JP2518352Y2 - Leveling condition adjustment device for aerial work vehicles - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leveling condition adjusting device for adjusting the leveling condition of a work table provided in an aerial work vehicle.

[0002]

2. Description of the Related Art A boom constructed so as to be capable of extending and contracting is pivotally mounted via a swivel base in the vicinity of the center of a vehicle body of an aerial work vehicle (see FIG. 2), and further, a boom of the boom is A workbench is attached to the tip. Here, the operation of the boom is performed by a hydraulic actuator that operates by receiving the supply of hydraulic oil via a boom hydraulic oil supply line that is connected to a hydraulic pump, and controls the supply of hydraulic oil (that is, boom operation control). ) Is performed by a boom control hydraulic valve such as an electromagnetic switching type that opens and closes the boom hydraulic oil supply line according to the operation of boom control operation means such as an operation switch provided on the vehicle body or workbench. . In such an aerial work vehicle, an operator on a workbench operates a boom control operation means provided on the workbench to operate a boom (including a swivel base) to move to an arbitrary height. It is possible to move the work table to a desired place, and if necessary, an operator on the ground can arbitrarily move the work table by operating the boom control operation means attached to the vehicle body.

By the way, the workbench is mounted so as to be swingable up and down with respect to the tip of the boom, and the working oil chamber (bottom oil chamber and rod) of the lower leveling cylinder mounted between the vehicle body and the boom is mounted. Side oil chamber) and an operating oil chamber (same as above) for the upper leveling cylinder mounted between the boom and the workbench are connected to each other, and the lower leveling cylinder is operated in accordance with the boom undulation operation. And the hydraulic oil discharged from the hydraulic pump is supplied to the upper leveling cylinder to operate it, so that the workbench can be leveled by the leveling hydraulic circuit, which swings the work table in accordance with the ups and downs of the boom. The control is performed so that the worker can safely work regardless of the ups and downs of the boom.

Therefore, the relationship between the operation of the lower leveling cylinder and the operation of the upper leveling cylinder needs to be properly maintained so that the workbench can always be held horizontally. However, while working many times, due to leakage of hydraulic oil in each cylinder, the above working relationship may not be maintained properly and the leveling state of the workbench may be deviated. Therefore, by connecting the above-mentioned boom hydraulic oil supply line and the leveling hydraulic circuit, and supplying hydraulic oil into the leveling hydraulic circuit via the boom hydraulic oil supply line, the working relationship between the both leveling cylinders,
That is, a leveling state adjusting hydraulic line for adjusting the leveling state of the workbench is provided. The hydraulic line for adjusting the leveling state is opened and closed by an on-off valve provided on the vehicle body (however, this on-off valve is generally not used very often, so the cost is reduced. In many cases, the on-off valve is constructed integrally with its operating part, and due to the arrangement of the hydraulic line for adjusting the leveling state, in the case of such a manual type Often mounted near the center of the car body, such as the top). For this reason, when adjusting the leveling state, first open the on-off valve, and then open the boom control hydraulic valve until the workbench becomes horizontal, and operate the boom control operating means. Manipulate.

[0005]

However, with respect to the opening / closing valve provided near the center portion of the vehicle body as described above, the boom control operating means on the vehicle body side has a tool box or the like arranged on the vehicle body. Therefore, it may be provided at the rear part of the vehicle body. In this case, since the positions of the vehicle body are separated from each other, such as the central portion and the rear portion of the vehicle body, the operator must move from the central portion of the vehicle body to the rear portion when opening / closing the boom control operation means and the opening / closing valve. However, there is a problem that it takes time for the above adjustment.

The present invention has been made in view of the above-mentioned problems, and is intended for an aerial work vehicle in which the leveling state of the workbench can be adjusted without a large movement of the adjuster. An object is to provide a leveling condition adjusting device.

[0007]

In order to achieve the above object, a leveling condition adjusting device for an aerial work vehicle according to the present invention comprises a lower leveling cylinder, an upper leveling cylinder, and a leveling hydraulic circuit connecting them. Boom control that controls the supply and discharge of hydraulic oil to and from the boom via the boom hydraulic oil supply line in response to the operation of the leveling device of the work platform and the boom control operation means usually provided on the vehicle body or the work table. Hydraulic valve and a leveling hydraulic circuit including both leveling cylinders for opening and closing the leveling state adjusting hydraulic line provided for connecting to the boom hydraulic oil supply line. There is. Also, by opening and closing the hydraulic line for adjusting the leveling state with the on-off valve and the hydraulic oil supply line for the boom with the boom control hydraulic valve, respectively, the hydraulic oil is supplied to and discharged from the leveling hydraulic circuit, which is used exclusively for adjusting the leveling state. The leveling state of the workbench can be adjusted by both leveling cylinders without using a switching valve. In addition to the boom control operation means, an adjustment opening / closing control means for opening / closing the boom control hydraulic valve at the time of leveling adjustment is provided, and the adjustment opening / closing control means and the opening / closing valve operation means are provided close to each other on the vehicle body. Are arranged.

[0008]

In such a leveling state adjusting device, the adjusting opening / closing operation means and the manual opening / closing valve are provided so close to each other that they can be operated without the operator moving. Can easily adjust the level link state without moving a lot.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. First, an aerial work vehicle equipped with the leveling condition adjusting device of the present invention will be described with reference to FIG. The aerial work vehicle 20 is provided with a swivel base 22 that is capable of swiveling with respect to the car body 21 at a substantially central portion of a car body 21, and a boom 23 that can be freely extended and retracted is erected above and below the swivel base 22. The boom 23 is pivotally attached freely, and a work table 25 is attached to the tip of the boom 23 via a vertical post 24 so that the work platform 25 can swing and swing horizontally relative to the boom 23 about the vertical post 24. ing.
In addition, a large tool box 26 is arranged around the swivel base 22 on the vehicle body 21 so that a tool or the like used for high-place work can be stored.

By the way, the swivel operation of the swivel base 22, the hoisting operation and the telescopic operation of the boom 23 are performed by a hydraulic swivel motor (see 31 in FIG. 1) mounted on the vehicle body 21, between the swivel base 22 and the boom 23. This is performed by the operation of the attached hydraulic hoisting cylinder 32 and the hydraulic telescopic cylinder (see 33 in FIG. 1) built in the boom 23. And, these hydraulic actuators 31 to 3
The hydraulic circuit 10 for boom operation shown in FIG.

The boom operating hydraulic circuit 10 is connected to the hydraulic pump 11 and two sets of hydraulic actuators 31 to 33 from the hydraulic pump 11 (two input / output in the swing motor 31). In each of the cylinders 32 and 33, the ports are connected to the bottom side oil chamber and the rod side oil chamber, respectively, and three sets of operating hydraulic pressures are supplied to the operating oil discharged from the hydraulic pump 11. An electromagnetic switching type boom control valve (a swing control valve 13, a swelling control valve 14 and a telescopic control valve 15) which is provided for each line 12 and its hydraulic actuator and which can be opened / closed to open / close the operating hydraulic line 12 is provided. ) And is composed of. In addition, in the opening operation of the undulation control valve 14 and the expansion / contraction control valve 15,
Each includes switching from the closed state to the extension side position for extending the undulating cylinder 32 and the telescopic cylinder 33 or the reduction side position for performing the contraction operation. Further, hereinafter, among the working hydraulic pressure lines 12 connected to the telescopic cylinder 33, the hydraulic hydraulic line 12 connected to the bottom side oil chamber is the telescopic bottom side hydraulic pressure line 12a, and the one connected to the rod side oil chamber is the telescopic rod side hydraulic pressure line 12b. Called.

Here, each of the boom control valves 13 to
As shown in FIG. 2, the opening / closing operation of 15 is performed by the upper boom control operation switch group 16 provided on the workbench 25 or the lower boom control operation attached to the rear end lower side of the large tool box 26. Switch group (lower swivel operation switch 1
7, consisting of the lower erection operation switch 18 and the lower extension / contraction operation switch 19), two solenoids S, S attached to both sides of the main body of each boom control valve 13-15 by an operation signal output in response to the operation. It is performed by exciting the one corresponding to the operation.

On the other hand, as shown in FIG. 2, the vertical post 24 and the workbench 25 (hereinafter, for convenience, collectively,
5) is attached to the tip of the boom 23 so as to be swingable up and down, and the swivel base 22 and the boom 2 are attached.
A lower leveling cylinder 101 mounted between the three (however, below the boom 23) and an upper leveling cylinder 102 mounted between the boom 23 and the workbench 25 (however, below the boom 23). The boom 23 is supported horizontally by the hydraulic pressure in the leveling hydraulic circuit regardless of the ups and downs of the boom 23.

Next, the leveling hydraulic circuit will be described with reference to FIG. This leveling hydraulic circuit 100
Are the lower leveling cylinder 101, the upper leveling cylinder 102, and the lower leveling cylinder 101.
Bottom side oil chamber 101a and the bottom side oil chamber 102a of the upper leveling cylinder 102, and a bottom side leveling hydraulic line 103a, and a rod side oil chamber 101b of the lower leveling cylinder 101 and a rod side oil chamber 102b of the upper leveling cylinder 102. It is composed of a rod-side leveling hydraulic line 103b connecting the two.

In such a leveling hydraulic circuit 100, for example, when the boom 23 is raised and lowered, the lower leveling cylinder 101 is extended and the hydraulic oil is discharged from the rod side oil chamber 101b. The discharged hydraulic oil is supplied to the upper leveling cylinder 102 via the rod side leveling hydraulic line 103b.
Flows into the rod-side oil chamber 102b. At the same time, the bottom side oil chamber 10 of the upper leveling cylinder 102 is
The hydraulic oil is discharged from 2a and flows into the bottom side oil chamber 101a of the lower leveling cylinder 101 via the bottom side leveling hydraulic line 103a. In this way, the upper leveling cylinder 102 is contracted, and the workbench 25 is kept at a horizontal level while being swung downward with respect to the boom 23 that is raised and lowered. This allows
An operator who is on the workbench 25 can safely work regardless of the ups and downs of the boom 23.

Here, such a leveling hydraulic circuit 1
Therefore, in order to ensure that the workbench 25 is kept horizontal regardless of the ups and downs of the boom 23, the relationship between the operation of the lower leveling cylinder 101 and the operation of the upper leveling cylinder 102 is set appropriately. There is a need. However, the properly set operating relationship may also change due to hydraulic oil leakage between the bottom side oil chamber and the rod side oil chamber in each of the leveling cylinders 101 and 102 as the boom 23 is repeatedly raised and lowered. Therefore, it is necessary to correct it and adjust the leveling state. Therefore, the leveling state adjusting device of the present invention is provided for adjusting such a leveling state.

As shown in FIG. 1, the leveling state adjusting device 1 includes a bottom side leveling state adjusting hydraulic line 2a and a rod side leveling state adjusting hydraulic line 2b.
And the bottom opening / closing valve 3a and the rod opening / closing valve 3
b and the adjustment opening / closing operation switch 4.

The bottom side leveling state adjusting hydraulic line 2a has one end having an extension control valve 15 and an extension cylinder 33 in the extension rod operating hydraulic line 12b.
And the other end is connected to the leveling hydraulic circuit 1
No. 00 is connected to the bottom side leveling hydraulic line 103a.

One end of the hydraulic line 2b for adjusting the rod-side leveling state has the above-mentioned telescopic bottom-side hydraulic line 12 for operation.
It is connected between the expansion and contraction control valve 15 and the expansion and contraction cylinder 33 in a, and the other end is connected to the rod side leveling hydraulic line 103b in the leveling hydraulic circuit 100.

The bottom side opening / closing valve 3a and the rod side opening / closing valve 3b are located above the swivel base 22, respectively,
It is a manual valve provided on the bottom side leveling state adjusting hydraulic line 2a and the rod side leveling state adjusting hydraulic line 2b and capable of opening and closing them. Note that FIG. 2 shows opening / closing handles 3h and 3h that are integrally formed with the opening / closing valves 3a and 3b and that are used to open and close them.

The adjustment opening / closing operation switch 4 is provided on the swivel base 22.
Of the expansion / contraction control valve 15 is provided on the upper part of the control valve 3h, that is, close to the opening / closing handles 3h and 3h (that is, the bottom side opening / closing valve 3a and the rod side opening / closing valve 3b). , S. For this reason, the adjustment opening / closing switch 4
Is operated to position the expansion / contraction control valve 15 at the extension side position (hereinafter, such an operation direction of the opening / closing operation switch 4 during adjustment is referred to as an upward swing side), or the expansion / contraction control valve 15 is set to the contraction side position. It can be positioned (hereinafter, such an operation direction is referred to as a downward swing side).

Relief valves 5 and 5 are provided on the bottom-side leveling condition adjusting hydraulic line 2a and the rod-side leveling condition adjusting hydraulic line 2b. Within the respective leveling condition adjusting hydraulic lines 2a and 2b. ,
That is, the excessive hydraulic pressure rise in the bottom-side leveling hydraulic line 103a and the rod-side leveling hydraulic line 103b is prevented.

Adjustment of the above-mentioned leveling state using such a leveling state adjusting device 1 is performed when the boom 23 is in an up-and-down state (note that the workbench 25 is
(For safety, no one is on board), when the workbench 25 is lowered from the horizontal level (that is, when the extension amount of the upper leveling cylinder 102 is insufficient), the adjuster first sets the work table on the large tool box 26. Climb near the swivel base 22 and open the bottom side opening / closing valve 3a by operating the opening / closing handle 3h. Here, conventionally, the adjuster must purposely go down to the ground and turn to the rear part of the vehicle body 21 to operate the lower expansion / contraction operation switch 19 (however, the expansion / contraction control valve 15 is operated to be positioned in the contraction side position). However, in the present leveling condition adjusting device 1, the swivel base 22
It suffices to operate the opening / closing operation switch 4 during adjustment to the upper swing side while climbing to the vicinity of. As a result, the expansion / contraction control valve 15 is opened to the contraction side position, hydraulic oil is supplied to the bottom leveling hydraulic line 103a via the bottom leveling state adjusting hydraulic line 2a, and the top leveling cylinder 102 is extended. The workbench 25 is swung upward so as to be positioned at the horizontal level.

On the other hand, when the workbench 25 is raised from the horizontal level (that is, when the extension amount of the upper leveling cylinder 102 is too large), the rod side opening / closing valve 3b is opened similarly to the above case. In addition, the expansion / contraction control valve 15 is opened to the extension side position by operating the adjustment opening / closing operation switch 4 to the downward swing side, and the rod side leveling hydraulic line for adjusting the rod side leveling state is supplied via the rod side leveling state adjusting hydraulic line 2b. The hydraulic oil is supplied to 103b, the upper leveling cylinder 102 is contracted, and the workbench 25 is swung downward so as to be positioned at the horizontal level.

In this way, by the present leveling state adjusting device 1, the adjuster does not move from the vicinity of the swivel base 22 and the work base 25 is positioned at the horizontal level.
The leveling state of No. 5 can be adjusted.

It should be noted that safety is taken into consideration when, for example, another operator accidentally touches the opening / closing operation switch 4 during adjustment while operating the boom 23 while the operator is on the workbench 25. Then, it is desirable to devise on the workbench 25 or the vehicle body 21 side so that the signal from the opening / closing operation switch 4 during adjustment can be blocked.

[0027]

As described above, by using the leveling condition adjusting device of the present invention, in addition to the boom controlling operation means,
Since the opening / closing operation means for adjustment is provided close to the opening / closing valve, the adjuster can operate these without moving, and the leveling state of the workbench can be adjusted much more easily than before. Therefore, it is effective in reducing the burden on the adjuster and shortening the adjustment time when the above adjustment is necessary. Further, since the adjustment opening / closing operation means and the like are arranged on the vehicle body to enable adjustment of the leveling state of the workbench when the boom is raised and lowered, a dedicated switch for controlling the supply / discharge of hydraulic oil to / from the leveling device. Normally, the boom control hydraulic valve, which controls the supply and discharge of hydraulic oil to and from the boom via the boom operation supply line for operating the boom without using a valve, is also used to adjust the leveling state of the workbench. It is possible to reduce the cost of the leveling condition adjusting device which is used less frequently.

[Brief description of drawings]

FIG. 1 is a hydraulic / electrical circuit diagram showing a leveling condition adjusting device according to the present invention.

FIG. 2 is a side view of an aerial work vehicle equipped with the leveling state adjusting device.

[Explanation of symbols]

 1 Leveling condition adjusting device 2a, 2b Leveling condition adjusting hydraulic line 3a, 3b Open / close valve 3h Open / close handle 4 Open / close operation switch for adjustment 15 Extension control valve 16 Upper boom control operation switch group 19 Lower extension operation switch 22 Swivel base 26 Large tool box 33 Telescopic cylinder 101 Lower leveling cylinder 102 Upper leveling cylinder 103a, 103b Leveling hydraulic line

Claims (1)

(57) [Scope of utility model registration request] 1. An aerial work vehicle comprising a boom mounted on a vehicle body such that it can be freely moved up and down, and a work platform mounted on a tip end portion of the boom so as to be vertically swingable. And a lower leveling cylinder mounted between the boom and the boom, an upper leveling cylinder mounted between the boom and the work table, a bottom side hydraulic oil chamber of the lower leveling cylinder and a bottom of the upper leveling cylinder. Side hydraulic oil chamber, the rod-side hydraulic oil chamber of the lower leveling cylinder and the rod-side hydraulic oil chamber of the upper leveling cylinder are connected to each other, and leveling control of the work table is possible along with the hoisting operation of the boom. The leveling hydraulic circuit and the operation of the boom control operating means provided on the vehicle body or the workbench. A boom control hydraulic valve that controls the opening and closing of a boom hydraulic oil supply line that supplies hydraulic oil to the boom, and a leveling hydraulic circuit that is connected to the boom hydraulic oil supply line and that can be opened and closed by an open / close valve. A hydraulic line for adjusting the leveling state, and the hydraulic line for adjusting the leveling state is opened by the opening / closing valve, and the boom hydraulic oil supply line is opened by the hydraulic valve for controlling the boom. A leveling condition adjusting device for an aerial work vehicle capable of adjusting the leveling condition of the work platform by the both leveling cylinders by supplying and discharging hydraulic oil to a hydraulic circuit, wherein the boom control operation means is Separately, when adjusting the leveling state, the boom control hydraulic valve is Adjusting opening and closing operating means for opening and closing control is provided, the adjustment time Aerial leveling conditioning device being characterized in that disposed in proximity to the opening and closing valve and on the vehicle body opening and closing means.