Closed-loop controlled film stretching device and spin coating system

Abstract

The invention discloses a closed-loop control film stretching device and a spin coating system, and the device comprises a parameter setting panel which is used for setting a target stretching parameter of a film; the clamping mechanism is used for clamping the film; the driving mechanism is connected with the clamping mechanism and used for driving the clamping mechanism to move in the plane so as to apply drawing force to the film; the feedback module is used for monitoring the output state of the driving mechanism in real time and generating a feedback signal; and the control module is connected with the parameter setting panel and the feedback module, and the control module is configured to dynamically adjust the output of the driving mechanism based on the deviation between the target stretching parameter and a feedback signal so as to realize the closed-loop control of the film stretching force. Target stretching parameters are input through the parameter setting panel, the feedback module is combined to monitor the output state of the driving mechanism in real time, the control module can dynamically adjust the driving mechanism based on the deviation between a set value and a feedback value, and it is ensured that the stretching parameters always meet the set requirement.

Description

Technical Field

[0001] The present invention relates to the technical field of material preparation, and particularly relates to a film stretching device and a spin coating system with closed-loop control. Background Art

[0002] A film stretching device is a device used to stretch a film, and its main function is to evenly tighten the film so that it can better meet various application requirements. The film stretching mechanism has broad application prospects in multiple fields such as packaging, printing, electronics, medical treatment, and material preparation. For different industry requirements, its structural design has corresponding differences. In the field of material preparation, especially preparing an ultra-thin and uniform material coating on a flexible substrate is a very important process. This process is highly dependent on the film stretching mechanism, requiring the uniformity of the film stretching force and the accuracy of stretching control.

[0003] The film stretching device usually clamps and fixes the four sides of the film through side clamps, and then tightens the film by raising the middle carrier platform, so as to increase the prestress of the film and make the film enter the tightened state. Although this method can achieve the stretching of the film, the upward movement of the carrier platform applying the pre-tightening force in contact with the film causes damage to the film, which may affect the quality of the film.

[0004] For this reason, the Chinese invention patent with the authorization announcement number CN108760496B discloses an involute flexible material multi-axis tensile testing machine, which drives the fixture to move synchronously through the cooperation of the involute guide groove and the linear guide groove to realize the multi-axis tensile testing of the material. The involute trajectory design reduces the movement friction and ensures the synchronism and uniformity of the tensile force. Although this device can achieve the uniform stretching of the film to a certain extent, it lacks the feedback control of the film stretching process, and the stretching speed and the magnitude of the stretching force cannot be effectively guaranteed, and it cannot meet the stretching force requirements of different film materials and thicknesses. Different specifications of films require different stretching forces. If the stretching force and the stretching speed cannot be adjusted in real time, the quality of the finally stretched film will be poor. Summary of the Invention

[0005] In view of this, the present invention provides a film stretching device and a spin coating system with closed-loop control to solve the problem that the current tensile testing machine lacks the feedback control of the film stretching process.

[0006] In a first aspect, the present invention provides a film stretching device with closed-loop control, including:

[0007] A parameter setting panel for setting the target stretching parameters of the film;

[0008] A clamping mechanism for clamping the film;

[0009] A driving mechanism, connected to the clamping mechanism, is used to drive the clamping mechanism to move in a plane so as to apply a tensile force to the film;

[0010] A feedback module is used to monitor the output state of the driving mechanism in real time and generate a feedback signal;

[0011] A control module is connected to the parameter setting panel and the feedback module. The control module is configured to dynamically adjust the output of the driving mechanism based on the deviation between the target stretching parameter and the feedback signal so as to achieve closed-loop control of the film tensile force.

[0012] The beneficial effects of the above-mentioned film stretching device with closed-loop control are as follows: By inputting the target stretching parameter through the parameter setting panel and combining the feedback module to monitor the output state of the driving mechanism in real time, the control module can dynamically adjust the driving mechanism based on the deviation between the set value and the feedback value. When the actual tensile force is lower than the target value, the driving force output is automatically increased, and vice versa, so as to ensure that the stretching parameter always meets the set requirements. The automated closed-loop control reduces manual intervention and avoids parameter fluctuations caused by lack of experience or operation delay in traditional manual adjustment. The present invention realizes precise setting, dynamic adjustment and real-time correction of the film stretching parameter through closed-loop control, and solves the problems such as film damage, poor adaptability and low consistency caused by the lack of feedback control in the traditional film stretching device.

[0013] The feedback module continuously collects data, and the control module quickly responds through the PID algorithm to make the output parameter stable within the target range. The closed-loop control ensures that the stretching conditions of each batch of films are consistent and avoids batch differences caused by equipment aging or environmental changes in traditional open-loop control.

[0014] In an optional embodiment, the driving mechanism includes:

[0015] A motor;

[0016] A transmission component, connected to the output shaft of the motor;

[0017] The clamping mechanism includes a plurality of clamping components. Each clamping component is evenly arranged at intervals in the circumferential direction on the transmission component and synchronously moves away from the center position of the film under the drive of the transmission component to tighten the film.

[0018] In an optional embodiment, the feedback module includes a torque sensor. One end of the torque sensor is connected to the output shaft of the motor, and the other end of the torque sensor is connected to the input end of the transmission component through a connecting shaft;

[0019] The parameter setting panel is configured to set the target torque required for film stretching, and the control module is configured to dynamically adjust the output of the driving mechanism based on the deviation between the target torque and the torque signal feedback by the torque sensor.

[0020] When the detected torque is less than the target torque, it indicates that the rotational speed of the transmission component is too fast at this time, and the stability of the transmission component is poor. If the film stretching is directly carried out, it is easy to cause damage to the film. Therefore, the control module controls the motor to reduce the speed. When the detected torque is greater than the target torque, it indicates that the rotational speed of the transmission component is too slow at this time. If the film stretching is directly carried out, the expected stretching effect cannot be achieved. Therefore, the control module controls the motor to increase the speed.

[0021] In an alternative embodiment, the feedback module further includes a tensile force sensor. One end of the tensile force sensor is connected to the clamping assembly, and the other end of the tensile force sensor is connected to the edge of the film.

[0022] The control module is configured to dynamically adjust the output of the driving mechanism based on the deviation between the target stretching parameter and the tensile force signal feedback by the tensile force sensor.

[0023] When the detected tensile force is greater than the target stretching parameter, it indicates that the tensile force on the film is too large at this time. If the film stretching is directly carried out, it is easy to cause damage to the film. Therefore, the control module controls the motor to reduce the speed. When the detected tensile force is less than the target stretching parameter, it indicates that the rotational speed of the transmission component is too slow at this time. If the film stretching is directly carried out, the expected stretching effect cannot be achieved. Therefore, the control module controls the motor to increase the speed.

[0024] In an alternative embodiment, the film tensioning device with closed-loop control further includes a frame body. The frame body includes a positioning disk and legs. The positioning disk is horizontally arranged, and the legs are arranged below the positioning disk. Both the clamping mechanism and the driving mechanism are connected to the positioning disk.

[0025] In an alternative embodiment, the transmission component includes:

[0026] A driving gear, coaxially connected to the output shaft of the motor and rotatably arranged within the positioning disk;

[0027] A driven gear, meshing with the driving gear and rotatably arranged within the positioning disk. A plurality of involute tooth profile tracks are circumferentially spaced on the driven gear;

[0028] A plurality of linear tracks are circumferentially spaced on the positioning disk. The linear tracks are arranged along the radial direction of the driven gear. Each clamping assembly is slidably arranged within the linear tracks and the involute tooth profile tracks through a positioning shaft provided at its bottom end.

[0029] The beneficial effects of the above technical solution are as follows: The combined use of the involute tooth profile track and the linear track enables the clamping assembly to achieve high-precision position control during movement. The involute tooth profile track provides accurate angle conversion, while the linear track ensures the accuracy of the radial position. The combination of the linear track and the involute tooth profile track enables the driven gear to drive the positioning shaft and the clamping assembly to perform linear movement when rotating, that is, converts the rotational movement of the driven gear into the linear movement of the clamping assembly, achieving effective force transmission. And because the linear track is radially arranged, a radial tensile force is generated on the film when stretching the film, and this radial tensile force passes through the central position of the film, thereby uniformly stretching the film in multiple directions and preventing the film from twisting during the stretching process.

[0030] In an alternative embodiment, the positioning disk is divided into an upper cover plate, a lower cover plate and a side frame. The upper cover plate and the lower cover plate are both provided with linear tracks in a penetrating manner; the positioning shaft sequentially passes through the linear track of the upper cover plate, the involute tooth profile track and the linear track of the lower cover plate from top to bottom, and is limited by a limiting piece.

[0031] In an alternative embodiment, the outer diameter of the driving gear is smaller than the outer diameter of the driven gear. Through the design of the reduction ratio of the driving gear and the driven gear, the motor torque is amplified, and a larger stretching load can be borne; and because the rotational speed of the driven gear is less than the rotational speed of the driving gear, the moving speed of the clamping assembly is relatively small, which can avoid damaging the film due to pulling the film too fast, and through speed reduction and torque increase, the movement of the driven gear driving the clamping assembly is more stable. By reducing the speed and increasing the torque through the gear set, the stretching rate and the magnitude of the prestress of the film can be controlled.

[0032] In an alternative embodiment, the clamping assembly includes:

[0033] A positioning frame, including a top plate, a bottom plate and side plates. The side plates are respectively connected to the side walls of the top plate and the bottom plate. The top plate, the bottom plate and the side plates enclose a frame structure with an open side;

[0034] A telescopic member. The top end of the telescopic member is a fixed end and is positioned on the bottom wall of the top plate. The bottom end of the telescopic member is a telescopic end and forms a film positioning gap with the top wall of the bottom plate.

[0035] In an alternative embodiment, the telescopic member is an air pump cylinder body. A pressure sensor for detecting the pressure received by the film is provided at the telescopic end of the air pump cylinder body, and a pressure regulating valve is provided at the air inlet end of the air pump cylinder body;

[0036] The parameter setting panel is configured to be able to set the target pressure parameter of the film;

[0037] The control module is configured to dynamically adjust the output of the pressure regulating valve based on the deviation between the target stretching parameter and the detected pressure signal, so as to achieve the closed-loop control of the film pressure.

[0038] In an alternative embodiment, a friction felt sheet is vertically disposed downward on the bottom wall of the positioning frame top plate. The bottom end of the friction felt sheet is a free end. When the telescopic end of the telescopic member clamps the film, the bottom end of the friction felt sheet abuts against the film to provide uniform friction.

[0039] In an alternative embodiment, an anti-slip pad is provided at the top end of the bottom plate, and a flexible pad is provided at the telescopic end of the telescopic member. The flexible pad and the anti-slip pad are arranged corresponding to each other up and down.

[0040] In a second aspect, the present invention provides a spin coating system, including:

[0041] The above-mentioned film tensioning device with closed-loop control;

[0042] A spin coating device for coating a coating on the film after the film tensioning device tightens the film.

[0043] The beneficial effects of the above-mentioned spin coating system are the same as those of the above-mentioned film tensioning device with closed-loop control, and will not be elaborated here.

[0044] In summary, the technical solution of the present invention has the following advantages:

[0045] Semi-automation: The semi-automated film tensioning mechanism designed by the present invention clamps and fixes the film edge through multiple air pump jigs, and sets the film stretching rate and prestress through the control panel, realizing the automated control of the film stretching process, saving manpower, reducing labor intensity, and improving production efficiency.

[0046] Precise control of prestress: The present invention controls the stretching speed and stretching force of the film tensioning mechanism through the feedback data of the stepping motor speed and torque sensor, and can accurately control the prestress, avoiding the problem that the upper top of the loading platform applying the pre-tightening force contacts the film and causes film damage in the prior art, thereby improving the quality of the film. At the same time, it has a large speed and torque adjustment range.

[0047] Rich applicable scenarios: The involute tooth profile track driving jig of the present invention runs continuously and stably, and can effectively control the stretching force to adapt to various films of different materials, expanding its application range in the preparation of different materials and improving its applicability.

[0048] Uniformity control: The stepping motor of the present invention rotates to drive the gear to rotate, driving a plurality of air pump jigs to move along the designed involute trajectory, stretching the film from different directions, which can control the uniformity of the forces in all directions of the film, avoiding the problem in the prior art that the uniformity of the forces in all directions of the film cannot be controlled, thereby improving the uniformity of film stretching and further improving the final coating quality.

[0049] Generally speaking, compared with the prior art, the present invention has the advantages of semi-automation, precise control of prestress, rich application scenarios and uniformity control, and is an ideal semi-automated film stretching mechanism for special material preparation. Brief Description of the Drawings

[0050] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0051] Figure 1 It is a schematic diagram of the first perspective structure of a film stretching device with closed-loop control provided by the present invention;

[0052] Figure 2 It is a schematic diagram of the second perspective structure of a film stretching device with closed-loop control provided by the present invention;

[0053] Figure 3 It is an exploded view of a film stretching device with closed-loop control provided by the present invention;

[0054] Figure 4 It is a cross-sectional view of a film stretching device with closed-loop control provided by the present invention;

[0055] Figure 5 It is a schematic diagram of the partial structure of a film stretching device with closed-loop control provided by the present invention;

[0056] Figure 6 It is a schematic diagram of the connection between the positioning frame and the positioning shaft of a film stretching device with closed-loop control provided by the present invention;

[0057] Figure 7 It is a feedback flow chart of a film stretching device with closed-loop control provided by the present invention.

[0058] Description of the Reference Numerals:

[0059] 1. Motor, 2. Motor cover plate, 3. Lower cover plate, 4. Torque sensor, 5. Connecting shaft, 6. Driving gear, 7. Driven gear, 71. Involute tooth profile track, 8. Upper cover plate, 10. Positioning frame, 101. Anti-slip pad, 11. Air pump cylinder block, 111. Flexible pad, 12. Air pump conduit, 13. Friction felt piece, 14. Frame body, 141. Positioning disc, 142. Leg, 143. Linear track, 15. Guide sleeve, 16. Gasket, 17. First bolt, 18. First positioning pin, 19. Second positioning pin, 20. Second bolt, 21. Third bolt, 22. Elastic retaining ring, 23. Positioning shaft, 231. Limit piece. Detailed implementation manners

[0060] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0061] The existing film stretching mechanism mainly clamps and fixes the four sides of the film through side clamps, and then tightens the film by rising the middle carrier platform, so as to increase the prestress of the film and make the film enter the tensioned state. Although this method can realize the stretching of the film, there are some limitations. First, the upward pushing of the carrier platform applying the pre-tightening force in contact with the film causes damage to the film, which may affect the quality of the film. Second, the force applied by mechanical movement pressing cannot be controlled, and the uniformity of the forces in all directions of the film cannot be controlled, which will cause uneven stretching of the film and affect the final coating quality. Third, the stretching force cannot be effectively controlled to adapt to various films of different materials, which limits its application in the preparation of different materials. Finally, manual operation is required throughout the process, which not only increases the labor intensity but also affects the production efficiency. Therefore, it is of far-reaching significance to design a semi-automatic film stretching mechanism dedicated to material preparation that can accurately control the prestress and has a rich application scenario.

[0062] Regarding the problem of film damage, the present invention clamps and fixes the edge of the film by using an air pump clamp, avoiding direct contact with the film, thereby reducing the possibility of film damage.

[0063] Regarding the problem of force uniformity control, the present invention sets the film stretching rate and prestress through a control panel, and controls the stretching speed and stretching force of the film stretching mechanism by the feedback data of the stepping motor speed and torque sensor, thereby realizing the precise control of the forces in all directions of the film.

[0064] Regarding the adaptability problem, the present invention enables the fixture to operate continuously and stably by designing an involute tooth profile track drive, which can adapt to various films made of different materials, thus expanding its application scope in the field of material preparation.

[0065] Regarding the automation level problem, the present invention realizes semi-automatic operation, saving manpower and improving production efficiency.

[0066] The present invention designs a semi-automatic film stretching mechanism dedicated to material preparation that can accurately control prestress and has a rich range of application scenarios. The following elaborates on the specific embodiments of the present invention in detail in combination with the film stretching device with closed-loop control in the first aspect of the present invention and the spin coating system in the second aspect of the present invention.

[0067] According to an embodiment of the present invention, in the first aspect, there is provided a film stretching device with closed-loop control, in combination with Figures 1 to 7 As shown, it includes a parameter setting panel, a clamping mechanism, a driving mechanism, a feedback module, and a control module. The parameter setting panel is used to set the target stretching parameters of the film. The clamping mechanism is used to clamp the film. The driving mechanism is connected to the clamping mechanism and is used to drive the clamping mechanism to move in a plane to apply multi-directional tensile forces to the film. The feedback module is used to monitor the output state of the driving mechanism in real time and generate a feedback signal. The control module is connected to the parameter setting panel and the feedback module. The control module is configured to dynamically adjust the output of the driving mechanism based on the deviation between the target stretching parameter and the feedback signal to achieve closed-loop control of the film tensile force. The control module is a hardware module, which can be a controller or a control panel.

[0068] For the above film stretching device with closed-loop control, the target stretching parameters are input through the parameter setting panel. Combining with the feedback module to monitor the output state of the driving mechanism in real time, the control module can dynamically adjust the driving mechanism based on the deviation between the set value and the feedback value. When the actual tensile force is lower than the target value, the driving force output is automatically increased, and vice versa, so as to ensure that the stretching parameters always meet the set requirements. Automatic closed-loop control reduces manual intervention and avoids parameter fluctuations caused by insufficient experience or operation delay in traditional manual adjustment. The present invention realizes precise setting, dynamic adjustment, and real-time correction of film stretching parameters through closed-loop control, solving problems such as film damage, poor adaptability, and low consistency caused by the lack of feedback control in traditional film stretching devices.

[0069] The feedback module continuously collects data, and the control module responds quickly through the PID algorithm, making the output parameters stable within the target range. Closed-loop control ensures that the stretching conditions of each batch of films are consistent, avoiding batch differences caused by equipment aging or environmental changes in traditional open-loop control.

[0070] In some embodiments, the driving mechanism includes a motor 1 and a transmission assembly. Among them, the motor 1 is a stepper motor. The stepper motor is connected to the motor cover plate 2 through the first bolt 17, gasket 16, and guide sleeve 15. The motor cover plate 2 is also connected to the lower cover plate 3 through bolts, gaskets, and guide sleeves. Among them, the first bolt 17 is an M3 bolt. The transmission assembly is connected to the output shaft of the motor 1 and is configured to convert the rotational motion of the motor into a linear or curvilinear motion of the clamping assembly.

[0071] The clamping mechanism includes a plurality of clamping assemblies for clamping the film. Each clamping assembly is evenly spaced circumferentially on the transmission assembly and moves synchronously away from the center position of the film under the drive of the transmission assembly to tighten the film.

[0072] In this embodiment, the driving mechanism applies force synchronously in multiple directions and combines the real-time monitoring of the feedback module to ensure uniform distribution of the tensile force and avoid excessive local stress or film tearing caused by traditional single-point jacking.

[0073] In some embodiments, the feedback module includes a torque sensor 4. One end of the torque sensor 4 is connected to the output shaft of the motor 1 through the first positioning pin 18. The other end of the torque sensor 4 is connected to the connecting shaft 5 through a flange interface. The connecting shaft 5 is connected to the input end of the transmission assembly. More specifically, the connecting shaft is fixedly connected to the driving gear 6 through the second positioning pin 19 to drive the driving gear 6 to rotate. The torque sensor 4 is used to monitor the driving torque of the motor in real time.

[0074] More specifically, a first groove is provided at one end of the torque sensor 4, and the output shaft of the motor 1 is fixedly installed in the first groove. A second groove is provided at the other end of the torque sensor 4, and the connecting shaft 5 is fixedly installed in the second groove.

[0075] The feedback module further includes a tension sensor. One end of the tension sensor is connected to the clamping assembly, and the other end of the tension sensor is connected to the edge of the film. Only one tension sensor is provided, and the clamping assembly can perform real-time tension detection through the tension sensor when pulling the film. The control module is configured to dynamically adjust the output of the driving mechanism based on the deviation between the target tensile parameter and the tension signal feedback by the tension sensor. When the detected tension is greater than the target tensile parameter, it indicates that the tensile force on the film is too large at this time. If the film is directly stretched, it is easy to cause damage to the film. Therefore, the control module controls the motor 1 to reduce the speed. When the detected tension is less than the target tensile parameter, it indicates that the rotational speed of the transmission assembly is too slow at this time. If the film is directly stretched, the expected stretching effect cannot be achieved. Therefore, the control module controls the motor 1 to increase the speed.

[0076] The parameter setting panel is configured to set the target torque required for film stretching. The control module is configured to dynamically adjust the output of the drive mechanism based on the deviation between the target torque and the torque feedback signal of the torque sensor 4, so as to control the rotational speed of the driven gear and the stability of the transmission component, thereby ensuring uniform stretching of the film. When the detected torque is less than the target torque, it indicates that the rotational speed of the transmission component is too fast at this time, and the stability of the transmission component is poor. If the film is directly stretched, it is easy to damage the film. Therefore, the control module controls the motor 1 to reduce the rotational speed. When the detected torque is greater than the target torque, it indicates that the rotational speed of the transmission component is too slow at this time. If the film is directly stretched, the expected stretching effect cannot be achieved. Therefore, the control module controls the motor 1 to increase the rotational speed.

[0077] In some embodiments, the film tensioning device with closed-loop control further includes a frame body 14. The frame body 14 includes a positioning disk 141 and legs 142. The positioning disk 141 is horizontally arranged, and the legs 142 are arranged below the positioning disk 141. Both the clamping mechanism and the drive mechanism are connected to the positioning disk 141.

[0078] In some embodiments, the transmission component includes a driving gear 6 and a driven gear 7. The driving gear 6 is directly coaxially connected to the motor output shaft, ensuring the high efficiency and stability of power transmission, reducing energy loss. The driving gear 6 is rotatably arranged within the positioning disk 141. The driven gear 7 meshes with the driving gear 6 and is rotatably arranged within the positioning disk 141. More specifically, the driven gear 7 is fixed to the lower cover plate 3 through the positioning shaft of the lower cover plate and rotates around the positioning shaft. The driving gear 6 drives the driven gear 7 to perform a rotational motion through gear meshing.

[0079] A plurality of involute tooth profile tracks 71 are circumferentially spaced on the driven gear 7. A plurality of linear tracks 143 are circumferentially spaced on the positioning disk 141. The linear tracks 143 are arranged along the radial direction of the driven gear 7. Each clamping component is slidably arranged within the linear tracks 143 and the involute tooth profile tracks 71 through the positioning shaft 23 provided at its bottom end.

[0080] In this embodiment, the combined use of the involute tooth profile tracks 71 and the linear tracks 143 enables high-precision position control of the clamping component during movement. The involute tooth profile tracks provide precise angle conversion, while the linear tracks ensure the accuracy of the radial position. The linear tracks 143 are combined with the involute tooth profile tracks 71, so that when the driven gear 7 rotates, it drives the positioning shaft and the clamping component to perform a linear movement, that is, converts the rotational motion of the driven gear 7 into the linear motion of the clamping component, realizing effective force transmission. And because the linear tracks 143 are radially arranged, a radial tensile force is generated on the film during film stretching. This radial tensile force passes through the central position of the film, thereby uniformly stretching the film in multiple directions and preventing the film from twisting during the stretching process.

[0081] In some embodiments, the positioning disc 141 is divided into an upper cover plate 8, a lower cover plate 3 and a side frame. The upper cover plate 8 is fixed to the lower cover plate 3 by bolts. Both the upper cover plate and the lower cover plate are provided with linear tracks 143 therethrough. The support legs 142 are fixed to the lower cover plate 3 by the third bolts 21 to play a supporting role. The positioning shaft 23 passes through the linear track of the upper cover plate, the involute tooth profile track 71 and the linear track of the lower cover plate from top to bottom in sequence, and is limited by the limiting piece 231. The minimum outer diameter of the limiting piece 231 is greater than the width of the linear track 143. In this embodiment, since the upper and lower parts of the positioning shaft 23 are limited by the linear tracks, the problem that the upper and lower parts of the positioning shaft 23 move out of sync will not occur.

[0082] Furthermore, the upper cover plate 8 and the lower cover plate 3 are symmetrically arranged with respect to the driven gear 7, further ensuring the synchronization of the movement of the upper and lower parts of the positioning shaft 23.

[0083] The positioning frame 10 is stably combined with the linear tracks of the lower cover plate 3, the driven gear 7 and the upper cover plate 8 through the positioning shaft 23 and the shaft retaining ring 22, and reciprocates around the linear track.

[0084] In some embodiments, the diameter of the driving gear 6 is smaller than the diameter of the driven gear 7. Through the design of the reduction ratio of the driving gear 6 and the driven gear 7, the motor torque is amplified, and a greater tensile load can be borne. And since the rotation speed of the driven gear 7 is less than the rotation speed of the driving gear 6, the moving speed of the clamping assembly is relatively small, which can avoid damaging the film due to pulling the film too fast. And through reducing speed and increasing torque, the movement of the driven gear 7 driving the clamping assembly is more stable. By reducing speed and increasing torque through the gear set, the stretching rate of the film and the magnitude of the prestress can be controlled.

[0085] In some embodiments, the clamping assembly includes a positioning frame 10 and a telescopic member. The positioning frame 10 includes a top plate, a bottom plate and side plates. The side plates are respectively connected to the side walls of the top plate and the bottom plate. The top plate, the bottom plate and the side plates enclose a frame structure with an open side. The top end of the telescopic member is a fixed end and is positioned on the bottom wall of the top plate, and the bottom end of the telescopic member is a telescopic end and forms a film positioning gap with the top wall of the bottom plate.

[0086] As a specific embodiment, the clamping assembly is an air pump clamp, the telescopic member is an air pump cylinder body 11, the air pump cylinder body 11 is fixed to the upper part of the positioning frame 10 by a second bolt 20, and the second bolt 20 is an M1.5 bolt. A pressure sensor for detecting the pressure exerted on the film is provided at the telescopic end of the air pump cylinder body 11, and a pressure regulating valve is provided on the air pump conduit 12 of the air pump cylinder body 11. The air pump conduit 12 is fixed to the air pump cylinder body 11 by a nut. The parameter setting panel is configured to be able to set the target pressure parameter of the film. The control module is configured to dynamically adjust the output of the pressure regulating valve based on the deviation between the target stretching parameter and the detected pressure signal to achieve closed-loop control of the film pressure.

[0087] In this embodiment, the pressure sensor detects the pressure exerted on the film in real time and transmits the signal to the control module. The control module dynamically adjusts the output of the pressure regulating valve according to the deviation between the set target pressure parameter and the actually detected pressure to ensure that the film is always within the set pressure range. When the actually detected pressure exceeds the set safety threshold, the system can quickly take measures (such as closing the intake valve) to prevent the film from being damaged due to excessive stretching or other safety hazards. The closed-loop control system can effectively eliminate the influence of external interference factors (such as temperature changes, mechanical vibrations, etc.) on the pressure stability and improve the reliability and accuracy of the system.

[0088] Moreover, different target pressure parameters are set for films of different materials, and thus the stretching operations of films of different specifications can be satisfied.

[0089] In some embodiments, a friction felt sheet 13 is vertically downwardly provided on the bottom wall of the top plate of the positioning frame 10. The friction felt sheet 13 is adhesively bonded to the bottom wall of the top plate of the positioning frame. The bottom end of the friction felt sheet 13 is a free end. When the telescopic end of the telescopic member clamps the film, the bottom end of the friction felt sheet 13 abuts against the film to provide uniform friction force. Due to the softness and compliance of the felt material, it can maintain a consistent friction force distribution on films of different shapes and thicknesses. The uniform friction force helps to prevent the film from sliding or shifting during the clamping process and ensures that the film maintains a stable position during stretching or other operations. And the high friction coefficient between the friction felt sheet and the film can significantly enhance the clamping force, making the clamping more firm and reliable.

[0090] In some embodiments, an anti-slip pad 101 is provided at the top end of the bottom plate, and a flexible pad 111 is provided at the telescopic end of the telescopic member. The flexible pad 111 and the anti-slip pad 101 are arranged corresponding to each other vertically. The anti-slip pad 101 is located at the top end of the bottom plate, contacts the film, and provides the first layer of anti-slip protection; the flexible pad 111 is located at the telescopic end of the telescopic member, presses the film from above, and provides the second layer of anti-slip protection. The synergistic effect of the two can effectively prevent the film from sliding or shifting during the clamping process. The soft characteristic of the flexible pad 111 enables it to closely fit the surface of the film, ensuring uniform pressure distribution and avoiding deformation or damage of the film caused by excessive local pressure.

[0091] According to an embodiment of the present invention, in a second aspect, a film stretching method is provided, and the specific implementation steps are as follows:

[0092] Step 1: Prepare the film and place the film on the platform of the film stretching mechanism. The material of the film can be selected according to needs, such as polyimide film, polyester film, etc.

[0093] Step 2: Use 12 air pump clamps to clamp and fix the edge of the film. The design of the air pump clamps ensures that the film will not be damaged by the air pump clamps during the stretching process. The pressure of the air pump clamps can be adjusted according to the material and thickness of the film to ensure that the film will not be damaged in the clamps.

[0094] Step 3: Set the film stretching rate and prestress through the control panel. The stretching rate can be set between 0.1 mm / s and 10 mm / s, and the prestress can be set between 0.1 N and 100 N.

[0095] Step 4: Control the stretching speed and stretching force of the film stretching mechanism through the feedback data of the stepping motor speed and torque sensor. The speed of the stepping motor can be set between 10 rpm and 100 rpm, and the feedback data of the torque sensor can adjust the speed of the stepping motor in real time to ensure the uniformity of the stretching force. The specific feedback adjustment process is as follows:

[0096] a. Set the target value: Input the film stretching rate (0.1 mm / s to 10 mm / s) and prestress (0.1 N to 100 N) through the control panel. The control system calculates the target speed and torque of the stepping motor according to the input target value.

[0097] b. Real-time monitoring: The stepping motor starts to work, and the torque sensor monitors the output torque of the motor in real time.

[0098] The torque sensor transmits the monitored data to the control system.

[0099] c. Data comparison: The control system compares the actually measured torque data with the preset target value. If the actual torque is consistent with the target value, the system continues to operate normally. If there is a deviation, the system enters the feedback regulation link.

[0100] d. Feedback regulation: The control system automatically adjusts the rotational speed and output torque of the stepper motor according to the magnitude of the deviation. If the actual torque is less than the target value, the system will reduce the rotational speed or output torque of the stepper motor; if the actual torque is greater than the target value, the system will increase the rotational speed or output torque of the stepper motor.

[0101] e. Closed-loop control: The entire adjustment process forms a closed-loop control system to ensure that the force and speed during the film stretching process are always stable. The system will continuously monitor and adjust until the film stretching is completed.

[0102] Algorithm of the control system: The control system adopts the PID (Proportional-Integral-Derivative) control algorithm, which can quickly respond to torque changes and ensure the stability and accuracy of the system.

[0103] User interface: The control panel provides an intuitive user interface, allowing users to easily set stretching parameters and real-time monitor the changes in force and speed during the stretching process.

[0104] Step Five: The stepper motor rotates to drive the gear to rotate, amplifying the driving torque of the motor, and driving 12 air pump clamps to move along the designed involute trajectory to stretch the film from different directions to reach the preset tensile force. The design of the involute tooth profile track makes the movement of the clamp more stable, thus improving the stability and efficiency of stretching.

[0105] Step Six: After the stretching is completed, the air pump clamps are released, and the film is evenly stretched on the positioning disk 141. Next, the preparation of the coating material can be carried out. Through the above semi-automatic film tensioning mechanism, precise control of the force in all directions of the film can be achieved, and at the same time, it can also adapt to various films of different materials, improving the production efficiency and coating quality.

[0106] According to an embodiment of the present invention, in the third aspect, a spin coating system is provided, including a film tensioning device with closed-loop control and a spin coating device. The spin coating device can be arranged above the film tensioning device with closed-loop control for coating a coating on the film after the film tensioning device tightens the film.

[0107] The application scenarios of the present invention are mainly for the preparation process of laboratory film materials and the preparation of vertical graphene materials. Among them, the process steps for preparing vertical graphene materials are as follows: stretching a flexible substrate, placing the prepared graphene film with a nano-scale to micro-scale thickness on the substrate with a pre-tightening force. Transfer water onto the graphene film, dry the water, and then release the clamping force, and a vertical structure of the graphene film appears.

[0108] Due to the advanced nature of the present invention, it can have a wide range of applications in application fields such as the field of material preparation technology, the field of coating technology, and the field of automated mechanical equipment.

[0109] In the field of material preparation technology, the semi-automated film stretching mechanism of the present invention can precisely control the stretching rate and prestress of the film, ensuring uniform stretching of the film and improving the quality and efficiency of material preparation. At the same time, by driving the fixture to run continuously and stably through the involute tooth profile track, it can adapt to various films of different materials, expanding its application range in the field of material preparation.

[0110] In the field of coating technology, the semi-automated film stretching mechanism of the present invention can precisely control the stretching rate and prestress of the film, ensuring uniform stretching of the film, thereby preparing an ultra-thin and uniform material coating. This is of great significance for preparing high-quality coatings, especially in the aspect of preparing ultra-thin and uniform material coatings on flexible substrates, and the present invention has broad application prospects.

[0111] In the field of automated mechanical equipment, the semi-automated film stretching mechanism of the present invention controls the stretching speed and stretching force of the film stretching mechanism by feedback data of the stepping motor speed and torque sensor, realizing automated operation, improving production efficiency, and reducing labor intensity. At the same time, by clamping and fixing the film edge with 12 air pump fixtures, rapid fixation of the film can be achieved, improving work efficiency.

[0112] Generally speaking, the semi-automated film stretching mechanism of the present invention has broad application prospects in application fields such as the field of material preparation technology, the field of coating technology, and the field of automated mechanical equipment, meeting the market's demand for high-efficiency, high-quality, and automated material preparation.

[0113] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A closed-loop controlled film stretching device, characterized in that: include: Parameter setting panel, used to set the target stretching parameters of the film; A clamping mechanism, used for clamping the film; A driving mechanism, connected to the clamping mechanism, for driving the clamping mechanism to move in a plane to apply a tensile force to the film; A feedback module, used for monitoring the output state of the driving mechanism in real time and generating a feedback signal; A control module is connected to the parameter setting panel and the feedback module, and is configured to dynamically adjust the output of the driving mechanism based on the deviation between the target stretching parameter and the feedback signal to achieve closed-loop control of the film stretching force.

2. The closed-loop controlled film stretching device according to claim 1, characterized in that: The driving mechanism comprises: Motor (1); A transmission assembly connected to the output shaft of the motor (1); The clamping mechanism comprises a plurality of clamping assemblies, each of which is evenly spaced along the circumferential direction and is synchronously moved away from the center of the film under the drive of the transmission assembly to tighten the film.

3. The closed-loop controlled film stretching device according to claim 2, characterized in that: The feedback module further comprises a tension sensor, one end of which is connected to the clamping assembly, and the other end of which is connected to the edge of the film; The control module is configured to dynamically adjust the output of the driving mechanism based on a deviation between a target stretching parameter and a tension signal fed back by a tension sensor.

4. The closed-loop controlled film stretching device according to claim 2, characterized in that: The feedback module comprises a torque sensor (4), one end of the torque sensor (4) is connected to the output shaft of the motor (1), and the other end of the torque sensor (4) is connected to the input end of the transmission component via a connecting shaft (5); The parameter setting panel is configured to set the target torque required for film stretching, and the control module is configured to dynamically adjust the output of the driving mechanism based on the deviation between the target torque and the torque signal fed back by the torque sensor (4).

5. The closed-loop controlled film stretching device according to claim 2, characterized in that: The closed-loop controlled film stretching device also includes a frame (14), the frame (14) includes a positioning plate (141) and a support leg (142), the positioning plate (141) is arranged horizontally, the support leg (142) is arranged below the positioning plate (141), and the clamping mechanism and the driving mechanism are both connected to the positioning plate (141).

6. The closed-loop controlled film stretching device according to claim 5, characterized in that: The transmission assembly comprises: A driving gear (6) is coaxially connected to the output shaft of the motor (1) and is rotatably disposed in the positioning plate (141); A driven gear (7) meshes with the driving gear (6) and is rotatably disposed in the positioning plate (141), wherein a plurality of involute tooth profile tracks (71) are circumferentially spaced apart on the driven gear (7); A plurality of linear tracks (143) are circumferentially spaced apart on the positioning plate (141), and the linear tracks (143) are arranged along the radial direction of the driven gear (7). Each of the clamping components is slidably arranged in the linear track (143) and the involute tooth profile track (71) via a positioning shaft (23) arranged at its bottom end.

7. The closed-loop controlled film stretching device according to claim 6, characterized in that: The positioning plate (141) is divided into an upper cover plate (8), a lower cover plate (3) and a side frame, and the upper cover plate and the lower cover plate are both provided with a linear track (143); the positioning shaft (23) passes through the linear track of the upper cover plate, the involute tooth profile track (71) and the linear track of the lower cover plate from top to bottom in sequence, and is limited by a limiting plate (231).

8. The closed-loop controlled film stretching device according to claim 6, characterized in that: The outer diameter of the driving gear (6) is smaller than the outer diameter of the driven gear (7).

9. The closed-loop controlled film stretching device according to any one of claims 2 to 7, characterized in that: The clamping assembly comprises: A positioning frame (10) comprises a top plate, a bottom plate and side plates, wherein the side plates are respectively connected to the side walls of the top plate and the bottom plate, and the top plate, the bottom plate and the side plates are arranged to form a frame structure with side openings; The telescopic member has a top end which is a fixed end and is positioned on the bottom wall of the top plate, and a bottom end which is a telescopic end and forms a film positioning gap with the top wall of the bottom plate.

10. The closed-loop controlled film stretching device according to claim 9, characterized in that: The telescopic member is an air pump cylinder (11), the telescopic end of the air pump cylinder (11) is provided with a pressure sensor for detecting the pressure exerted on the film, and the air inlet end of the air pump cylinder (11) is provided with a pressure regulating valve; The parameter setting panel is configured to be able to set a target pressure parameter of the film; The control module is configured to dynamically adjust the output of the pressure regulating valve based on the deviation between the target stretching parameter and the detected pressure signal to achieve closed-loop control of the film pressure.

11. The closed-loop controlled film stretching device according to claim 9, characterized in that: A friction felt sheet (13) is vertically arranged on the bottom wall of the top plate of the positioning frame (10), the bottom end of the friction felt sheet (13) is a free end, and when the telescopic end of the telescopic member clamps the film, the bottom end of the friction felt sheet (13) abuts against the film to provide uniform friction force; And / or, a non-slip pad (101) is provided at the top of the bottom plate, a flexible pad (111) is provided at the telescopic end of the telescopic member, and the flexible pad (111) and the non-slip pad (101) are arranged correspondingly up and down.

12. A spin coating system, characterized in that: include: The closed-loop controlled film stretching device according to any one of claims 1 to 11; The spin coating device is used to coat the coating on the film after the film is stretched by the film stretching device.

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