JPS5924080B2 - Remote control device for aerial work vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remote control device for an aerial work vehicle.

Conventionally, in high-altitude work vehicles such as snorkel vehicles, hydraulic cylinders for raising and lowering each boom and human-powered directional control valves for hydraulic motors for rotating the turntable are installed in parallel on the turntable of the chassis, and each lower operation lever is installed in parallel. and each operating lever installed in parallel on the basket section at the tip of the boom are connected along the boom by wires, carts, links, etc., and when one operating lever is operated, the other operating lever is moved to follow the operation. It was also possible to remotely control it from the side.

However, this mechanical remote control method has the problem that the mounting structure is complicated and expensive, and it is prone to failure.

In addition, in order to automatically stop the boom at a predetermined stop angle position within the working range, it is necessary to operate a lever and link mechanism in conjunction with the movement of the boom, and return the operating lever to neutral.
I have the same problem as above.

As a countermeasure to this problem, it may be possible to use an electromagnetic directional control valve instead of a manual directional control valve, and to combine it with an electric switch and remotely control it electrically. If the spool is attracted and moved by excitation and then returned by a spring by demagnetization, it is not possible to adjust the valve opening and flow rate like a manual directional control valve.

In other words, the operating speed of the boom cannot be controlled, resulting in poor work efficiency.

In view of the above points, the present invention has been improved, and its configuration will be explained as follows based on the drawings.

In Figure 1, 1 is the first boom, 2 is the second boom, 3
4 indicates a third boom, 4 indicates a boom support frame on the turntable of the chassis, 5 indicates a basket at the tip of the boom, and 6 indicates a hydraulic cylinder for raising and lowering the first boom.

7 is a lower operation box on the turntable, 8 is a first boom raising/lowering operation lever, and a variable resistor 9 is assembled thereto as follows.

A brush 11 is attached to the lever shaft 10 as a volume shaft, and a pair of resistors 112a and 12b are wound around a shaft or the like and fixedly arranged along the left and right rotation operation sides for lowering and raising.

An electromagnetic proportional switching valve 13 is provided on the turntable.

This valve 13 is a four-point, three-position switching valve, and each port is connected to the hydraulic cylinder 6, hydraulic pump 14, and tank 15 by piping hoses 16, 17, 18, and 19.

Each resistance wire 12a. The output terminal of 12b is connected by wiring 20.21 to each solenoid 5OL1.5OL2 on the corresponding side of the electromagnetic proportional switching valve 13.

An operating lever 22 is provided on the basket 5, and a variable resistor 23 is assembled to the lever in the same manner as the lower operating section.

24 is a brush mounted on the lever shaft 22';25a;
, 25b are a pair of resistance wires arranged along the left and right rotation operation sides for lodging and raising, and each output terminal is connected to the middle of the corresponding wiring t120, 21 by wiring 26, 27, respectively. .

A cam 28 is connected to the lower operating lever shaft 10 in parallel with the variable resistor 9.
A limit switch LSI is installed near the concave side when the lever is upright and neutral, and the C0M terminal and the power supply are connected by wiring 29, and the a contact and the input terminal of the brush 11 are connected by a30, and further b The contacts and the input terminals of the brush 24 are connected by wires 31, respectively.

When each operating lever 8, 22 is in an upright neutral state, the C0M terminal of the limit switch LSI is connected to the b contact.

Moreover, each brush 11°24 has a respective pair of resistors i12a
, 12b, 25a.

25b and is not in contact with them.

In this state, when the worker rotates the lever 8 to the upright side, the cam 28 rotates and the limit switch LSI is activated, which switches the connection between the C0M terminal and the a contact, and at the same time the brush 11 connects to the resistance wire. 12b in a contact state, a voltage corresponding to this position is taken out, and a current is applied to the solenoid 5OL2,
This excites the spool of the switching valve 13 and moves it to the upright side by an amount corresponding to the degree of excitation.

Then, the pressure oil generated by the hydraulic pump 14 flows to the head side of the cylinder 6, and the hydraulic oil on the rond side is returned to the tank 15, the cylinder 6 is extended, and the first boom 1 is erected.

At this time, by making the rotation angle of the lever 8 small or small, the variable resistor 9 makes the current supplied to the solenoid SQL, 2 of the electromagnetic proportional switching valve 13 small or small, and proportionally The operating speed of the boom 1 can be controlled by moving the valve spool to adjust the oil flow rate.

Note that even if the lever 22 is operated to the upright or down side during the upright operation of the lever 8, the b of the limit switch LSI
Since the contacts are OFF, no problems occur.

Next, when lever 8 is returned to neutral, the limit switch LSI
The actuating piece of is restored by the spring, and the C0M terminal and b
Switch to connection with contact, resistance wire 12b and solenoid 5
The power supply to OL2 is cut off, it is demagnetized, and the valve 13 is switched to neutral by the spring.

When the lever 8 is rotated to the lowering side, the limit switch LSI is activated by the cam 28, and at the same time, the brush 11 slides on the resistance wire 12a, a voltage corresponding to this position is taken out, and a current is applied to the solenoid 5OL1. The spool of the switching valve 13 is moved to the lodging side by an amount corresponding to the degree of excitation, the cylinder 6 is shortened, and the first boom 1 is laid down.

During this operation of lowering the lever 8, even if the lever 22 is operated to the standing or lowering side, the b contact of the limit switch LSI remains open.
Since it is FF, there will be no problem.

Next, with the lever 8 in the neutral position, when the lever 22 is rotated to the upright side, current is applied to the C0M terminal of the limit switch LSI, the b contact, the brush 24, the resistance wire 25b, and the solenoid 5OL2.

Also, when the lever 22 is rotated to the lowering side, the load is applied to the C0M terminal of the limit switch LSI, the b contact, and the brush 24.
, resistor fa 25 a solenoid 5OL1 is energized.

Then, the electromagnetic proportional switching valve 13 is switched to a predetermined side, and the first cylinder 1 is extended or shortened.

This operating speed is adjusted by adjusting the operating angle of the lever 22.

Also, when the lever 22 is operated to stand up or fall down, when the lever 8 is operated to stand up or fall down, the cam 28 switches the limit switch LSI to connect the C0M terminal and the a contact, and the lower operating lever 8 preferentially switches the limit switch LSI to the connection between the C0M terminal and the a contact. Can be operated.

In addition, if the structure allows the basket part and the lower operation part to be operated together without any priority relationship, if the upper and lower levers are operated at the same time, for example to the standing side, the resistances of the upper and lower variable resistors will become a parallel circuit, and if only one is operated. A problem occurs where the boom operation speed is different.

Furthermore, if the upper and lower levers are operated in different directions at the same time, each solenoid of the electromagnetic proportional switching valve will be energized, causing a problem in which the spools will be attracted to each other.

If the basket part and the lower operating part are switched by a switch, the above-mentioned problem can be solved, but when there is no worker on the switch side, for example, at the lower operating part, the basket part cannot be operated.

According to the above structure of the present invention, remote control can be performed from either side of the basket section or the lower operation section without any trouble, and since the lower operation section is given priority, for example, the basket cannot be operated safely by a person operating the basket due to a fire or the like. Can be operated safely and accurately remotely from the bottom.

The above is about the remote control device of the first boom 1.
Remote control devices such as hydraulic cylinders for raising and lowering the second boom 2 and the third boom 3 (not shown) and a hydraulic motor for rotating the turntable are also provided in parallel in the above manner.

In FIG. 2, 13' is an electromagnetic proportional switching valve of the second boom hoisting hydraulic cylinder, 13'' is an electromagnetic proportional switching valve of the third boom hoisting hydraulic cylinder, 8' is a second boom hoisting control lever, 8' is the third boom hoisting operation lever, 9'
, 9'' indicate those variable resistors.

LS2. LS4. LS6 is an automatic stop limit switch provided between the first, second, and third booms so as to be turned ON when the booms reach the full standing angle within the working range; LS3. L
S5. LS7 is an automatic stop limit switch that is turned on between the first, second and third booms when they reach the full lodging angle within the working range, and these are connected to the corresponding electromagnetic proportional switching valves 13 and 13'. , 13" relays R2, R3, R4, R5゜R6, R7 inserted in the solenoid coil circuit
When the above switches are mechanically turned on at the end of raising and lowering each boom, the corresponding relay coil is energized and energized, and the solenoid coil circuit is de-energized and automatically stopped. .

The present invention incorporates an electromagnetic proportional switching valve whose opening area of the spool is sterilized in proportion to the strength of the current into the hydraulic circuit of a hydraulic actuator for operating the boom. An operating lever is provided on each of the baskets, a brush is provided on each operating lever, and a variable resistor is provided with a pair of resistance wires arranged along the left and right rotation range of the operating lever excluding the neutral position. Connect the resistance wire of the variable resistor in parallel to the solenoid coils on both sides of the electromagnetic proportional switching valve, and connect the brushes of each operating lever to the power supply via the switching limit switch provided in the lower operating box. Since this switching limit switch is connected to the basket side via the cam on the lower operation lever in the neutral position and to the lower side in other positions, it can be operated at the same time in the basket part and the lower part. can be prevented and operations at the bottom can be prioritized.

In other words, if the top and bottom are operated at the same time, the variable resistors are connected in parallel, and the operating speed may be different from when only one is operated. Also, if the top and bottom are operated at the same time but in the opposite direction, the electromagnetic proportional switching Although there are disadvantages such as valves not working, these disadvantages can be eliminated by prioritizing the lower part as described above.

In this case, it may be possible to provide a changeover switch on the basket part and the bottom, but this would require a means for interlocking the upper and lower changeover switches, which would complicate the configuration, and it would be impossible to operate one side alone. I end up.

Therefore, even if a person at the top falls down in the event of a fire, there will always be people waiting at the bottom, so if only the bottom is prioritized, there will be fewer problems.

What's more, when you operate the lower operating lever, you can automatically switch to the lower position.

Furthermore, a limit switch that is turned on when the boom reaches the limit of its operating range is provided, and an automatic stop relay is provided that turns off the electric circuit of the electromagnetic proportional switching valve when the limit switch is turned on, so that the boom and basket can be moved to a specified position. It can be automatically stopped when the limit angle is reached, and the mounting structure is simpler than the conventional one that mechanically returns the operating lever to neutral, and an automatic stop device when the boom is fully raised or fully lowered can be easily obtained at low cost.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a remote control device for a high-altitude work vehicle according to the present invention, and FIG. 2 is an electric circuit diagram of the automatic stop device. 8.22... Operation lever, 11, 24...
...Brush, 12a, 12b, 25a, 25b=
-・Resistance wire, 9.23...Variable resistor, 6...
...Hydraulic actuator, 13...Electromagnetic proportional switching valve, 10.22'...Lever shaft, 28
---Cam, LSI, limit switch, 5, basket, 1, 2, 3, etc.
·boom.

Claims (1)

[Claims] 1. An electromagnetic proportional switching valve in which the opening area of the spool is controlled in proportion to the strength of the current is inserted into the hydraulic circuit of a hydraulic actuator for operating the boom, and the lower operation box of the aerial work vehicle and the boom are connected. A control lever is provided for each basket at the tip,
A brush is provided on each operating lever, and a variable resistor is provided with a pair of resistance wires arranged along the left and right rotation range of the operating lever excluding the neutral position. It is connected in parallel to the solenoid coils on both sides of the proportional switching valve, and the brushes of each operating lever are connected to the power supply via the switching limit switch provided in the lower operation box, and the switching limit switch is connected to the lower operation box. A remote control device for an aerial work vehicle, characterized in that a power source is connected to the basket side in a neutral position via a cam on a lever, and a power source is connected to the bottom side in a position other than neutral. 2. Insert an electromagnetic proportional switching valve whose opening area of the spool is controlled in proportion to the strength of the current into the hydraulic circuit of the hydraulic actuator for boom operation, and install it in the lower operation box of the aerial work vehicle and the basket at the tip of the boom, respectively. Equipped with an operating lever,
A brush is provided on each operating lever, and a variable resistor is provided with a pair of resistance wires arranged along the left and right rotation range of the operating lever excluding the neutral position. It is connected in parallel to the solenoid coils on both sides of the proportional switching valve, and the brushes of each operating lever are connected to the power supply via the switching limit switch provided in the lower operation box, and the switching limit switch is connected to the lower operation box. A power supply is connected to the basket side in the neutral position through a cam on the lever, and a power supply is connected to the bottom side in other than the neutral position.Furthermore, a limit switch is provided that is turned on when the boom reaches the limit of its operating range. A remote control device for an aerial work vehicle, characterized in that an automatic stop relay is provided that turns off the electrical circuit of the electromagnetic proportional switching valve when the valve is turned on.