JPH06345392A - Hydraulic jack control system - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a hydraulic jack control system capable of performing an accurate load control test even with a commercially available hydraulic jack. [Structure] Pressure sensors 11 and 12 for detecting the pressures in both hydraulic chambers of the hydraulic jack 1, input means 13A for inputting a physical quantity relating to a pressure receiving area of a piston of the hydraulic jack 1 according to an external operation, and the pressure and the physical quantity The calculation means 14-16 for calculating the thrust of the hydraulic jack based on the above, and the hydraulic control means 30 for controlling the pressure oil guided to the hydraulic jack 1 according to the deviation between the thrust and the target load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for driving and controlling a commercially available double-acting hydraulic jack used in, for example, material testing or static load testing of civil engineering and building structures.

[0002]

2. Description of the Related Art A commercially available hydraulic jack may be used to perform the above-mentioned test while changing the load along a predetermined target pattern. When carrying out this type of load control test, use a system that provides a load detector (for example, a load cell) that detects the load applied to the sample and automatically controls the hydraulic pressure guided to the hydraulic jack based on the output value. Can be considered. If a load detector cannot be prepared depending on the test location, calculate the thrust of the hydraulic jack from the pressure of the bottom chamber and rod chamber of the hydraulic jack, and the bottom side pressure receiving area of the piston and the rod chamber side pressure receiving area. The above hydraulic control valve may be controlled so as to follow the target pattern.

[0003]

However, since the commercially available jacks have different bottom side pressure receiving areas and rod chamber side pressure receiving areas depending on the type, an ordinary hydraulic jack control system (system adapted only to a specific hydraulic jack). Even if is used, the thrust of the jack cannot be obtained and the load control test cannot be performed. For this reason, conventionally, while the operator monitors the output of the oil pressure gauge, the operator manually switches the hydraulic control valve to perform a load control test using a commercially available hydraulic jack. The load cannot be set.

An object of the present invention is to provide a hydraulic jack control system capable of performing an accurate load control test even on a commercially available hydraulic jack.

[0005]

A hydraulic jack control system according to the present invention is a control system for driving and controlling a double-acting hydraulic jack to load a sample with a predetermined target load. A pressure sensor that detects the pressure in the chamber, an input means that inputs a physical quantity related to the pressure receiving area of the piston of the hydraulic jack according to an external operation, and the thrust of the hydraulic jack is calculated based on the detected pressure and the input physical quantity. The calculation means and the hydraulic control means for controlling the pressure oil guided to the hydraulic jack according to the deviation between the calculated thrust of the hydraulic jack and the target load are provided to solve the above problems.

[0006]

The physical quantity relating to the pressure receiving area of the piston of the hydraulic jack is input from the input means according to the external operation. The calculating means calculates the thrust of the hydraulic jack based on the detected pressure of each hydraulic chamber and the input physical quantity relating to the pressure receiving area. As described above, in the present invention, since the physical quantity related to the pressure receiving area of the piston can be input, the thrust can be obtained for any commercially available hydraulic jack. Then, the pressure oil guided to the hydraulic jack is controlled according to the deviation between the calculated thrust of the hydraulic jack and the target load, whereby the sample is loaded with a predetermined target load.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 1 indicates, for example, a material test or civil engineering,
A commercially available double-acting hydraulic jack used for a static load test of a building structure, 2 is a load cell that detects the load applied to the sample TP, and 3 is a displacement sensor that detects the amount of displacement of the sample TP. Reference numeral 100 denotes a high-pressure jack control system connected to the hydraulic jack 1 via a high-pressure rubber hose HS,
The jack control system 100 includes a first calculator 10 that calculates a deviation between a target load to be applied to the sample TP and a thrust of the jack 1, a deviation between the target load and a load detected by the load cell 2, or a displacement sensor 3. 2 and a target control displacement, a second calculation unit 20 for calculating a deviation between the output and the target control displacement, and a servo control unit 30 for driving and controlling the hydraulic jack 1 based on the output of any of the calculation units 10 and 20. .

The first arithmetic unit 10 is configured so that the pressure of the pipeline connected to the bottom chamber 1a and the rod chamber 1b of the jack 1 via the rubber hose HS, that is, the pressure P of each chamber 1a, 1b.
Pressure sensors 11 and 12 for detecting ₁ and P ₂ , respectively, a bottom chamber side pressure receiving area A _{1 of} the piston 1c, and a ratio Kat (= A ₂ / A ₁ ) of this A ₁ to the rod chamber side pressure receiving area A _2. And a first input unit 13A for inputting. These values A ₁ and Kat are input by the operator's external operation. The output P ₂ of the bottom chamber side pressure sensor 11 is
It is amplified by the amplifier AMP1 and input to the subtractor 14, while
The output of the rod chamber side pressure sensor 12 is amplified by the amplifier AMP2 and input to the multiplier 15. The multiplier 15 multiplies the amplified pressure signal P ₂ by the input area ratio Kat and inputs the product to the subtractor 14. The subtractor 14 receives the input P ₁
And Kat · P ₂ are obtained by P ₁ −Kat · P ₂ , and this value is input to the multiplier 16. That is, the pressure P ₂ is converted into the pressure in the bottom chamber 1a, and the pressure difference with the bottom chamber 1a as a reference is obtained. The multiplier 16 multiplies the input value by the input pressure area A ₁ on the bottom chamber side to obtain A ₁ (P ₁ −Kat · P ₂ ).

[0009] Here, the thrust F ₀₁ of the hydraulic jack 1 is generally used and the pressure P _1, P ₂ and receiving area _{A 1, A 2, F 01} = P 1 · A 1 -P 2 · A 2 It is represented by. When this equation is modified, F ₀₁ = A ₁ (P ₁ − (A ₂ / A ₁ ) · P ₂ ) = A ₁ (P ₁ −Kat · P ₂ ), and therefore the output of the multiplier 16 is jack 1
Of thrust F ₀₁ . The thrust F ₀₁ is externally displayed on the display 17 and also input to the subtractor 18.

The subtractor 18 also has a second input section 13B.
From the above, the change pattern Fpt of the target load with respect to time is input, and the average load value Fmean in the case of repeating the increase and decrease of the load as in the fatigue test is input from the third input unit 13C. A value obtained by adding Fpt to this Fmean corresponds to the target load signal F ₁ . The subtractor 18 obtains the deviation ΔF ₁ between the target load signal F ₁ and the thrust F _{01 of the} jack 1 by ΔF ₁ = F ₁ −F ₀₁ , and inputs it to the multiplier 19. The multiplier 19 outputs a value (K ₁ · ΔF ₁ ) obtained by multiplying ΔF ₁ by a predetermined gain K ₁ as a control signal.

On the other hand, the second calculation unit 20 detects the detection output F _{02 of the} load cell 2 or the detection output X of the displacement sensor 3.
The fourth input unit 21A for inputting ₀ , the fifth input unit 21B for inputting the change pattern Fpt of the target load or the change pattern Fpt of the target control displacement described above, and the load average value F
mean or a sixth input portion 21C for inputting the mean value Xmean of the control displacements, and the signal from each input portion is the subtractor 2
Entered in 2. Here, plus Fpt to the Fmean corresponds to target load signal F _2, plus Xpt to Xmean corresponds to target controlled displacement signal X _1. Subtractor 22
Outputs the deviation between the target signal and the detected output by ΔF ₂ = F ₂ −F ₀₂ or ΔX = X ₁ −X _0, and outputs it to the multiplier 23. The multiplier 23 multiplies ΔF ₂ or ΔX by a predetermined gain K ₂ (K
₂ · ΔF ₂ ) or (K ₂ · ΔX) is output as a control signal. Reference numeral 40 denotes a control changeover switch, which inputs either the control signal from the first calculation unit 10 or the control signal from the second calculation unit 20 to the servo control unit 30 according to the change position.

The servo control unit 30 includes the hydraulic jack 1 described above.
High-pressure hydraulic pump 31 for sending pressure oil to the oil, a high-pressure servo valve 32 for controlling the direction and flow rate of oil discharged from the hydraulic pump 31, and a controller for switching control of the servo valve 32 based on the input control signal. And 33.

Next, a description will be given of the operation when the pressure test of the sample TP such as concrete is conducted using the above-mentioned commercially available hydraulic jack 1. First, the pipe lines connected to the high-pressure servo valve 32 are connected to the bottom chamber 1a and the rod chamber 1b of the hydraulic jack 1 via the high-pressure rubber hose HS. If the load cell 2 is not present, the control changeover switch 40 is switched to the position shown in order to use the calculation result of the first calculation unit 10. In this state, when the pressure receiving area A ₁ , the area ratio Kat and the target load F ₁ are input from the input sections 13A, 13B (13C), the thrust F ₀₁ of the hydraulic jack 1 is calculated in the first calculating section 10 as described above. At the same time, the deviation ΔF ₁ between the target load F ₁ and the thrust F ₀₁ is calculated, and then the control signal (K ₁ · ΔF ₁ ) is obtained.

The control signal (K ₁ · ΔF ₁ ) is input to the controller 33 of the servo control unit 30 via the control changeover switch 40. The controller 33 controls the control signal (K
_The high pressure servo valve 32 is switched and controlled based on ₁ · ΔF ₁ ),
The direction and flow rate of the oil discharged from the hydraulic pump 31 are controlled.
By repeating this operation, the load applied to the sample TP changes along a predetermined target load pattern, and the load control test is performed.

On the other hand, when the load cell 2 is present, the control changeover switch 40 may be switched to use the output of the second arithmetic unit 20. In this case, load cell 2
The load detection output F ₀₂ is input from the fourth input unit 21A, the deviation ΔF ₂ between the target load F ₂ and the load detection output F ₀₂ is calculated, and then the control signal (K ₂ · ΔF ₂ ) is obtained.
This control signal (K ₂ · ΔF ₂ ) is input to the controller 33 of the servo control unit 30 via the control changeover switch 40, and the load control test is performed by the same control as described above.

In the case of displacement control, instead of the detection output of the load cell 2, the displacement detection output X ₀ of the displacement sensor 3 is input from the fourth input section 21A. In this case, the deviation ΔX between the target control displacement X ₁ and the displacement detection output X ₀ is calculated,
Then the control signal (K ₂ · ΔX) is determined. This control signal (K ₂ · ΔX) is input to the controller 33, and a displacement control test is performed in which the displacement amount of the sample TP changes along a predetermined target displacement pattern by the same control as described above.

As described above, in this embodiment, since the physical quantity relating to the pressure receiving area A ₁ of the piston 1c of the hydraulic jack ₁ and the area ratio A ₂ / A ₁ can be inputted, the pressure receiving area depends on the type. The thrust force can be obtained for various hydraulic jacks on the market. Therefore, even if the load cell 2 is not provided, a desired load control test can be accurately performed using these commercially available hydraulic jacks. When the load cell 2 is present, the load control test based on the output of the load cell 2 and the displacement control test based on the output of the displacement sensor 3 can be performed simply by switching the control changeover switch 40.

In the configuration of the above embodiment, the first input section 13A serves as the input means, the subtractor 14 and the multiplier 15,
Reference numeral 16 constitutes an arithmetic means, and servo control section 30 constitutes a hydraulic control means.

In the above description, A ₁ and A ₂ / A ₁ are input, but A ₁ and A ₂ may be input, for example. In this case, a multiplier is provided between the amplifier AMP1 and the subtractor 14 in place of the multiplier 16, P ₁ · A ₁ is obtained by this multiplier, and P ₂ · A ₂ is obtained by the multiplier 15. It suffices that the subtractor 14 obtain P ₁ · A ₁ −P ₂ · A ₂ (= F ₀₁ ). Moreover, although the example in which the arithmetic means is configured by hardware is shown, it can be realized by software.

[0020]

According to the present invention, since the physical quantity relating to the pressure receiving area of the piston of the hydraulic jack can be inputted, the thrust can be obtained for various commercially available hydraulic jacks having different pressure receiving areas. it can. Therefore, even when a load detector cannot be prepared, a desired load control test can be accurately performed using a commercially available hydraulic jack.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a hydraulic jack control system according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic jack 1a Bottom chamber 1b Rod chamber 1c Piston 2 Load cell 3 Displacement sensor 10 1st calculating part 11,12 Pressure sensor 13A-13C, 21A-21C input part 14,18,22 Subtractor 15,16,19,23. Multiplier 20 Second arithmetic unit 30 Servo control unit 31 Hydraulic pump 32 High pressure servo valve 33 Controller TP Sample

Claims (1)

[Claims] 1. A control system for driving and controlling a double-acting hydraulic jack to load a sample with a predetermined target load, comprising a pressure sensor for detecting the pressure in both hydraulic chambers of the hydraulic jack, and an external operation. According to the input means for inputting a physical quantity related to the pressure receiving area of the piston of the hydraulic jack; a calculating means for calculating the thrust of the hydraulic jack based on the detected pressure and the input physical quantity; A hydraulic jack control system, comprising: hydraulic control means for controlling pressure oil guided to the hydraulic jack according to a deviation between a thrust of the hydraulic jack and the target load.