Control system and control method for displaying material film tension in real time through electric air transformer

Abstract

This invention discloses a control system for real-time display of film tension via an electro-pneumatic converter. The system includes an unwinding unit, a winding unit, and a drive roller. A pressure roller is positioned above the drive roller. Swing rollers a and b are arranged on either side of the drive roller. Guide rollers are arranged on both sides of swing rollers a and b, and angle detection sensors are connected to their ends. The angle detection sensors share a common signal connection to a PLC. The PLC is connected to the electro-pneumatic converter, which is connected to a cylinder. The cylinder's extension and retraction end acts on the swing rollers. The control method of this invention for real-time display of film tension via an electro-pneumatic converter involves the angle detection sensors detecting and collecting the included angle information and sending it to the PLC. The PLC calculates the angular acceleration of the swing rollers, thereby calculating and displaying the actual film tension. This control system and method for real-time display of film tension via an electro-pneumatic converter offer the advantages of real-time film tension display and cost savings.

Description

Technical Field

[0001] This invention belongs to the field of roller control technology for roll forming equipment, specifically relating to a control system for real-time display of film tension via an electro-pneumatic converter, and also relating to a method for real-time display of film tension via an electro-pneumatic converter. Background Technology

[0002] The winding and unwinding unit of roll material equipment generally uses a swing roller for tension control. The tension at the swing roller is set by an electro-pneumatic converter. During the operation of the whole machine, the user can only know the set value of the tension at that point, but cannot obtain the specific tension value. The traditional technology is to add a tension sensing roller in the relevant material path as a tension display. This approach often leads to the complexity of the material path. In addition, the price of tension sensors is high, which increases the cost. Summary of the Invention

[0003] The purpose of this invention is to provide a control system that displays the film tension in real time via an electro-pneumatic converter, which features real-time display of film tension and cost savings.

[0004] Another objective of this invention is a method for controlling film tension by real-time display using an electro-pneumatic converter.

[0005] The technical solution adopted in this invention is a control system that displays the tension of the film in real time through an electro-pneumatic converter. The system includes an unwinding unit and a winding unit. An active roller is arranged between the unwinding and winding units. A pressure roller is positioned above the active roller to ensure that the film runs at the same speed as the active roller. A swing roller a is positioned between the active roller and the unwinding unit, and a swing roller b is positioned between the active roller and the winding unit. Guide rollers for changing the feeding direction are arranged on both sides of swing roller a and swing roller b. An angle detection sensor is connected to the ends of both swing roller a and swing roller b. The two angle detection sensors are connected to a PLC controller via a common signal. The PLC controller is electrically connected to the electro-pneumatic converter. The electro-pneumatic converter is connected to cylinders via an air circuit. The extension and retraction ends of the two cylinders are respectively connected to swing roller a and swing roller b.

[0006] The invention is further characterized by:

[0007] The PLC controller is connected to the human-machine interface via a wire.

[0008] The cylinder is a low-friction cylinder. Both the swing roller a and the swing roller b have a deep groove ball bearing embedded at the end near the angle detection sensor. The swing roller rotation shaft passes through the deep groove ball bearing.

[0009] Another technical solution adopted in this invention is a control method that displays the film tension in real time using an electro-pneumatic converter. The control system that displays the film tension in real time using an electro-pneumatic converter is implemented according to the following steps:

[0010] Step 1: The angle detection sensor detects and collects the angle information between the axis of the swing roller and the axis when the swing roller is in a vertical position, and sends it to the PLC controller. The PLC controller calculates the angular acceleration of the swing roller in every three consecutive scanning cycles.

[0011] Step 2: Calculate the thrust exerted by the cylinder on the swing roller based on the current cylinder pressure value;

[0012] Step 3: Based on the angular acceleration from Step 1 and the thrust value from Step 2, calculate the actual tension value of the film and output it to the human-machine interface via the PLC controller.

[0013] Another feature of the technical solution of the present invention is that:

[0014] Step 1 specifically involves: Angle detection sensor 9 detecting and acquiring the angle β between the axis of the swing roller and the axis when the swing roller is in a vertical position during its movement. The detection data is then transmitted to the PLC controller. Every three scanning cycles, the PLC controller records the angles β1, β2, and β3 within three consecutive scanning cycles, as well as the time interval T between the three scanning cycles. 12 T 23 And calculate the average angular velocity within the corresponding time interval.

[0015] T 12 The average angular velocity ω over the time period 12 =(β2-β1) / T 12 ;T 23 The average angular velocity ω over the time period 23 =(β3-β2) / T 23 ;

[0016] Then calculate the angular acceleration α of the oscillating roller during the three scanning cycles:

[0017] α = 2 × (ω) 23 -ω 12 ) / (T 12 +T 23 (1).

[0018] Step 2 is as follows: Based on the feedback air pressure value of the electro-pneumatic converter at the current moment, refer to the cylinder sample manual to obtain the thrust value of cylinder 8.

[0019] Step 3 specifically involves: the oscillating roller rotating around its axis of rotation, and all external forces and the supporting force F of the bearing on the entire system. 支撑 In equilibrium, with only a residual couple acting, calculate the resultant moment M. 合 :

[0020] M 合 =2×F 张力 ×L3-F 气缸 ×L1+G重力 ×L2×sinβ(2;

[0021] Among them, F 气缸 F represents the thrust exerted by the cylinder on the swing roller. 张力 The force exerted by the film on the system is represented by G, where G is the gravitational force of the oscillating part of roller a or roller b. 重力 L1 represents F 气缸 The lever arm, where L2 represents G. 重力 The lever arm is the distance between the center of gravity of the entire system and the rotation axis of the swing roller, and β represents the angle between the axis of the swing roller and the axis when the swing roller is in a vertical state.

[0022] Assuming the resultant couple is positive when it rotates clockwise, when the cylinder's extension rod is halfway extended to the middle position, the swing roller is in a vertical state, at which point β is 0. When the cylinder is in the extended state, β is positive, and when the cylinder is in the retracted state, β is negative.

[0023] Under the action of a resultant couple, the pendulum roller rotates, as shown by the following formula:

[0024] M 合 =α×J(3;

[0025] Where J is the moment of inertia of the swing roller system;

[0026] By solving equations (1) and (3) simultaneously, F can be calculated. 张力 The value, i.e., the actual tension value of the film, is output to the human-machine interface for display via the PLC controller.

[0027] The beneficial effects of this invention are:

[0028] This invention provides a control system for real-time display of film tension via an electro-pneumatic converter. By analyzing the relationship between tension and the position of the swing roller, the PLC calculates the film tension and outputs it, thus achieving the goal of real-time display of film tension through internal data calculation.

[0029] This invention provides a control method for real-time display of film tension using an electro-pneumatic converter. Compared with the traditional structure that uses a tension sensor to achieve this function, the material path is simpler, the installation accuracy is higher, and the cost is reduced. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the control system of the present invention that displays the tension of the film in real time through an electro-pneumatic converter;

[0031] Figure 2 This is a schematic diagram of the structure of the control system cylinder for real-time display of film tension via an electro-pneumatic converter, as described in this invention.

[0032] Figure 3This is a diagram showing the usage status of the swing roller in the control method of real-time display of film tension via an electro-pneumatic converter in this invention.

[0033] Figure 4 This is a diagram of the processing scheme of the existing technology in the background technology.

[0034] In the diagram, 1. Unwinding unit, 2. Swing roller a, 3. Guide roller, 4. Drive roller, 5. Pressure roller, 6. Swing roller b, 7. Rewinding unit, 8. Cylinder, 9. Angle detection sensor, 10. Swing roller rotation shaft, 11. Sensing roller. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] This invention relates to a control system that uses an electro-pneumatic converter to display the film tension in real time. It is used for controlling and displaying the film tension at the swing roller of a roll-to-roll equipment. The structure is as follows: Figure 1 and Figure 2 As shown, the system includes an unwinding unit 1 and a rewinding unit 7. An active roller 4 and a pressure roller 5 are arranged between the unwinding unit 1 and the rewinding unit 7. The pressure roller 5 ensures that the film and the active roller 4 run at the same speed. A swing roller a2 is arranged between the active roller 4 and the unwinding unit 1, and a swing roller b6 is arranged between the active roller 4 and the rewinding unit 7. Swing rollers a2 and b6 ensure smooth film movement. Guide rollers 3 are arranged on both sides of swing roller a2 and on both sides of swing roller b6 to change the material feeding direction to meet the requirements of various functional structures. Angle detection sensors 9 are connected to the ends of rollers a2 and b6. The signals from angle detection sensors 9 are transmitted unidirectionally to the PLC controller. The PLC controller is electrically connected to an electro-pneumatic converter. The PLC controller is also connected to a human-machine interface via a line. Data can be transmitted bidirectionally between the electro-pneumatic converter, the human-machine interface, and the PLC controller. The electro-pneumatic converter is connected to cylinders 8 via an air circuit. The extension and retraction ends of the two cylinders 8 are connected to rollers a2 and b6, respectively. The electro-pneumatic converter outputs air pressure to the cylinders 8 to act on rollers a2 and b6.

[0038] Cylinder 8 is a low-friction cylinder. Deep groove ball bearings are used at the rotation shafts of swing rollers a2 and b6, and the swing roller rotation shaft 10 is sleeved inside the deep groove ball bearing.

[0039] Example 2

[0040] The control method of the present invention, which displays the tension of the film in real time through an electro-pneumatic converter, is implemented using the control system of Example 1, specifically according to the following steps:

[0041] Step 1: The angle sensor 9 collects the angle information between the axis of the swing roller and the axis when the swing roller is in a vertical position during three consecutive scanning cycles, and sends it to the PLC controller. Based on the three angles and the scanning cycle, the angular acceleration of the swing roller during this process is calculated.

[0042] The cylinder 8 selected for the entire system is a low-friction cylinder, and the rotating shafts of the swing rollers a2 and b6 use deep groove ball bearings. Therefore, the influence of system frictional resistance on tension is ignored in the calculation process.

[0043] Step 1 specifically involves: (e.g.) Figure 2 As shown, angle detection sensor 9 detects the angle between the axis of the swing roller and the axis when the swing roller is in a vertical position during its movement, and transmits this data to the PLC. Every three scanning cycles, the PLC calculates the angular acceleration of the swing roller. Using the angles β1, β2, and β3 recorded by the PLC over three consecutive scanning cycles, with a time interval T... 12 ;T 23 .

[0044] Calculate at T 12 The average angular velocity ω over the time period 12 =(β2-β1) / T 12 ;T 23 The average angular velocity ω over the time period 23 =(β3-β2) / T 23 .

[0045] Calculate the angular acceleration during this time interval:

[0046] α = 2 × (ω) 23 -ω 12 ) / (T 12 +T 23 (1);

[0047] The angular acceleration calculated at this time is the angular acceleration at time T2, while the PLC's scan cycle is on the order of milliseconds. Therefore, the calculated angular acceleration α will be processed according to the angular acceleration at the current time.

[0048] Step 2: Calculate the thrust exerted by cylinder 8 on the swing roller based on the current air pressure value of cylinder 8.

[0049] Based on the feedback air pressure value of the electro-pneumatic converter at the current moment, refer to the cylinder sample manual to obtain the cylinder thrust value;

[0050] Step 3: Under the combined action of the film tension and the cylinder thrust, the motion state of the swing roller has been calculated in Step 1. Based on the angular acceleration in Step 1 and the thrust value in Step 2, as well as Newton's second law, the actual tension value of the film is calculated and output to the human-machine interface through the PLC controller. At the same time, it is output to the electro-pneumatic converter to be converted into the corresponding air pressure output to the cylinder 8. The optimal parameters are set according to the winding situation to control the film tension.

[0051] Example 3

[0052] Based on Example 2, step 3 specifically involves taking the swing roller rotation shaft 10 as the research object, and determining the force situation of the entire system when the cylinder is in a certain retracted position, as follows: Figure 3 As shown, the supporting force F of the bearing on the entire system 支撑 The gravity of the oscillating part of oscillating roller a2 or oscillating roller b6 is expressed as G. 重力 The thrust exerted by cylinder 8 on the swing roller is expressed as F. 气缸 The tensile force exerted by the film on the system is expressed as F. 张力 .

[0053] In the calculation process, firstly, because the swing angle of the swing roller is small, F 气缸 and F 张力 The direction is always horizontal. Of course, subsequent calculations can be made based on the position of the swing roller and geometric relationships, but such calculations have little impact on the results. Secondly, the weight of the cylinder is negligible for the entire swing roller system.

[0054] according to Figure 3 As shown, the motion of the swing roller is a rotational motion around the swing roller rotation axis 10, and all external forces and supporting forces F 支撑 Calculate the resultant torque M for rotational motion under equilibrium and only the action of a residual couple. 合 ;

[0055] M 合 =2×F 张力 ×L3-F 气缸 ×L1+G 重力 ×L2×sinβ(2;

[0056] Where L1 represents F 气缸 The lever arm, where L2 represents G. 重力 The lever arm is the distance between the center of gravity of the entire system and the rotation axis 10 of the swing roller, and β represents the angle between the axis of the swing roller and the axis when the swing roller is in a vertical state.

[0057] The direction of the above formula is defined as follows:

[0058] The resultant couple is positive when it rotates clockwise;

[0059] When the telescopic rod of cylinder 8 is extended halfway to the middle position, the swing roller is in a vertical state, such as... Figure 3 As shown, β is 0 at this time. β is positive when the cylinder is in the extended state and negative when the cylinder is in the retracted state.

[0060] Under the action of a resultant couple, the pendulum roller rotates, as shown by the following formula:

[0061] M 合 =α×J(3;

[0062] Where J is the moment of inertia of the oscillating roller system, and its value is fixed.

[0063] By solving equations (1) and (3) simultaneously, F can be calculated. 张力 The value, i.e. the actual tension value of the film, is obtained and output to the human-machine interface for display via the PLC controller. At the same time, it is output to the electro-pneumatic converter to be converted into the corresponding air pressure and output to the cylinder 8.

[0064] The control method of the present invention, which displays the tension of the film in real time through an electro-pneumatic converter, is based on the following principle: the system is subjected to force analysis by the force state determined by the cylinder thrust, the gravity of the swing roller, and the motion state of the swing roller, and the film tension is calculated and displayed in real time.

[0065] The control system and control method of the present invention for real-time display of film tension by electro-pneumatic converter have the following advantages: by analyzing and studying the relationship between tension and the position of the swing roller, the tension of the film is calculated by PLC and output, thereby achieving the purpose of displaying the film tension. Figure 4 The diagram shows the processing scheme of the prior art in the background, that is, a tension sensing roller 11 is added between the swing roller b6 and the winding unit 7 in the material feeding path as a tension display. Compared with this, the material feeding path of the present invention is simpler, the installation accuracy is higher, and the cost is lower than that of the tension sensing roller 11.

Claims

1. A control method for real-time display of film tension via an electro-pneumatic converter, characterized in that, A control system that displays the film tension in real time via an electro-pneumatic converter is adopted. The system structure includes an unwinding unit (1) and a winding unit (7). An active roller (4) is arranged between the unwinding unit (1) and the winding unit (7). A pressure roller (5) is arranged above the active roller (4) to ensure that the film runs at the same speed as the active roller (4). A swing roller a (2) is arranged between the active roller (4) and the unwinding unit (1). A swing roller b (6) is arranged between the active roller (4) and the winding unit (7). The swing roller a (2) has two sides. Guide rollers (3) for changing the material feeding direction are arranged on both sides of the swing roller b (6). Angle detection sensors (9) are connected to the ends of the swing roller a (2) and the swing roller b (6). The two angle detection sensors (9) are connected to a PLC controller. The PLC controller is electrically connected to an electro-pneumatic converter. The electro-pneumatic converter is connected to a cylinder (8) through an air circuit. The extension and retraction ends of the two cylinders (8) are connected to the swing roller a (2) and the swing roller b (6) respectively. The PLC controller is connected to a human-machine interface through a line. The specific steps are as follows: Step 1: Angle detection sensor (9) detects and collects the angle information between the axis of the swing roller and the axis when the swing roller is in a vertical position and sends it to the PLC controller. The PLC controller calculates the angular acceleration of the swing roller in every three consecutive scanning cycles. Step 2: Calculate the thrust of the cylinder (8) on the swing roller based on the current air pressure value of the cylinder (8); Step 3: Based on the angular acceleration from Step 1 and the thrust value from Step 2, calculate the actual tension value of the film and output it to the human-machine interface via the PLC controller. Step 1 specifically involves: the angle detection sensor (9) detecting and acquiring the angle β between the axis of the swing roller and the axis when the swing roller is in a vertical position during its movement, and transmitting the detection data to the PLC controller. Every three scanning cycles, the PLC controller records the angles β1, β2, and β3 within three consecutive scanning cycles, as well as the time interval T between the three scanning cycles. 12 T 23 And calculate the average angular velocity within the corresponding time interval. T 12 The average angular velocity ω over the time period 12 =(β2-β1) / T 12 ;T 23 The average angular velocity ω over the time period 23 =(β3-β2) / T 23 ; Then calculate the angular acceleration α of the oscillating roller during the three scanning cycles: α=2×(ω) 23 -oh 12 ) / (T 12 +T 23 )(1); Step 3 specifically involves: the swing roller rotating around the swing roller rotation axis (10), and all external forces and the supporting force F of the bearing on the entire system. 支撑 In equilibrium, with only a residual couple acting, calculate the resultant moment M. 合 : M 合 =2×F 张力 ×L3-F 气缸 ×L1+G 重力 ×L2×sinβ(2) Among them, F 气缸 F represents the thrust exerted by the cylinder (8) on the swing roller. 张力 The gravitational force of the oscillating part of the oscillating roller a(2) or oscillating roller b(6) on the system, representing the tension of the film, is expressed as G. 重力 L1 represents F 气缸 The lever arm, where L2 represents G. 重力 The lever arm is the distance between the center of gravity of the entire system and the rotation axis (10) of the swing roller, and β represents the angle between the axis of the swing roller and the axis when the swing roller is in a vertical state. Assuming the resultant couple is positive when it is clockwise, when the telescopic rod of the cylinder (8) is extended halfway to the middle position, the swing roller is in a vertical state, at which time β is 0, β is positive when the cylinder (8) is in the extended state, and β is negative when the cylinder (8) is in the retracted state. Under the action of a resultant couple, the pendulum roller rotates, as shown by the following formula: M 合 =α×J(3) Where J is the moment of inertia of the swing roller system; By solving equations (1) and (3) simultaneously, F can be calculated. 张力 The value, i.e., the actual tension value of the film, is output to the human-machine interface for display via the PLC controller.

2. The control method for real-time display of film tension via an electro-pneumatic converter according to claim 1, characterized in that, The cylinder (8) is a low-friction cylinder. Deep groove ball bearings are embedded at the ends of the swing rollers a (2) and b (6) near the angle detection sensor (9). The swing roller rotation shaft (10) is inserted inside the deep groove ball bearing.

3. The control method for real-time display of film tension via an electro-pneumatic converter according to claim 1, characterized in that, Step 2 specifically involves: based on the feedback air pressure value of the electro-pneumatic converter at the current moment, referring to the cylinder sample manual to obtain the thrust value of cylinder (8).

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