JPH0742077B2 - Work range control device for aerial work vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention is used in the field of aerial work vehicles that restrict the operation of the boom device on the dangerous side when the work table exceeds the safe working range. is there.

(B) Conventional technology The work range control device in the conventional aerial work vehicle is fair 1
As disclosed in Japanese Patent Publication No. 14640, the limit value corresponding to the allowable limit of the boom falling direction moment is stored for each boom hoisting angle, and the angle signal from the angle detector is used as a read signal for the boom hoisting angle at that time. The limit value of the moment is read out, and the read limit value is compared with the moment detected by the load detector. When the latter value reaches the former value, the movement of the boom is limited.

(C) Problems to be Solved by the Invention Generally, a work vehicle for aerial work is performed by extending the boom and positioning the workbench at a high place.

Therefore, the workbench and the boom oscillate up and down due to wind pressure, and when the boom operates, the oscillating angle of the boom is difficult to be accurately detected because of inertial force.

By the way, in the regulation device, the limit value is read out at the boom hoisting angle at that time, and the detected value to be compared with the limit value is also a moment derived from the boom hoisting angle at that time, and both are based on the hoisting angle. Since it is a value, an accurate value cannot be obtained, and therefore, there is a problem that the function as a regulation device cannot be sufficiently fulfilled.

The present invention provides a work range control device for an aerial work vehicle in which the accuracy of the control device is improved by comparing the boom length with less fluctuation and the limit value of the boom length.

(D) Means for Solving the Problems The present invention provides a work platform for aerial work, in which a boom device is provided on a vehicle body, a work platform is provided at a tip of the boom device, and the boom device is capable of undulating / extending / retracting / turning. A limit value table that stores the limit value of the boom length corresponding to each load that acts on the work platform and each hoisting angle of the boom device, and the load that acts on the work platform that is detected by the moment from the hoisting center of the boom device. Limit value output means for extracting the limit value of the boom length from the limit value table based on the undulation angle detected by the angle detection means, and the limit value and the boom length detection means extracted from the limit value output means. And a boom length of the boom device detected by the above, and when the boom length exceeds a limit value, a work range regulating device for an aerial work vehicle, which comprises a discrimination regulating means for regulating work on the dangerous side of the boom device. It is about.

(E) Action When the boom length of the boom device asks for the limit value of the boom length extracted by the limit value output means during operation,
The work on the dangerous side of the boom device is stopped by the discrimination regulation means.

(F) Embodiments Embodiments of the present invention will be described below with reference to the drawings. (1) is a vehicle body, and a column (3) is erected on the vehicle body (1) via a swivel base (2). A telescopic boom device (4) is pivotally supported on the support column (3), and a workbench (6) is attached to the tip of the boom device (4) via a mounting bracket (5).

A hoisting cylinder (7) for hoisting the boom device (4) is provided between the column (3) and the boom device (4), and a load cell (load detecting means, which is a load detecting means, is provided at a shaft support portion of the boom device (4). 8) is provided.

(9) is a workbench automatic balancing device, which equips the lower horizontal level cylinder (10) between the column (3) and the boom device (4), the boom device (4) and the mounting bracket (9). An upper horizontal level cylinder (11) is provided between the two cylinders (5) and (5), and the two cylinders (10) and (11) are connected by pipes (12) and (12) so that they extend and contract in opposite directions. .

Further, on the lower horizontal level cylinder (10) side, there is provided a pressure sensor (13) which is load auxiliary detection means for detecting a load based on the pressure difference between the bottom side and the rod side.

Reference numeral (14) is an inclination sensor which is an angle detection means for detecting the undulation angle of the boom device (4), and the inclination sensor (14) detects a change in liquid level as a change in capacitance and converts it into an electric signal. It is provided at the base of the boom device (4).

(15) is a length sensor which is a boom length detecting means for detecting the boom length of the boom device (4).
As shown in FIG. 3, 5) is a chain (18) stretched on the intermediate boom (16) via brackets (17) (17) and hung on a sprocket (20) attached to the base boom (19).
The rotation of the sprocket (20) is converted into an electric signal by the variable resistor (21) to detect the boom length.

Since the expansion and contraction of the front boom (22) is synchronized with the expansion and contraction of the intermediate boom (16), it is possible to detect the total length of the boom device (4) by detecting the expansion and contraction of the intermediate boom (16). There is.

As shown in FIG. 5, the relationship between the workbench (6) and the mounting bracket (5) is such that the supporting shaft (23) is erected on the mounting bracket (5) pivotally supported at the tip of the boom device (4). (2
A support bracket (24) extending from the workbench (6) is rotatably provided at 3).

The support bracket (24) is integrally provided with a gear (25), and the gear (25) can be rotated by a motor (26) on the mounting bracket (5).

The platform (27) above the motor (26) is provided with a workbench rotation angle detection sensor (28), and the detection sensor (28) is connected to the gear (2).
It can be detected from the rotation of 5).

(29) is a turning angle detection sensor for detecting the turning angle β of the boom device (4), and the sensor (29) is located at the center of the turning base (2).

(30) (30) are outriggers that support the vehicle body (1). Reference numeral (31) is a cover for protecting the variable resistor (21). Next, the control device which is the regulation means will be explained with reference to FIG. 6. (32) is a calculation processing portion which is a calculation means for guiding the workbench load (the load generated by putting a load on the work size). The processing unit (32) receives the boom length R from the length sensor (15), the boom device hoisting angle θ from the tilt sensor (14), and the load F1 from the load cell (8) of the hoisting cylinder (7). , Load F2 from the pressure sensor (13) on the lower horizontal level cylinder (10) side, and platform rotation angle detection sensor (28)
The large work load W3 is calculated by the following equation from the turning angle α from

F1 ・ R4 ＋ F2 ・ R5 ＝ W1 ・ R1cosθ ＋ W2 （R2cosα ＋ Rcosθ） ＋ W3 ・ (R3cosα ＋ Rcosθ) R4 and R5 are the distance from the center of undulation of the boom device (4) to each cylinder (7) (10), and can be obtained from the undulation angle θ. .

W1 is the weight of the boom device (4), W2 is the weight of the workbench (6), and the weight is constant.

R1 is the distance to the center of gravity of the boom device (4) and the boom length R
Can be obtained from

R2 is the distance from the line X orthogonal to the boom device (4) to the center of gravity of the workbench (6) as shown in FIG.

R3 is the distance from the line X to the position to load the workbench (6).

(33) is a limit value output unit which is a limit value output means for extracting a limit value from the boom length and limit value table (34), and the output unit (33) is the work guided by the processing unit (32). Platform load
W3, undulation angle θ and turning angle β by turning angle detection sensor (29)
The limit value R0 of the boom length is extracted at and.

The limit table (34) is for workbench load 0Kg, 100Kg, 150K
g, 200Kg and 0 to 75 degrees for every 1 degree of undulation and 0 to 360 degrees for every 10 degrees of turning angle are mutually combined, and the limit value of the boom length corresponding to each is set. .

Incidentally, the turning angle β is also taken into consideration in order to correspond to the safety range in the lateral direction of the vehicle which is narrower than the longitudinal direction of the vehicle as shown in FIG.

(35) is a discrimination regulation unit which is discrimination regulation means, and compares and discriminates the extracted limit value R0 and the boom length R by the length sensor (15), and the boom length R exceeds the limit value R0. In this case, the work on the dangerous side of the boom device (4), that is, the work of lying down the boom device (4) and the turning work to the extension side are stopped. The operation of the present invention having the above-mentioned construction will be described below. First, after stopping at a work place, the outriggers (30) are grounded to stabilize the vehicle body (1).

Next, the boom device (4) is hoisted by the hoisting cylinder (7), and also expanded and contracted and swung to move the workbench (6) to the work position.

At this time, the workbench (6) is always held horizontally by the workbench automatic balancing device (9).

By the way, when moving the workbench (6), the load F1 from the load cell (8), the load F2 from the pressure sensor (13),
From the platform rotation angle detection sensor (28), the rotation angle α, from the length sensor (15) to the boom length R, from the tilt sensor (14) to the undulation angle θ, and from the boom device rotation angle detection sensor (29). The boom length limit value R0 is extracted through the arithmetic processing unit (32) and the limit value output unit (33) based on the detected angle value of the turning angle β, and the boom length R at that time and the discrimination regulation unit (35). It is designed to be compared and judged at. At this time, as shown in FIG. 7, when the boom device (4) is laid down and exceeds the safe range (within the solid line), the boom length R becomes larger than the limit value R0, and therefore the discrimination device (35) determines the boom device. The dangerous operation (4), that is, the fall and extension is restricted.

If the workbench load W3 increases, the safe range is shown in FIG.
It becomes narrow like the chain double-dashed line, and the limit value of the boom length that meets it is set.

Further, as shown in FIG. 8, the boom device (4) is swung to the side,
If the safe range (within the solid line) is exceeded, then the boom length R
Is larger than the limit value R0, the discrimination restricting portion (35) restricts the operation of the boom device (4) on the dangerous side, that is, the operation in the arrow direction.

In the embodiment, the limit value of the boom length is extracted from a large number of detection values. However, if the limit value table is set to the boom length with respect to the angular undulation angle, the detection value is only the undulation angle and the boom length. It is possible to regulate the working range.

(G) Effects of the Invention As described above, according to the present invention, the boom length limit value is extracted from the limit value table storing the boom length limit value for each hoisting angle and compared with the boom length at that time. Therefore, when the boom length exceeds the limit value, the work on the dangerous side of the boom device is restricted.Therefore, as in the conventional case, the undulating angle with remarkable fluctuation is involved in any of the compared values. It is possible to increase the accuracy of the discrimination as compared with the case where the operation is restricted, and it is possible to perform highly accurate work range regulation.

[Brief description of drawings]

1 is an overall view, FIG. 2 is an enlarged view of main parts, FIG. 3 is an enlarged view of a length sensor, FIG. 4 is a top view of a workbench, and FIG. 5 is an enlarged view of a connecting portion of the workbench. FIG. 6 is a control system diagram, and FIGS. 7 and 8 are schematic diagrams of the safety range. (4) is a boom device, (6) is a workbench, (14) is a tilt sensor, (15) is a length sensor, (32) is an arithmetic processing unit, and (3)
4) is the limit value table, (33) is the limit value output section, (35)
Is the discrimination control department.

Claims (1)

[Claims] Claims: 1. A boom apparatus is provided on a vehicle body, a work platform is provided at a tip of the boom system, and in an aerial work vehicle in which the boom system can be raised, retracted, and swiveled, each load acting on the work platform is provided. A limit value table storing the limit value of the boom length corresponding to each hoisting angle of the boom device, the load acting on the work table detected by the moment from the hoisting center of the boom device, and the angle detection means Limit value output means for extracting the limit value of the boom length from the limit value table by the undulation angle, and the limit value extracted from the limit value output means and the boom device detected by the boom length detection means. A work range control device for an aerial work vehicle comprising: a comparison control means for comparing the boom length with the boom length to limit the work on the dangerous side of the boom device when the boom length exceeds a limit value.