JP2548984Y2 - Leveling equipment for aerial work vehicles - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leveling device for holding a work table horizontally in an aerial work vehicle having a work table at the tip of a boom which can be raised and lowered freely.

[0002]

2. Description of the Related Art In such an aerial work vehicle, an operator rides on a work table to perform work, and it is required that the work table be kept horizontal regardless of the boom undulation or the like. Conventionally, various types of leveling devices are known. For example, actual fair 1-1640
In this publication, an upper leveling cylinder is provided between the boom and the workbench, and a lower leveling cylinder is provided between the vehicle body and the boom, and the bottom oil chambers and the rod side oil chambers of both cylinders are connected to each other. A leveling device communicating with each is disclosed.

In the leveling device disclosed in this publication, one upper and one lower leveling cylinder are used, respectively. However, when the work table is large, a pair of upper and lower leveling cylinders are arranged in parallel with each other, and the leveling device is used. May be configured. Also in the leveling device having such a configuration, as shown in FIG. 3, the bottom side oil chambers 31 a, 32 a, 35 a, 36 a of the left and right upper leveling cylinders 31, 32 and the left and right lower leveling cylinders 35, 36 pass through the communication passage 33. And the rod side oil chambers 31b, 32b, 35
The b and 36b are communicated via the communication passage 34, and a leveling operation for holding the work table horizontally regardless of the ups and downs of the boom is performed.

[0004]

In the case where the upper and lower leveling cylinders are arranged in a pair in parallel with each other, when the load on the work table is uneven, the upper and lower leveling cylinders act on the left and right leveling cylinders. This causes a problem in that the work table is tilted so as to be twisted in the left-right direction, and the support thereof becomes unstable.

As shown in FIG. 4, the bottom-side oil chambers 31a, 35a and the rod-side oil chambers 31b, 35b of the left leveling cylinders 31, 35 are connected to communication passages 41, 4 respectively.
3 and the bottom side oil chambers 32a and 36a of the right leveling cylinders 32 and 36 and the rod side oil chambers 32b and 36b are independently connected via the communication passages 42 and 44, respectively. That is, if the conventional leveling device including the upper and lower one leveling cylinders is arranged in parallel on the left and right sides, the problem that the worktable is tilted so as to be twisted to the left and right with respect to the above-mentioned eccentric load is avoided. be able to. However, in this case, there is a problem that the number of hydraulic hoses 41 to 44 that communicate between the oil chambers of each leveling cylinder increases, and the configuration becomes complicated. In particular, the hose that communicates between the upper and lower leveling cylinders is located inside the boom,
There is a problem that the hose installation space in the boom is narrow, and it is difficult to arrange the hose in the boom.

The present invention has been made in view of such a problem.
It is an object of the present invention to provide a leveling device for an aerial work vehicle that can stably maintain the leveling of a worktable even when an eccentric load is applied to the worktable and has a relatively simple configuration (particularly, a piping configuration). Aim.

[0007]

According to the present invention, a pair of left and right upper leveling cylinders are disposed in parallel between a work table and a boom, and a space between the boom and the vehicle body is provided. A pair of left and right lower leveling cylinders are disposed in parallel with each other, and the bottom side oil chamber of the left upper leveling cylinder and the bottom side oil chamber of the left lower leveling cylinder communicate with each other through the first communication passage. The bottom oil chamber communicates with the bottom oil chamber of the right lower leveling cylinder via the second communication passage, and the rod oil chambers of the left and right upper leveling cylinders and the rod oil chambers of the left and right lower leveling cylinders ( That is, the leveling device is configured such that all the rod-side oil chambers communicate with each other through the third communication passage.

[0008]

When the leveling device having such a configuration is used, the bottom oil chambers of the left upper and lower leveling cylinders and the bottom oil chambers of the right upper and lower leveling cylinders are independent of each other. Since the communication is established, even when an eccentric load is applied to the work table and the loads applied to the left and right leveling cylinders are different, the work table is stably held horizontally. Further, in this device, since the rod-side oil chambers of all the leveling cylinders are communicated via the third communication passage, the third communication passage is configured by simply disposing one hose in the boom, The configuration is simple.

The rod-side oil chamber of the left upper leveling cylinder communicates with the rod-side oil chamber of the left lower leveling cylinder through a first communication passage, and the rod-side oil chamber of the right upper leveling cylinder and the right lower leveling cylinder. And a bottom oil chamber of the left and right upper leveling cylinders and a bottom oil chamber of the left and right lower leveling cylinders in the third communication path.
You may comprise so that it may communicate through a communication path. Even in this case, the stability against the uneven load is maintained, and the piping configuration is simplified.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an aerial work vehicle equipped with the leveling device according to the present invention. This aerial work vehicle has a vehicle body 1b that can turn freely on a frame 1a that can travel with wheels 2 and 2, and a boom 3 is attached to the vehicle body 1b so as to be able to move up and down. The boom 3 is composed of three boom members 3a, 3b, 3c which can be telescopically extended and retracted by a built-in telescopic cylinder (not shown). An up-and-down cylinder 4 is disposed between the boom 3 and the vehicle body 1b, and the boom 3 is moved up and down by the expansion and contraction operation of the up-and-down cylinder 4.

A work table 5 is attached to the end of the boom 3 so as to swing up and down. While the worker is on the work table 5, the turning of the vehicle body 1b, the raising and lowering of the boom 3 and the expansion and contraction operations are controlled to move the worker who is riding on the work table 5 together with the work table 5 to a predetermined height. Work is performed. In this case, a leveling device 10 is provided to always keep the work table 5 horizontal.

The leveling device 10 includes the tip boom member 3.
c and the work table 5, a pair of left and right upper leveling cylinders 11 and 12 arranged in parallel on the left and right of the distal boom 3c, and a proximal boom member between the proximal boom member 3a and the vehicle body 1b. 3a, a pair of left and right lower leveling cylinders 15, 16 arranged side by side in parallel on the left and right. These leveling cylinders 11, 12, 1
The pistons are inserted into the bottom oil chambers 11a, 12a, 15a, 16a and the rod oil chambers 11 and 16, respectively.
b, 12b, 15b, and 16b, and the respective oil chambers are connected as shown in FIG.

More specifically, the bottom oil chamber 11a of the left upper leveling cylinder 11 and the bottom oil chamber 15a of the left lower leveling cylinder 15 are communicated through a first communication passage 21, and the lower oil chamber 11a of the right upper leveling cylinder 12 The bottom side oil chamber 12a and the bottom side oil chamber 16a of the right lower leveling cylinder 16 are communicated via the second communication passage 22,
Further, all the leveling cylinders 11, 12, 15, 16
Rod-side oil chambers 11b, 12b, 15b, 16b
The communication is performed through the communication passage 23.

In the leveling device 10 having such a configuration, even if an eccentric load is applied to the work table 5, the left and right bottom oil chambers are independently communicated with each other. No occurrence occurs, and the worktable 5 is stably held in a horizontal state. On the contrary,
As shown in FIG. 3, in a case where all the rod-side oil chambers are communicated and all the bottom-side oil chambers are also communicated,
For example, when an eccentric load is applied to the work table and a large load is applied to the left leveling cylinder, the left upper leveling cylinder 31 is contracted more than the right upper leveling cylinder 32, and the work table is tilted to be twisted right and left.
For this reason, the leveling and holding of the worktable becomes unstable, and an overload acts on the mounting part of the worktable at the end of the boom. In the case of the leveling device of the present invention shown in FIG. 2, the upper leveling cylinder side and the lower leveling cylinder side communicate with each other, so that three pipes (hoses) provided in the boom 3 are provided. Compared with the conventional piping configuration of FIG. 4, the configuration is simple, and the arrangement in the boom 3 is easy.

In the piping shown in FIG. 2, the first to third communication passages 21, 22, 23 are provided with branch passages 21a, 21a, respectively.
22a and 23a are connected, and a manual valve 25 is disposed in each of these branches, and is connected to an expansion circuit. This is for adjusting the leveling of the worktable 5 at the start of the work or the like. At the start of the work, the manual valve 25 is opened to supply and discharge the oil to and from each of the communication passages 21, 22, and 23. Adjust the leveling of.

In the example shown in FIG. 2, the left and right bottom oil chambers communicate with each other independently, and all the rod oil chambers communicate with one communication passage. However, the present invention is not limited to this. Conversely, the left and right rod-side oil chambers may be independently communicated with each other, and all the bottom-side oil chambers may be communicated with one communication passage.

[0017]

[Effects of the Invention] As described above, according to the present invention,
The bottom oil chamber of the left upper leveling cylinder communicates with the bottom oil chamber of the left lower leveling cylinder via the first communication passage, and the bottom oil chamber of the right upper leveling cylinder and the bottom oil chamber of the right lower leveling cylinder are connected. Are communicated via the second communication path, so that even if an eccentric load acts on the worktable and the loads acting on the left and right leveling cylinders differ, the worktable is stably held horizontally. Further, in this device, since the rod-side oil chambers of all the leveling cylinders are communicated through the third communication passage, the third communication passage is configured by simply arranging one hose in the boom. The configuration is simple.

In the present invention, the rod-side oil chamber of the left upper leveling cylinder and the rod-side oil chamber of the left lower leveling cylinder communicate with each other via the first communication passage, and the rod-side oil chamber of the right upper leveling cylinder is connected. And a rod-side oil chamber of the right lower leveling cylinder through a second communication path, and a third communication path between a bottom-side oil chamber of the left and right upper leveling cylinder and a bottom-side oil chamber of the left and right lower leveling cylinder. May be configured to communicate with each other. Even in this case, the stability against the uneven load is maintained, and the piping configuration is simplified.

[Brief description of the drawings]

FIG. 1 is a front view of an aerial work vehicle having a leveling device according to the present invention.

FIG. 2 is a hydraulic circuit diagram showing a leveling device configuration according to the present invention.

FIG. 3 is a hydraulic circuit diagram showing a configuration of a conventional leveling device.

FIG. 4 is a hydraulic circuit diagram showing a configuration of a conventional leveling device.

[Explanation of symbols]

 Reference Signs List 3 Boom 4 Undulating cylinder 5 Work table 10 Leveling device 11, 12 Upper leveling cylinder 15, 16 Lower leveling cylinder

Claims (2)

(57) [Scope of request for utility model registration] 1. A leveling device for an aerial work vehicle, comprising: a boom mounted on a vehicle body so as to be able to move up and down at least; and a work table mounted on a tip end of the boom so as to swing up and down. A pair of left and right upper leveling cylinders disposed in parallel between the worktable and the boom; a pair of left and right lower leveling cylinders disposed in parallel between the boom and the vehicle body; A first communication passage communicating the bottom oil chamber of the upper leveling cylinder with the bottom oil chamber of the left lower leveling cylinder; a bottom oil chamber of the right upper leveling cylinder and a bottom oil chamber of the right lower leveling cylinder; And a rod-side oil chamber of the left and right upper leveling cylinders and a second communication passage communicating with the left and right lower leveling cylinders. Aerial leveling device characterized by comprising a head side oil chamber and a third communication passage communicating. 2. A leveling device for an aerial work vehicle, comprising a boom mounted at least on a vehicle body so as to be able to move up and down, and a work table mounted at the tip of the boom so as to be swingable up and down. A pair of left and right upper leveling cylinders disposed in parallel between the worktable and the boom; a pair of left and right lower leveling cylinders disposed in parallel between the boom and the vehicle body; A first communication passage communicating the rod-side oil chamber of the upper leveling cylinder with the rod-side oil chamber of the left lower leveling cylinder; a rod-side oil chamber of the right upper leveling cylinder and a rod-side oil chamber of the right lower leveling cylinder; A second communication passage communicating with the lower and right lower leveling cylinders, and a bottom oil chamber of the left and right upper leveling cylinders; Aerial leveling device characterized by comprising a third communication passage communicating Tom side oil chamber.