JPH02178198A - Method and apparatus for controlling hydraulic jacks on a plurality of stands - Google Patents

Abstract

PURPOSE:To lift and lower safely a weight without preventing the weight from large inclination on the way of lifting and lowering the weight by providing a controller for commanding the stepwise positioning of the weight lifted and lowered by H per time T and checking the inclination of the weight to controllably correct the inclination after lifting and lowering the weight in the first half of the time T. CONSTITUTION:A controller 5A checks the inclination of a weight on the basis of an inclination value from an inclinometer 3 in time t2. Unless the inclination is found, a positional command H for the next step is given after the passage of time t2 to control stepwise the position of the weight until the inclination is caused. Next, when the inclination is caused, lifting and lowering are interrupted by a controller 5 to correct controllably the inclination. This inclination correction is controlled by obtaining the deviation values of other hydraulic jacks 1 relative to that of a reference jack in the controller 5A and controlling respectively the positions of the other hydraulic jacks 1 on the basis of said deviation value. When the reference jack reaches a final desired value and the weight is placed in the horizontal position without any inclination, the lifting of the weight is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control method and a control device for a plurality of hydraulic jacks for raising and lowering heavy objects.

[Prior art and problems to be solved by the present invention] For example, when transporting a large caisson weighing 5,000 tons, as shown in FIG. After arranging the hydraulic jacks 1 of the stand and raising the caisson C by these hydraulic jacks 1, the support stand S is removed, and then the caisson C is lowered.

When ascending and descending in this way, to ensure work safety,
It is necessary to synchronize and drive multiple hydraulic jacks 1 without tilting a heavy object, and conventionally, each hydraulic jack 1 is equipped with a potentiometer to detect the extension/retraction position, and the extension/retraction position is controlled by feedback while each The hydraulic jack 1 is gradually raised and lowered so that its extension and contraction positions are equal.

However, such a position control method has the problem that detection errors and the like are added and accumulated, causing the heavy object to tilt.

This invention was made to solve these problems, and its purpose is to provide a control method and a control device for multiple hydraulic jacks that can raise or lower heavy objects in a horizontal state without tilting them. It is about providing.

[Means to solve the problem]

In the method for controlling a plurality of hydraulic jacks according to the present invention, when a heavy object C is raised or lowered by a plurality of hydraulic jacks 1, as shown in FIGS.
Give a step-like position command that increases or decreases by ΔH every time, detects the expansion/contraction position of each hydraulic jack and performs feedback control, and during the first ΔL of ΔT (=ΔL, -tΔL2), Extend or retract each hydraulic jack L, and during the remaining step L2, check the inclination of the heavy object C. If there is no inclination, perform the next step of raising or lowering, and if there is an incline, , inclination correction control is performed.

The control device for a plurality of hydraulic jacks according to the present invention is a device for raising and lowering a heavy load C using a plurality of hydraulic jacks 1, and as shown in FIG. It consists of a detector 2, a tilt detector 3 that detects the tilt of the heavy object C, a control valve 4 that controls each hydraulic jack 1, and a controller 5.

The controller 5 gives step-like position commands to each hydraulic jack 1 to raise or lower by ΔH every 61 hours, performs feedback control based on the detected value of the displacement detector 2, and performs feedback control based on the detected value of the tilt detector 3. to control the slope correction, and Δ
It is configured such that T and ΔH can be set arbitrarily.

As shown in FIG. 5, the tilt detector 3 has two orthogonal X-axes,
In order to detect the tilt in the Y-axis direction, a pair of inclinometers installed on the top surface of the heavy object C or a pair of non-melting type sensors such as optical sensors installed on the sides of the heavy object C are used.

As the displacement detector 2, a potentiometer, a magnescale, or other device capable of detecting linear displacement is used. The control valve 4 includes a servo valve and a proportional control valve.

Use a solenoid control valve, etc.

[For production]

The case of raising the temperature will be explained.

(i) One of each hydraulic jack is a reference jack.

(ii) The controller 4 outputs an increase amount ΔH (a sufficiently small value) to each hydraulic jack 1 every ΔH.

(iii) Each hydraulic jack 1 is subjected to position feedback control so as to be at the command position given by the displacement detector 2. Since the actual lifting of the hydraulic jack 1 is performed as shown by the solid line in FIG. 2, ΔL is set to a length of time sufficient to reach the commanded position. Each hydraulic jack 1 is △t
The commanded position is reached after 1.

(iv) Check in the controller 5A based on the detected inclination value from the inclination detector 3 within the time period ΔL2.

(v) (If it is not tilted, the position command ΔH for the next step is given after Δt2, and (iii) ~ (V)
This is repeated, and step-like position control is performed until an inclination is achieved.

(vi) When a tilt occurs, the lifting and lowering is interrupted and the controller 5 performs tilt correction control. This inclination correction control is performed by determining the deviation amounts of the other hydraulic jacks from the reference jack in the controller 5A, and controlling the positions of the other hydraulic jacks based on the deviation amounts.

(vi) Compare the extended position of the reference jack with the final target position.

(Report) If the final target position has not been reached, (ii) ~ (
Repeat vi).

(ix) When the reference jack reaches the final target value and the heavy object is in a horizontal state with no inclination, a lifting completion signal is output.

When lowering it, it is carried out in the same way, only the direction is different.

[Embodiment] As shown in FIG. 4, a large number of hydraulic jacks 1 are divided into groups A, B, . . . , and each group is equipped with a potentiometer 2. A pair of inclinometers 3 are provided on the control valve 42 and the heavy object C,
This is an example of controlling the elevation for each group.

The hydraulic jack 1 has a double-acting cedar hydraulic cylinder structure, and the control valve 4 is a closed center 3-position switching valve type servo valve.
Each jack 1 in the group is raised and lowered in synchrony by one control valve 4.

That is, by merging the head side and rond side piping 6.7 of each jack 1 in the group on the outlet side of the control valve 4,
The hydraulic pressure of each hydraulic jack 1 is made to be the same under load (principle of water pillow). As a result, each hydraulic jack 1 receives an equal load.

As shown in FIGS. 3 and 4, the controller 5 compares the step-like position command that increases or decreases by ΔH every T time with the detected value from the potentiometer 2, and determines the position based on the deviation. The control valve 4 is controlled to control the position of the hydraulic jack 1, and the tilt amount signal from the program stored controller 5A is compared with the position command, and the tilt correction control of the hydraulic jack 1 is performed based on the deviation. It is configured.

A detection signal from the inclinometer 3 is input to the controller 5A, and it is possible to arbitrarily set t and t. The controller 5A also stores a program for lifting and lowering a heavy object during Δm, checking the inclination of the heavy object during Δtz, and performing inclination correction control as described later.

The tilt correction control calculates the amount of deviation between the standard jack group and other hydraulic jack groups based on the tilt direction and amount from the inclinometer 3. This is done by sending it to the deviation device of the Jatsuki group.

It is also programmed to compare and process the extended position of the reference jack group and the final target position.

ΔT and ΔH are input based on the shape and size of the weight.

Although the above example shows a case where there are a large number of hydraulic jacks 1 and they cannot be controlled individually and are divided into groups, the present invention is not limited to this, and can also be applied to cases where a plurality of hydraulic jacks 1 are individually controlled. Needless to say, it is applicable.

〔Effect of the invention〕

As mentioned above, in this invention, a step-like position command is given to raise and lower by ΔH every ΔT time, and after the lift is performed in the first half of ΔT, the tilt of the heavy object is checked and the tilt is corrected. By performing a horizontal check every sufficiently small lifting amount ΔH, heavy objects can be lifted and lowered safely without causing a large inclination during lifting.

Further, since the parameters for ΔH9ΔT can be set arbitrarily depending on the shape and size of the heavy object, safety and operability are excellent.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the control method according to the present invention, and FIG.
The figure is a partially enlarged view of FIG. 1, FIG. 3 is a schematic diagram showing the control device, FIG. 4 is a circuit diagram showing an embodiment of the present invention, and FIG.
The figure is a perspective view showing an example of a tilt detector, and FIG. 6 is a schematic diagram showing the lifting and lowering of a heavy object. ■...Hydraulic jack, 2...Displacement detector, 3...
Inclination detector, 4... Control valve, 5... Controller, 6.7
···Piping.

Claims (2)

[Claims] (1) When lifting or lowering a heavy object using multiple hydraulic jacks, a step-like position command is given to each hydraulic jack to raise or lower by ΔH every ΔT time, and the extension/contraction position of each hydraulic jack is detected and fed back. control, Δ
During T, after extending or retracting each hydraulic jack, check the slope of the heavy object. If there is no slope, perform the next step of raising or lowering, and if there is a slope, correct the slope. A method for controlling multiple hydraulic jacks, characterized by performing control. (2) A device that lifts and lowers heavy objects using multiple hydraulic jacks, which includes a displacement detector that detects the amount of expansion and contraction of each hydraulic jack, a tilt detector that detects the inclination of the heavy object, and controls each hydraulic jack. A control valve that provides a step-like position command to raise or lower by ΔH every ΔT time to each hydraulic jack, performs feedback control based on the detected value of the displacement detector, and performs feedback control based on the detected value of the tilt detector. A control device for a plurality of hydraulic jacks, comprising a controller that performs tilt correction control and can arbitrarily recognize ΔT and ΔH.