting means for selectively switching,
A generator driven by hydraulic pressure generated by the power from the hydraulic drive source, and a supply permitting unit for supplying the generated hydraulic pressure to the generator; A hydraulic control device for an aerial work vehicle is configured to drive the generator by supplying the hydraulic pressure by the supply permitting means when the switching is disabled.

According to the hydraulic control device having such a configuration, when the operating device is validated by the operating device selecting means and the workbench is raised or lowered, the hydraulic pressure is not supplied to the generator, and the target is not supplied. When reaching the high position and the operation by the operation device is invalidated, the hydraulic pressure is supplied to drive the generator. That is, the hydraulic pressure is supplied to the generator only when the workbench where the work is performed using the electric tool is stopped to generate necessary electric power, and the hydraulic pressure is not supplied when the workbench moves without using such a tool. For this reason, the hydraulic pressure for raising and lowering operation and the hydraulic pressure for power generation do not require the maximum capacity at the same time, so that the boom drive and the generator drive can be efficiently covered with the power of the limited drive source, It is possible to provide an aerial work vehicle in which ineffective energy consumption is reduced and oil temperature rise is reduced.

The workbench has generator drive switch means for selecting the drive of the generator, the operation of the operating device is switched to invalid by the operation device selection means, and the generator is switched by the generator drive switch means. Preferably, when the drive of the generator is selected, the hydraulic control device is configured to drive the generator by supplying the hydraulic pressure by the supply permitting means. According to the hydraulic control device having such a configuration, when the operating device is invalidated, instead of uniformly supplying hydraulic pressure to the generator to generate power, when the operator attempts to use the power tool. That is, the generator is supplied with hydraulic pressure and power only when needed. Therefore,
In addition to the above effects, it is possible to provide an aerial work vehicle in which ineffective energy consumption is further reduced and the rise in oil temperature is further reduced.

As the above-mentioned operating device selecting means, a foot switch arranged on a workbench for switching signals is preferable, and the first operating device connected to the operating device when the foot switch is depressed is preferred. A signal is supplied to the contact to enable the operation by the operating device, and when the foot switch is not depressed, the signal to the first contact is cut off to disable the operation by the operating device, and the second contact is It is preferable to configure the hydraulic control device of the aerial work vehicle so that a signal is supplied to a contact to which the generator drive switch means is connected to enable selection of driving of the generator by the generator drive switch means. .

[0011] According to the above arrangement, the operator who gets on the worktable depresses the foot switch when moving the worktable, for example, to move the worktable up and down, and performs the movement operation and the like by the operation device. . Then, after moving to the target height, the foot switch that has been depressed is released, and the work is started at the work position. At this time, the signal to the operating device is cut off, so that it is configured not to malfunction even if it accidentally comes into contact with the operating lever or the like. On the other hand, when the foot switch is released, a signal is sent to the circuit connected to the generator drive switch means, and the generator drive can be selected by the generator drive switch means arranged in this circuit. Becomes That is, the generator drive switch means is connected in series to the B contact side of the foot switch. For this reason,
When the foot switch is released to the working position, selection by the generator drive switch means can be automatically performed. When the switch means is turned on, the generator is driven.
Therefore, it is possible to configure a hydraulic control device having both a safety device and a generator driving preparation circuit with a simple configuration.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the aerial work vehicle according to the present invention will be described below with reference to the drawings.
FIG. 3 is a side view of a self-propelled aerial work vehicle equipped with the hydraulic control device according to the present invention, and the structure will be described first. The aerial work vehicle 1 is provided with a swivel base 4 that is configured to be able to swing horizontally with respect to the vehicle body 3 by the operation of a swing motor 11 on a vehicle body 3 that is configured to run. A boom 5 configured to be able to move up and down with respect to the vehicle body 3 by an expansion and contraction operation of an up and down cylinder 12 is pivotally mounted on an upper end portion of the swivel base 4.

The boom 5 includes a base boom 5a, an intermediate boom 5b, and a tip boom 5c pivotally attached to the four swivel bases.
Each of them is loosely inserted into a telescope shape, and is configured to be extendable and contractible by the operation of a telescopic cylinder 13 disposed therein. At the tip of the boom 5, a vertical post 6 is provided which is always kept vertical regardless of the elevation angle of the boom 5 by the operation of a leveling cylinder (not shown). Thus, a worktable 8 configured to be swingable about the vertical post 6 about the vertical post 6 as a central axis is disposed.

An operation device 20 for operating the boom 5 and operating the vehicle is provided on the work table 8, and responds to an operation command from an operator who gets on the work table 8 within predetermined conditions. The command signal is output to a hydraulic unit 40 provided on the swivel 4. The hydraulic unit 40 generates hydraulic pressure by an engine-driven hydraulic pump,
A hydraulic oil supply unit that supplies the generated hydraulic pressure to each of the hydraulic actuators 10 such as the above-described turning motor 11 and the up-and-down cylinder 12, and proportionally controls the opening of the boom control valve based on an operation signal from the operation device 20. ,
It is distributed and supplied to each of the above hydraulic actuators. For this reason,
An operator who rides on the worktable 8 can freely move the boom 5 by swiveling, raising and lowering, and expanding and contracting by operating the operation device 20, thereby moving the worktable 8 to an arbitrary height. To perform desired height work.

The work table 8 includes a work floor 8a serving as a base, as shown in a detailed view in FIG. 4, and a handrail portion 8b erected on the work floor and configured to cover the upper periphery of the work floor. The operation device 20 is disposed on the upper part, and the foot switch 2 is mounted on the work floor 8a below the operation device 20.
5 are provided. The foot switch 25 is provided for the purpose of safety to prevent a malfunction in a state where there is no clear operation intention such as a case where a work tool is accidentally brought into contact. When an operator on board attempts to perform a boom operation or a traveling operation, a control current is supplied to the boom operation device 20 only by stepping on the device, and the boom operation or the like by the operation device 20 can be performed only while the operator is stepping on the vehicle. is there.

The workbench 8 is provided with a power supply take-out terminal (so-called outlet) 53 so that the power tool can be used when working at a high place. Generator (not shown) that generates working power by driving a hydraulic motor to supply power
Is provided, and a generator switch 26 for selecting the driving of the generator is provided in the vicinity of the power supply take-out terminal.

FIG. 1 shows a hydraulic control system (solid line) and a control system (dotted line) of a first preferred embodiment of the hydraulic control device according to the present invention.
The hydraulic control device 1 shown in FIG.
Reference numeral 00 denotes a hydraulic unit 40 provided on the swivel 4, a hydraulic motor driven generator 50 provided on the worktable 8, an operating device 20, a foot switch 25, a generator switch 26, and the like.

The hydraulic unit 40 uses hydraulic pumps 42, 43 connected in parallel to the engine 41 and driven, and a hydraulic pressure generated by the hydraulic pump 43 to proportionally control the valve opening based on a control signal from the operating device 20. A boom control valve 46 for controlling a flow path switching valve 45 for switching between supplying a hydraulic pressure generated by a hydraulic pump 42 to a generator 50 driven by a hydraulic motor or draining to a tank T
And so on. The hydraulic control valve 45 may be disposed in the hydraulic unit as shown in the drawing or may be disposed on the work table 8 side.

The above-mentioned operating device 20, foot switch 2
5, and the generator switch 26 are arranged as shown in the figure to form a selection circuit. That is, foot switch 2
While the step 5 is depressed, control power is supplied to the operation device 20, and a boom operation or the like can be performed by the operation device 20, and an operation signal (command signal) generated by an operation by a boarding operator is a hydraulic unit. It is transmitted to the boom control valve 46 of the forty. At this time, power is not supplied to the generator switch 26 that switches the flow path switching valve 45, and therefore, even when the switch is operated, the flow path switching valve 45 does not operate and the generator 50 is not driven. On the other hand, when the foot switch 25 is released from being depressed, the power supply to the operation device 20 is turned off, and the boom operation and the like by the operation device 20 are invalidated. At this time, power is supplied to the generator switch 26, and this switch operation enables the switching operation of the flow path switching valve 45, that is, the supply of hydraulic oil to the generator 50, and the power generated by switching in this manner is generated. The power is supplied to the outlet 53 on the work table.

Therefore, according to the hydraulic control device 100 configured as described above, the worker who gets on the workbench depresses the foot switch 25 when trying to move the workbench 8 to a target high place. Thereby, the operation operation by the operation device 20 is made effective, and the movement operation and the like are performed. Then, after moving to the target height, the foot switch 25 which has been depressed is released, and the work is started at the work position. At this time, the operating device 2
Since the control current to 0 is cut off, the boom control valve 46 does not operate even if it accidentally comes into contact with the operation lever or the like, and therefore the boom 5 does not malfunction.

On the other hand, when the foot switch 25 is released, the current is supplied to the circuit to which the generator switch 26 is connected, and the drive of the generator 50 can be selected. For this reason, when the foot switch 25 is released to the working position, the drive of the generator 50 can be automatically selected by the generator switch 26, and the generator is driven by turning on the switch means. Accordingly, hydraulic pressure is supplied to the hydraulic circuit of the high-load generator 50 only when the operator needs to use the power tool, and when the power tool is not used, such as when operating a boom, the tank T is passed through the low-load drain circuit to the tank T. Hydraulic pressure is drained. Thus, the engine torque is effectively used, and when power is not required, invalid power is generated and consumed, and the oil temperature does not increase due to passing through a high load circuit. In addition, a hydraulic control device having both a safety device and a generator drive preparation circuit can be configured with a simple configuration as illustrated.

Next, FIG. 2 shows another preferred embodiment of the hydraulic control device according to the present invention. This hydraulic control device 110 does not connect the foot switch 25, the generator switch 26, and the operation device 20 in the above-described embodiment in series, but separately arranges them in parallel.
Signals from the foot switch 25 and the generator switch 26 are received by the controller 30 of the hydraulic control device, and the controller 30 determines operating conditions. That is, when it is determined that the foot switch 25 is depressed, the controller 30 enables the boom operation and the like by the operation device 20 and disables the flow path switching operation by the generator switch 26. On the other hand, when it is determined that the foot switch 25 is not depressed,
Is invalidated, and the flow path switching operation by the generator switch 26 is validated.

Therefore, when the foot switch 25 is not depressed, the flow path switching valve 45 is
The flow path is switched only when the driving of the generator is selected by 6, and the driving of the generator 50 becomes possible. Therefore, as in the above-described embodiment, there is no need to generate and consume ineffective electric power when electric power is not required, or to cause an increase in oil temperature due to passing through a high load circuit.

In the embodiment described above, the hydraulic pressure generated by the hydraulic pump 42 is supplied to the generator circuit by using the flow path switching valve 45 as a supply permitting means for supplying the hydraulic pressure to the hydraulic drive generator 50. Although the example in which the circuit and the supply are switched has been described, the present invention is not limited to the above-described embodiment, and the supply of the hydraulic pressure to the power generator 50 is allowed using the hydraulic pressure generated by the power from the drive source 41. What is necessary is just what is comprised. As is apparent from the above description, in the present invention, the hydraulic pumps 42 and 41 do not need to be simultaneously driven with the maximum displacement. Therefore, for example, without providing the flow path switching valve 45, the drive source 4
The first drive shaft is configured to be capable of engaging and disengaging an impeller via a clutch means such as an electromagnetic clutch so that the clutch can be engaged only when the generator is used and act as a pump. It is also possible to configure the load on the source to be almost zero. Alternatively, it is also possible to adopt a configuration in which the output of the hydraulic pump 43 is divided into two without providing the hydraulic pump 42 and supplied to the respective valves 45 and 46.

Further, in the embodiment shown in FIG. 1, the electrical connection mode using electricity as a signal of each switch is shown for simplicity of description, but these are partially or immediately before the last stage valve. An optical connection mode using light (for example, a fiber transmission system using a photo interrupter or an optical switch) may be used. Further, the generator switch 26
Is a plug detection type in which a worker himself / herself opens and closes contacts, such as a toggle switch. For example, a plug is detected by inserting a plug into an outlet 53 and detecting this plug to close the contact. Switch.

[0026]

As described above, according to the present invention, a workplace at a high place, which has a hydraulic drive source on a vehicle body and raises and lowers a workbench based on an operation command from an operating device by power from the hydraulic drive source In the vehicle, an operating device selecting means disposed on the workbench and selectively switching on / off of the operating operation by the operating device, and a generator driven using hydraulic pressure generated by power from a hydraulic drive source, A supply permitting means for supplying the generated hydraulic pressure to the generator, and when the operation operation by the operating device is switched to invalid by the operating device selecting means, the supply permitting means supplies the hydraulic pressure to drive the generator. The hydraulic control device of the aerial work vehicle is configured as described above.

According to the hydraulic control device having such a configuration, the hydraulic pressure is not supplied when the workbench is moved without using the power tool, and the hydraulic pressure is supplied to the generator only when the workbench performing the work at a height is stopped. Generate electricity. For this reason, the hydraulic pressure for raising and lowering operation and the hydraulic pressure for power generation do not require the maximum capacity at the same time, so that the boom drive and the generator drive can be efficiently covered with the power of the limited drive source, It is possible to provide an aerial work vehicle in which ineffective energy consumption is reduced and oil temperature rise is reduced.

The workbench has generator driving switch means for selecting the driving of the generator, the operation of the operating device is switched to invalid by the operating device selecting means, and the generator is switched by the generator driving switch means. Preferably, when the drive of the generator is selected, the hydraulic control device is configured to drive the generator by supplying the hydraulic pressure by the supply permitting means. According to the hydraulic control device having such a configuration, when the operating device is invalidated, instead of uniformly supplying hydraulic pressure to the generator to generate power, when the operator attempts to use the power tool. That is, hydraulic pressure is supplied to the generator only when power supply is really needed, and power is supplied. Therefore, in addition to the above-described effects, it is possible to provide a high-working vehicle in which the ineffective energy consumption is further reduced and the rise in oil temperature is further reduced.

As the above-mentioned operating device selecting means, a foot switch arranged on a workbench for switching signals is preferable, and the first operating device connected to the operating device when the foot switch is depressed is preferred. A signal is supplied to the contact to enable the operation by the operating device, and when the foot switch is not depressed, the signal to the first contact is cut off to disable the operation by the operating device, and the second contact is It is preferable to configure the hydraulic control device of the aerial work vehicle so that a signal is supplied to a contact to which the generator drive switch means is connected to enable selection of driving of the generator by the generator drive switch means. .

According to the above configuration, the foot switch which has been depressed after moving to the target height is released to reach the work position, so that the operation by the operation device is invalidated. Does not work. On the other hand, when the foot switch is released, a signal is sent to the circuit connected to the generator drive switch means,
It is possible to select the driving of the generator by the generator driving switch means provided in this circuit. Therefore, in addition to the above effects, a hydraulic control device having both a safety device and a generator driving preparation circuit with a simple configuration can be configured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a first embodiment of a hydraulic control device for an aerial work vehicle according to the present invention.

FIG. 2 is a configuration diagram illustrating a configuration of a second embodiment of the hydraulic control device for a high-place work vehicle according to the present invention.

FIG. 3 is a side view showing the overall configuration of the aerial work vehicle.

FIG. 4 is a perspective view showing a portion near a work bench of the aerial work vehicle;

[Explanation of symbols]

 Reference Signs List 1 aerial work vehicle 3 body 4 turning table (body) 8 work table 20 operating device 25 foot switch (operating device selecting means) 26 generator switch (generator driving switch means) 30 controller (hydraulic control device) 40 hydraulic unit 41 Hydraulic drive source (engine) 42, 43 Hydraulic pump 45 Flow path switching valve (supply permitting means) 50 Generator 100, 110 Hydraulic control device

Continued on the front page F term (reference) 3F333 AA08 AB04 CA19 DB07 FA31 FA34 FH08 3H089 AA76 BB01 BB28 CC01 CC08 CC11 DA02 DB46 DB48 EE31 GG02 JJ20 5H590 AA02 CA23 CA30

Claims (2)

[Claims] 1. A hydraulic drive source on a vehicle body, a work table arranged to be able to move up and down using hydraulic pressure generated by power from the hydraulic drive source, and a work table provided on the work table An operating device operated to raise and lower the worktable, operating device selecting means disposed on the worktable and selectively switching validity / invalidity of an operation operation by the operation device; and A generator driven by using a hydraulic pressure generated by the power of the power supply; and a supply permitting unit configured to supply the generated hydraulic pressure to the power generator. A hydraulic control device for an aerial work vehicle, wherein the generator is driven by supplying hydraulic pressure by the supply permitting means when the switch is disabled. 2. The workbench has generator drive switch means for selecting the drive of the generator, the operating device selecting means invalidating the operation by the operating device, and the generator When the drive of the generator is selected by the drive switch means,
A hydraulic control device for an aerial work vehicle, wherein the generator is driven by supplying hydraulic pressure by the supply permitting means.