JPS5932400B2 - Work platform storage device for aerial work vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a work platform that is attached to the tip of a boom installed in an aerial work vehicle for performing aerial work, and particularly to a storage device thereof.

Conventionally, high-altitude work vehicles have been equipped with a telescoping boom on the vehicle body, a work platform is attached to the tip of the boom, and the work platform can be moved to any height by extending/contracting, rotating, and raising/elevating the boom to perform work in high places. Configurations that can do this have already been put into practical use.

By the way, this type of aerial work vehicle is generally configured so that the work platform attached to the tip of the boom is always maintained horizontally regardless of changes in the elevation or elevation of the boom so that workers can work safely on it. Even in the storage position where the boom is retracted and laid down almost horizontally, the workbench is held horizontally, which occupies wasted space and usually causes the workbench to be in a high position, resulting in a lack of driving safety. It had become.

Therefore, in the industry, the workbench is always held horizontally in the working position, allowing safe work, and in the retracted position, the workbench can be stored compactly by cleverly utilizing the space above the vehicle body. It has been requested for a long time.

The present invention answers this need, and embodiments of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes the body of the aerial work vehicle, 2 a support stand pivotally mounted to the rear of the vehicle body 1 so as to be able to rotate horizontally, and 3 a boom whose base end is pivoted to the support stand 2 so as to be able to move up and down. The main boom 4 consists of a telescopic main boom 4 in the form of a cylinder, and a sub-boom 5 pivoted to the tip of the main boom 4 so that it can be folded horizontally along the main boom 4. A hydraulic cylinder 6 is interposed to raise and lower the boom 3.

Further, the sub-boom 5 is extended over the main boom 4 via a hydraulic cylinder (not shown) equipped with a link mechanism, and is folded sideways, but the connecting portion between the sub-boom 5 and the main boom 4 is Since the specific structure in is not the gist of the present invention, it will be omitted for the sake of simplification.

Reference numeral 7 denotes a workbench, which is vertically rotatably attached to the tip of the sub-boom 5 via a mounting member 8 having a crank 8', and a balance cylinder 9 is provided between the tip of the sub-boom 5 and the crank 8'. It is interposed to hold the workbench 7 horizontally and to fold and rotate it.

That is, a sensing cylinder 10 is interposed between the base of the main boom 4 and the support base 2 to sense the up/down state of the main boom 4, and a check valve 11 is connected between the head side of the sensing cylinder 10 and the head side of the balance cylinder 9. A safety valve mechanism 11 consisting of a relief valve 11'' and a relief valve 11'' are communicated with each other through a connecting pipe 12, and the rod side of the sensing cylinder 10 and the rod side of the balance cylinder 9 are connected through a connecting pipe 13. Let's communicate.

Further, branch pipes 14 and 15 are provided from the middle of each connecting pipe 12 and 13, respectively, and each branch pipe 14 and 15 is connected to an on-off valve 1, respectively.
6 and 17 are interposed and connected to the three-position switching valve 18.

This switching valve 18 is connected to a pressure oil circuit 19 consisting of a pump, a tank, etc.

Since the present invention is configured as described above, in FIG. 3, when the boom 3 extends and its elevation angle α with respect to the horizontal plane increases, the sensing cylinder 10 is extended as the boom 3 extends, and pressure is applied from the rod side. The oil is sent to the rod side of the balance cylinder 9 through the connecting pipe 13 to contract the balance cylinder 9, and the work platform 7 is rotated downward so that its angle of inclination β with respect to the sub-boom 5 decreases to a horizontal state. Hold.

Conversely, if the boom 3 moves downward and the elevation angle α decreases, the boom 3
As the sensing cylinder 10 moves downward, the sensing cylinder 10 is contracted, and pressure oil is sent from the head side to the head side of the balance cylinder 9 through the connecting pipe 12 and the check valve 11', thereby extending the balance cylinder 9. The workbench 7 is rotated upward so that the inclination angle β increases and is held in a horizontal state.

Similarly, in FIG. 3, the workbench 7 is rotated by the balance cylinder 9 which is interlocked with the sensing cylinder 10 that senses the elevation and elevation of the boom 3 so that α+β=180°.

In addition, in order to release the horizontal state of the workbench 7 in the retracted position and rotate it downward, after opening the on-off valves 16 and 17, the switching valve 18 is operated to supply pressure oil from the pressure oil circuit 19. This is done by forcibly introducing it into the rod side of the balance cylinder 9, which will be described in detail later.

That is, when taking the working position, the main boom 4 is retracted and lowered to a substantially horizontal state, and the sub-boom 5 is folded sideways along with the main boom 4 via a hydraulic cylinder (not shown).

Even in this state, the workbench 7 is held in a horizontal state (dotted line (position) in Figure 1), so open the on-off valves 16 and 17 and operate the switching valve 18 to the right position (upper position in Figure 2). Pressure oil is introduced from the pressure oil circuit 19 to the rod side of the balance cylinder 9 through the branch pipe 15 and the connecting pipe 13, and the work platform 7 is rotated downward until it is approximately perpendicular to the sub-boom 5. The folding valves 16 and 17 are closed and the switching valve 18 is neatly stored in the neutral position.

Similarly, the pressure oil introduced from the pressure oil circuit 19 into the branch pipe 15 and the connecting pipe 13 via the switching valve 18 is also sent to the sensing cylinder 10. Since the sensing cylinder 10 is in a locked state, pressure oil is introduced only into the balance cylinder 9.

Next, when changing to the working position, follow the steps in the reverse order of the opening/closing valve 16.
．． 17 is opened, the switching valve 18 is operated to the left position (upper side in FIG. 2), and pressure oil from the pressure oil circuit 19 is introduced into the head side of the balance cylinder 9 via the branch pipe 14 and the connecting pipe 12. Rotate the workbench 7 upward and place it in a horizontal position to open the on-off valve 1.
6. Close the switch 17 and bring the switching valve 18 to the neutral position.

After the sub-boom 5 is extended and fixed on the extension of the main boom 4, the main boom 4 is extended/contracted, rotated, and raised/raised.
The workbench 7 is appropriately moved to an elevated work position.

The workbench storage device of the present invention releases the horizontal state of the workbench and folds it during an interlocking circuit of a sensing cylinder that detects the up-and-down state and a balance cylinder that works with this to keep the workbench at the tip of the boom always horizontal. A switching valve for storage is provided, and by operating the switching valve, the work platform can be selected between its working position and storage position. Conventionally, the work platform was held horizontally even in the storage position; The workbench, which was previously located in a large area, can now be folded and stored by making effective use of the space above the vehicle body, making the storage position more compact, increasing driving stability, and improving safety. In addition, the boom is configured with a sub-boom that can be folded horizontally, which is pivoted to the tip of the main boom that is extendable and retractable, and the work platform is pivoted to the tip of the sub-boom, so that it can be mounted on the rear vehicle body behind the driver's cab. The workbench can be easily stored in a low position, the total extension of the boom can be increased in the working position, the range of work at height can be significantly expanded, and the overall structure can be simplified and lightened. This is an excellent invention.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is an overall front view of a worker at height, Fig. 2 is an explanatory system diagram of the main parts, and Fig. 3 is an interlocking movement between the rotation of the work platform and the elevation and elevation of the boom. It is an explanatory diagram showing a relationship. 1...Car body, 2...Support stand, 3...
...Boom, 4...Main boom, 5...
・Secondary boom, 6...Hydraulic cylinder, 7...
...Workbench, 8...Mounting parts, 9...
・Equilibrium cylinder, 10... Sensing cylinder,
11 safety valve mechanism, 12... connection pipe, 13...
...Connecting pipe, 14... Branch pipe, 15...
... Branch pipe, 16... Open/close valve, 17...
・On-off valve, 18...Three-position switching valve, 19...
...Pressure oil circuit.

Claims (1)

[Claims] 1. A workbench that is vertically rotatably pivoted to the tip of the boom, a sensing cylinder that senses the up-and-down state of the boom, and an equilibrium that is linked to the sensing cylinder to keep the workbench horizontal at all times. In a high-altitude worker equipped with a cylinder, a switching valve for canceling the horizontal state of the work platform and folding it for storage is interposed in the interlocking circuit of the balance cylinder and the sensing cylinder,
A work platform storage device for an aerial work vehicle, characterized in that the work platform can be selected between its working position and storage position by operating the switching valve. 2. The boom is composed of a main boom that is extendable and retractable, and a sub-boom that can be folded laterally and pivoted to the tip of the main boom, and the work platform is pivoted to the tip of the sub-boom. A work platform storage device for an aerial work vehicle as described in Patent 1.