Lithium battery no-swing roller diaphragm coating machine and control method

Abstract

A kind of lithium battery no swing roller diaphragm coating machine and control method, the coating machine includes diaphragm, unwinding device, machine head, discharging device, winding device, data acquisition device and control device;The diaphragm is exported by the unwinding device, in turn through the machine head, the discharging device and the winding device;The data acquisition device is arranged in the unwinding device, the machine head or the discharging device interior;The control device is electrically connected with the data acquisition device;The method steps include: setting diaphragm target tension value, and according to the target tension value, calculate preset torque;Real-time acquisition diaphragm tension value, and based on the target tension value, calculate the tension deviation value of multiple time points;According to the tension deviation value of multiple time points, calculate torque control increment;The present application is adjusted diaphragm tension by torque, realizes high-precision control, and based on no swing roller realizes the adjustment of diaphragm and each roller contact angle, greatly reduces the possibility of large package angle, avoids wrinkling.

Description

Technical Field

[0001] This invention relates to the field of diaphragm coating machine technology, and more specifically to a lithium battery diaphragm coating machine without oscillating rollers and its control method. Background Technology

[0002] Currently, most lithium battery separator coating machines on the market use oscillating rollers for tension control. This involves controlling the cylinder thrust via compressed air pressure to regulate tension, and simultaneously controlling the speed of the unwinding, traction, and rewinding motors by detecting the oscillating roller's position using a potentiometer or position sensor. A PID control method is then used to stabilize the oscillating roller at a set position, ensuring constant tension of the separator during coating machine operation. However, because the oscillating roller tension control is pendulum-like, the contact angle between the roller and the separator at the unwinding and traction points is nearly 180°. This can easily cause wrinkles in separators with indentations, especially those thinner than 7μm, when passing through rollers with large wrap angles. Furthermore, the oscillating roller controls tension by swinging like a pendulum rather than moving linearly, resulting in varying output tension at different positions and significantly reducing the accuracy of separator tension control.

[0003] Other coating machines on the market use magnetic powder clutches to control tension. Although this method does not require a swing roller, the magnetic powder clutch has low control precision and slow response speed, making it unsuitable for use on diaphragm coating machines.

[0004] Therefore, how to provide a lithium battery non-swinging roller diaphragm coating machine and control method to improve tension control accuracy and coating quality is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a lithium battery diaphragm coating machine without a swing roller, which can solve the surface defects such as wrinkling that are easily caused by the large wrap angle of the belt threading required by the swing roller tension control structure of the diaphragm coating machine, reduce the control difficulty requirements, and proposes a torque control method to improve control accuracy.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A lithium battery non-swinging roller separator coating machine includes: separator, unwinding device, die head, discharge device, winding device, data acquisition device and control device;

[0008] The diaphragm is output from the unwinding device and passes sequentially through the die head, the discharge device, and the winding device;

[0009] The data acquisition device is located inside the unwinding device, the die head, or the discharge device;

[0010] The control device is electrically connected to the data acquisition device.

[0011] Furthermore, the unwinding device includes an unwinding roller, a first guide roller, and a first connecting roller group disposed at the exit end of the unwinding roller; the first guide roller is electrically connected to a first servo motor; the diaphragm is output to the machine head through the first guide roller and the first connecting roller group, and the contact angle between the diaphragm and the first guide roller and the first connecting roller group is less than or equal to 90°.

[0012] Furthermore, the data acquisition device includes an ultrasonic sensor mounted on the unwinding roller, the ultrasonic sensor being electrically connected to the control device and used to detect the diameter of the roll material on the unwinding roller.

[0013] Furthermore, the die head includes a reference roller, a coating roller, a first intermediate roller and a second intermediate roller distributed on both sides of the coating roller, and a second pass roller disposed at the exit of the die head;

[0014] The reference roller, the first intermediate roller, and the second intermediate roller are respectively connected to a second servo motor and a third servo motor; the second servo motor and the third servo motor are electrically connected to the control device;

[0015] The diaphragm is conveyed through the reference roller and passes sequentially through the first intermediate roller, the coating roller, the second intermediate roller, and the second pass roller, and the contact angle between the diaphragm and the coating roller, the first intermediate roller, the second intermediate roller, and the second pass roller is less than or equal to 90°.

[0016] Furthermore, it also includes a second connecting roller group connecting the first connecting roller group and the reference roller, the second connecting roller group being used to adjust the transmission angle of the diaphragm and to increase the wrap angle between the diaphragm and the reference roller.

[0017] Furthermore, the reference roller, the first intermediate roller, and the second intermediate roller are respectively connected to a second servo motor, a third servo motor, and a fourth servo motor; the second servo motor and the third servo motor are electrically connected to the control device.

[0018] Furthermore, a flattening roller is provided between the reference roller and the first intermediate roller. The flattening roller has concave and convex surfaces for flattening the diaphragm.

[0019] Furthermore, the data acquisition device includes multiple tension sensors, which are respectively installed between the unwinding device and the die head, between the die head and the discharge device, and between the discharge device and the winding device, for collecting the tension of the diaphragm.

[0020] Furthermore, the data acquisition device includes multiple ultrasonic sensors, which are respectively installed in the unwinding device, the discharge device, and the winding device, for collecting the diameter of the roll material.

[0021] Furthermore, it also includes a baking device. After the diaphragm is coated by the die head, it enters the baking device for drying, and the dried diaphragm enters the discharge device.

[0022] A control method for a lithium battery non-swinging roller separator coating machine includes the following steps:

[0023] Set the target tension value for the diaphragm and calculate the preset torque based on the target tension value;

[0024] The diaphragm tension value is collected in real time, and the tension deviation value at multiple times is calculated based on the target tension value;

[0025] The torque control increment is calculated based on the tension deviation values ​​at the aforementioned multiple moments.

[0026] Furthermore, the real-time acquisition of diaphragm tension values ​​includes:

[0027] Collect the diaphragm tension value between the unwinding device and the machine head;

[0028] Collect the diaphragm tension value between the die head and the discharge device;

[0029] Collect the diaphragm tension value between the discharge device and the winding device.

[0030] Furthermore, the steps also include:

[0031] Set the friction parameters and obtain the roll diameter;

[0032] The motor torque value is calculated based on the target tension value, the friction parameters, and the roll diameter, and then input into the servo motor.

[0033] Furthermore, the roll diameter includes the roll diameter of the unwinding roller, the roll diameter inside the discharge traction roller, and / or the roll diameter of the take-up roller.

[0034] The beneficial effects of this invention are:

[0035] As can be seen from the above technical solutions, compared with the prior art, the present invention discloses a lithium battery non-swinging roller separator coating machine and control method, which can solve the surface defects such as wrinkling that are easily caused by the large wrap angle of the belt threading required by the swing roller tension control structure of the separator coating machine, reduce the control difficulty requirements, and propose a torque control method to improve control accuracy; the present invention achieves high precision of tension control and stability under high precision through tension monitoring and roll diameter monitoring, respectively. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1 The attached figure is a schematic diagram of a lithium battery non-swinging roller separator coating machine provided in an embodiment of the present invention;

[0038] Figure 2 The attached figure is a schematic diagram of the tension control method provided in an embodiment of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please see Figure 1 This invention discloses a lithium battery non-swinging roller separator coating machine, comprising: separator, unwinding device, die head, discharge device, winding device, data acquisition device and control device;

[0041] The diaphragm is output from the unwinding device and passes sequentially through the die head, the discharge device, and the winding device;

[0042] The data acquisition device is installed inside the unwinding device, die head, or discharge device;

[0043] The control device is electrically connected to the data acquisition device.

[0044] In one embodiment, a display device, such as a touch screen, is also included; the touch screen is electrically connected to the control device for enabling human-computer interaction.

[0045] In one embodiment, the unwinding device includes an unwinding roller, a first guide roller, and a first connecting roller group disposed at the exit end of the unwinding roller; the first guide roller is electrically connected to a first servo motor; the diaphragm is output to the die head through the first guide roller and the first connecting roller group, and the contact angle between the diaphragm and the first guide roller and the first connecting roller group is less than or equal to 90°.

[0046] Specifically, Figure 1The diaphragm is released from the unwinding roller and then passes through the first connecting roller group consisting of roller 1, roller 2, and roller 3. During the transmission and movement of the diaphragm, the transmission direction of the diaphragm is controlled by roller 1, roller 2, and roller 3. The contact angle between all rollers inside the unwinding device and the diaphragm is less than or equal to 90°.

[0047] If the diaphragm uses a swivel roller to thread the tape, the substrate must be in the opposite direction to the diaphragm's running direction when the swivel roller is threading the tape over the roller. Therefore, the contact angle between the swivel roller and the diaphragm must be greater than 90°, which can easily cause the diaphragm to wrinkle during operation.

[0048] In this embodiment, the first servo motor controls the first roller to generate torque on the diaphragm in the opposite direction to the diaphragm transmission. During operation, the head reference roller conveys the diaphragm forward at a set speed. When the force on the tension generated by the head reference roller is greater than the unwinding tension value set, the unwinding roller will be pulled and rotated by the diaphragm. The torque of the unwinding roller driving the servo motor is controlled by the PLC (programmable controller) according to the tension set on the touch screen (human-machine interface) in either open-loop or closed-loop mode.

[0049] In one embodiment, the data acquisition device includes a tension sensor, which collects the diaphragm tension and, in conjunction with a control device, achieves closed-loop mode control.

[0050] Specifically, the control device is a PLC. The unwinding mechanism is equipped with a tension sensor to detect the physical quantity of the diaphragm unwinding tension in real time and output it to the PLC. The PLC converts the physical quantity detected by the unwinding tension sensor into the actual tension value. When the value detected by the tension sensor deviates from the tension value set on the touch screen, the PLC adjusts the torque of the servo motor driven by the unwinding roller in real time through program calculation to achieve precise tension control. The PLC compares the tension value set on the touch screen with the sampled value in real time and adjusts the torque value of the unwinding roller drive in real time, outputting it to the servo motor driver. Then, the driver automatically controls the torque of the unwinding roller drive servo motor according to the torque physical quantity given by the PLC to generate precise tension on the diaphragm, so that the diaphragm can maintain the unwinding tension in a high-precision constant tension manner.

[0051] In another embodiment, a tension sensor is installed in the rollers inside the die head, the unwinding device, or the winding device to detect diaphragm tension. This allows for tension control at various stages of the diaphragm operation. By installing a tension sensor in the rollers inside the die head, diaphragm tension between the unwinding device and the die head is detected, and tension control is achieved in conjunction with a control device and a corresponding servo motor. Alternatively, by setting a tension sensor in the unwinding device, diaphragm tension between the rollers inside the die head and the rollers inside the unwinding device is detected, and tension control is achieved in conjunction with a control device and a corresponding servo motor.

[0052] In one embodiment, the data acquisition device includes an ultrasonic sensor mounted on the unwinding roller, the ultrasonic sensor being electrically connected to a control device for detecting the diameter of the roll material on the unwinding roller.

[0053] In this embodiment, open-loop control is achieved by combining the roll diameter collected by the ultrasonic sensor with the control device.

[0054] Specifically, the unwinding roller uses an ultrasonic sensor to detect the diameter of the unwound material in real time. Since the unwound material is continuously conveyed forward during the coating process, its diameter gradually decreases. Therefore, the PLC (Programmable Logic Controller) calculates and adjusts the torque of the unwinding roller's servo motor in real time based on the diameter change to achieve precise tension control. The PLC calculates the setting on the touchscreen: (tension + friction force set on the touchscreen) * unwound material diameter = servo motor torque value, and outputs this value to the servo motor driver. The driver then automatically controls the torque of the unwinding roller's servo motor based on the torque value provided by the PLC to generate precise tension on the diaphragm. Because the roll diameter is a linear variable, the torque value output to the servo motor also changes linearly. This prevents tension fluctuations in the base film caused by sensor signal interference or malfunction, providing significant protection for diaphragms requiring low tension.

[0055] In another implementation, in addition to detecting the diameter of the roll material in the unwinding device, the ultrasonic sensor can also be installed in the discharge device or the winding device to detect the diameter of the roll material, or a combination of the above two or more applications, and combined with the program in the control device to realize open-loop tension control in each structure.

[0056] In one embodiment, the die head includes a reference roller, a coating roller, a first intermediate roller and a second intermediate roller distributed on both sides of the coating roller, and a second pass roller disposed at the die head outlet;

[0057] The diaphragm is conveyed through a reference roller and passes sequentially through a first intermediate roller, a coating roller, a second intermediate roller, and a second pass roller. The contact angle between the diaphragm and the coating roller, the first intermediate roller, the second intermediate roller, and the second pass roller is less than or equal to 90°.

[0058] The reference roller, the first intermediate roller, and the second intermediate roller are respectively connected to a second servo motor, a third servo motor, and a fourth servo motor; the second and third servo motors are electrically connected to the control device. The reference roller, also known as the guide roller 6, is driven by the second servo motor, which provides forward power for the diaphragm transport of the entire machine. The first intermediate roller, also known as the guide roller 8, and the second intermediate roller, also known as the guide roller 10, are driven by the third and fourth servo motors respectively, used to achieve tension control and ensure stable tension in the working areas of the first and second intermediate rollers during the coating process. The guide roller 8 maintains the angle between the diaphragm and the roller while changing its direction, allowing the diaphragm to contact the anilox roller 9 vertically upwards for coating. The guide roller 10 is an adsorption roller that controls the tension of the diaphragm in the coating area. The coating roller, also known as the guide roller 9, is an anilox roller, which adheres to the slurry and contacts the diaphragm for coating.

[0059] In another embodiment, a second connecting roller is further included to connect the first connecting roller group and the reference roller. The second connecting roller group is used to adjust the conveying angle of the diaphragm and to increase the wrap angle between the diaphragm and the reference roller.

[0060] Specifically, the second connecting roller consists of a guide roller 4 and a guide roller 5. It receives the diaphragm from the guide roller 3 and adjusts its angle. The guide roller 4 and the guide roller 5 contact different sides of the diaphragm. The contact surfaces of the reference roller and the guide roller 5 with the diaphragm are also different sides. After the angle adjustment of the guide roller 4, the contact angle between the diaphragm and the guide roller 5 is controlled to be less than or equal to 90°. The diaphragm is transferred from the guide roller 5 to the reference roller. After the angle adjustment of the guide roller 5, the contact wrap angle between the diaphragm and the reference roller can be increased.

[0061] In another embodiment, a flattening roller is provided between the reference roller and the first intermediate roller. The flattening roller has concave and convex surfaces to flatten the diaphragm and prevent wrinkles from being generated during the conveying of the diaphragm at a large wrap angle on the reference roller.

[0062] In one embodiment, a baking device is provided between the die head and the discharge device. The diaphragm passes through the second roller, namely the roller 11. The roller 11 ensures the angle between the diaphragm and the roller while changing the direction, and enters the baking device for drying.

[0063] In this embodiment, after the diaphragm is dried, it enters the discharge device and passes through the third connecting roller group composed of roller 12 and roller 13 in sequence before being adsorbed by roller 14. Rollers 12 and 13 increase the contact angle between the diaphragm and roller 14 by adjusting the diaphragm angle. Roller 14 controls the diaphragm tension between roller 10 and roller 14 through a connected fifth servo motor.

[0064] In another embodiment, after the diaphragm passes through roller 14, the output angle of the diaphragm is adjusted by roller 15 and output to the winding device. Roller 16 in the winding device ensures the angle between the diaphragm and the roller while changing its direction to ensure the wrap angle of roller 17. Roller 17 is a flattening roller used to ensure the flatness of the diaphragm during winding. Roller 18 ensures the angle between the diaphragm and the roller while changing its direction to ensure the angle of the winding roller. Finally, the winding roller rotates and winds up the coated diaphragm.

[0065] like Figure 2 The present invention also proposes a control method for a lithium battery non-swinging roller separator coating machine, comprising the following steps:

[0066] S1: Set the target tension value of the diaphragm and calculate the preset torque based on the target tension value;

[0067] S2 collects diaphragm tension values ​​in real time and calculates tension deviation values ​​at multiple times based on the target tension value;

[0068] In one embodiment, real-time acquisition of diaphragm tension values ​​includes: acquiring the diaphragm tension value between the unwinding device and the die head; acquiring the diaphragm tension value between the die head and the discharge device; and acquiring the diaphragm tension value between the discharge device and the winding device.

[0069] S3: Calculate the torque control increment based on the tension deviation values ​​at multiple moments;

[0070] In one embodiment, the specific control method is as follows: the PLC calculates the deviation value E based on the target tension value SV set on the touch screen and the diaphragm tension value PV detected by the tension sensor, and then uses an incremental PID algorithm to calculate ΔU = KP*[E(n)-E(n-1)]+KI*E(n)+KD*[E(n)-2E(n-1)+E(n-2)]

[0071] Where ΔU is the unwinding servo torque control increment; KP is the proportional coefficient; KI is the integral coefficient; KD is the differential coefficient; E(n) is the current deviation value; E(n-1) is the deviation value calculated at the previous moment; and E(n-2) is the deviation value calculated at the previous two moments.

[0072] The PLC program first calculates a preset servo torque based on the tension parameter SV set on the touchscreen. Then, it outputs the servo torque value by adding the preset torque to the calculated result ΔU. Since ΔU is a real-time adjustable variable, it controls the current loop of the servo motor, enabling the tension of the unwinding mechanism to quickly reach the set value. Furthermore, it can adjust and eliminate tension deviations in real time during operation, achieving high-precision tension control. PV is displayed in real-time on the touchscreen; SV, KP, KI, and KD all have input boxes on the touchscreen that allow users to adjust according to process requirements.

[0073] In another embodiment, the steps further include:

[0074] S4: Set the friction parameters and obtain the roll diameter;

[0075] In one embodiment, the roll diameter includes the roll diameter of the unwinding roller, the roll diameter in the discharge traction roller, and / or the roll diameter of the take-up roller.

[0076] S5: Calculate the motor torque value based on the target tension value, friction parameters, and roll diameter, and input it into the servo motor.

[0077] In another embodiment, the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0078] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lithium battery swingless roll diaphragm coater characterized by, The application relates to a diaphragm production device, which comprises a diaphragm, a unwinding device, a head, a discharging device, a winding device, a data acquisition device and a control device. The diaphragm is output by the unwinding device, sequentially passes through the head, the discharging device and the winding device. The data acquisition device is arranged inside the unwinding device, the head or the discharging device. The control device is electrically connected with the data acquisition device. The unwinding device comprises an unwinding roller, a first over roller arranged at the outlet end of the unwinding roller and a first connecting group roller; the first over roller is electrically connected with a first servo motor; the diaphragm passes through the first over roller and the first connecting group roller and is output to the head, and the contact angle between the diaphragm and the first over roller and the first connecting group roller is less than or equal to 90 DEG. The data acquisition device comprises an ultrasonic sensor arranged on the unwinding roller, and the ultrasonic sensor is electrically connected with the control device and is used for detecting the diameter of the winding material on the unwinding roller. The head comprises a reference roller, a coating roller, first and second intermediate rollers arranged on both sides of the coating roller and a second over roller arranged at the outlet of the head. The diaphragm is transmitted through the reference roller, sequentially passes through the first and second intermediate rollers, the coating roller and the second over roller, and the contact angle between the diaphragm and the coating roller, the first and second intermediate rollers and the second over roller is less than or equal to 90 DEG. The control steps of the control device comprise the following steps: a target tension value of the diaphragm is set, and a preset torque is calculated according to the target tension value; a diaphragm tension value is collected in real time, and tension deviation values at multiple time points are calculated based on the target tension value; a torque control increment is calculated according to the tension deviation values at the multiple time points. The application further comprises a second connecting group roller connected with the first connecting group roller and the reference roller, the second connecting group roller is used for adjusting the transmission angle of the diaphragm and enlarging the wrap angle between the diaphragm and the reference roller.

2. The lithium battery swing-free roller diaphragm coater according to claim 1, characterized in that, A flattening roller is arranged between the reference roller and the first intermediate roller, and the flattening roller has a concave-convex surface and is used for flattening the diaphragm.

3. The lithium battery swing-free roll diaphragm coater of claim 1, wherein, The real-time collection of the diaphragm tension value comprises the following steps:

4. The lithium battery swing-free roll diaphragm coater of claim 1, wherein, a diaphragm tension value between the unwinding device and the head is collected; a diaphragm tension value between the head and the discharging device is collected; a diaphragm tension value between the discharging device and the winding device is collected. The steps further comprise the following steps:

5. The lithium battery swing-free roller die coater of claim 1, wherein, a friction parameter is set and the diameter of the winding material is obtained; a motor torque value is calculated according to the target tension value, the friction parameter and the diameter of the winding material and is input into the servo motor. The diameter of the winding material comprises the diameter of the winding material of the unwinding roller, the diameter of the winding material in the discharging traction roller and / or the diameter of the winding material of the winding roller.

6. The lithium battery swing-free roller diaphragm coater of claim 5, wherein, ​

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