A press control system

Abstract

The present invention discloses a press control system, including: a controller, an encoder, a parallel cylinder pressure sensor and a first servo valve, wherein the encoder is used to collect the initial position data of the slider; the controller is used to calculate the pressure of the parallel cylinder on both sides of the slider according to the collected initial position data of the slider; the parallel cylinder pressure sensor is used to obtain the actual pressure of the parallel cylinder; the controller is also used to calculate the target opening value of the first servo valve according to the pressure of the parallel cylinder on both sides of the slider and the actual pressure of the parallel cylinder, and then generate an opening adjustment instruction according to the target opening value, and send the opening adjustment instruction to the first servo valve; the first servo valve is used to adjust the degree of valve opening according to the received opening adjustment instruction to control the discharge amount of hydraulic oil so that the slider is leveled. The present invention effectively reduces the failure rate of press operation by leveling the initial position of the slider.

Description

Technical Field

[0001] The invention relates to the field of automatic control, and in particular to a press control system. Background Art

[0002] As a key equipment in the production process of mold materials, the press has high requirements on the control of the internal slider. In the prior art, since the initial position of the slider is not adjusted, the press faces greater risks during operation. Especially when the initial position deviation of the slider is large, the press will forcefully act and generate a series of eccentric loads, which can easily cause damage to the guide rails, columns and the press body, and thus cause a series of failures. Summary of the invention

[0003] In order to overcome the above-mentioned deficiencies of the prior art, the present invention proposes a press control system that can perform leveling at the initial position of the slider, thereby making the control process of the press more stable and effectively reducing the failure rate of the press operation.

[0004] The embodiment of the present invention provides a press control system, including: a controller, an encoder, a parallel cylinder pressure sensor and a first servo valve,

[0005] The encoder is used to collect the initial position data of the slider;

[0006] The controller is used to calculate the pressure of the parallel cylinder on both sides of the slider according to the collected initial position data of the slider;

[0007] The parallel cylinder pressure sensor is used to obtain the actual pressure of the parallel cylinder;

[0008] The controller is further used to calculate the target opening value of the first servo valve according to the pressure of the parallel cylinder on both sides of the slider and the actual pressure of the parallel cylinder, and then generate an opening adjustment instruction according to the target opening value, and send the opening adjustment instruction to the first servo valve;

[0009] The first servo valve is used to adjust the degree of valve opening according to the received opening adjustment instruction to control the discharge amount of hydraulic oil so that the slider is leveled.

[0010] Furthermore, it also includes: a hydraulic pad pressure sensor and a second servo valve,

[0011] The hydraulic pad pressure sensor is used to obtain the actual pressure of the hydraulic pad;

[0012] The controller is further used to calculate the target opening value of the second servo valve according to the actual pressure of the hydraulic pad and the preset pressure, and then generate an opening adjustment instruction according to the target opening value, and send the opening adjustment instruction to the second servo valve;

[0013] The second servo valve is used to adjust the degree of valve opening according to the received opening adjustment instruction to control the discharge amount of hydraulic oil so that the actual pressure of the hydraulic pad is the same as the preset pressure.

[0014] Furthermore, the second servo valve is also used to detect the position of the valve core of the second servo valve, generate a position feedback signal, and transmit the feedback signal to the controller;

[0015] The controller is also used to calculate the offset according to the position feedback signal and the control signal corresponding to the opening adjustment instruction, and automatically compensate and calibrate the actual pressure of the hydraulic pad according to the offset.

[0016] Furthermore, before the controller calculates the target opening value of the first servo valve according to the pressure of the parallel cylinder on both sides of the slider and the actual pressure of the parallel cylinder, it also includes:

[0017] The controller compares the pressure on both sides of the slider with the actual pressure of the parallel cylinder, and calculates the target opening value of the first servo valve when it is determined that the pressure on either side of the slider is different from the actual pressure of the parallel cylinder.

[0018] Furthermore, the controller, before calculating the target opening value of the second servo valve according to the actual pressure of the hydraulic pad and the preset pressure, further comprises:

[0019] The controller compares the actual pressure of the hydraulic pad with the preset pressure, and calculates the target opening value of the second servo valve when it is determined that the actual pressure of the hydraulic pad is different from the preset pressure.

[0020] Furthermore, the controller, before calculating the offset according to the position feedback signal and the control signal corresponding to the opening adjustment instruction, further includes:

[0021] The controller compares the position feedback signal with the control signal corresponding to the opening adjustment instruction, and calculates the offset when it is determined that the position feedback signal is different from the control signal corresponding to the opening adjustment instruction.

[0022] Furthermore, the press control system also includes a high-frequency signal converter for converting the digital control signal corresponding to the opening adjustment instruction into an analog control signal.

[0023] Furthermore, the press control system also includes a top-level display for displaying control reference data at each moment, wherein the control reference data includes any one of the following items or a combination thereof: slider position data, pressure value of the slider on both sides of the parallel cylinder, actual pressure of the parallel cylinder, target opening value of the first servo valve, target opening value of the second servo valve, preset hydraulic pad pressure, and actual pressure of the hydraulic pad.

[0024] The following beneficial effects are achieved by implementing the embodiments of the present invention:

[0025] The present invention collects the initial position data of the slider through an encoder, and uses a controller to calculate the initial position data of the slider and the actual pressure of the parallel cylinder to obtain the target opening value of the servo valve, and then controls the servo valve to discharge hydraulic oil according to the target opening value, so that the slider is leveled, achieving the purpose of leveling at the initial position of the slider, thereby making the control process of the press more stable and effectively reducing the failure rate of the press operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A structural diagram of a press control system provided by an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of a connection between a high-frequency signal converter and a controller provided by an embodiment of the present invention;

[0028] Figure 3 A structural diagram of a press system with hydraulic pad control provided by an embodiment of the present invention;

[0029] Figure 4 A schematic diagram of connecting a host display and a controller provided in an embodiment of the present invention; DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] Please refer to Figure 1 , which is an embodiment of the present invention, provides a press control system, including: a controller, an encoder, a parallel cylinder pressure sensor and a first servo valve,

[0032] The encoder is used to collect the initial position data of the slider;

[0033] The controller is used to calculate the pressure of the parallel cylinder on both sides of the slider according to the collected initial position data of the slider;

[0034] The parallel cylinder pressure sensor is used to obtain the actual pressure of the parallel cylinder;

[0035] The controller is further used to calculate the target opening value of the first servo valve according to the pressure of the parallel cylinder on both sides of the slider and the actual pressure of the parallel cylinder, and then generate an opening adjustment instruction according to the target opening value, and send the opening adjustment instruction to the first servo valve;

[0036] The first servo valve is used to adjust the degree of valve opening according to the received opening adjustment instruction to control the discharge amount of hydraulic oil so that the slider is leveled.

[0037] In a preferred embodiment, the above-mentioned device connection method is as follows Figure 1 , the encoder collects the initial position data of the slider, including the positions of the left and right sides of the slider, and the parallel cylinder pressure sensor collects the actual pressure of the parallel cylinder, and then transmits both measurement data to the controller. After receiving the position data of the left and right sides of the slider, the controller uses the primary PID algorithm to calculate the pressure of the parallel cylinder on both sides of the slider, and then uses the PID algorithm to calculate the pressure on both sides of the slider and the actual pressure of the parallel cylinder. After obtaining the opening value of the first servo valve, the system generates an adjustment instruction carrying the opening value, that is, the opening adjustment instruction. The first servo valve receives the adjustment instruction carrying the target opening value, adjusts the valve opening according to the size of the opening value, and then discharges the hydraulic oil, gradually forming a pressure difference between the left and right cylinders, and finally leveling the slider. It should be noted that the PID algorithm involved in this embodiment is a prior art.

[0038] Preferably, before calculating the target opening value of the first servo valve according to the pressure of the parallel cylinder on both sides of the slider and the actual pressure of the parallel cylinder, the controller further includes:

[0039] The controller compares the pressure on both sides of the slider with the actual pressure of the parallel cylinder, and calculates the target opening value of the first servo valve when it is determined that the pressure on either side of the slider is different from the actual pressure of the parallel cylinder.

[0040] In a preferred embodiment, after the pressure of the parallel cylinder on both sides of the slider is calculated, the obtained pressure is compared with the actual pressure collected by the parallel cylinder sensor. As long as any one of the pressures on both sides of the slider is not equal to the actual pressure of the parallel cylinder, it means that the slider is not leveled, and then the target opening value of the first servo valve is calculated.

[0041] Preferably, the press control system further comprises a high-frequency signal converter for converting a digital control signal corresponding to the opening adjustment instruction into an analog control signal.

[0042] In a preferred embodiment, Figure 2 The high-frequency signal converter is directly connected to the controller to convert the opening adjustment instruction into an analog control signal, which is then sent to the first servo valve.

[0043] The press control system further includes: a hydraulic pad pressure sensor and a second servo valve,

[0044] The hydraulic pad pressure sensor is used to obtain the actual pressure of the hydraulic pad;

[0045] The controller is further used to calculate the target opening value of the second servo valve according to the actual pressure of the hydraulic pad and the preset pressure, and then generate an opening adjustment instruction according to the target opening value, and send the opening adjustment instruction to the second servo valve;

[0046] The second servo valve is used to adjust the degree of valve opening according to the received opening adjustment instruction to control the discharge amount of hydraulic oil so that the actual pressure of the hydraulic pad is the same as the preset pressure.

[0047] In a preferred embodiment, the above-mentioned device connection method is as follows Figure 3 , the hydraulic pad pressure sensor collects the actual pressure of the hydraulic pad and transmits the data to the controller. At the same time, a preset pressure is obtained according to the process requirements and input into the controller. Then, the PID algorithm is used to calculate the preset pressure and the actual pressure of the hydraulic pad. After obtaining the target opening value of the second servo valve, the system generates an adjustment instruction carrying the opening value, i.e., an opening adjustment instruction. The second servo valve receives the adjustment instruction carrying the target opening value, adjusts the valve opening according to the opening value, and then discharges the hydraulic oil, so that the actual pressure value of the hydraulic pad gradually becomes the same as the preset one. It should be noted that the PID algorithm involved in this embodiment is a prior art.

[0048] Preferably, before calculating the target opening value of the second servo valve according to the actual pressure of the hydraulic pad and the preset pressure, the method further includes:

[0049] The controller compares the actual pressure of the hydraulic pad with the preset pressure, and calculates the target opening value of the second servo valve when it is determined that the actual pressure of the hydraulic pad is different from the preset pressure.

[0050] In a preferred embodiment, after the controller obtains a preset pressure, the controller then compares the preset pressure with the actual pressure collected by the hydraulic pad sensor. As long as the actual pressure of the hydraulic pad is different from the preset pressure, it means that the hydraulic pad has not reached the target value, and then the second servo valve opening value is calculated.

[0051] Preferably, the second servo valve is further used to detect the position of the valve core of the second servo valve, generate a position feedback signal, and transmit the feedback signal to the controller;

[0052] The controller is also used to calculate the offset according to the position feedback signal and the control signal corresponding to the opening adjustment instruction, and automatically compensate and calibrate the actual pressure of the hydraulic pad according to the offset.

[0053] Preferably, the controller, before calculating the offset according to the position feedback signal and the control signal corresponding to the opening adjustment instruction, further comprises:

[0054] The controller compares the position feedback signal with the control signal corresponding to the opening adjustment instruction, and calculates the offset when it is determined that the position feedback signal is different from the control signal corresponding to the opening adjustment instruction.

[0055] In a preferred embodiment, the control system uses a servo valve to detect the position of the servo valve core, generates a position feedback signal, and then transmits the feedback signal to the controller, and compares the feedback signal with the control signal corresponding to the opening adjustment instruction. When the two are the same, it means that the control has not produced zero drift. If they are different, the offset of the two is calculated, and automatic compensation adjustment is performed to realize the zero drift calibration function. It should be noted that the compensation calibration is implemented based on existing software.

[0056] Preferably, the press control system further comprises a high-frequency signal converter for converting a digital control signal corresponding to the opening adjustment instruction into an analog control signal.

[0057] In a preferred embodiment, Figure 2 The high-frequency signal converter is directly connected to the controller, converting the opening adjustment instruction into an analog control signal, which is then sent to the second servo valve.

[0058] Preferably, the press control system further comprises an upper display, the connection method of which is as follows: Figure 3 , used to display the control reference data at each moment, the control reference data including any one of the following items or a combination thereof: slider position data, slider pressure value on both sides of the parallel cylinder, actual pressure of the parallel cylinder, target opening value of the first servo valve, target opening value of the second servo valve, preset hydraulic pad pressure, actual pressure of the hydraulic pad.

[0059] The following beneficial effects are achieved by implementing the embodiments of the present invention:

[0060] An embodiment of the present invention provides a parallelism control system, which collects the initial position data of the slider through an encoder, and uses a controller to calculate the initial position data of the slider and the actual pressure of the parallel cylinder to obtain the target opening value of the first servo valve, and then controls the servo valve to discharge hydraulic oil according to the target opening value, so that the slider is leveled, thereby achieving the purpose of leveling the slider at the initial position. In addition, the control system also integrates the control of the hydraulic pad, calculates according to the actual pressure of the hydraulic pad and the preset pressure, and obtains the target opening value of the second servo valve, and adjusts the valve port so that the actual pressure value of the hydraulic pad gradually becomes the same as the preset pressure value. Furthermore, according to the relevant opening adjustment instructions and the feedback signal of the valve core position, the actual pressure value of the hydraulic pad is compared, and the control system is used to compensate and calibrate the actual pressure value of the hydraulic pad to eliminate the zero drift. Through the above method, the control process of the press is made more stable, and the failure rate of the press operation is effectively reduced.

[0061] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A press control system, characterized in that: include: controller, encoder, parallel cylinder pressure sensor and first servo valve, The encoder is used to collect the initial position data of the slider; The controller is used to calculate the pressure of the parallel cylinder on both sides of the slider according to the collected initial position data of the slider; The parallel cylinder pressure sensor is used to obtain the actual pressure of the parallel cylinder; The controller is further used to calculate the target opening value of the first servo valve according to the pressure of the parallel cylinder on both sides of the slider and the actual pressure of the parallel cylinder, and then generate an opening adjustment instruction according to the target opening value, and send the opening adjustment instruction to the first servo valve; The first servo valve is used to adjust the degree of valve opening according to the received opening adjustment instruction to control the discharge amount of hydraulic oil so that the slider is leveled; Also included is a hydraulic pad pressure sensor and a second servo valve; The hydraulic pad pressure sensor is used to obtain the actual pressure of the hydraulic pad; The controller is further used to calculate the target opening value of the second servo valve according to the actual pressure of the hydraulic pad and the preset pressure, and then generate an opening adjustment instruction according to the target opening value, and send the opening adjustment instruction to the second servo valve; The second servo valve is used to adjust the degree of valve opening according to the received opening adjustment instruction to control the discharge amount of hydraulic oil so that the actual pressure of the hydraulic pad is the same as the preset pressure; The second servo valve is further used to detect the position of the valve core of the second servo valve, generate a position feedback signal, and transmit the position feedback signal to the controller; The controller is also used to calculate the offset according to the position feedback signal and the control signal corresponding to the opening adjustment instruction, and automatically compensate and calibrate the actual pressure of the hydraulic pad according to the offset.

2. A press control system according to claim 1, characterized in that: Before the controller calculates the target opening value of the first servo valve according to the pressure of the parallel cylinder on both sides of the slider and the actual pressure of the parallel cylinder, the controller further includes: The controller compares the pressure on both sides of the slider with the actual pressure of the parallel cylinder, and calculates the target opening value of the first servo valve when it is determined that the pressure on either side of the slider is different from the actual pressure of the parallel cylinder.

3. A press control system according to claim 1, characterized in that: The controller, before calculating the target opening value of the second servo valve according to the actual pressure of the hydraulic pad and the preset pressure, further comprises: The controller compares the actual pressure of the hydraulic pad with the preset pressure, and calculates the target opening value of the second servo valve when it is determined that the actual pressure of the hydraulic pad is different from the preset pressure.

4. A press control system according to claim 1, wherein the controller, before calculating the offset according to the position feedback signal and the control signal corresponding to the opening adjustment instruction, further comprises: The controller compares the position feedback signal with the control signal corresponding to the opening adjustment instruction, and calculates the offset when it is determined that the position feedback signal is different from the control signal corresponding to the opening adjustment instruction.

5. A press control system according to claim 1, characterized in that: It also includes a high-frequency signal converter, which is used to convert the digital control signal corresponding to the opening adjustment instruction into an analog control signal.

6. A press control system according to claim 1, further comprising an upper display for displaying control reference data at each moment, wherein the control reference data comprises any one of the following items or a combination thereof: slider position data, pressure value of the slider on both sides of the parallel cylinder, actual pressure of the parallel cylinder, target opening value of the first servo valve, target opening value of the second servo valve, preset hydraulic pad pressure, actual pressure of the hydraulic pad.

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