JPH0417880B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a safe traveling device for a self-propelled aerial work vehicle.

(Prior art) In recent years, self-propelled vehicles specifically designed for on-site work have been developed, which are equipped with equipment for working at high places on the body frame and do not need to extend outriggers during work, making it easy to move around the work site. .

In such a self-propelled aerial work vehicle, the worker stands on a work platform attached to the tip of the boom, and from this work platform can monitor the vehicle's traveling speed, steering, boom extension/contraction, elevation, and turning. It is now possible to operate such things.

The traveling speed of this self-propelled vehicle is determined by controlling the pressure oil supplied to the traveling motor using a selection switch that selects between high-speed traveling and low-speed traveling.
h) and low-speed driving (2 km/h) can be selected. By the way, traveling at high speed while working at heights is extremely dangerous from the standpoint of vehicle stability and worker safety.

In view of this, there is a system that disables high-speed travel when the undulation angle of the boom reaches a predetermined angle or more, as disclosed in Japanese Utility Model Application Publication No. 57-67100.

However, even if the boom angle is within the specified angle, if the boom is extended beyond the specified length, a large impact will be applied to the worker while traveling, and at the same time the work platform may come into contact with the ground. There is a fear.

(Problems to be Solved by the Invention) The present invention has been made in view of the above points, and even when high-speed running is selected, the boom does not rise above a predetermined angle, or the boom does not rise to a predetermined angle. To provide a safe running device that prevents damage to a self-propelled vehicle while ensuring the safety of workers by disabling high-speed running if it extends beyond its length.

(Means for Solving the Problems) The present invention provides a first detection device for detecting the up-and-down angle of a telescoping boom, and a second detection device for detecting the length of the telescoping boom.
Various information from the detection device, the travel operation member that controls the travel control valve of the travel motor, and the selection switch that selects high-speed travel and low-speed travel is input to the control device.
Even if the selection switch is set to high-speed travel, if the telescopic boom stands up at a predetermined angle or more or extends beyond a predetermined length, the pressure oil supplied to the travel motor is switched to the flow control device. The system is configured to control the vehicle through the vehicle and disable high-speed travel.

(Example) Examples of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an aerial work vehicle which is a self-propelled vehicle. A swivel base 3 is rotatably mounted on a body frame 2, and the base end of a boom 4 is pivotally attached to the swivel base 3. The boom 4 has a luffing angle controlled by a luffing cylinder (not shown) interposed between the boom 4 and the swivel base 3, and has a built-in telescopic cylinder (not shown), so that the boom 4 can be extended and retracted in multiple stages with variable length. A workbench 5 is attached to the tip of the tip boom 4a.

As is well known in the art, the workbench 5 is configured to maintain a horizontal state at all times by means of a pair of balance cylinders in response to the raising and lowering operations of the boom 4.

In addition, the swivel table 3 and the work table 5 are provided with operation parts 6 and 7, respectively, and an engine part 8 is arranged at the rear of the swivel table 3, and a counterweight 9 is attached to the lower side of the engine part 8. It is being

Although the operating section 6 on the swivel platform 3 is not shown in detail, it includes a swing operating member for the workbench 5, a telescopic operating member for the boom 4, a raising/lowering operating member for the boom 4, a swing operating member for the boom 4, and a traveling control member. Travel operation members and the like are provided.

On the other hand, the operation unit 7 on the workbench 5 side similarly includes a swinging operation member, a telescoping operation member, a levitation operation member, a turning operation member, a running operation member, etc., as well as an operation member for vertically moving the workbench 5 up and down, and a horizontal operation member. An operating member for forward and backward movement is provided.

The boom 4 also has a boom angle detector (potentiometer) 1 that detects the up-and-down angle of the boom 4.
0, and a boom length detector (potentiometer) 11 for detecting the extension/contraction length of the boom 4.

On the other hand, wheels 2a rotatably mounted on the vehicle body frame 2 are driven by a hydraulic motor 1 with a reduction gear for traveling.
It is designed to be driven by 2.

Further, on the side of the swivel table 3, together with the operation section 6, a hydraulic control valve 13 and these hydraulic control valves 1 are installed.
A control device 14 is installed to switch and control 3.

This hydraulic control valve 13 controls a hoisting control valve for a hoisting cylinder that hoists and lowers a boom, a telescoping control valve for a telescoping cylinder that extends and retracts a boom, a swing control valve for a swing motor that swings a boom 4 (swivel base 3), and a work platform 5. An electromagnetic control valve 15 for high-altitude work consisting of a swing control valve for a swinging cylinder that rotates, a travel control valve for a travel motor 12 that rotates the wheels 2a, and a steering control valve for a steering cylinder that steers the wheels 2a. It consists of an electromagnetic control valve 16 for traveling work, among which an undulation control valve, a telescopic control valve, a swing control valve, and a travel control valve are constituted by electromagnetic proportional control valves.

These hydraulic systems are driven by being supplied with pressure oil from a tandem pump P driven by an engine E, as will be described later, and the discharge amount of the hydraulic pump is controlled by an engine control pulse motor 17. It can be increased or decreased depending on the engine speed.

By the way, the control device 14 controls the hydraulic control valve 13 using a microcomputer, and includes the detectors 10 and 11, the operating sections 6 and 7, the control device 14, and the electromagnetic control valve for high-altitude work. 15, the relationship between the traveling work electromagnetic control valve 16 and the pulse motor 17 is shown in FIG.

First, the operating members other than the swing operating member of the operating section 7 and the travel operating member of the operating section 6 are provided with operating levers, and each operating lever is linked with a potentiometer and a limit switch. When the operating lever is operated, the potentiometer can output a speed signal proportional to the tilting angle of the operating lever, and the limit switch can output a switch signal that detects the tilting direction of the operating lever to the control device 14, respectively.

The control device 14 includes a workbench 5 side operation section 7, a swivel platform 3 side operation section 6, a boom angle detector 10 as a first detector, a boom length detector 11 as a second detector, and a device for high-place work. Solenoid control valve 15, travel work solenoid control valve 16, and engine control pulse motor 1
7, and performs calculation processing based on various operation information from both operation parts 6 and 7, boom angle information from the boom angle detector 10, and boom length information from the boom length detector 11. However, the electromagnetic control valves 15 and 16 and the pulse motor 17 are controlled according to the results.

As shown in FIG. 3, the control device 14 basically includes a CPU 21, a memory 22 that stores a predetermined program, and a parallel interface 2.
3, 24, an analog-to-digital conversion interface 25, and a digital-to-analog conversion interface 26.

Therefore, digital information (switch signals) among the various operation information from both operation units 6 and 7 is input to the parallel interface 23, but analog information is input to the boom angle information and boom length from both detectors 10 and 11. It is designed to be input to the analog-to-digital conversion interface 25 together with the digital information. In addition, parallel interface 24
outputs to the electromagnetic control valve 15 for working at heights, the electromagnetic control valve 16 for traveling work, and the pulse motor 17, and the digital-to-analog conversion interface 26 outputs to the solenoid control valve 15 for working at heights and the solenoid control valve 16 for traveling work, respectively. I'm starting to do that.

Next, regarding the processing flow of the device 14,
This will be explained along with FIG.

First, in block 31, various types of operation information are input from the operation section 7 on the workbench 5 side, and in block 32, from the operation section 6 on the swivel table 3 side.

Subsequently, in block 33, it is determined which of the following () to () the various types of operation information correspond to (operation information determination means).

() If a single operation related to high-altitude work is required, such as swinging operation of the work platform 5, extension and retraction operation of the boom 4, swinging operation of the boom 4 (swivel platform 3), and raising and lowering operation of the boom 4, ( ) When multiple operations related to work at height are requested; () When vertical movement or horizontal movement of the work platform 5 is requested; () When the operation information is traveling information or steering information. In the case of () above, block 34 calculates valve information for performing a predetermined high-place work-related operation, and block 35 controls the electromagnetic control valve 15 corresponding to the predetermined high-place work-related operation. (Solenoid control valve control means) performs a predetermined operation.

In the case of () above, block 36 calculates the same as in block 34 above, and block 35 controls the electromagnetic control valve 15 (electromagnetic control valve control means), and performs multiple operations to increase the output. Therefore, the required flow rate is calculated, and the pulse motor 17 is controlled in block 37 (engine control means) so that the engine rotation speed becomes equal to the required rotation speed corresponding to the required flow rate.

In the case of (), block 38 obtains boom angle information from the boom angle detector 10, block 39 obtains boom length information from the boom length detector 11, and block 40 obtains boom length information from the boom length detector 11, and then blocks 40 obtains the boom angle information from the boom angle detector 10, and obtains the boom length information from the boom length detector 11 in block 40. (boom position calculation means), and calculates the valve information and required flow rate in block 41 so that the work platform 5 moves vertically up and down or horizontally back and forth based on the current position, and then calculates the valve information and required flow rate in blocks 35 and 37. to control the electromagnetic control valve 15 and pulse motor 17 (electromagnetic control valve control means, engine control means).

In the case of (), based on the current position calculated in block 40, block 42 determines whether the mode is high speed mode or low speed mode. 16 and the pulse motor 17, and only the electromagnetic control valve 16 is controlled by the block 35 in the low speed mode.

Note that the above-mentioned high-speed running and low-speed running will be specifically explained with reference to FIG.

Pressure oil from the tandem pump P driven by the engine E is supplied to the travel motor 12 via a travel control valve (electromagnetic proportional control valve) 43, but a relief valve 44 is branch-connected to the discharge circuit of the tandem pump P. The vent circuit of the relief valve 44 is connected to an electromagnetic on-off valve 45, which serves as a flow rate control device that normally opens the vent circuit to the atmosphere. Therefore, the pressure oil from the first hydraulic pump P1 is normally returned to the oil reservoir T via the relief valve 44, and the travel motor 12 is provided with a second hydraulic oil.
Only a small flow of pressure oil is supplied from hydraulic pump P2 to drive the vehicle (approximately 1 km/h).

In this case, when the traveling operation member of the aforementioned operating section 6 or 7 is operated, the traveling control valve 43 is switched and controlled in proportion to the tilt angle of the operating lever, and the engine control pulse motor 17 is operated to rotate the engine. By increasing the number of pumps, the discharge amount of the tandem pump P can be increased.

Here, the traveling speed obtained when the operating lever of the traveling operating member is fully pushed down is approximately 2 km/h.

On the other hand, if the selection switches of the operating units 6 and 7 are switched to the high speed side, the operating signal is outputted to the electromagnetic on-off valve 45 via the control device 14, and the on-off valve 45 is switched to the left.

Then, the pressure oil from the first hydraulic pump P1 is transferred to the second hydraulic pump P1.
It is combined with the pressure oil from the hydraulic pump P2, and a large flow of pressure oil is supplied to the travel motor 12 for driving (approximately 2
Km/h).

When the operating lever of the travel operating member is operated, the speed of the engine E is increased in proportion to the amount of operation as described above, and the travel control valve 43 is controlled to switch.

Here, the travel speed obtained when the operating lever of the control operating member is fully pushed down is approximately 4 km/h.

By the way, when trying to move the work site with the selection switch set to high-speed travel,
When a self-propelled vehicle is working at a height and the ground is uneven, there is a risk that the worker may be thrown off by the impact.

In this case, high-speed travel is possible only when the current position of the workbench 5 obtained from the boom angle detector 10 and the boom length detector 11 is in the retracted state.

That is, when the boom 4 is upright for more than a certain amount or when the boom 4 is extended for more than a certain amount, even if the selection switch is switched to the high-speed traveling side, the flow control device is activated via the control device 14. The electromagnetic on-off valve 45 is controlled to be held at the neutral position, thereby preventing high-speed running.

In addition, modifications of the flow rate control device include controlling the discharge amount of a hydraulic pump with a flow rate control valve 51 (FIG. 6), or configuring the hydraulic pump with a variable discharge amount pump 61 and controlling its discharge amount. (Fig. 7) This is also possible.

Furthermore, the aforementioned engine control pulse motor 1
7 so as not to rotate at increased speed (Fig. 8),
The amount of signal applied to the travel control valve 43 may be controlled (FIG. 9).

In addition, in this embodiment, the boom angle detector 1
0 and the signals from the boom length detector 11. However, a limit switch for detecting the fully retracted state of the boom 4 and a limit switch for detecting the substantially horizontal state of the boom 4 are separately provided, and these limit switches It may also be possible to disable high-speed travel if no signal is detected.

(Effects) As described above, in the present invention, even if high-speed travel is selected, if the boom is erected for more than a predetermined amount or if the boom is extended for more than a predetermined amount, high-speed travel will be impossible and the worker will be forced to Safety is ensured and damage to equipment can be prevented.

[Brief explanation of drawings]

The drawings illustrate embodiments of the invention.
The figure is a side view of the aerial work vehicle, Figure 2 is an explanatory diagram of the input and output of the control device, Figure 3 is a configuration diagram of the control device, and Figure 4 is a diagram of the control device.
The figure is a block diagram showing the process flow, Figure 5 is a hydraulic circuit diagram of the travel motor, Figure 6 is a schematic diagram showing a modified embodiment of the flow rate control device, and Figure 7 is another modified embodiment of the flow rate control device. FIG. 8 is a schematic diagram showing a third modified embodiment of the flow rate control device, and FIG. 9 is a schematic diagram showing a fourth modified embodiment of the flow rate control device. 1...Aerial work vehicle, 2...Vehicle body frame, 3...
...Swivel base, 4...Boom, 5...Work platform, 6,7
...Operation unit, 10...Boom angle detector, 11...
...Boom length detector, 14...Control device, 15...
... Solenoid control valve for high-place work, 16 ... Solenoid control valve for traveling work, 17 ... Pulse motor for engine control.

Claims (1)

[Scope of Claims] 1. A vehicle body frame, wheels rotatably mounted on the front, rear, left and right sides of the vehicle body frame, a travel motor mounted on at least one of the front and rear wheels of the wheels, and the vehicle body frame. In a self-propelled aerial work vehicle consisting of a self-propelled aerial work vehicle consisting of an aerial work device in which a telescopic boom is rotatably mounted on the top and a workbench is installed at the tip of the telescopic boom, the raising angle of the telescopic boom is a first detection device that detects the length of the telescoping boom; a second detection device that detects the telescoping length of the telescoping boom;
an operating section installed on the workbench and having at least a travel operation member for controlling a travel control valve of the travel motor and a selection switch for selecting high-speed travel and low-speed travel; and pressurized oil supplied to the travel motor. It consists of a flow rate control device that controls the flow rate, and a control device that receives and processes various information from the detection device and the operation unit and controls the travel control valve and the flow rate control device, and the detection device controls the boom. When it is determined that the angle exceeds a predetermined angle or a predetermined length, the pressure oil supplied to the travel motor is controlled via the flow control device even if the selection switch is set to high speed travel. A safe running device for a self-propelled aerial work vehicle, which is characterized by being unable to run. 2. The safe travel device for a self-propelled aerial work vehicle according to claim 1, wherein the flow rate control device is an electromagnetic on-off valve that controls the merging of pressure oil from a plurality of constant discharge amount hydraulic pumps. 3. The safe travel device for a self-propelled aerial work vehicle according to claim 1, wherein the flow rate control device is a flow rate control valve that controls the flow rate of pressure oil from a hydraulic pump. 4. The safe traveling device for a self-propelled aerial work vehicle according to claim 1, wherein the flow rate control device is a tilting angle control device that controls the discharge amount of a variable discharge amount hydraulic pump. 5. The safe travel device for a self-propelled aerial work vehicle according to claim 1, wherein the flow rate control device is a pulse motor that controls engine speed. 6. The safe traveling device for a self-propelled aerial work vehicle according to claim 1, wherein the flow rate control device is a traveling control valve, and the traveling control valve is an electromagnetic proportional control valve.