Paper feeding and winding tension stabilizing control device and method

Abstract

The application provides a paper feeding and winding tension stable control device and method, and the method comprises the following steps: obtaining an arm swing angular velocity time domain signal in a feeding process; substituting the arm swing angular velocity time domain signal into a preset arm swing angular velocity, telescopic cylinder thrust and paper tension relationship formula to obtain the telescopic cylinder thrust; and compensating the paper tension by using the telescopic cylinder thrust according to a preset paper tension fluctuation range. The application can eliminate paper shaking, so that the feeding mechanism can smoothly feed, and the printing product quality is improved.

Description

Technical Field

[0001] The present invention relates to the field of automatic control of mechanical equipment, and more particularly to a device and method for stabilizing the tension of paper rewinding and unrewinding materials. Background Art

[0002] like Figure 1 The figure shows the structure of a conventional industrial printer's unwinding and rewinding system during paper feeding. The unwinding and rewinding system is divided into two sections, separated by a paper pressing rod 6 and arranged in the direction of paper 1's movement: the unwinding section and the rewinding section. The first section is the unwinding section: the unwinding motor 2 drives the unwinding roller 3 to unwind the paper, while the unwinding rocker 5 adjusts the direction of the paper 1 before continuing to the second section. In this section, an ultrasonic unwinding sensor 4 provides feedback on the position of the unwinding rocker 5, controlling the operation of the unwinding motor 2 to ensure sufficient paper is unwound within a single printing cycle. The second part is the receiving part: the traction motor 7 and the receiving motor 13 are started synchronously, the paper pressing rod 6 presses the paper 1 against the surface of the traction active roller 8 to increase the friction, and the traction motor 7 drives the traction active roller 8 to rotate, thereby pulling the paper 1 toward the printing platform 9; after the paper 1 passes through the printing process, the angle is adjusted by the first driven roller 10, and then the receiving rocker 11 tensions the paper 1, and passes through the second driven roller 12 to the receiving active roller 14, and the receiving motor 13 drives the receiving active roller 14 to retract the feed of a single printing cycle. The receiving part relies on the receiving ultrasonic sensor 15 to feedback the position of the receiving rocker 11 to control the operation of the receiving motor 13, and recycle the length of the discharged paper 1 within a single printing cycle. During the entire receiving and releasing process, it is mainly the receiving rocker 11 part that provides tension for the printing paper. The side of the receiving rocker 11 is always in contact with the printing paper 1, such as Figure 2 As shown, the receiving rocker 11 is a roller structure, and a gear 11a is provided at the end of the receiving rocker 11, which can rotate relative to the roller surface of the receiving rocker 11. The gear 11a is engaged with the rack 16 on the equipment support frame, and automatically adjusts its engagement position on the rack 16 according to the tension of the paper 1 and the gravity of the receiving rocker 11, thereby adjusting the paper tension. For example, when the paper 1 is not taut, the paper tension is small, so the resistance of the receiving rocker 11 in the direction of gravity is small, and the receiving rocker 11 moves downward along the rack 16, thereby tautening the paper 1 to increase the tension of the paper 1.

[0003] However, due to the structure of the receiving rocker arm 11, during the initial stage of paper feeding by the traction motor 7, the paper 1 will suddenly relax, and the receiving rocker arm 11 will drop to provide tension on the paper, making it difficult to ensure that the paper is always taut, and the paper is prone to jitter during paper feeding. In order to eliminate the jitter of the paper, it is necessary to increase the tension of the paper during paper feeding. The existing receiving rocker arm 11 structure is generally achieved by increasing the weight of the receiving rocker arm 11, which makes the receiving rocker arm 11 very heavy and increases the load on the receiving motor 13, greatly increasing the cost of the receiving and unloading device. Even if the weight of the receiving rocker arm 11 is increased, the tension of the paper will still fluctuate within a large range after the size of the current receiving and unloading system structure is fixed. In addition, different tension requirements are required for papers of different thicknesses, which cannot be met by the current receiving rocker arm 11 structure. Therefore, it is necessary to improve the structure of the receiving rocker arm 11 to ensure that the paper 1 is taut during paper feeding and eliminate the jitter of the paper 1 during paper feeding.

[0004] In summary, since the existing printer rewinding and unwinding device often has large fluctuations in paper tension when rewinding and unwinding industrial printer roll paper, it is prone to jitter, which increases the load on the rewinding motor and reduces printing efficiency. The jitter causes uneven rewinding, affecting product quality. Therefore, it is of great significance to design a simple and quick solution to maintain or stabilize the tension of the paper roll. Summary of the Invention

[0005] In response to the technical problems existing in the prior art, the present invention provides a paper feeding and unfeeding tension stabilization control device and method, which can eliminate paper jitter, enable the feeding mechanism to feed paper smoothly, and improve the quality of printed products.

[0006] According to a first aspect of the present invention, a paper feeding and unfeeding tension stabilization control device is provided, comprising a traction mechanism, a tension adjustment mechanism, and a feeding mechanism sequentially arranged along a paper moving path.

[0007] The traction mechanism is used to pull the paper to move according to the feeding signal;

[0008] The tension adjustment mechanism collects the action signal of the traction mechanism and actively keeps the paper taut according to the action signal of the traction mechanism and its own rotation angle, so as to dynamically adjust the tension of the paper;

[0009] The material receiving mechanism is used to drive the paper to be reeled in accordance with the feeding signal.

[0010] On the basis of the above technical solution, the present invention can also make the following improvements.

[0011] Optionally, the tension adjusting mechanism comprises a first driven roller, a tension roller and a second driven roller arranged in sequence along the moving path of the paper, the roller surface of the first driven roller, the roller surface of the tension roller and the roller surface of the second driven roller are respectively in rolling cooperation with the paper; further comprising a swing arm, an angle detection module, a telescopic cylinder and a driving module, the end of the tension roller is hinged with the end of the second driven roller through the swing arm, so that the swing arm can drive the tension roller to rotate around the circumference of the second driven roller; the angle detection module is arranged at the hinge point of the swing arm and the second driven roller, and is used to measure the angle of the swing arm rotating around the second driven roller; the movable end of the telescopic cylinder is hinged with the swing arm to drive the swing arm to rotate around the circumference of the second driven roller, and the driving module is connected with the telescopic cylinder to drive the movable end of the telescopic cylinder to extend and retract.

[0012] Optionally, the traction mechanism comprises a paper pressing rod, a traction motor and a traction driving roller,

[0013] The paper pressing rod, the traction driving roller and the first driven roller are arranged in sequence along the moving path of the paper, and the paper pressing rod, the traction driving roller and the first driven roller are all arranged perpendicularly to the moving direction of the paper, and the paper pressing rod, the traction driving roller and the first driven roller are arranged in parallel with each other.

[0014] The paper pressing rod and the traction driving roller are arranged on the two sides of the paper respectively and are in close contact with the paper, and the traction motor is in transmission connection with the traction driving roller to drive the traction driving roller to rotate.

[0015] Optionally, the material collecting mechanism comprises a material collecting driving roller and a material collecting motor, the second driven roller and the material collecting driving roller are arranged in sequence along the moving path of the paper, and the second driven roller and the material collecting driving roller are arranged in parallel and the side surfaces of both are in cooperation with the paper, the material collecting motor is in transmission connection with the material collecting driving roller to drive the material collecting driving roller to rotate, and the material collecting driving roller rotates to roll up the paper.

[0016] According to the second aspect of the present application, based on the foregoing paper feeding and discharging tension stabilizing control device, a paper feeding and discharging tension stabilizing control method is further provided, comprising:

[0017] Obtaining the swing arm angular velocity time domain signal in the feeding process;

[0018] Substituting the swing arm angular velocity time domain signal into the preset relationship between the swing arm angular velocity, the telescopic cylinder thrust and the paper tension to obtain the telescopic cylinder thrust;

[0019] According to the preset paper tension fluctuation range, the telescopic cylinder thrust is used to compensate the paper tension.

[0020] Optionally, the method further comprises selecting the structural parameters of the paper feeding and discharging tension stabilizing control device, specifically comprising:

[0021] The paper is arranged to frictionally engage with the first driven roller, the tensioning roller and the second driven roller in sequence in the forward path;

[0022] Define the axis of the first driven roller as C, the axis of the tensioning roller as B, and the axis of the second driven roller as A. The radius of the first driven roller 10 is r3, the radius of the tensioning roller is r2, and the radius of the second driven roller is r1. The length of the swing arm of the traction mechanism is AB. The hinge point of the telescopic cylinder on the swing arm is D. The end of the telescopic cylinder away from the swing arm is E. The length of the telescopic cylinder ED can change synchronously according to the telescopic state of the telescopic cylinder. The tangent point of the paper on the first driven roller near the tensioning roller is C1. The two tangent points of the paper on the tensioning roller are B1 and B2, respectively. The tangent point B2 is close to the first driven roller, the tangent point B1 is close to the second driven roller, and the tangent point of the paper on the second driven roller near the tensioning roller is A1.

[0023] Assume that the mass of the swing arm is m1, the mass of the tension roller is m2, the length of the swing arm AB = L1, the length from the hinge point D to the axis A of the second driven roller AD = L2, and the coordinates of each point are defined as follows: A(x1, y1), B(x2, y2), C(x3, y3), A1(x4, y4), B1(x5, y5), B2(x6, y6), C1(x7, y7), E(x0, y0), D(x8, y8), the angle between AB and the horizontal direction is θ1, the angle between A1B1 and the horizontal direction is θ2, the angle between ED and the vertical direction is θ, the angle between BC and the vertical direction is θ3, and the angle between B2C1 and the vertical direction is θ4;

[0024] Points A, E, and C are fixed points with fixed coordinates. Radius r1, r2, and r3 are fixed values. Set A as the origin, and let its coordinates x1 = 0 and y1 = 0. Since the paper is tangent to the rollers in a taut state, the following relationship can be obtained:

[0025] Point B coordinates (x2, y2) and BC length:

[0026] x2=cosθ1·L1, y2=sinθ1·L1,

[0027] According to the angle relationship, we can get:

[0028] θ2=θ1+α1,

[0029] Among them, α1 is the difference between the angle θ2 and the angle θ1;

[0030] Then, from vectors AA1 and BB1, we can get the coordinates of the tangent point A1 (x4, y4) and the tangent point B1 (x5, y5):

[0031]

[0032] Then according to the B, C coordinates and BC length, the included angles θ3, θ4 can be obtained:

[0033] θ4=θ3-α2,

[0034] Wherein, α2 is the difference between the included angle θ3 and the included angle θ4;

[0035] The B2 coordinate (x6, y6) and C1 coordinate (x7, y7) can be obtained by the following formula:

[0036]

[0037] For the telescopic cylinder length ED, the D coordinate (x8, y8) can be obtained according to the length AD from the hinge point D to the second driven roller shaft center A and the included angle θ1 between AB and the horizontal direction, and the included angle θ between ED and the vertical direction can be obtained according to the D coordinate (x8, y8) and the E coordinate (x0, y0).

[0038] D (x8, y8): x8=cosθ1·L2, y8=sinθ1·L2,

[0039] In summary, under the premise of knowing each constant parameter, only the included angle θ1 between AB and the horizontal direction needs to be detected to obtain the remaining structure parameters, and then the device structure is set according to all the obtained structure parameters.

[0040] Optionally, the step of analyzing the relationship between the swing arm angular velocity, the telescopic cylinder thrust and the paper tension comprises:

[0041] Suppose the paper is in a taut state, and take the swing arm, the tension roller and the paper attached thereto as a whole, and decompose each force along the swing arm direction and perpendicular to the swing arm direction respectively;

[0042] The force condition of the tension roller along the swing arm direction is analyzed to obtain the force expression of the tension roller perpendicular to the swing arm direction:

[0043] F1·cosα1+m2g sinθ1=N+F2·sin(θ4-θ1)

[0044]

[0045] Where, F1 is the tension of the paper segment A1B1, F2 is the tension of the paper segment B2C1, N is the support force of the swing arm on the tension roller, Δr2 is the inner diameter of the bearing inside the tension roller, ΔF=F1-F2, α1 is the difference between the angle θ2 and the angle θ1, m2 is the mass of the tension roller, g is the gravity coefficient, J is the moment of inertia of the swing arm and the tension roller relative to the axis A of the second driven roller, ω is the swing angular velocity of the swing arm, J2 is the moment of inertia of the tension roller, μ2 is the friction coefficient between the roller surface of the tension roller and the internal rolling bearing, and ω2 is the angular velocity of the tension roller; ΔF is the tension difference of the paper on both sides of the tension roller. When the friction coefficient μ2 between the roller surface of the tension roller and the internal rolling bearing and the moment of inertia J2 of the tension roller are small, ΔF can be regarded as a small value.

[0046] By analyzing the force on the tension roller perpendicular to the swing arm, the force expression of the tension roller perpendicular to the swing arm is obtained:

[0047]

[0048] Simplifying the force expression of the tension roller perpendicular to the swing arm direction, we can get:

[0049]

[0050] Among them, F is the thrust of the telescopic cylinder. It can be seen from the above formula that when the thrust F of the telescopic cylinder increases, the paper tension will increase proportionally. By changing the thrust of the telescopic cylinder, the tension of the paper during printing can be adjusted.

[0051] Optionally, the step of analyzing the fluctuation range of paper tension includes:

[0052] Obtain the variation trend of paper tension with swing arm angle under static state and various levels of telescopic cylinder thrust value, so as to fit the relationship between the influence of telescopic cylinder thrust on paper tension;

[0053] Obtain the time domain signal of the swing arm angular velocity, integrate the swing arm angular velocity based on time, and obtain the swing arm angle fluctuation range based on the time domain;

[0054] Substituting the swing arm angle fluctuation range into the relationship between the swing arm angular velocity, the thrust of the telescopic cylinder and the paper tension, the paper tension fluctuation range based on the time domain without compensation is obtained.

[0055] Optionally, the paper tension can be compensated by using the telescopic cylinder thrust, including:

[0056] Subtract the paper tension fluctuation range from the preset optimal paper tension value to obtain the paper tension adjustment range based on the time domain;

[0057] Performing linear fitting on the paper tension adjustment range to obtain a relationship between the paper tension adjustment value and time; obtaining the start time of the traction mechanism and using the start time of the traction mechanism as the initial time of the paper tension adjustment;

[0058] Combining the relationship between the influence of the telescopic cylinder thrust on the paper tension and the relationship between the paper tension adjustment value and time, the thrust adjustment value of the telescopic cylinder thrust that changes with time is obtained;

[0059] The thrust adjustment value is used to control the thrust of the telescopic cylinder.

[0060] Optionally, the method further includes calculating an optimal paper tension according to paper parameters, specifically including:

[0061] Get the paper parameters and calculate the paper density D according to the following formula:

[0062] D=G / σ,

[0063] Where D is the density of the paper, in g / cm 3 ; G is the basis weight of the paper, in g / cm 2 ;σ is the thickness of the paper, in cm;

[0064] According to the paper density D and printing width H, the optimal paper tension F1 is calculated using the following formula:

[0065] F1=K·H·D,

[0066] Where K is the tension coefficient, which is determined based on experience.

[0067] The present invention provides a paper feeding and rewinding tension stabilization control device and control method. During feeding, the tension adjustment mechanism actively adjusts the paper tension by adjusting its own rotation angle to keep the paper taut, eliminate paper jitter, and enable the feeding mechanism to smoothly feed the paper, thereby improving the quality of printed products. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 This is the schematic diagram of the existing retracting and unretracting system;

[0069] Figure 2 Schematic diagram of the existing effective swing arm structure;

[0070] Figure 3 A schematic diagram of the structure of the tension adjustment mechanism in the paper feeding and unfeeding tension stabilization control device provided by the present invention;

[0071] Figure 4 This is a schematic diagram of the process flow for stabilizing the tension of retracting and unreeling materials during each printing cycle;

[0072] Figure 5 Schematic diagram of the structural relationship between the tensioning roller and the swing arm;

[0073] Figure 6 This is a schematic diagram of the force analysis of the tension roller;

[0074] Figure 7 This is a graph showing the variation trend of paper tension with the swing arm angle and telescopic cylinder pressure;

[0075] Figure 8 The following is a graph showing the variation of paper tension with the swing arm angle when the cylinder pressure F = 100N.

[0076] Figure 9 The following is a graph showing the variation trend of paper tension with cylinder pressure when the swing arm angle is 30°;

[0077] Figure 10 This is a schematic diagram of the swing arm angle fluctuation range when printing paper;

[0078] Figure 11 This is a diagram showing the paper tension fluctuation range during printing without increasing the tension adjustment;

[0079] Figure 12 Schematic diagram of the range in which paper tension needs to be adjusted.

[0080] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0081] 1. Paper, 2. Unloading motor, 3. Unloading roller, 4. Unloading ultrasonic sensor, 5. Unloading rocker, 6. Paper pressing rod, 7. Traction motor, 8. Traction active roller, 9. Printing platform, 10. First driven roller, 11. Rewinding rocker, 11a, Gear, 12. Second driven roller, 13. Rewinding motor, 14. Rewinding active roller, 15. Rewinding ultrasonic sensor, 16. Rack, 17. Tensioning roller, 18. Swing arm, 19. Angle detection module, 20. Telescopic cylinder, 21. Drive module. DETAILED DESCRIPTION

[0082] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0083] like Figure 1 The following is a schematic diagram of the principle of the material retracting and unreeling system for industrial printers. Figure 2 It is a schematic diagram of the structure of the existing printer receiving swing rod 11. Figure 1 The receiving swing rod 11 shown in the dotted box is improved to achieve the tension of the paper 1 during feeding and eliminate the shaking of the paper 1 during feeding. The rest of the receiving and unloading system can be used. Figure 1 The structures outside the dotted box shown, such as the unwinding motor 2 driving the unwinding roller 3 to unwind the material, and the receiving motor 13 driving the receiving active roller 14 to receive the material.

[0084] The paper feeding and discharging tension stabilizing control device provided by the embodiment comprises a traction mechanism, a tension adjusting mechanism and a receiving mechanism arranged in sequence along a moving path of the paper 1,

[0085] The traction mechanism is used for moving the paper 1 according to a feeding signal;

[0086] The tension adjusting mechanism collects an action signal of the traction mechanism, and actively keeps the paper 1 taut according to the action signal of the traction mechanism and a rotation angle of the tension adjusting mechanism, so as to dynamically adjust the tension of the paper 1;

[0087] The receiving mechanism is used for winding the paper 1 according to the feeding signal.

[0088] It can be understood that, based on the defects in the background art, the paper feeding and discharging tension stabilizing control device is provided in the embodiment to eliminate the paper 1 shaking. The difficulty of the improvement lies in that the paper flowing to the receiving mechanism will be relaxed at the initial stage of the paper feeding of the traction mechanism. Therefore, how to ensure that the tension of the paper is not too small to cause shaking when the weight of the receiving swing rod 11 is unchanged needs to be considered. The improvement idea of the embodiment is that the tension adjusting mechanism is started to act synchronously after the traction mechanism starts to act, and an additional force is applied to the tension adjusting mechanism to adjust the rotation angle of the tension adjusting mechanism, so that the paper 1 is kept taut at all times, the tension of the paper is maintained in a large state, the paper 1 shaking is eliminated, the receiving mechanism can smoothly receive the paper, and the printing product quality is improved. The defects in the background art are solved by adjusting the rotation angle of the tension adjusting mechanism, instead of relying on increasing the device quality to press the paper 1 and increase the tension, so that the equipment cost is reduced.

[0089] In a possible embodiment mode, as shown in Figure 3 The tension adjusting mechanism comprises a first driven roller 10, a tension roller 17 and a second driven roller 12 arranged in sequence along the moving path of the paper 1, the roller surface of the first driven roller 10, the roller surface of the tension roller 17 and the roller surface of the second driven roller 12 are respectively in rolling cooperation with the paper 1; the tension adjusting mechanism further comprises a swing arm 18, an angle detection module 19, a telescopic cylinder 20 and a driving module 21, the end of the tension roller 17 is hinged with the end of the second driven roller 12 through the swing arm 18, so that the swing arm 18 can drive the tension roller 17 to rotate around the circumference of the second driven roller 12; the angle detection module 19 is arranged at the hinge point of the swing arm 18 and the second driven roller 12, and is used for measuring the angle of the swing arm 18 rotating around the second driven roller 12; the movable end of the telescopic cylinder 20 is hinged with the swing arm 18 to drive the swing arm 18 to rotate around the circumference of the second driven roller 12, and the driving module 21 is connected with the telescopic cylinder 20 and is used for driving the movable end of the telescopic cylinder 20 to extend and retract.

[0090] It can be understood that the first driven roller 10 and the second driven roller 12 are used to adjust the forward direction of the paper 1. The paper 1 driven by the traction mechanism passes through the first driven roller 10 to move toward the tensioning roller 17, and the paper 1 that passes through the tensioning roller 17 passes through the second driven roller 12 and moves toward the material receiving mechanism. In this embodiment, the pressure of the telescopic cylinder 20 is added to the swing arm 18 to assist, so that the tension fluctuation of the paper is smaller and the paper is always in a taut state. Specifically, during the movement of the paper 1, the driving module 21 drives the telescopic cylinder 20 to extend and retract according to the action signal of the traction mechanism, thereby adjusting the rotation angle of the swing arm 18. The swing arm 18 drives the tensioning roller 17 at its end, so that the roller surface of the tensioning roller 17 keeps pressing the paper 1, so that the paper 1 is in a taut state during the entire printing process, and at the same time has a better tension to prevent the paper 1 from shaking and ensure the printing quality. The angle detection module 19 can be a goniostat. It detects the rotation angle / angular velocity of the swing arm 18 and provides feedback to a controller, such as a single-chip microcomputer or PLC system, to establish closed-loop control of the swing arm 18's rotation angle, improving control accuracy. The telescopic cylinder 20 can be a pneumatic cylinder, a hydraulic cylinder, or an electric cylinder. The configuration of the drive module 21 is accordingly tailored to the specific type of telescopic cylinder 20. For example, in this embodiment, a pneumatic cylinder is used as the telescopic cylinder 20. Accordingly, the drive module 21 uses an electric proportional valve that matches the cylinder to control the cylinder pressure, thereby driving the swing arm 18.

[0091] The improvement idea of ​​this embodiment is to apply additional force to the tension adjustment mechanism to adjust the rotation angle of the swing arm 18, so that the descending speed of the tensioning roller 17 is greater than the paper feeding speed of the traction mechanism, thereby maintaining a large tension on the paper 1 and keeping the paper 1 in a taut state.

[0092] In one possible embodiment, Figure 1 As shown, the traction mechanism includes a paper pressing rod 6, a traction motor 7 and a traction active roller 8.

[0093] The paper pressing rod 6, the traction active roller 8 and the first driven roller 10 are sequentially arranged along the moving path of the paper 1, and the paper pressing rod 6, the traction active roller 8 and the first driven roller 10 are all arranged perpendicular to the moving direction of the paper 1, and the paper pressing rod 6, the traction active roller 8 and the first driven roller 10 are arranged parallel to each other;

[0094] The paper pressing rod 6 and the traction active roller 8 are respectively arranged on both sides of the paper 1 and are both in contact with the paper 1. The traction motor 7 is transmission-connected to the traction active roller 8 to drive the traction active roller 8 to rotate.

[0095] It can be understood that during the paper feeding process, the paper pressing rod 6 presses the paper 1 toward the roller surface of the traction active roller 8, so that there is sufficient friction between the roller surface of the traction active roller 8 and the paper 1, and the traction motor 7 drives the traction active roller 8 to rotate. Due to the existence of rolling friction, the traction active roller 8 continuously pushes the paper 1 toward the printing platform 9 to complete the printing process. After printing, the paper 1 continues to flow to the tension adjustment mechanism.

[0096] In one possible embodiment, Figure 1 As shown, the material receiving mechanism includes a material receiving active roller 14 and a material receiving motor 13. The second driven roller 12 and the material receiving active roller 14 are arranged in sequence along the moving path of the paper 1. The second driven roller 12 and the material receiving active roller 14 are arranged in parallel, and the sides of both are matched with the paper 1. The material receiving motor 13 is connected to the material receiving active roller 14 to drive the material receiving active roller 14 to rotate. When the material receiving active roller 14 rotates, the paper 1 is rolled up.

[0097] It is understandable that after detecting the action of the traction motor 7 , the receiving motor 13 provides power to the receiving active roller 14 , drives the receiving active roller 14 to rotate, and reels the printed paper 1 .

[0098] Based on the mechanical structure of the device in the aforementioned embodiment, this embodiment provides a method for stabilizing tension control of paper reeling and unreeling, the method comprising:

[0099] Obtain the time domain signal of the swing arm angular velocity during the feeding process;

[0100] Substituting the swing arm angular velocity time domain signal into a preset relationship formula among the swing arm angular velocity, telescopic cylinder thrust and paper tension to obtain the telescopic cylinder thrust;

[0101] According to the preset paper tension fluctuation range, the paper tension is compensated by the thrust of the telescopic cylinder.

[0102] It is understandable that if Figure 4 The figure shows the process flow of tension stabilization control of retracting and unretracting materials in a single printing cycle, where Figure 4 (a) is a schematic diagram of the timing of the action of the traction motor 7 and the material receiving motor 13, Figure 4 (b) is a schematic diagram of the control flow of the cooperation among the traction motor 7, the material receiving motor 13 and the telescopic cylinder 20.

[0103] In a stationary state, the cylinder applies pressure to the swing arm 18, thereby pressing the tensioning roller 17 downward to tighten the paper. By calculating the influence of the cylinder pressure and the initial angle of the swing arm 18 on the force of the paper 1 and selecting appropriate cylinder and swing arm 18 sizes, it is possible to achieve that when the swing arm 18 fluctuates within a small range, the tension of the paper remains almost unchanged.

[0104] In the printing state, Figure 4 As shown in (a), time 0 is when the traction motor 7 starts feeding the paper, t1 is when the rewinding motor 13 starts, and t2 is when the traction motor 7 stops. During printing, the swing arm 18 and tension roller 17 inevitably swing. When the traction motor 7 starts, the paper initially slackens. At this point, the controller (using a PLC, for example) receives the signal indicating the movement of the traction motor 7 and, at time t1, sends a signal to the drive module 21 (electric proportional valve) on the telescopic cylinder 20 (pneumatic cylinder). This increases the cylinder pressure, adjusts the swing arm angle, and increases the pressure of the tension roller 17 on the paper, thereby keeping the slack paper taut. Simultaneously, the rewinding motor 13, upon receiving the signal indicating the movement of the traction motor 7, also begins feeding the paper. When traction motor 7 stops feeding paper, the PLC receives the signal and sends a signal to control the electric proportional valve on the cylinder, restoring the cylinder's air pressure to maintain constant paper tension until tension roller 17 stops and paper rewinding is complete. Finally, rewinding motor 13 rewinds slowly, uniformly pulling swing arm 18 and tension roller 17 back to their initial positions, and the next round of paper feeding and rewinding begins. This keeps paper 1 taut throughout the printing process, ensuring stable paper tension.

[0105] In one possible embodiment, in order to analyze and calculate the ideal stable tension of the paper 1, the method further includes selecting structural parameters of the paper unwinding and rewinding tension stabilization control device, such as the size of the structure and the pressure of the cylinder, specifically including:

[0106] like Figure 5 The schematic diagram of the structural relationship between the tensioning roller 17 and the swing arm 18 is shown, and it is set that the paper 1 frictionally cooperates with the first driven roller 10, the tensioning roller 17 and the second driven roller 12 in the forward path;

[0107] Define the axis of the first driven roller 10 as C, the axis of the tensioning roller 17 as B, and the axis of the second driven roller 12 as A. The radius of the first driven roller 10 is r3, the radius of the tensioning roller 17 is r2, and the radius of the second driven roller 12 is r1. The length of the swing arm 18 of the traction mechanism is AB. The hinge point of the telescopic cylinder 20 on the swing arm 18 is D. The end of the telescopic cylinder 20 away from the swing arm 18 is E. The length of the telescopic cylinder 20 is ED, and the length ED of the telescopic cylinder 20 can change synchronously according to the telescopic state of the telescopic cylinder 20. The tangent point of the paper 1 on the first driven roller 10 near the tensioning roller 17 is C1. The two tangent points of the paper 1 on the tensioning roller 17 are B1 and B2, respectively. The tangent point B2 is close to the first driven roller 10, and the tangent point B1 is close to the second driven roller 12. The tangent point of the paper 1 on the second driven roller 12 near the tensioning roller 17 is A1.

[0108] Assume that the mass of the swing arm 18 is m1, the mass of the tension roller 17 is m2, the length of the swing arm 18 AB = L1, the length from the hinge point D to the axis A of the second driven roller 12 AD = L2, and the coordinates of each point are defined as follows: A(x1, y1), B(x2, y2), C(x3, y3), A1(x4, y4), B1(x5, y5), B2(x6, y6), C1(x7, y7), E(x0, y0), D(x8, y8), the angle between AB and the horizontal direction is θ1, the angle between A1B1 and the horizontal direction is θ2, the angle between ED and the vertical direction is θ, the angle between BC and the vertical direction is θ3, and the angle between B2C1 and the vertical direction is θ4;

[0109] Points A, E, and C are fixed points with fixed coordinates. Radiuses r1, r2, and r3 are fixed. Set A as the origin, with coordinates x1 = 0 and y1 = 0. Since paper 1 is tangent to the rollers in a taut state, the following relationship can be obtained:

[0110] Point B coordinates (x2, y2) and BC length:

[0111] x2=cosθ1·L1, y2=sinθ1·L1,

[0112] According to the angle relationship, we can get:

[0113] θ2=θ1+α1,

[0114] Among them, α1 is the difference between the angle θ2 and the angle θ1;

[0115] Then, from vectors AA1 and BB1, we can get the coordinates of the tangent point A1 (x4, y4) and the tangent point B1 (x5, y5):

[0116]

[0117] Then, according to the B coordinate (x2, y2), C coordinate (x3, y3) and BC length, the angles θ3 and θ4 can be obtained:

[0118] θ4=θ3-α2,

[0119] Among them, α2 is the difference between the angle θ3 and the angle θ4;

[0120] Then, we can get the coordinates of B2 (x6, y6) and C1 (x7, y7) by the following formula:

[0121]

[0122] For the telescopic cylinder length ED, the length AD from the hinge point D to the axis A of the second driven roller and the angle θ1 between AB and the horizontal direction can be obtained as the D coordinate (x8, y8). The angle θ between ED and the vertical direction can be obtained as the D coordinate (x8, y8) and the E coordinate (x0, y0):

[0123] D(x8, y8): x8=cosθ1·L2, y8=sinθ1·L2,

[0124] In summary, under the premise of knowing all the fixed value parameters, it is only necessary to detect the angle θ1 between AB and the horizontal direction to obtain the remaining structural parameters, and then set the device structure according to all the obtained structural parameters.

[0125] It is understandable that this structure is chosen to maintain the tension of the paper 1 while reducing the vibration of the tension roller 17, making it easier to brake the paper receiving motor 13 and ensuring smoother paper receiving. The vibration of the tension roller 17 mainly comes from the initial rotation of the traction motor 7 (traction active roller 8) during high-speed paper feeding during the printing process. The falling speed of the tension roller 17 cannot keep up with the paper feeding speed, resulting in the paper no longer being stressed and the tension suddenly dropping to 0. Then, after the paper receiving motor 13 receives the paper, the tension roller 17 falls onto the paper, causing the tension of the paper 1 to surge and the tension roller 17 to vibrate. Therefore, it is necessary to ensure that the paper 1 remains taut during the high-speed paper feeding driven by the traction active roller 8. In other words, the cylinder drives the swing arm 18, causing the swing arm 18 to rotate faster than the paper feeding speed, thereby achieving the effect of quickly and accurately adjusting the tension.

[0126] In one possible embodiment, the step of analyzing and obtaining a relationship between the swing arm angular velocity, the thrust of the telescopic cylinder, and the paper tension includes:

[0127] Assuming that the paper 1 is in a taut state, the swing arm 18, the tension roller 17 and the paper 1 attached thereto are considered as a whole, and the forces are decomposed into the direction along the swing arm 18 and the direction perpendicular to the swing arm 18;

[0128] like Figure 6 The figure shows a schematic diagram of the force analysis of the tension roller when the paper is stretched tight. By analyzing the force on the tension roller 17 along the direction of the swing arm 18, the force expression of the tension roller 17 perpendicular to the swing arm 18 is obtained:

[0129] F1*cosα1+m2g sinθ1=N+F2·sin(θ4-θ1)

[0130]

[0131] Wherein, F1 is the tension of the paper segment A1B1, F2 is the tension of the paper segment B2C1, N is the support force of the swing arm 18 on the tension roller 17, Δr2 is the inner diameter of the bearing inside the tension roller 17, ΔF=F1-F2, α1 is the difference between the angle θ2 and the angle θ1, m2 is the mass of the tension roller 17, g is the gravity coefficient, J is the moment of inertia of the swing arm 18 and the tension roller 17 relative to the axis A of the second driven roller 12, ω is the swing angular velocity of the swing arm 18, J2 is the rotational moment of inertia of the tension roller 17, μ2 is the friction coefficient between the roller surface of the tension roller 17 and the internal rolling bearing, and ω2 is the rotational angular velocity of the tension roller 17; ΔF is the tension difference of the paper 1 on both sides of the tension roller 17. When the friction coefficient μ2 between the roller surface of the tension roller 17 and the internal rolling bearing and the rotational moment of inertia J2 of the tension roller 17 are small, ΔF can be regarded as a small value.

[0132] By analyzing the force on the tension roller perpendicular to the swing arm, the force expression on the tension roller 17 perpendicular to the swing arm 18 is obtained:

[0133]

[0134] Simplifying the force expression of the tension roller perpendicular to the swing arm direction, we can get:

[0135]

[0136] Among them, F is the thrust of the telescopic cylinder. It can be seen from the above formula that when the thrust F of the telescopic cylinder increases, the paper tension will increase proportionally. By changing the thrust of the telescopic cylinder, the tension of the paper 1 during printing can be adjusted.

[0137] From the above force analysis expression, it can be seen that when the telescopic cylinder thrust (such as the pressure of the cylinder) increases, the tension of the paper will increase proportionally. Different telescopic cylinder thrusts can ensure that the paper is under different tensions during printing.

[0138] In the prior art, the paper tension varies significantly when the paper receiving swing arm 11 is in different positions. During the receiving process, the paper receiving swing arm 11 inevitably fluctuates within a certain range, causing significant fluctuations in the paper tension. This can easily lead to uneven paper delivery, paper buckling, and increased load on the receiving motor 13. The solution of the present invention overcomes this problem of significant paper tension fluctuations.

[0139] In one possible embodiment, the step of analyzing the paper tension fluctuation range includes:

[0140] Obtain the variation trend of paper tension with swing arm angle under static state and various levels of telescopic cylinder thrust value, so as to fit the relationship between the influence of telescopic cylinder thrust on paper tension;

[0141] Obtain the time domain signal of the swing arm angular velocity, integrate the swing arm angular velocity based on time, and obtain the swing arm angle fluctuation range based on the time domain;

[0142] Substituting the swing arm angle fluctuation range into the relationship between the swing arm angular velocity, the thrust of the telescopic cylinder and the paper tension, the paper tension fluctuation range based on the time domain without compensation is obtained.

[0143] To explain the present embodiment more intuitively, based on the frame parameters of a certain machine model in a specific implementation scenario, the swing arm 18 structure of the tension adjustment mechanism proposed in each embodiment of the present invention is used to set some relevant parameters to analyze the paper tension of the swing arm 18. For example, the coordinate data of each point and structure are set (unit: mm): A(0,0), C(0,757), E(100,300), AB=L1=350, AD=L2=250, r1=50, r2=40, r3=60, initial angle θ1=30°, cylinder pressure F=100N, mass m1=1.5kg of the swing arm 18, mass m2=15kg of the tension roller 17, and moment of inertia J=2.43kg / m of the swing arm 18 and the tension roller 17 relative to the axis of the receiving active roller 14. 2 , gravitational acceleration g = 9.8 m / s 2 , the friction coefficient of all bearings is taken as 0.05, and substituted into the above formula to calculate the tension F1 and F2 of the paper at rest using MATLAB software.

[0144] When the tension adjustment mechanism swings the swing arm 18, the paper tension changes with the angle between the swing arm 18 and the horizontal plane and the telescopic cylinder thrust (cylinder pressure) F as shown in the following figure: Figure 7 In order to better analyze the fluctuation range of paper tension, a detailed analysis is performed when the cylinder pressure F = 100N. Figure 8 The graph is a trend diagram of the change of paper tension with the angle of the swing arm 18 when the cylinder pressure F=100N.

[0145] Depend on Figure 7 and Figure 8 As can be seen, the paper tension F1 increases uniformly with increasing cylinder pressure F, and the controllable range of tension F1 is extremely wide, ranging from approximately 140N to 410N. When the cylinder pressure F = 100N is fixed, and the angle θ1 between the swing arm 18 and the horizontal plane varies between 20° and 40°, the change in the paper tension F1 is minimal and almost negligible (a 20° change in angle results in only a 3% change in tension). Only when the angle θ1 exceeds 50° does the paper tension F1 experience significant changes with the change in angle θ1.

[0146] Taking the swing arm angle of 30° as an example, draw a graph showing the effect of cylinder pressure F on paper tension F1 under the current parameters, as shown in the figure below: Figure 9 shown. Figure 9It can be seen that under static conditions, the increase or decrease of the cylinder pressure F is proportional to the paper tension F1, and the influence is more significant. The linear relationship between the two is approximately F1=1.5F+149, where 149 is a constant determined by the mechanical structure parameters of the device. Therefore, if the paper needs to be under different tensions, it is only necessary to change the corresponding cylinder pressure. This can be achieved conveniently and simply. Using different tension measures for paper 1 of different widths, thicknesses, and humidity can greatly improve the efficiency of diversified printing.

[0147] pass Figure 9 The effect of cylinder pressure F on paper force F1 in the static state shows that when cylinder pressure F is constant and swing arm 18 is within a certain range, paper tension F1 remains almost constant (varies by approximately 3%). During printing, the paper becomes slack due to the activation of traction motor 7 to feed the paper. Therefore, we control the cylinder with an electric proportional valve to increase cylinder pressure when paper feeding is activated to ensure that the paper remains taut. Actual measurements of the device structure and printing paper feeding revealed that swing arm 18 swings approximately 10° in approximately 0.4 seconds, and the approximate path of its angular velocity ω is as follows: Figure 10 shown.

[0148] from Figure 10 The swing arm angle fluctuation range of the displayed paper 1 during printing can be seen. The area enclosed by the angular velocity and time is the swing arm angle, which is about 10°. Based on the swing arm angle fluctuation and the aforementioned formula F1=1.5F+149, we can use MATLAB to calculate the paper tension fluctuation range without increasing the electric proportional valve to adjust the cylinder pressure, as shown in the following example: Figure 11 shown.

[0149] Figure 11 The following is a diagram showing the fluctuation range of paper tension during printing without increasing the tension adjustment. Figure 11 It can be seen from the figure that if the tension adjustment part is not added, the paper tension fluctuation is about 260N-350N, and the fluctuation range reaches 34.6%. This will have a great impact on the printing accuracy, winding neatness, and the material receiving motor 13. When the cylinder pressure F is 100N and the initial angle of the swing arm 18 is 30°, Figure 8 It can be seen that the paper tension is about 299N. We adjust it with a paper force of 300N. The curve of the tension part that needs to be adjusted changes with time as shown below: Figure 12 shown. Figure 12 In the figure, the part above the arrow indicates that the tension needs to be increased, and the part below the arrow indicates that the tension needs to be reduced.

[0150] In a possible embodiment, the paper tension is compensated by using the thrust of the telescopic cylinder, including:

[0151] Subtract the paper tension fluctuation range from the preset optimal paper tension value to obtain the paper tension adjustment range based on the time domain;

[0152] Performing linear fitting on the paper tension adjustment range to obtain a relationship between the paper tension adjustment value and time; obtaining the start time of the traction mechanism and using the start time of the traction mechanism as the initial time of the paper tension adjustment;

[0153] Combining the relationship between the influence of the telescopic cylinder thrust on the paper tension and the relationship between the paper tension adjustment value and time, the thrust adjustment value of the telescopic cylinder thrust that changes with time is obtained;

[0154] The thrust adjustment value is used to control the thrust of the telescopic cylinder.

[0155] Specifically, the tension range that needs to be adjusted is linearly fitted, and the fitting result is as follows: Figure 12 The arrows indicate the line segments, and the relationship between the paper tension adjustment and time is obtained.

[0156] ΔF1=40-217.5t,

[0157] Wherein, ΔF1 is the paper tension adjustment value, and t is the time from the start of the traction motor 7 as the zero point.

[0158] Based on Figure 9 The obtained F1=1.5F+149 can be used to get the adjustment value ΔF (in N) of the cylinder pressure F over time, then

[0159]

[0160] Then convert the cylinder pressure F adjustment value over time into the input pressure adjustment value ΔP (unit: Pa):

[0161]

[0162] Where S is the effective area of ​​the cylinder, in m 2 The obtained air pressure adjustment value ΔP is converted into an electrical signal and applied to the electrical proportional valve to keep the paper tension constant during the printing process.

[0163] Since different sizes of printing paper have different requirements for tension, for example, thicker paper requires more force to keep it taut, it is also necessary to find the optimal paper tension corresponding to the current paper 1.

[0164] In a possible embodiment, the method further includes calculating an optimal paper tension according to paper parameters, including:

[0165] Get the paper parameters and calculate the paper density D according to the following formula:

[0166] D=G / σ,

[0167] Where D is the density of the paper, in g / cm 3 ; G is the basis weight of the paper, in g / cm 2 ;σ is the thickness of the paper, in cm;

[0168] According to the paper density D and printing width H, the optimal paper tension F1 is calculated using the following formula:

[0169] F1=K·H·D,

[0170] Where K is the tension coefficient, which is determined based on experience.

[0171] It is understandable that the current retractable and rewinding system can provide the same tension fluctuation for printing papers of different sizes, which is unreasonable. For wider and thicker papers, greater tension should be provided to ensure consistent paper tension. However, the existing retractable and rewinding structure and system can only choose to replace the weight of the rocker arm to adjust the tension, which will greatly increase the additional material cost, labor and working hours, and increase the burden on the entire organization.

[0172] In this embodiment, the paper density is used as a standard to establish the appropriate printing tension of the paper. For example, in a specific implementation scenario, through the test of printing experience on different papers, it is found that the appropriate printing tension is K≈0.35-0.45m·s2. Here, K=0.4m·s2 is taken. For example, for a density D of 32g / m 2 , the appropriate printing tension F1 for paper with a thickness of 0.1 mm and a width of 1620 mm is:

[0173]

[0174] F1=0.4×1620×0.32≈207N.

[0175] Therefore, by inputting the parameters of paper of different thicknesses and printing widths, we can obtain the corresponding paper tension F1. Then, through the above-mentioned constant tension method, the paper tension is kept constant to ensure that paper of different sizes is still at the same tightness, which can meet the diverse needs of printing paper.

[0176] The embodiments of the present invention provide a device and method for stabilizing the tension of paper reeling and unreeling, which, compared with existing printer reeling and unreeling systems, can ensure stable and long-lasting printing, and have a simpler and easier-to-use structure; ensure that the tension of the paper during printing fluctuates very little from the tension when stationary, and maintain constant tension of the paper during dynamic printing; and are suitable for diversified printing, and can automatically adjust the tension of paper of different thicknesses, thereby greatly improving production efficiency.

[0177] It should be noted that, in the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0178] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0179] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for stabilizing the tension of paper rewinding and unrewinding, characterized in that: A paper feeding and unfeeding tension stabilization control device is provided, comprising a traction mechanism, a tension adjustment mechanism and a feeding mechanism sequentially arranged along a paper (1) moving path; The traction mechanism is used to pull the paper (1) to move according to the feeding signal; The tension adjustment mechanism collects the action signal of the traction mechanism and actively keeps the paper (1) taut according to the action signal of the traction mechanism and its own rotation angle, so as to dynamically adjust the tension of the paper (1); the tension adjustment mechanism comprises a first driven roller (10), a tensioning roller (17) and a second driven roller (12) arranged in sequence along the moving path of the paper (1), the roller surface of the first driven roller (10), the roller surface of the tensioning roller (17) and the roller surface of the second driven roller (12) respectively rollingly cooperate with the paper (1); and further comprises a swing arm (18), an angle detection module (19), a telescopic cylinder (20) and a driving module (21), the tensioning roller (17) and the second driven roller (12) respectively rollingly cooperate with the paper (1). ) is hinged to the end of the second driven roller (12) through a swing arm (18), so that the swing arm (18) can drive the tensioning roller (17) to rotate around the circumference of the second driven roller (12); the angle detection module (19) is arranged at the hinge point between the swing arm (18) and the second driven roller (12), and is used to measure the angle of rotation of the swing arm (18) around the second driven roller (12); the movable end of the telescopic cylinder (20) is hinged to the swing arm (18) to drive the swing arm (18) to rotate around the circumference of the second driven roller (12), and the driving module (21) is connected to the telescopic cylinder (20) and is used to drive the movable end of the telescopic cylinder (20) to extend and retract; The material receiving mechanism is used to drive the paper (1) to be reeled in accordance with the feeding signal; Methods include: Obtain the time domain signal of the swing arm angular velocity during the feeding process; Substituting the swing arm angular velocity time domain signal into a preset relationship formula among the swing arm angular velocity, telescopic cylinder thrust and paper tension to obtain the telescopic cylinder thrust; According to the preset paper tension fluctuation range, the paper tension is compensated by the thrust of the telescopic cylinder.

2. A method for controlling the tension stability of paper taking-up and untaking according to claim 1, characterized in that: The traction mechanism comprises a paper pressing rod (6), a traction motor (7) and a traction active roller (8); The paper pressing rod (6), the traction active roller (8) and the first driven roller (10) are arranged in sequence along the moving path of the paper (1), and the paper pressing rod (6), the traction active roller (8) and the first driven roller (10) are all arranged perpendicular to the moving direction of the paper (1), and the paper pressing rod (6), the traction active roller (8) and the first driven roller (10) are arranged parallel to each other; The paper pressing rod (6) and the traction active roller (8) are respectively arranged on both sides of the paper (1) and are both in contact with the paper (1). The traction motor (7) is connected to the traction active roller (8) in a transmission manner to drive the traction active roller (8) to rotate.

3. A method for controlling the tension stability of paper taking-up and untaking according to claim 1 or 2, characterized in that: The material receiving mechanism includes a material receiving active roller (14) and a material receiving motor (13), the second driven roller (12) and the material receiving active roller (14) are arranged in sequence along the moving path of the paper (1), the second driven roller (12) and the material receiving active roller (14) are arranged in parallel, and the sides of both are matched with the paper (1), the material receiving motor (13) is connected to the material receiving active roller (14) to drive the material receiving active roller (14) to rotate, and the material receiving active roller (14) reels the paper (1) when rotating.

4. A method for controlling the tension stability of paper taking-up and untaking according to claim 3, characterized in that: It also includes the selection of structural parameters of the paper feeding and unfeeding tension stabilization control device, specifically including: The paper (1) is arranged to frictionally engage with the first driven roller (10), the tensioning roller (17), and the second driven roller (12) in sequence in the forward path; Define the axis of the first driven roller (10) as C, the axis of the tensioning roller (17) as B, the axis of the second driven roller (12) as A, the radius of the first driven roller (10) as r3, the radius of the tensioning roller (17) as r2, the radius of the second driven roller (12) as r1, the length of the swing arm (18) of the traction mechanism as AB, the hinge point of the telescopic cylinder (20) on the swing arm (18) as D, and the end of the telescopic cylinder (20) away from the swing arm (18) as E. Then the length of the telescopic cylinder (20) is The length of the telescopic cylinder (20) is ED, and the length ED of the telescopic cylinder (20) can be changed synchronously according to the telescopic state of the telescopic cylinder (20); the tangent point of the paper (1) on the first driven roller (10) close to the tension roller (17) is C1, and the two tangent points of the paper (1) on the tension roller (17) are B1 and B2, respectively, wherein the tangent point B2 is close to the first driven roller (10), and the tangent point B1 is close to the second driven roller (12), and the tangent point of the paper (1) on the second driven roller (12) close to the tension roller (17) is A1; Assume that the mass of the swing arm (18) is m1, the mass of the tension roller (17) is m2, the length of the swing arm (18) is AB=L1, the length from the hinge point D to the axis A of the second driven roller (12) is AD=L2, and the coordinates of each point are defined as follows: A(x1,y1), B(x2,y2), C(x3,y3), A1(x4,y4), B1(x5,y5), B2(x6,y6), C1(x7,y7), E(x0,y0), D(x8,y8), the angle between AB and the horizontal direction is θ1, the angle between A1B1 and the horizontal direction is θ2, the angle between ED and the vertical direction is θ, the angle between BC and the vertical direction is θ3, and the angle between B2C1 and the vertical direction is θ4; Points A, E, and C are fixed points with fixed coordinates. Radius r1, r2, and r3 are fixed values. Set A as the origin, and let its coordinates x1 = 0 and y1 = 0. Since the paper (1) is tangent to each roller in a taut state, the following relationship can be obtained: Point B coordinates (x2, y2) and BC length: ， According to the angle relationship, we can get: ， in, is the difference between the angle θ2 and the angle θ1; Then, from vectors AA1 and BB1, we can get the coordinates of the tangent point A1 (x4, y4) and the tangent point B1 (x5, y5): Then, according to the B, C coordinates and the BC length, the angles θ3 and θ4 can be obtained: ， in, is the difference between the angle θ3 and the angle θ4; Then, we can get the coordinates of B2 (x6, y6) and C1 (x7, y7) by the following formula: ， For the telescopic cylinder length ED, the length AD from the hinge point D to the axis A of the second driven roller and the angle θ1 between AB and the horizontal direction can be obtained as the D coordinate (x8, y8). The angle θ between ED and the vertical direction can be obtained as the D coordinate (x8, y8) and the E coordinate (x0, y0): ； In summary, under the premise of knowing all the fixed value parameters, it is only necessary to detect the angle θ1 between AB and the horizontal direction to obtain the remaining structural parameters, and then set the device structure according to all the obtained structural parameters.

5. A method for controlling the tension stability of paper taking-up and untaking according to claim 4, characterized in that: The steps for analyzing and obtaining the relationship between the swing arm angular velocity, the thrust of the telescopic cylinder, and the paper tension include: Assuming that the paper (1) is in a taut state, the swing arm (18), the tension roller (17) and the paper (1) attached thereto are taken as a whole, and each force is decomposed into a direction along the swing arm (18) and a direction perpendicular to the swing arm (18); By analyzing the force on the tension roller (17) along the direction of the swing arm (18), the force expression of the tension roller (17) perpendicular to the direction of the swing arm (18) is obtained: ， in, is the tension of the paper segment A1B1, is the tension of the paper segment B2C1, N is the support force of the swing arm (18) on the tension roller (17), is the inner diameter of the bearing inside the tension roller (17), = - , is the difference between the angle θ2 and the angle θ1, is the mass of the tensioning roller (17), g is the gravity coefficient, J is the moment of inertia of the swing arm (18) and the tensioning roller (17) relative to the axis A of the second driven roller (12), ω is the swing angular velocity of the swing arm (18), is the rotational inertia of the tensioning roller (17), is the friction coefficient between the roller surface of the tension roller (17) and the internal rolling bearing, is the rotational angular velocity of the tensioning roller (17); is the tension difference between the paper (1) on both sides of the tension roller (17), when the friction coefficient between the roller surface of the tension roller (17) and the internal rolling bearing is and the rotational inertia of the tension roller (17) When it is small, ΔF can be regarded as a small quantity; The force acting on the tension roller (17) perpendicular to the swing arm (18) is analyzed, and the force expression of the tension roller (17) perpendicular to the swing arm (18) is obtained: ， Simplifying the force expression of the tension roller (17) perpendicular to the swing arm (18) can be obtained: ， Among them, F is the thrust of the telescopic cylinder. It can be seen from the above formula that when the thrust F of the telescopic cylinder increases, the paper tension F1 will increase proportionally. By changing the thrust F of the telescopic cylinder, the paper tension F1 during printing can be adjusted.

6. A method for controlling the tension stability of paper taking-up and untaking according to claim 5, characterized in that: The steps to analyze the paper tension fluctuation range include: Obtain the variation trend of paper tension with swing arm angle under static state and various levels of telescopic cylinder thrust value, so as to fit the relationship between the influence of telescopic cylinder thrust on paper tension; Obtain the time domain signal of the swing arm angular velocity, integrate the swing arm angular velocity based on time, and obtain the swing arm angle fluctuation range based on the time domain; Substituting the swing arm angle fluctuation range into the relationship between the swing arm angular velocity, the thrust of the telescopic cylinder and the paper tension, the paper tension fluctuation range based on the time domain without compensation is obtained.

7. A method for controlling the tension stability of paper taking-up and untaking according to claim 6, characterized in that: The paper tension is compensated by the thrust of the telescopic cylinder, including: Subtract the paper tension fluctuation range from the preset optimal paper tension value to obtain the paper tension adjustment range based on the time domain; Performing linear fitting on the paper tension adjustment range to obtain a relationship between the paper tension adjustment value and time; obtaining the start time of the traction mechanism and using the start time of the traction mechanism as the initial time of the paper tension adjustment; Combining the relationship between the influence of the telescopic cylinder thrust on the paper tension and the relationship between the paper tension adjustment value and time, the thrust adjustment value of the telescopic cylinder thrust that changes with time is obtained; The thrust adjustment value is used to control the thrust of the telescopic cylinder.

8. A method for controlling the tension stability of paper taking-up and untaking according to claim 7, characterized in that: It also includes calculation of optimal paper tension based on paper parameters, including: Get the paper parameters and calculate the paper density D according to the following formula: ， Where D is the density of the paper, in g / cm 3 ; G is the basis weight of the paper, in g / cm 2 ;σ is the thickness of the paper, in cm; According to the paper density D and printing width H, the optimal paper tension F1 is calculated using the following formula: ， Where K is the tension coefficient, which is determined based on experience.

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