JPH0575299U - Misoperation prevention device for aerial work vehicles - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To prevent the carriage from moving and the work floor from rising and falling due to erroneous operations, and to prevent erroneous operation prevention switches from getting in the way and improving operability. [Structure] A traveling operation lever 8 and an erroneous operation preventing switch 8a are provided on the traveling operation lever 8 so that the trolley does not travel unless the erroneous operation preventing switch 8a is turned on. The raising / lowering operation lever 9 and the raising / lowering operation lever 9 are provided with an erroneous operation prevention switch 9a so that the work floor will not be raised or lowered unless the erroneous operation prevention switch 9a is turned on.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an erroneous operation prevention device for an aerial work vehicle.

[0002]

[Prior Art]

 As an aerial work vehicle, it is known that a work floor is provided on a bogie so that the work floor can be raised and lowered by an elevating mechanism, and the work vehicle rides on the work floor to perform work at a high place. Such an operating device for an aerial work vehicle is provided with an operation lever on the work floor, and the operation lever is operated so that the trolley travels and the work floor is raised and lowered. If operated, the dolly will run and the work floor will rise and fall, which is extremely dangerous. Therefore, conventionally, there has been proposed an erroneous operation preventing device in which a foot switch is provided on the work floor and the trolley does not run or the work floor does not move up and down even if the operating lever is operated unless the foot switch is depressed to turn it on.

[0003]

[Problems to be solved by the device]

 If the above-mentioned erroneous operation prevention device is used, the foot switch on the work floor not only interferes with the work, but it is also not preferable for safety because it may cause the operator to catch his or her foot. When the vehicle travels on the dolly and raises or lowers the work floor, the operating lever may be operated without stepping on the foot switch.In that case, the trolley may not move or the work floor may not move up and down, resulting in poor operability. Become.

Therefore, an object of the present invention is to provide an erroneous operation preventing device for an aerial work vehicle that can solve the above-mentioned problems.

[0005]

[Means for Solving the Problems]

 The operation lever 8 for traveling that outputs an operation command to the rotation drive source of the drive wheel 2 and the elevation drive source of the elevating mechanism 5 and the operation lever 9 for elevation are provided with erroneous operation prevention switches 8a and 9a. An erroneous operation prevention device for an aerial work vehicle that does not output an operation command even if the operation lever is operated when 9a is not turned on.

[0006]

[Work]

 When erroneous operation prevention switches 8a and 9a provided on the traveling operation lever 8 and the elevating operation lever 9 are not turned on, the trolley 3 does not run even if the operation lever is operated and the work floor 5 does not move up and down, which is safe. Not only does the erroneous operation prevention switches 8a and 9a not interfere with the operation, but also the erroneous operation prevention switches 8a and 9a can be easily turned on when the operator holds the operating lever to operate the vehicle. When you try to move up and down, you can always run and move up and down to improve operability.

[0007]

【Example】

 As shown in FIG. 1, a trolley body 1 is provided with drive wheels 2 to form a trolley body 3, and a trolley body 1 is provided with a work floor 4 which can be lifted and lowered by an elevator groove 5 such as a link that expands and contracts with a cylinder. A control box 7 is connected to a cord 6 extending from the floor 4, and the control box 7 is provided with a traveling operation lever 8 and an elevating operation lever 9. Above these operation levers 8 and 9, respectively. Misoperation prevention switches 8a and 9a are provided.

As shown in FIG. 2, the traveling operation lever 8 is connected to the transistor drive circuit 11 of the traveling motor controller 10, and the transistor drive circuit 11 turns on the switch circuit 12 to energize the traveling motor 13. This switch circuit is connected to the power source 15 via the normally open contact 14a of the relay switch 14, and the coil 14b of the relay switch 14 is connected to the power source 15 via the erroneous operation prevention switch 8a. . As a result, unless the erroneous operation prevention switch 8a is turned on, the coil 14b of the relay switch 14 is not energized, the normally open contact 14a remains open, and the switch circuit 12 is not connected to the power supply 15. Even if operated, the traveling motor 13 is not driven and the carriage 3 does not travel.

As shown in FIG. 2, a discharge passage 18a of a hydraulic pump 18 driven by an electric motor 17 is connected to a raising chamber 16a of a lift cylinder 16 of the lifting mechanism 5, and this discharge passage 18a is an electromagnetic valve. The solenoid valve 19 is connected to and cut off from the drain passage 20 at 19, and its solenoid valve 19 is always held at the cut-off position A, and when the solenoid 19a is energized, it is switched to the throttle communication position B. The electric motor 17 is connected to the power supply 15 via the normally open contact 21a of the first relay switch 21, and its coil 21b is connected to the first normally open contact 22a of the second relay switch 22 to connect the solenoid valve 19 The solenoid 19a is connected to the second normally open contact 22b of the second relay switch 22, and its coil 22c is connected to the power supply 15 via the erroneous operation prevention switch 9a. The lifting operation lever 9 connects the movable contact 23a of the switch 23 to one of the first and second contacts 23b and 23c. The movable contact 23a is connected to the power source 15 and the first contact 23b is The second relay switch 22 is connected to the first normally open contact 22a, and the second contact 23c is connected to the second normally open contact 22b.

When the erroneous operation prevention switch 9a is turned on, the coil 22c of the second relay switch 22 is energized and the first and second normally open contacts 22b and 22c are turned on. When the operating lever 9 for raising and lowering is operated to the raised position in this state, the coil 21b of the first relay switch 21 is energized through the first contact point 23b and the first normally open contact point 22a to turn on the normally open contact point 21a, and the electric motor The hydraulic pump 18 is rotated by driving 17 to discharge the pressure oil, and the discharged pressure oil is supplied to the raising chamber 16a of the lift cylinder 16 to be extended, so that the work floor 4 rises. When the raising / lowering operation lever 9 is in the lowered position, the solenoid 19 is throttled to the communication position B by energizing the solenoid 19a through the second contact 23c and the second normally open contact 22b of the second relay switch 22. Since the coil 21b of the relay switch 21 is no longer energized and the normally open contact 21a is turned off and the electric motor 17 is stopped, the pressure oil in the raising chamber 16a of the lift cylinder 16 passes through the solenoid valve 19 and the drain passage 20. The work floor descends as it flows out to the ground and contracts.

If the erroneous operation prevention switch 9a is not turned on, the first and second normally open contacts 22a and 22b of the second relay switch 22 remain off. Therefore, the lifting operation lever 9 is operated to operate the switch 23. Even when the movable contact piece 23a is brought into contact with the first or second contact points 23b, 23c, the normally open contact point 21a of the first relay switch 21 does not turn on, and the solenoid 19a of the solenoid valve 19 is not energized, so the lift cylinder 16 expands and contracts. Without doing this, the work floor 5 does not move up and down.

[0012]

[Effect of the device]

 When erroneous operation prevention switches 8a, 9a provided on the traveling operation lever 8 and the elevating operation lever 9 are not turned on, the trolley 3 does not travel even if the operation lever is operated and the work floor 5 does not move up and down. Not only do the erroneous operation prevention switches 8a and 9a not interfere with the operation, but also the erroneous operation prevention switches 8a and 9a can be easily turned on when the operator holds the operation lever to operate the vehicle. When you try to move up and down, you can always run and move up and down to improve operability.

[Brief description of drawings]

FIG. 1 is a perspective view of an aerial work vehicle.

FIG. 2 is a control circuit diagram for traveling and lifting.

[Explanation of symbols]

2 ... driving wheel, 3 ... carriage, 4 ... work floor, 5 ... lifting mechanism, 8
… Running control lever, 8a… Misoperation control switch, 9
... Lifting operation lever, 9a ... Misoperation prevention switch, 1
3 ... traveling motor, 17 ... electric motor, 18 ... hydraulic pump, 19 ... solenoid valve.

Claims (1)

[Scope of utility model registration request] 1. An aerial work vehicle in which a work floor 4 is provided on a carriage 3 equipped with drive wheels 2 so that the work floor 4 can be lifted and lowered by an elevating mechanism 5. Erroneous operation preventing switches 8a and 9a are provided on the traveling operation lever 8 and the elevating operation lever 9 which output operation commands, and when the operation operation preventing switches 8a and 9a are not turned on, the operation commands are issued even if the operation levers are operated. An erroneous operation prevention device for aerial work vehicles that does not output.