A device and method for controlling constant pressure of a rotating disc pressing roller

Abstract

The application relates to the technical field of strip winding mechanisms, and discloses a device and a method for constant-pressure control of a rotating disc pressing roller, which comprises a rotating disc and a controller, and an encoder is arranged on the rotating disc; a material collecting roller is symmetrically arranged in the circumferential direction of the rotating disc; a pressing roller and an air cylinder are fixedly connected to the rotating disc and correspond to the material collecting roller; the air cylinder is fixed on the rotating disc, and the pressing roller is slidingly connected to the rotating disc; the sliding direction of the pressing roller pushed by the air cylinder passes through the shaft center of the material collecting roller; and the encoder and the air cylinder are electrically connected to the controller. In the scheme, the air cylinder directly pushes the pressing roller to act on the material roll, force transmission is more direct, interference factors affecting the actual action of the pressing roller on the material roll are effectively reduced, the difficulty of constant-pressure control is reduced, and the stability and accuracy of constant-pressure control are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of strip winding mechanism, and particularly relates to a device and method for constant pressure control of a rotary disc pressure roller. BACKGROUND

[0002] At present, most strip winding mechanisms adopt double-station A-axis and B-axis switching winding materials to realize non-stop material changing. In the process of winding, a pressure roller is used to press against the material roll to realize compact winding of the material. However, when the winding material is switched from the A-axis to the B-axis, the winding pressure roller changes with the rotary disc, and the winding roller (i.e. the A-axis and the B-axis) has a certain influence on the winding tension, so in the winding process, winding slippage, winding wrinkles and other problems are easily caused, which affects the compactness of the winding material and even the quality of the material (such as film).

[0003] The prior art CN113860031A discloses a control method of a non-weighted material receiving pressure roller, which comprises the following steps: setting a pressure roller cylinder 8 and a swing arm 10 (the structure is shown in detail in Figure 1 ), collecting the position data of the current rotary frame; calculating the component force of the gravity acting on the material roll 12 according to the lengths and position relationships of the components; calculating the pressure of the material receiving pressure roller cylinder acting on the material roll 12; calculating the input air pressure of the pressure roller cylinder 8 when the material is received under the condition of constant pressure (the calculation formula is as shown in

[0004] Formula 1), and realizing the control of the material receiving pressure roller 14 by controlling the input air pressure of the pressure roller cylinder 8.

[0005]

[0006] In Formula 1, F is the pressure of the pressure roller acting on the material roll, B is the length of the swing arm, G1 represents the weight of the swing arm, G2 represents the weight of the material receiving pressure roller, g is the acceleration of gravity, the axis center line of the material shaft a and the material shaft b is l1, and a is the included angle between l1 and the swing arm; l1 passes through the rotary frame axis center O, the straight line in the horizontal direction and passing through the axis center O in the cross section is l2, and b is the included angle between l1 and l2.

[0007] However, the prior art still has the following technical problems: (1) As can be seen from the above formula 1, there are many factors affecting the pressure value P of the cylinder in the prior art, and many factors change in real time, resulting in that the change of the pressure value P of the cylinder calculated in the presence of multiple variables is large and uncontrollable, increasing the difficulty of the pressure control of the pressure roller on the material roll, and leading to the control delay and reducing the stability and accuracy of the pressure control; (2) Because there is an included angle between l1 and l2, the cylinder pressure in the prior art is transmitted to the pressure roller through the swing arm, resulting in more loss, thereby increasing the production energy consumption; (3) In the prior art, when the cylinder pushes or tightens the pressure roller with the help of the swing arm, the force applied to the swing arm is easy to accelerate the wear of the swing arm, thereby easily leading to the reduction of the stability and accuracy of the constant pressure control, and even leading to the inability to realize the constant pressure control of the pressure roller on the material roll; (4) In the prior art, the swing arm is broken at both ends by the pressure of the pressure roller and the reaction force of the material roll in opposite directions, increasing the equipment maintenance cost and replacement cost; (5) The swing arm in the prior art not only has a complex structure, needs more running avoidance space, but also may hinder the winding of the material roller in space, affecting the winding thickness. SUMMARY

[0008] The present application aims to provide a device and method for constant pressure control of a rotary disc pressure roller, to solve the technical problems of the prior art that the pressure control of the pressure roller on the material roll is difficult, and the control stability effect is poor, and to effectively reduce the influence of the pressure roller on the winding tension.

[0009] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: a device for constant pressure control of a rotary disc pressure roller, comprising a rotary disc and a controller, an encoder is arranged on the rotary disc; a material winding roller is symmetrically arranged on the rotary disc; a pressure roller and a cylinder are fixedly connected on the rotary disc corresponding to the material winding roller; the cylinder is fixed on the rotary disc, and the pressure roller is slidingly connected on the rotary disc; the sliding direction of the pressure roller pushed by the cylinder passes through the axis of the material winding roller; the encoder, the cylinder and the controller are electrically connected.

[0010] The principle of the present application is as follows:

[0011] In the present application, the pressure roller and the cylinder are fixedly connected on the rotary disc corresponding to the material winding roller, and the cylinder is fixed on the rotary disc, and the pressure roller is slidingly connected on the rotary disc, so that the pressure of the cylinder can be directly transmitted to the pressure roller, reducing the loss in the pressure transmission process and reducing the energy consumption; after the cylinder transmits the pressure to the pressure roller, it directly acts on the material roll of the material winding roller in contact with it, and in the present application, the sliding direction of the pressure roller pushed by the cylinder passes through the axis of the material winding roller, which not only facilitates the pressure roller to uniformly press the material roll on the material winding roller, but also avoids the fact that when the pressure F1 of the pressure roller on the material roll has an included angle (such as the included angle is within the range of 0-90°) with the surface of the material roll, the material is easily damaged due to the obvious change of the local tension of the material.

[0012] On the basis of the structure, in the production process of the roll material, the position relationship between the pressure roller and the roll material changes in real time with the rotation of the rotating disc in one direction, the pressure F of the pressure roller on the roll material mainly considers the cylinder pressure F1, the gravity G of the pressure roller, and the reaction force F2 of the pressure roller with the increase of the thickness of the roll material, and in the present scheme, the F1 and F2 are opposite and equal because the sliding direction of the pressure roller passes through the shaft center of the material collecting roller, so that the factors affecting the constant pressure control are simplified to the relative spatial position of the pressure roller and the material collecting roller (i.e. the rotating angle α of the rotating disc), effectively reducing the interference factors affecting the actual action of the pressure roller on the roll material, reducing the difficulty of constant pressure control, and improving the stability and accuracy of constant pressure control.

[0013] The present scheme sets an electrically connected encoder, a cylinder and a controller, the encoder obtains the rotating angle α of the rotating disc in real time and transmits it to the controller, the controller calculates the required pressure value P when the pressure F of the pressure roller on the roll material is constant according to the received rotating angle α, and then adjusts the size of the proportional valve of the cylinder in real time according to the required pressure value P, so as to realize the constant pressure control of the rotating disc pressure roller on the roll material.

[0014] The advantages of the present scheme are:

[0015] 1. Compared with the prior art that sets a swing arm to transmit the cylinder pressure to the pressure roller and then acts on the roll material, resulting in more interference factors affecting the constant pressure control of the pressure roller on the roll material and reducing the stability of the constant pressure control, in the present scheme, the cylinder pressure F1 can be directly transmitted to the pressure roller, and the F1 direction passes through the shaft center of the material collecting roller, so that the factors affecting the constant pressure control are simplified to the relative spatial position of the pressure roller and the material collecting roller (i.e. the rotating angle α of the rotating disc and the thickness of the roll material), effectively reducing the interference factors affecting the actual action of the pressure roller on the roll material, reducing the difficulty of constant pressure control, and improving the stability and accuracy of constant pressure control.

[0016] 2. Compared with the prior art that sets a swing arm to connect the cylinder and the pressure roller, making the swing arm easy to break at both ends due to the opposite cylinder pressure F1 and the reaction force F2 of the roll material on the pressure roller, in the present scheme, there is no need for a swing arm, the cylinder is in contact with the pressure roller and fixed, which not only makes the pressure transmission more direct, reduces energy consumption, reduces the factors affecting the constant pressure control, and improves the stability and accuracy of the constant pressure control, but also makes the device structure simpler, more compact and stable, without the need for more equipment avoiding space, effectively improving the continuity of roll material winding, and improving production efficiency.

[0017] 3. Compared with the prior art that the cylinder pressure is transmitted to the pressure roller through the swing arm, which will have more pressure loss and equipment wear, in the present scheme, the cylinder directly pushes the pressure roller to slide towards the shaft center of the winding roller, so that the sliding direction and the pressure F direction are the same, which not only effectively reduces the energy consumption loss, but also reduces the equipment wear, effectively improves the service life of the equipment, and reduces the replacement cost of the equipment; and less equipment wear helps to improve the effect of constant pressure control of the pressure roller.

[0018] Preferably, the rotating disc is radially provided with a slide rail passing through the center of the rotating disc, and the compression roller is slidingly connected in the slide rail.

[0019] Beneficial effects: the above-mentioned arrangement facilitates the sliding of the compression roller driven by the cylinder, and further reduces energy loss and equipment wear.

[0020] Preferably, the rotating disc is circumferentially and symmetrically provided with two material collecting rollers, including a first material collecting roller and a second material collecting roller, the first material collecting roller is correspondingly provided with a first compression roller and a first cylinder, the first compression roller is slidingly connected in the slide rail, the first cylinder is fixed on one side of the slide rail, and the piston rod of the first cylinder is fixedly connected with the side surface of the first compression roller; the second material collecting roller is correspondingly provided with a second compression roller and a second cylinder, the second compression roller is slidingly connected in the slide rail, the second cylinder is fixed on the other side of the slide rail, and the piston rod of the second cylinder is fixedly connected with the side surface of the second compression roller; the first cylinder and the second cylinder are electrically connected with the controller.

[0021] Beneficial effects: the above-mentioned arrangement realizes constant pressure control of the rotating disc compression roller on the material roll through the controller to real-time adjust the size of the proportional valve of the cylinder according to the calculated required pressure value P, and when it is needed to switch from the first material collecting roller to the second material collecting roller (equivalent to switching from the A shaft to the B shaft in the prior art), the controller immediately switches from controlling the size of the proportional valve of the first cylinder to controlling the size of the proportional valve of the second cylinder, avoiding material damage caused by uneven pressure control of the compression roller on the material roll during winding or switching winding.

[0022] Preferably, the encoder is fixed on the center shaft of the rotating disc and rotates synchronously with the rotating disc.

[0023] Beneficial effects: the above-mentioned arrangement makes the encoder record the rotating angle value as the rotating angle a of the rotating disc.

[0024] Preferably, the encoder is an absolute value encoder.

[0025] Beneficial effects: the above-mentioned arrangement facilitates to improve the timeliness and accuracy (to the sub-micron level) of the rotating angle detection.

[0026] Preferably, the rotating disc is provided with a driving motor, a belt is arranged between the driving motor and the center shaft of the rotating disc, and the driving motor is electrically connected with the controller.

[0027] Beneficial effects: the above-mentioned arrangement facilitates the controller to drive the rotating disc to rotate through the belt after starting the driving motor.

[0028] The scheme also provides a rotary disc pressure roller constant pressure control method, which is performed in the rotary disc pressure roller constant pressure control device, and includes that an encoder collects position data of the pressure roller and the material collecting roller in real time to form a position signal and transmits the position signal to a controller; after the controller receives the position signal, the controller calculates a cylinder pushing air pressure P value according to the position signal on the premise of assuming that a pressure F of the pressure roller on the material roll is constant; and the controller controls a size of a control valve of the cylinder according to the pushing air pressure P value.

[0029] Beneficial effects: The scheme adopts the above setting, calculates the cylinder pushing air pressure P value through the data collected by the encoder in real time, and controls the size of the control valve of the cylinder according to the pushing air pressure P value, so that the constant pressure control of the pressure roller on the material roll can be realized. In the scheme, the interference factors of the pressure F of the pressure roller on the material roll are less, the pressure F of the pressure roller on the material roll can be controlled in real time by using the above scheme, so that the material can be wound in a constant pressure state, and the material quality can be effectively avoided from being affected by the change of the local surface tension of the material caused by the change of the pressure F of the pressure roller on the material roll in the material winding process.

[0030] Preferably, before the encoder collects the data, the material collecting roller and the pressure roller are installed in a horizontal position as an initial position, at which the gravity of the pressure roller does not affect the pressure F of the pressure roller on the material roll, that is, a pushing force F1 of the cylinder is equal to the pressure F of the pressure roller on the material roll; and it can be known from a pressure formula that F=F1=PS, and P=F / S (formula 2), in which F is a theoretical constant pressure value of the pressure roller on the material roll, P is the air pressure of the cylinder, and S is a cross section of the cylinder.

[0031] Beneficial effects: The scheme limits the initial position of the material collecting roller and the pressure roller to be the horizontal position, which not only meets the equipment installation principle at the start, but also facilitates the determination of the cylinder pushing force / air pressure in the initial state under the constant pressure, so that the size of the cylinder pushing force can be adjusted in real time on this basis to realize the constant pressure control of the pressure roller on the material roll.

[0032] Preferably, the position signal includes an angle signal and a distance signal, the angle signal is an included angle ɑ of a material collecting roller and pressure roller axis center connecting line L and an initial position material collecting roller and pressure roller axis center connecting line L0, a normal line of the material collecting roller and pressure roller axis center connecting line L is L', and the included angle ɑ is also an angle between the gravity G of the pressure roller and the normal line L'; and the distance signal is a material roll thickness D.

[0033] Beneficial effects: The scheme adopts the above setting, facilitates the encoder to quickly obtain the angle signal and the distance signal and transmit the signals to the controller to calculate the real-time pushing air pressure P value of the cylinder, so that the constant pressure control of the pressure roller on the material roll can be realized.

[0034] Specifically, as Figure 3As shown, the line connecting the axes of the take-up roller and the pressure roller is L, and the initial position of the line connecting the axes of the take-up roller and the pressure roller is L0; L0' is parallel to L0; according to Euclidean law, ∠OAB=∠AOC; we draw a normal line L' perpendicular to the line connecting the axes of the take-up roller and the pressure roller, and we know that ∠AOG+∠OAB=90°, ∠AOG+∠OGB=90°, therefore ∠OAB=∠OGB=ɑ.

[0035] Preferably, the formula for calculating the cylinder-driven air pressure P is as follows: the pressure F of the pressure roller on the material roll is composed of the cylinder pressure F1 and the component of the pressure roller's gravity G on the line L connecting the take-up roller and the pressure roller's axis. 分 The effect of the reaction force F2 of the material roll on the pressure roller, where F2 is the component of the weight of the material roll and the take-up roller along the line L connecting the axes of the take-up roller and the pressure roller, that is:

[0036] F = F1 - F2 - G 分 (Equation 3);

[0037] According to the pressure formula, F1 = PS, where P is the cylinder air pressure and S is the cross-section of the cylinder.

[0038] According to the sine formula sinɑ=G 分 / G 压 and gravity formula G 压 =M 压 As can be seen from the deformation, the formula for calculating the component of the weight of the pressure roller along line L connecting the axes of the take-up roller and the pressure roller as the rotation angle α of the rotating disk is as follows:

[0039] G 分 =M 压 g·sinɑ (Equation 4);

[0040] In Equation 4, M 压 Let g be the mass of the pressure roller, g be the acceleration due to gravity, and α be the angle by which the line connecting the axes of the pressure roller and the take-up roller deviates from the horizontal plane.

[0041] Combining the mass-volume formula M=ρV, the volume formula V=S·l, and the sine formula sinɑ=F2 / G (料+收卷) and the gravity formula G 收卷 =M 料 g+M 收卷 As can be seen from the deformation, the calculation formula for the component of the gravity of the take-up roller and the material roll along the line L connecting the axes of the take-up roller and the pressure roller, as the rotation angle α of the rotary disk changes, is as follows:

[0042] F2={ρ 料 [π(Dd) 2 ·L-πd 2 ·l]g+M 收卷 g}·sinα (Equation 5);

[0043] In Equation 5, ρ 料 Where D is the density of the coil, d is the thickness of the coil, d is the radius of the take-up roll, L is the length of the coil, l is the length of the take-up roll, and M is the density of the coil. 收卷 For the quality of the take-up roller;

[0044] Where F is the constant pressure exerted by the pressure roller on the material roll during production. During the winding process, according to the transformation of Equations 3 to 5, the formula for calculating the cylinder pressure p is as follows:

[0045]

[0046] Beneficial effects: In formula 6 for calculating the cylinder pressure P obtained in this scheme, the fixed parameters include: the cross-sectional area S of the cylinder, the constant pressure F exerted by the pressure roller on the material roll during production, and the mass M of the pressure roller. 压 Gravitational acceleration g, density of the roll ρ 料 1. Rewinding roll radius d, coil length L, rewinding roll length l, rewinding roll mass M 收卷 .

[0047] The varying parameters include: the angle α between the axis of the pressure roller and the take-up roller and the horizontal plane, and the thickness D of the roll.

[0048] Therefore, in Equation 6, the calculation formula for the cylinder pressure P obtained in this scheme, there are only two changing quantities, both of which can be directly detected. The absolute encoder detects these two changing quantities (α and D) in real time, generating position signals that are transmitted to the controller. The controller can quickly calculate the cylinder pressure P based on the received position signals and Equation 6, and adjust the cylinder control valve according to the P value to achieve constant pressure control of the pressure roller on the material roll. Compared to the existing technology where the pressure change process is more complex and involves more calculation variables when adding a swing arm to transmit thrust (as in Equation 1), this scheme has fewer changing factors, and both changing quantities can be directly detected by the encoder, effectively improving the stability and accuracy of constant pressure control.

[0049] Preferably, the steps include:

[0050] S1. Preset device parameters and formula 6 in the controller: After installing the device, preset the device parameters and formula 6 into the controller;

[0051] S2. Start-up: Based on the initial positions of the pressure roller and the take-up roller, the controller calculates the required pressure P of the cylinder and starts the cylinder and pressure roller according to the value of P.

[0052] S3. Real-time calculation: The encoder collects the position data of the pressure roller and the take-up roller in real time, forms an angle signal α and a thickness signal D, and transmits them to the controller; after receiving the angle signal α and the thickness signal D, the controller calculates the real-time air pressure P value according to Equation 6.

[0053] S3, real-time regulation: the controller controls the size of the control valve of the cylinder according to the calculated air pressure P value in S2;

[0054] S4, continuous regulation: the controller repeatedly runs S2 and S3 in real time to realize constant pressure control of the pressure roller on the material roll.

[0055] Beneficial effects: the above-mentioned arrangement is adopted to calculate the air pressure P value pushed by the cylinder through the data collected by the encoder in real time, and then the size of the control valve of the cylinder is controlled according to the air pressure P value, so that constant pressure control of the pressure roller on the material roll can be realized. In the present application, the interference factors of the pressure F of the pressure roller on the material roll are less, and the above-mentioned scheme can be used to control the pressure F of the pressure roller on the material roll in real time, so that the material can be wound under constant pressure, thereby effectively avoiding the change of the local surface tension of the material caused by the change of the pressure F of the pressure roller on the material roll during the material winding process, and affecting the quality of the material. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 The structure diagram of the swing arm-containing rotary frame in the prior art CN113860031A.

[0057] Figure 2 The structure diagram of the constant pressure control device of the rotary disc pressure roller in the embodiment 1 of the present application.

[0058] Figure 3 The rotation angle relationship diagram during the operation of the constant pressure control device of the rotary disc pressure roller in the embodiment 1 of the present application.

[0059] Figure 4 The force direction diagram when the winding roller and the pressure roller are in state one in the embodiment 1 of the present application.

[0060] Figure 5 The force direction diagram when the winding roller and the pressure roller are in state two in the embodiment 1 of the present application. DETAILED DESCRIPTION

[0061] The following will be further described in detail through specific embodiments:

[0062] The reference signs in the drawings of the specification include: rotary disc 1, first material winding roller 21, material roll 211, first pressure roller 22, first cylinder 23, second material winding roller 31, second pressure roller 32, second cylinder 33, chute 4, pressure roller cylinder 8, swing arm 10, material roll 12, material winding pressure roller 14.

[0063] Embodiment 1

[0064] The present embodiment is basically as follows Figure 2The device for controlling the constant pressure of the rotating disc and the roller comprises a rotating disc 1 and a controller.

[0065] The rotating disc 1 is circumferentially symmetrical with a material collecting roller, and the rotating disc 1 is provided with a fixedly connected pressure roller and a cylinder corresponding to the material collecting roller, the rotating disc 1 is radially provided with a slide rail passing through the center of the rotating disc 1, the cylinder is fixed on both sides of the slide rail on the rotating disc 1, and the pressure roller is slidably connected in the slide rail, and the sliding direction of the pressure roller passes through the axis of the material collecting roller.

[0066] The rotating disc 1 is provided with a driving motor, and a belt is arranged between the driving motor and the center shaft of the rotating disc 1.

[0067] As a reference, the controller in the scheme is specifically a PLC controller, and the PLC controller, the absolute value encoder, the cylinder and the driving motor in the scheme can be purchased according to the actual needs of equipment installation, and details are not repeated here.

[0068] In the scheme, the cylinder pressure F1 can be directly transmitted to the pressure roller, and the direction of F1 passes through the axis of the material collecting roller, so that the factors affecting the constant pressure control are simplified to the relative spatial position of the pressure roller and the material collecting roller (i.e. the rotating angle α of the rotating disc 1 and the thickness of the material roll 211), effectively reducing the interference factors affecting the actual action of the pressure roller on the material roll 211, reducing the difficulty of constant pressure control, and improving the stability and accuracy of constant pressure control.

[0069] Further, in the present application, the swing arm is not needed, the cylinder is in contact with the compression roller and is fixed, which not only makes the pressure transmission more direct, reduces the energy consumption, reduces the factors affecting the constant pressure control, and improves the stability and accuracy of the constant pressure control; in the present application, the cylinder directly pushes the compression roller to slide towards the center of the winding roller shaft, so that the sliding direction and the pressure F direction are the same, which can also significantly reduce the energy consumption loss and equipment wear, effectively improve the service life of the equipment, and reduce the replacement cost of the equipment; and the structure of the equipment in the present application is simpler, more compact and stable, without the need for more equipment avoiding space, effectively improving the continuity of the material roll 211 winding, and improving the production efficiency.

[0070] The present application also provides a rotating disc compression roller constant pressure control method, which is performed in the rotating disc compression roller constant pressure control device, and includes that an encoder collects position data of the compression roller and the material receiving roller in real time to form a position signal and transmits the position signal to a controller; after receiving the position signal, the controller calculates a cylinder pushing air pressure P value on the premise of assuming that the compression roller has a pressure F on the material roll; and the controller controls a control valve size of the cylinder according to the pushing air pressure P value.

[0071] Taking the first material receiving roller 21 (i.e. Figure 2 the winding roller A in the middle), the first compression roller 22, and the first cylinder 23 as an example, the rotating disc compression roller constant pressure control method in the present application is specifically described, which specifically includes the following steps:

[0072] S1, presetting device parameters in the controller and a calculation formula of the cylinder pushing air pressure P value: after installing the device, the device parameters and the calculation formula are preset in the controller;

[0073] As shown in the formula, the calculation process of the cylinder pushing air pressure P value is as follows: Figure 2

[0074] The material receiving roller and the compression roller are installed in a horizontal position and are sequentially in an initial position, at which time the gravity of the compression roller does not affect the pressure of the compression roller on the material roll, that is, the pushing force F1 of the cylinder is equal to the pressure F of the compression roller on the material roll; it can be known from the pressure formula that F=F1=PS:

[0075] P=F / S (formula 2);

[0076] In formula 2, F is the theoretical constant pressure value of the compression roller on the material roll, P is the air pressure of the cylinder, and S is the cross section of the cylinder;

[0077] Further, the pressure F of the compression roller on the material roll is affected by the cylinder pressure F1, the gravity G of the compression roller on the material receiving roller and the compression roller shaft center, the force F2 of the material roll on the compression roller, and the force F2 of the material roll on the compression roller, that is: 分

[0078] F=F1-F2-G 分 (formula 3);​​

[0079] According to the pressure formula, F1=PS, P is the cylinder pressure in formula 3, and S is the cross section of the cylinder.

[0080] According to the sine formula sinɑ=G 分 / G 压 and the gravity formula G 压 =M 压 g, the force of the compression roller gravity on the line L between the compression roller and the winding roller can be calculated as follows with the change of the rotation angle ɑ of the rotating disc:

[0081] G 分 =M 压 g·sinɑ (formula 4);

[0082] In formula 4, M 压 is the mass of the compression roller, g is the acceleration of gravity, and ɑ is the angle of the line between the compression roller and the winding roller deviating from the horizontal plane.

[0083] According to the mass-volume calculation formula M=ρV, the volume formula V=S·l, the sine formula sinɑ=F2 / G (料+收卷) , and the gravity formula G 收卷 =M 料 g+M 收卷 g, the force of the winding roller and the roll gravity on the line L between the winding roller and the compression roller can be calculated as follows with the change of the rotation angle ɑ of the rotating disc:

[0084] F2={ρ 料 [π(D-d) 2 ·L-πd 2 ·l]g+M 收卷 g}·sinα (formula 5);

[0085] In formula 5, ρ 料 is the density of the roll, D is the thickness of the roll, d is the radius of the winding roller, L is the length of the roll, l is the length of the winding roller, and M 收卷 is the mass of the winding roller.

[0086] Where F is the constant pressure of the compression roller acting on the roll during production. According to the deformation of formulas 3-5, the calculation formula of the cylinder pressure p during the winding process is as follows:

[0087]

[0088] S2, start-up: according to the initial positions of the compression roller and the winding roller, the required pressure P of the cylinder is calculated, and then the controller starts the cylinder and the compression roller according to the value of P.

[0089] S3, Real-time calculation: the encoder collects the position data of the pressure roller and the receiving roller in real time to form the angle signal a and the thickness signal D and transmits them to the controller; after receiving the angle signal a and the thickness signal D, the controller calculates the real-time air pressure P value according to formula 6;

[0090] In the scheme, the position signal includes an angle signal and a distance signal, the angle signal is the included angle a of the receiving roller and the pressure roller axis connecting line L and the receiving roller and the pressure roller axis connecting line L0 at the initial position, the normal line of the receiving roller and the pressure roller axis connecting line L is L', and the included angle a is also the angle between the pressure roller gravity G and the normal line L'; the distance signal is the thickness D of the material roll.

[0091] S3, Real-time regulation: the controller controls the size of the control valve of the air cylinder according to the air pressure P value calculated in S2;

[0092] S4, Continuous regulation: the controller repeatedly runs S2 and S3 in real time to realize the constant pressure control of the pressure roller on the material roll.

[0093] In the scheme, the air cylinder pushing air pressure P value is calculated by the data collected by the encoder in real time, and then the size of the control valve of the air cylinder is controlled according to the pushing air pressure P value, so that the constant pressure control of the pressure roller on the material roll can be realized. In the scheme, the interference factors of the pressure F of the pressure roller on the material roll are less, and the above scheme can be used to control the pressure F of the pressure roller on the material roll in real time, so that the material can be wound under constant pressure, thereby effectively avoiding the change of the local surface tension of the material caused by the change of the pressure F of the pressure roller on the material roll during the material winding process, which affects the quality of the material.

[0094] Experimental example 1: verification of formula 6

[0095] Initial position: as shown in Figure 2 , it is assumed that the parallel position of the winding roller and the pressure roller is the initial position, the pressure applied by the air cylinder drives the pressure roller to give the winding pressure, this pressure is F1, at this time the gravity of the winding roller and the pressure roller does not affect the pressure F of the pressure roller on the material roll, F1 is also equal to the pressure F of the pressure roller on the material roll, that is, F1=F.

[0096] State one: as shown in Figure 4 , with the rotation of the rotating disc, the relative position relationship of the winding roller and the pressure roller from the initial position enters state one, that is, the winding roller and the pressure roller move to the upper side of the air cylinder, at this time, the pressure F of the pressure roller on the surface of the material roll on the winding roller will be affected by the weight of the pressure roller, the gravity of the winding roller and the material roll, at this time the pushing force of the air cylinder to drive the pressure roller includes the component force G 分 of the pressure roller gravity on the receiving roller and the pressure roller axis connecting line L, the component force F2 of the gravity of the winding roller and the material roll on the receiving roller and the pressure roller axis connecting line L and the pressure F of the pressure roller on the material roll, that is, F1=F+G 分 +F2, a larger air cylinder pushing air pressure P is needed to maintain the constant pressure F of the pressure roller on the material roll.

[0097] In this state (i.e., 0° < ɑ < 180°), in Formula 6 of this solution, sinɑ > 0, making F1 > F. This calculation result is consistent with the inference in the above State 1 that "a greater air pressure P for the cylinder is required to maintain a constant pressure F of the pressure roller on the material roll".

[0098] State 2: As Figure 5 shown, as the rotating disk rotates, the relative positional relationship between the winding roller and the pressure roller changes from State 1 to State 2, that is, the winding roller and the pressure roller move below the cylinder. At this time, the component forces of the weight of the pressure roller, the gravity of the winding roller and the material roll on the connecting line L between the axes of the winding roller and the pressure roller all contribute to pressing the pressure roller against the material roll.

[0099] That is, F1 = F - G 分 - F2, and a smaller air pressure P for the cylinder is required to maintain a constant pressure F of the pressure roller on the material roll.

[0100] In this state (i.e., 180° < ɑ < 360°), in Formula 6 of this solution, sinɑ < 0, making F1 < F. This calculation result is consistent with the inference in the above State 1 that "a smaller air pressure P for the cylinder is required to maintain a constant pressure F of the pressure roller on the material roll".

[0101] Experimental Example 2: Application of the constant pressure control method for the rotating disk pressure roller

[0102] This solution also includes an application of the constant pressure control method for the rotating disk pressure roller, specifically including the application of the constant pressure control device for the rotating disk pressure roller and the constant pressure control method for the rotating disk pressure roller in winding PE films. When using the constant pressure control device for the rotating disk pressure roller and the constant pressure control method for the rotating disk pressure roller of this solution to wind PE films, there are basically no wrinkles inside the wound material roll, indicating that the winding pressure of the pressure roller during winding the PE film is relatively constant and there is no local stretching phenomenon; while when using the control method of the non - counterweight winding pressure roller in the prior art CN113860031A to wind the same PE film, due to the periodic change of the reaction force of the gravity of the material roll and the winding roller on the pressure roller, and this part of the pressure change is not considered in the constant pressure control calculation formula of the pressure roller, resulting in a periodic change in the pressure of the pressure roller cylinder, and there are still local periodic stretching phenomena in the wound material roll, thus causing wrinkles inside the material roll and affecting the application of the PE film in the material roll. By comparison, the constant pressure control device for the rotating disk pressure roller and the constant pressure control method for the rotating disk pressure roller of this solution have a significantly lower impact on the surface tension of the material during the winding of PE films than the prior art. It can not only effectively reduce the energy consumption of the operation of the pressure roller cylinder; and the constant pressure control device for the pressure roller of this solution can also significantly reduce the losses during the operation of the equipment, and can also achieve the constant pressure control of the pressure roller on the material roll, significantly reducing the impact of the pressure roller on the surface tension of the material during winding and ensuring the quality of the material.

[0103] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for controlling constant pressure on a rotating disc pressure roller, characterized in that: The constant pressure control of the rotary disc pressure roller is performed in a device that includes a rotary disc and a controller. The rotary disc is equipped with an encoder. A take-up roller is symmetrically arranged around the rotary disc. A pressure roller and a cylinder are fixedly connected to the take-up roller on the rotary disc, with the cylinder fixed to the rotary disc and the pressure roller slidably connected to the rotary disc. The cylinder pushes the pressure roller in a sliding direction past the axis of the take-up roller. The encoder, cylinder, and controller are electrically connected. The control method includes an encoder acquiring position data of the pressure roller and take-up roller in real time to form a position signal and transmitting the position signal to the controller; after receiving the position signal, the controller calculates the cylinder pushing air pressure P value based on the position signal, assuming the pressure F of the pressure roller on the material roll; the controller then controls the size of the cylinder control valve based on the pushing air pressure P value. Before the encoder collects data, the take-up roller and pressure roller are installed in a horizontal position as the initial position. At this time, the weight of the pressure roller does not affect the pressure of the pressure roller on the material roll, that is, the thrust of the cylinder F1 = the pressure of the pressure roller on the material roll F; combined with the pressure formula, we know that F=F1=PS, P=F / S (Equation 2), where F is the theoretical constant pressure value of the pressure roller on the material roll, P is the air pressure of the cylinder, and S is the cross-section of the cylinder. The position signal includes an angle signal and a distance signal. The angle signal is the angle α between the line L connecting the axes of the take-up roller and the pressure roller and the line L0 connecting the axes of the take-up roller and the pressure roller at the initial position. The normal to the line L connecting the axes of the take-up roller and the pressure roller is L'. The distance signal is the thickness D of the roll. The formula for calculating the cylinder-driven air pressure P is as follows: the pressure F of the pressure roller on the material roll is composed of the cylinder pressure F1 and the component of the pressure roller's gravity G on the line connecting the take-up roller and the pressure roller's axis G. 分 The effect of the reaction force F2 of the material roll on the pressure roller, where F2 is the component of the weight of the material roll and the take-up roller along the line connecting the axes of the take-up roller and the pressure roller, that is: F = F1 - F2 - G 分 (Equation 3); According to the pressure formula, F1=PS, where P is the cylinder air pressure and S is the cross-section of the cylinder. According to the sine formula sinɑ=G 分 / G 压 and gravity formula G 压 =M 压 As can be seen from the deformation, the formula for calculating the component of the weight of the pressure roller along line L connecting the axes of the take-up roller and the pressure roller as angle α changes is as follows: G 分 =M 压 g·sinɑ (Formula 4); In Equation 4, M 压 Let g be the mass of the pressure roller, and g be the acceleration due to gravity. Combining the mass-volume formula M=ρV, the volume formula V=S·l, and the sine formula sinɑ=F2 / G （料+收卷） and the gravity formula G 收卷 =M 料 g+M 收卷 As can be seen from the deformation, the calculation formula for the component of the gravity of the take-up roller and the material roll along line L connecting the axes of the take-up roller and the pressure roller, as the angle α changes, is as follows: F2 = {ρ 料 [π(D - d) 2 ·L - πd 2 ·l]g + M 收卷 g}·sinɑ (Equation 5); In Equation 5, ρ 料 Where D is the density of the coil, d is the thickness of the coil, d is the radius of the take-up roll, L is the length of the coil, l is the length of the take-up roll, and M is the density of the coil. 收卷 For the quality of the take-up roller; Where F is the constant pressure exerted by the pressure roller on the material roll during production. During the winding process, according to the transformation of Equations 3 to 5, the formula for calculating the cylinder pressure p is as follows: (Formula 6).

2. The method for controlling constant pressure of a rotating disc pressure roller according to claim 1, characterized in that: The rotating disk is provided with a radial slide rail passing through the center of the rotating disk, and the pressure roller is slidably connected in the slide rail.

3. The method for controlling constant pressure of a rotary disc pressure roller according to claim 1, characterized in that: The rotating disk is symmetrically equipped with two receiving rollers, including a first receiving roller and a second receiving roller. The first receiving roller is equipped with a first pressure roller and a first cylinder. The first pressure roller is slidably connected in a slide rail, and the first cylinder is fixed on one side of the slide rail. The piston rod of the first cylinder is fixedly connected to the side of the first pressure roller. The second receiving roller is equipped with a second pressure roller and a second cylinder. The second pressure roller is slidably connected in a slide rail, and the second cylinder is fixed on the other side of the slide rail. The piston rod of the second cylinder is fixedly connected to the side of the second pressure roller. Both the first cylinder and the second cylinder are electrically connected to the controller.

4. The method for controlling constant pressure of a rotating disc pressure roller according to claim 1, characterized in that: The encoder is fixed on the central shaft of the rotating disk and rotates synchronously with the rotating disk.

5. The method for controlling constant pressure of a rotary disc pressure roller according to claim 1, characterized in that: The encoder is an absolute encoder; the rotary disk is equipped with a drive motor, and a belt is stretched between the drive motor and the central shaft of the rotary disk. The drive motor is electrically connected to the controller.

6. The method for controlling constant pressure of a rotating disc pressure roller according to claim 1, characterized in that: Includes the following steps: S1. Preset device parameters and formula 6 in the controller: After installing the device, preset the device parameters and formula 6 into the controller; S2. Start-up: Based on the initial positions of the pressure roller and the take-up roller, the controller calculates the required pressure P of the cylinder and starts the cylinder and pressure roller according to the value of P. S3. Real-time calculation: The encoder collects the position data of the pressure roller and the take-up roller in real time, forms an angle signal α and a thickness signal D, and transmits them to the controller; after receiving the angle signal α and the thickness signal D, the controller calculates the real-time air pressure P value according to Equation 6. S4. Real-time control: The controller controls the size of the cylinder's control valve based on the air pressure P value calculated by S3. S5. Continuous control: The controller repeatedly runs S3 and S4 in real time to achieve constant pressure control of the pressure roller on the material roll.

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