Anti-unbalance loading sliding block active deviation rectifying method for hydraulic machine sliding block

Abstract

The invention discloses an anti-unbalance-loading sliding block active deviation correction method for a hydraulic machine sliding block, and the method specifically comprises the following steps: 1, unbalance loading detection: collecting displacement deviations [delta] x and [delta] y of the sliding block in X / Y directions in real time, installing a pressure sensor in a hydraulic cylinder oil path, detecting to obtain pressure data N, obtaining the pressure value of each supporting point, and calculating the deviation of the sliding block in the X / Y direction; calculating an offset center distance e and an offset load moment M according to the pressure data; the displacement deviation delta x and the displacement deviation delta y are compared with a preset threshold value, whether deviation rectification is triggered or not is judged, and if the deviation rectification is triggered, the mapping relation between the sliding block inclination angle theta and the hydraulic cylinder pressure compensation amount delta P is established through a mechanical model. According to the anti-unbalance-load active deviation correction method for the hydraulic press sliding block, displacement, pressure and dip angle data are combined, the unbalance-load recognition precision is improved, response is fast, PID parameters are adjusted in real time according to load changes, the accuracy of the position of the sliding block under different working conditions is adapted, and high-precision deviation correction is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic press slider deviation correction, and specifically to an active deviation correction method for a hydraulic press slider against eccentric load. Background Technique

[0002] A hydraulic press is a machine that uses liquid as the working medium and is made according to Pascal's principle to transfer energy to achieve various processes. A hydraulic press generally consists of three parts: the machine itself (mainframe), the power system, and the hydraulic control system. Hydraulic presses are classified into valve hydraulic presses, liquid hydraulic presses, and engineering hydraulic presses.

[0003] Referring to the patent publication number "CN102336030A", a slider deviation correction mechanism for a hydraulic press is disclosed. The center of the slider of this hydraulic press is connected to a main oil cylinder controlled by a main hydraulic system. The deviation correction mechanism includes at least one group of deviation correction cylinders. Each group of deviation correction cylinders consists of a first deviation correction cylinder and a second deviation correction cylinder. The first deviation correction cylinder and the second deviation correction cylinder are connected to the slider in a symmetrical structure with the main oil cylinder as the center; the lower chamber of the first deviation correction cylinder is connected to the upper chamber of the second deviation correction cylinder, and the upper chamber of the first deviation correction cylinder is connected to the lower chamber of the second deviation correction cylinder through pipelines respectively.

[0004] As shown in the above technology, the slider of a hydraulic press is prone to tilt due to eccentric load during stamping, forging, etc., resulting in mold wear, workpiece precision decline, and even equipment damage. In the prior art, the deviation correction methods are mostly passive adjustment or closed-loop control based on position feedback, which have problems such as response lag and insufficient precision. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the present invention provides an active deviation correction method for a hydraulic press slider against eccentric load, which solves the problems of response lag and insufficient precision in the existing active deviation correction of a hydraulic press slider against eccentric load.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: An active deviation correction method for a hydraulic press slider against eccentric load specifically includes the following steps:

[0007] Step 1:

[0008] Eccentric load detection: Arrange two misaligned displacement sensors on the front and back of the slider to collect the displacement deviations Δx and Δy of the slider in the X / Y directions in real time. Install a pressure sensor in the oil circuit of the hydraulic cylinder, and the detected pressure data is N. Obtain the pressure values of each support point, and the pressure value is P 1 -P 2 ;

[0009] Calculate the eccentricity e and the eccentric load moment M according to the pressure data;

[0010] Step 2:

[0011] Deviation correction decision: Compare the displacement deviations Δx and Δy with the preset threshold values to determine whether to trigger deviation correction. If triggered, establish the mapping relationship between the tilt angle θ of the slider and the hydraulic cylinder pressure compensation ΔP through a mechanical model:

[0012]

[0013] where K p 、K i and K d are PID control parameters;

[0014] Step three:

[0015] Dynamic compensation: Control the servo valve opening of the two side hydraulic cylinders, dynamically adjust the pressure output to make the slider return to horizontal, and adopt feedforward-feedback composite control: The feedforward module predicts the compensation amount based on the eccentric load force, and the feedback module corrects it through the displacement deviation closed loop.

[0016] Preferably, the preset threshold value in step one is 0.05 mm, and the deviation correction program is started when Δx ≥ 0.05 mm.

[0017] Preferably, the calculation formula for the eccentric load moment in step one is:

[0018] M = ∑(P i ·L i )

[0019] where L i is the fulcrum distance, that is, the distance between the four corner support points of the slider and the resultant force action point of the hydraulic cylinders.

[0020] Preferably, the calculation formula for the eccentricity in step one is:

[0021]

[0022] where N is the pressure value in the hydraulic cylinder oil circuit, which is the same as the pressure value of each support point.

[0023] The present invention also discloses a hydraulic press slider anti-eccentric load slider active deviation correction system, including a sensor module, a PLC controller and an execution module. The displacement sensor, pressure sensor and inclination sensor all belong to the sensor module. The sensor module is connected to the PLC controller. The hydraulic execution mechanism is controlled by the PLC controller. The PLC controller is the PLC controller and has a built-in fuzzy PID algorithm. The execution module includes a hydraulic press main body and a hydraulic execution mechanism. The PLC controller is fixedly installed on the right side of the hydraulic press.

[0024] Preferably, the hydraulic press includes a base and a top block. Four columns are installed between the base and the top block. A slider is slidably connected to the surface of the columns between the base and the top block. A main hydraulic cylinder is fixedly installed on the top of the top block. The telescopic end of the main hydraulic cylinder is fixedly connected to the top of the slider. Two auxiliary hydraulic cylinders are fixedly connected to the top of the top block on the left and right. The telescopic ends of the two auxiliary hydraulic cylinders are both fixedly connected to the top of the slider. The main hydraulic cylinder and the auxiliary hydraulic cylinders are both connected to the hydraulic actuator through an oil circuit.

[0025] Preferably, the displacement sensor is installed on the slider through an installation component. The installation component includes a bottom plate and a rubber pad. The rubber pad is placed behind the bottom plate, and the bottom plate is fixed to the slider by four bolts. A first chute is opened on the front of the bottom plate. A lead screw is rotatably connected to the right side of the first chute. A slider is threadedly connected to the surface of the lead screw in the first chute. A moving block is fixedly connected to the front of the slider.

[0026] Preferably, two second chutes are opened on the front of the moving block. A bidirectional threaded rod is rotatably connected to the left side of the inner wall of the left second chute. The bidirectional threaded rod passes through the right second chute. The inner surfaces of the two second chutes are both slidably connected with clamping plates. The two clamping plates are respectively threadedly connected to both sides of the surface of the bidirectional threaded rod.

[0027] Advantageous Effects

[0028] The present invention provides a method for actively correcting the offset of a slider of a hydraulic press against eccentric loading. Compared with the prior art, the following advantageous effects are achieved:

[0029] 1. This method for actively correcting the offset of a slider of a hydraulic press against eccentric loading improves the accuracy of eccentric load identification by combining displacement, pressure, and inclination data, has a fast response, and adjusts the PID parameters in real time according to the load change to adapt to the accuracy of the slider position under different working conditions, realizing high-precision correction.

[0030] 2. This method for actively correcting the offset of a slider of a hydraulic press against eccentric loading realizes active correction through the independent control of multiple hydraulic cylinders, and accurately controls the pressure exerted by the multiple hydraulic cylinders through corresponding algorithms, ensuring the balanced movement of the slider.

[0031] 3. This method for actively correcting the offset of a slider of a hydraulic press against eccentric loading installs the displacement sensor through an installation component. During installation, only the bidirectional threaded rod needs to be rotated, which is convenient and fast. Moreover, the left and right positions of the displacement sensor can be adjusted after installation, ensuring the accuracy of the detection data and further ensuring the correction accuracy. Description of the Drawings

[0032] Figure 1 It is a schematic external view of the main body of the hydraulic press of the present invention;

[0033] Figure 2 It is a partial schematic view of the main body of the hydraulic press of the present invention;

[0034] Figure 3 It is a schematic view of the installation component of the present invention.

[0035] In the figure: 1. Base; 2. Column; 3. Top block; 4. Main hydraulic cylinder; 5. Slide block; 6. Installation component; 61. Bottom plate; 62. Rubber pad; 63. First chute; 64. Lead screw; 65. Slide block; 66. Moving block; 67. Second chute; 68. Bidirectional threaded rod; 69. Clamp; 7. Displacement sensor; 8. Tilt sensor; 9. Auxiliary hydraulic cylinder; 10. Hydraulic actuator; 11. Control module. Specific embodiments

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Please refer to Figures 1-3 , for the anti-eccentric load slide block active deviation correction method of the hydraulic press slide block, which specifically includes the following steps:

[0038] Step 1:

[0039] Eccentric load detection: Two misaligned displacement sensors are arranged on the front and back of the slide block to collect the displacement deviations Δx and Δy in the X / Y directions of the slide block in real time. A pressure sensor is installed in the oil circuit of the hydraulic cylinder, and the detected pressure data is N, and the pressure values of each support point are obtained, and the pressure value is P 1 -P 2 ;

[0040] Calculate the eccentricity e and the eccentric load moment M according to the pressure data;

[0041] Step 2:

[0042] Deviation correction decision: Compare the displacement deviations Δx and Δy with a preset threshold to determine whether to trigger deviation correction. If triggered, establish a mapping relationship between the tilt angle θ of the slide block and the hydraulic cylinder pressure compensation amount ΔP through a mechanical model:

[0043]

[0044] Where K p , K i and K d are PID control parameters;

[0045] Step 3:

[0046] Dynamic compensation: Control the servo valve opening degrees of the two side hydraulic cylinders, dynamically adjust the pressure output, and make the slider return to horizontal. A feedforward-feedback composite control is adopted: the feedforward module predicts the compensation amount based on the eccentric load force, and the feedback module corrects it through a displacement deviation closed loop.

[0047] The preset threshold value in Step 1 is 0.05 mm, and the deviation correction program is started when Δx ≥ 0.05 mm.

[0048] The calculation formula for the eccentric load moment in Step 1 is:

[0049] M = ∑(P i ·L i )

[0050] where is the fulcrum distance, that is, the distance between the four corner support points of the slider and the resultant force action point of the hydraulic cylinders.

[0051] The calculation formula for the eccentricity in Step 1 is:

[0052]

[0053] where N is the pressure value in the hydraulic cylinder oil circuit, which is the same as the pressure value of each support point.

[0054] The present invention also discloses an active deviation correction system for a hydraulic press slider against eccentric load, and provides the following two technical solutions:

[0055] The first implementation mode: It includes a sensor module, a PLC controller 11 and an execution module. The displacement sensor 7, the pressure sensor and the inclination sensor 8 all belong to the sensor module. The sensor module is connected to the PLC controller 11. The hydraulic execution mechanism 10 is controlled through the PLC controller 11. The PLC controller 11 is a PLC controller and has a built-in fuzzy PID algorithm. The execution module includes the hydraulic press main body and the hydraulic execution mechanism 10. The PLC controller 11 is fixedly installed on the right side of the hydraulic press.

[0056] The hydraulic press includes a base 1 and a top block 3. Four columns 2 are installed between the base 1 and the top block 3. A slider 5 is slidably connected to the surface between the base 1 and the top block 3. A main hydraulic cylinder 4 is fixedly installed on the top of the top block 3. The telescopic end of the main hydraulic cylinder 4 is fixedly connected to the top of the slider 5. Two auxiliary hydraulic cylinders 9 are fixedly connected to the top of the top block 3. The telescopic ends of the two auxiliary hydraulic cylinders 9 are both fixedly connected to the top of the slider 5. The main hydraulic cylinder 4 and the auxiliary hydraulic cylinders 9 are both connected to the hydraulic execution mechanism 10 through oil circuits.

[0057] By combining displacement, pressure, and inclination data, the off-load recognition accuracy is improved, the response is rapid, and the PID parameters are adjusted in real time according to the load change to adapt to the accuracy of the slider position under different working conditions, achieving high-precision deviation correction. Through the independent control of multiple hydraulic cylinders, active deviation correction is realized, and the pressure exerted by multiple hydraulic cylinders is accurately controlled through corresponding algorithms to ensure the balanced movement of the slider.

[0058] The second implementation mode is mainly different from the first implementation mode in that the displacement sensor 7 is installed on the slider 5 through the installation component 6. The installation component 6 includes a bottom plate 61 and a rubber pad 62. The rubber pad 62 is placed behind the bottom plate 61, and the bottom plate 61 is fixed to the slider 5 by four bolts. A first chute 63 is opened on the front surface of the bottom plate 61. A lead screw 64 is rotatably connected to the right side of the first chute 63. A slider 65 is threadedly connected to the surface of the lead screw 64 located in the first chute 63. A moving block 66 is fixedly connected to the front surface of the slider 65. Two second chutes 67 are opened on the front surface of the moving block 66, one on the left and one on the right. A bidirectional lead screw 68 is rotatably connected to the left side of the inner wall of the left second chute 67, and the bidirectional lead screw 68 passes through the right second chute 67. Two clamping plates 69 are slidably connected to the inner surfaces of the two second chutes 67, and the two clamping plates 69 are respectively threadedly connected to both sides of the surface of the bidirectional lead screw 68.

[0059] The displacement sensor 7 is installed through the installation component. During installation, only the bidirectional lead screw 68 needs to be rotated, which is convenient and fast. Moreover, the left and right positions of the displacement sensor 7 can be adjusted after installation, ensuring the accuracy of the detected data and further ensuring the deviation correction accuracy.

[0060] Install the displacement sensor 7 on the slider 5 through the installation component 6. During installation, place the rubber pad 62 behind the bottom plate 61 and fix it to the front and back of the slider 5 with bolts. Place the displacement sensor 7 between the two clamping plates 69. Rotate the bidirectional lead screw 68 to make the two clamping plates 69 approach each other and clamp the displacement sensor 7, and rotate the slider 65 to make the moving block 66 move left or right, so that the displacement sensor 7 is directly opposite to the column 2.

[0061] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0062] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for actively correcting the deviation of a hydraulic press slider against eccentric load, characterized in that: The specific steps include: Step 1: Offset load detection: Two offset displacement sensors are arranged on the front and back of the slider to collect the displacement deviation Δx and Δy of the slider in the X / Y direction in real time. A pressure sensor is installed in the hydraulic cylinder oil circuit to detect the pressure data and obtain the pressure value of each support point. The pressure value is P1-P2. Calculate the eccentricity e and eccentric load moment M based on the pressure data; Step 2: Correction decision: Compare the displacement deviations Δx and Δy with the preset thresholds to determine whether correction is triggered. If triggered, the mapping relationship between the slider inclination angle θ and the hydraulic cylinder pressure compensation amount ΔP is established through the mechanical model: Where K p , K i With K d is the PID control parameter; Step 3: Dynamic compensation: Control the servo valve opening of the hydraulic cylinders on both sides, dynamically adjust the pressure output, restore the slider to the horizontal state, and adopt feedforward-feedback composite control: the feedforward module predicts the compensation amount based on the eccentric load force, and the feedback module corrects the displacement deviation through a closed loop.

2. The method for actively correcting the slide block of a hydraulic press slide block against eccentric load according to claim 1, characterized in that: The preset threshold in step 1 is 0.05 mm, and the deviation correction procedure is started when Δx≥0.05 mm.

3. The method for actively correcting the deviation of a hydraulic press slider against eccentric load according to claim 1, characterized in that: The calculation formula of the eccentric load moment in step 1 is: M=∑(P i ·L i ) Where L i The fulcrum distance is the distance between the four corner support points of the slider and the point where the resultant force of the hydraulic cylinder acts.

4. The method for actively correcting the slide block of a hydraulic press slide block against eccentric load according to claim 3, characterized in that: The calculation formula of the eccentricity in step 1 is: Where N is the pressure value in the hydraulic cylinder oil circuit, which is the same as the pressure value at each support point.

5. A hydraulic press slider anti-eccentric load slider active deviation correction system, used to implement the hydraulic press slider anti-eccentric load slider active deviation correction method according to any one of claims 1 to 4, characterized in that: The invention comprises a sensor module, a PLC controller (11) and an execution module, wherein the displacement sensor (7), the pressure sensor and the inclination sensor (8) all belong to the sensor module, the sensor module is connected to the PLC controller (11), the hydraulic actuator (10) is controlled by the PLC controller (11), the PLC controller (11) is a PLC controller with a built-in fuzzy PID algorithm, the execution module comprises a hydraulic press body and a hydraulic actuator (10), and the PLC controller (11) is fixedly installed on the right side of the hydraulic press.

6. The hydraulic press slider anti-eccentric load slider active deviation correction system according to claim 5, characterized in that: The hydraulic press body comprises a base (1) and a top block (3), four columns (2) are installed between the base (1) and the top block (3), a sliding block (5) is slidably connected to the surface of the column (2) located between the base (1) and the top block (3), a main hydraulic cylinder (4) is fixedly installed on the top of the top block (3), the telescopic end of the main hydraulic cylinder (4) is fixedly connected to the top of the sliding block (5), two left and right auxiliary hydraulic cylinders (9) are fixedly connected to the top of the top block (3), the telescopic ends of the two auxiliary hydraulic cylinders (9) are fixedly connected to the top of the sliding block (5), and the main hydraulic cylinder (4) and the auxiliary hydraulic cylinder (9) are connected to a hydraulic actuator (10) via an oil circuit.

7. The hydraulic press slider anti-eccentric load slider active deviation correction system according to claim 5, characterized in that: The displacement sensor (7) is installed on the slider (5) through an installation component (6). The installation component (6) includes a base plate (61) and a rubber pad (62). The rubber pad (62) is placed behind the base plate (61), and the base plate (61) is fixed to the slider (5) through four bolts. A first slide groove (63) is provided on the front of the base plate (61). A screw rod (64) is rotatably connected to the right side of the first slide groove (63). A slider (65) is threadedly connected to the surface of the screw rod (64) located in the first slide groove (63). A moving block (66) is fixedly connected to the front of the slider (65).

8. The hydraulic press slider anti-eccentric load slider active deviation correction system according to claim 7, characterized in that: The front face of the moving block (66) is provided with two left and right second sliding grooves (67), the left side of the inner wall of the left second sliding groove (67) is rotatably connected with a bidirectional threaded rod (68), and the bidirectional threaded rod (68) passes through the right second sliding groove (67), the inner surfaces of the two second sliding grooves (67) are slidably connected with clamping plates (69), and the two clamping plates (69) are respectively threadedly connected to the two sides of the surface of the bidirectional threaded rod (68).

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