JP2591353Y2 - Work range control device for telescopic boom type work vehicle - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work range control device for a work vehicle having a telescopic boom, such as a crane truck or an aerial work vehicle.

[0002]

2. Description of the Related Art In a working vehicle such as a crane truck or an aerial work vehicle, if the position of the telescopic boom is greatly extended from the base surface of the installed vehicle, the installation stability of the vehicle is impaired, and the vehicle may fall. Occurs.

[0003] Therefore, in this type of work vehicle, a work range in which the telescopic boom can be moved is determined, and when the telescopic boom is moved beyond this work range, the telescopic boom must be stopped near the boundary of the work range. And

In the conventional working vehicle of this type, the work range is regulated on the front side of the telescopic boom. However, the rear side of the telescopic boom is mechanically maximally undulated. Since the angle is limited to a value smaller than the value that makes the working range a problem, the same restriction as that on the distal end side is not performed.

[0005]

That is, in this type of conventional working vehicle, the working range on the rear side of the telescopic boom is made somewhat smaller.

In order to expand the working range on the rear side of the telescopic boom, it is conceivable to stop the telescopic boom by restricting the same working range as the front side of the telescopic boom. In the work area on the rear side of the telescopic boom, the operation of the telescopic boom is stabilized, as opposed to the operation on the front side of the telescopic boom. Therefore, it is difficult for the operator to immediately understand the operation after the stop.

The present invention has been made in view of such circumstances, and aims at expanding the working range behind the telescopic boom of this type of working vehicle, but it is difficult for the operator to understand the telescopic boom. The purpose of the present invention is to reduce the number of stops and improve the workability of this type of work vehicle.

[0008]

SUMMARY OF THE INVENTION To achieve this object, an invention according to claim 1 is a work vehicle having a telescopic boom, the telescopic boom having a work area defined by a predetermined regulation line. A restricting device that stops the movement of the telescopic boom when the telescopic boom is deviated, while setting a regulating line by the restricting device to the rear side of the telescopic boom, and by performing a retracting operation of the telescopic boom, When the regulation line set on the side is reached, the regulating device causes the telescopic boom to fall down at the same time while continuing the contracting operation of the telescopic boom.

[0009]

According to the first aspect of the present invention, the telescopic boom does not reach the rear regulation line due to the tilting operation of the telescopic boom, so that the telescopic boom can be continuously reduced.

Therefore, the stop of the telescopic boom which is difficult for the operator to understand can be reduced, and the workability is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment of an aerial work vehicle shown in the drawings.

First, a general description of an aerial work vehicle will be described. In FIG. 2, 1 is an aerial work vehicle, 2 is a crawler type traveling body, and 3 is a swivel base.

The swivel 3 is driven to rotate about a vertical axis PP by a hydraulic motor, and is installed on the traveling body 2.

An extensible boom 4 is pivotally supported on the swivel base 3 via a pivot 5 so as to be able to move up and down.

The telescopic boom 4 has a three-stage structure including a base boom 4a, an intermediate boom 4b, and a distal boom 4c.
It is fitted to each other and is telescopically expandable and contractible by a telescopic cylinder 11 composed of a hydraulic cylinder. A worktable 6 is mounted on a distal end portion of a distal end boom 4 c by pivotally supporting a mounting bracket 7 with a mounting bracket pivot shaft 8. Have been.

The telescopic boom 4 is raised and lowered by a lifting cylinder 12 composed of a hydraulic cylinder and mounted between the swivel base 3 and the base end boom 4a.

Therefore, in this aerial work vehicle 1,
The worktable 6 can be positioned at an appropriate aerial position by the operation of the swivel 3, the telescopic cylinder 11, and the up-and-down cylinder 12.

In the aerial work vehicle 1 of this embodiment, the work table 6 is fixed by a hydraulic device such as a leveling cylinder 13 or the like, regardless of the undulation angle of the telescopic boom 4, such as a horizontal inclined position. In FIG. 2, reference numeral 9 denotes an operation panel installed on the work table 6.

In the aerial work vehicle 1, for example, R ₁ and R ₂ shown in FIG.
A work range regulation line is provided, and the front side of the regulation line is the work range.

In FIG. 1, the regulation line indicated by R ₁ is indicated by the position of the rear end of the work table 6, and R ₂ is indicated by the position of the mounting bracket pivot 8 of the tip boom 4 c. is there.

Each of these restriction lines R ₁ and R ₂ is formed in a bent straight line so as to connect a point D ₁ , a point E and a point B ₂ which will be described later with respect to the restriction line R ₂ , for example. .

The control lines R ₁ and R ₂ are provided by a control device 15 (see FIG. 3) for electrically controlling the operation of the telescopic cylinder 11 and the up-and-down cylinder 12. _{Since 1} and R ₂ are equivalent, a description will be given below with reference to the regulation line R ₂ .

The regulating device 15 shown in FIG. 3 is a hydraulic circuit 1 for driving the telescopic cylinder 11 and the up-and-down cylinder 12.
6 and a control circuit 17 for appropriately electrically controlling the hydraulic pressure in the hydraulic circuit 16.

The hydraulic circuit 16 has a hydraulic pump 21, a first electromagnetic switching valve 22, and a second electromagnetic switching valve 23. The first electromagnetic switching valve 22 and the second electromagnetic switching valve 23 A circuit which is arranged in series with the discharge-side pipe of the hydraulic pump 21 and reaches the oil tank 24 is formed.

The first electromagnetic switching valve 22 switches the supply of pressure oil to the up-and-down cylinder 12, and the second electromagnetic switching valve 23 switches the supply of pressure oil to the telescopic cylinder 11.

The control circuit 17 includes an arithmetic unit 26 composed of a microcomputer, a storage medium 27, and a controller 28 for controlling the power supply current to the exciting portions of the first and second electromagnetic switching valves 22 and 23. It is.

The arithmetic unit 26 has a boom length detector 31 for detecting the length of the telescopic boom 4, a boom angle detector 32 for detecting the ground angle of the telescopic boom 4, and a load for the telescopic boom 4. An electrical signal from the load detector 33 is input.

The controller 28 is provided with a first changeover switch 35 and a second changeover switch 36.

The first changeover switch 35 is used to operate the first electromagnetic changeover valve 22. By manually operating the first changeover switch 35, the up / down cylinder 12 is operated.
Is to operate.

The second changeover switch 36 operates the second electromagnetic changeover valve 23. By manually operating the second changeover switch 36, the telescopic cylinder 11 is operated.
Is to operate.

Then, based on predetermined programs and data stored in the storage medium 27 and signals from the respective detectors, a boundary of a work range in which the installation stability of the aerial work vehicle 1 is maintained at a certain level or more is determined. When calculated, the regulation lines R ₁ , R ₂
Is obtained.

In the presence of such a regulation line R ₂ ,
The telescopic boom 4 and thus to move within the working range of the front of the regulating line R ₂ by telescoping the telescopic cylinder 11 and derricking cylinder 12.

[0033] Then, the position of the telescopic boom 4 are monitored constantly by the boom length detector 31 and the like, when the telescopic boom 4 is outside the regulation line R ₂ are constant Aerial 1 It is controlled by a program to stop in the vicinity of the regulating line R ₂ a telescopic boom 4 for more installation stability can not be ensured.

By the way, in the aerial 1 of this embodiment, in relation to the regulating line R _2, when it reaches the regulated line R ₂ by reducing operation of the telescopic boom 4, the operation The device 26 controls the controller 28 by a program to supply the power supply current to the second electromagnetic switching valve 23 while supplying the power supply current so that the first electromagnetic switching valve 22 is at the right offset position.

[0035] Thus, reducing the telescopic cylinder 11 of the telescopic boom 4 and the derricking cylinder 12 is simultaneously telescopic boom 4 is turned to continue the reduction operation while lodging telescopic boom 4 without departing from the regulation line R ₂ , it is possible to continue the shrink along the regulation line R _2.

Therefore, the frequency of stoppage of the telescopic boom 4 which is difficult for the operator to understand is reduced.

[0037] To be more specific by 1 the reducing operation of the telescopic boom 4, now, the telescopic boom 4 is in the fully extended state, the position D of the mounting bracket pivot shaft 8 nearest inner regulating line R _{2 Assume that} it is in ₁ .

When the telescopic cylinder 11 is reduced by operating the second changeover switch 36 in this state, the contraction operation is performed along the regulation line R ₂ inside the regulation line R ₂ up to the point E.

The regulation line R ₂ is from point E to point B ₂ below point E, and from point E to point B _1.
Since the installation stability of the aerial work vehicle 1 at a certain level or more is impaired in the reduction toward, the first solenoid-operated directional control valve 22 is set to the right offset position at the point E as described above, and the reduction of the hoist cylinder 12 is started. , Telescopic boom 4 regulation line R
Continue shrinking along ₂ .

It is to be noted that the restriction line R
₂ , the first changeover switch 35
When the telescopic boom 4 has reached the regulation line R ₂ by a by operating extending the derricking cylinder 12, the standing operation of the telescopic boom 4 is intended to be stopped by the control circuit 17.

The working range behind the telescopic boom 4 of the aerial work vehicle 1 having such a function is as follows when compared with the conventional one in FIG.

In FIG. 1, L ₁ indicates the pivot 5 and the mounting bracket when the aerial work vehicle ₁ of the above embodiment has its telescopic boom 4 fully contracted and the boom angle is at the maximum angle α. It is a straight line passing through the axis 8.

The boundary of the working range in the telescopic boom 4 in this state is a regulation line R ₂ as described above, the point D _1,
Point E, is forward of the line connecting the point B ₂ is the working range.

On the other hand, in the conventional case, as described above, the working range does not consider the stability of installation of the aerial work platform 1 to a certain level or more due to mechanical structural limitations. a front of the line connecting E and point B ₂ points R _2, forward of the line connecting the point D ₂ and the point B ₂ at most is a conventional working range.

Therefore, in the conventional case, the boom angle β at that time is smaller than α in the embodiment.

Further, the working range of the telescopic boom 4 according to the present invention is expanded by the portion surrounded by the points D ₂ , B ₂ , E, and D ₁ as compared with the related art.

Although the embodiment described above relates to an aerial work vehicle, the present invention is not limited to this, and the present invention is not limited to this, and the work of the telescopic boom when the overhang amount of the outrigger device is small or the outrigger device is small. It can be used as a range control device.

[0048]

As described above, according to the first aspect of the present invention, the telescopic boom does not reach the rear regulation line and the contracting operation of the telescopic boom can be continued by the falling operation of the telescopic boom. it can.

Therefore, the stop of the telescopic boom which is difficult for the operator to understand can be reduced, and the workability is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a work range.

FIG. 2 is a schematic explanatory view of an aerial work vehicle.

FIG. 3 is an explanatory diagram of a configuration of a regulating device.

[Explanation of symbols]

 R1, R2 regulation line 1 aerial work vehicle (working vehicle) 4 telescopic boom 15 regulation device

Claims (1)

(57) [Scope of request for utility model registration] 1. A work vehicle having a telescopic boom, comprising a regulating device for stopping the movement of the telescopic boom when the telescopic boom departs from a working range defined by a predetermined restriction line. When the regulation line by the regulating device is set on the rear side of the telescopic boom, and when the regulating line set on the rear side of the telescopic boom is reached by the contraction operation of the telescopic boom,
The work range control device for a telescopic boom type working vehicle, wherein the restricting device causes the telescopic boom to fall down while continuing the contracting operation of the telescopic boom.