Lithium battery diaphragm casting piece forming device and method

Abstract

The invention discloses a lithium battery diaphragm casting piece forming device which comprises a die head comprising a plurality of fine adjustment bolts used for adjusting the opening degree of a die lip; a chilling roller; the first thickness gauge is used for measuring the thickness of each transverse interval of the casting piece; the second thickness gauge is used for measuring the thickness of each transverse interval of the diaphragm; the die lip opening control device comprises a controller and a screwing assembly, the controller is preset with the target thickness of a casting piece, and the controller is used for correcting the target thickness of the casting piece according to the comparison result of the actual thickness of the diaphragm and the target thickness of the diaphragm and controlling the screwing assembly to rotate a fine adjustment bolt according to the corrected target thickness of the casting piece. And the thickness of the casting piece is stabilized within the corrected target thickness range of the casting piece. According to the invention, an engineering and digital control method is adopted to replace a manual mode to control the opening degree of the die lip of the die head, the adjustment result of the opening degree of the die lip can be obtained in a short time, the phenomena of low control precision, long time consumption and large waste of the die lip are eliminated, and a high-consistency diaphragm can be stably produced.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery diaphragm preparation, and in particular to a lithium battery diaphragm casting sheet forming device and method. Background Art

[0002] The thickness of lithium battery separator is the core parameter that determines the battery performance and safety, and its uniformity control is a key quality indicator in the production process. When the thickness of the separator is unevenly distributed, it will not only significantly deteriorate the charging and discharging efficiency and cycle stability of the battery, but may also cause safety hazards such as local thermal runaway or internal short circuit. For this reason, precise thickness detection must be implemented before the separator winding process, and the die lip opening must be dynamically adjusted based on real-time detection data to ensure product homogeneity.

[0003] There are two main implementation schemes for the current die lip opening adjustment technology: the traditional manual adjustment method uses a mechanical fine-tuning bolt structure. The operator analyzes the real-time data of the thickness gauge or records the thickness distribution by the touch of the winding, and uses professional tools to physically adjust the bolts at specific positions to change the die lip gap to the preset parameters. Although this method can achieve the thickness control of the diaphragm, its control effect depends entirely on the operator's experience and skill level, resulting in a large dispersion of adjustment accuracy, fluctuations in product qualification rate, and poor quality consistency. Another adjustment method uses heat-sensitive materials to process fine-tuning bolts, and controls the die lip gap by adjusting the bolt length through electric heating. However, due to the physical properties of the material's thermal expansion coefficient, its adjustment range is limited and it is difficult to adapt to production needs. Summary of the invention

[0004] In view of the above technical problems, the purpose of the present invention is to provide a lithium battery diaphragm casting sheet forming device and method, which can achieve uniform thickness of the diaphragm and obtain the adjustment result of the die lip opening in a shorter time. It has strong control stability and short regulation cycle, which helps to reduce waste of raw materials.

[0005] In order to achieve the above-mentioned object, the lithium battery separator casting sheet forming device proposed in the present invention comprises:

[0006] A die head, including a plurality of fine-tuning bolts for adjusting the die lip opening;

[0007] Chilled rollers, used to cool the sheet into cast sheets;

[0008] The first thickness gauge is used to measure the thickness of each transverse section of the casting;

[0009] The second thickness gauge is used to measure the thickness of each lateral section of the diaphragm;

[0010] A die lip opening control device comprises a controller and a twisting assembly, wherein the controller is preset with a target thickness of the casting sheet, and the controller is used to correct the target thickness of the casting sheet according to a comparison result between the actual thickness of the diaphragm and the target thickness of the diaphragm, and to control the twisting assembly to rotate a fine-tuning bolt according to the corrected target thickness of the casting sheet, so that the thickness of the casting sheet is stabilized within the corrected target thickness range of the casting sheet.

[0011] In some embodiments, when the thickness data within a period of time on the thickness data change curve of a certain transverse interval of the diaphragm exceeds a minimum threshold and the slope of the curve within this time period exceeds a certain threshold, the target thickness of the casting is corrected based on the relationship between the actual thickness of the casting and the actual thickness of the diaphragm during this time period.

[0012] In some embodiments, when the thickness data within a period of time on the thickness data change curve of a certain transverse interval of the casting exceeds a minimum threshold and the slope of the curve within the time period exceeds a certain threshold, the controller controls the screwing assembly to rotate the fine-tuning bolt to stabilize the thickness of any transverse interval of the casting within the corresponding target range.

[0013] In some embodiments, the thickness data of the casting sheet and the diaphragm are read from the first thickness gauge and the second thickness gauge at every preset time interval;

[0014] The thickness data of the casting sheet and the diaphragm are compared with a preset target thickness data range, and when any of the thickness data exceeds the target thickness range, a sound alarm is issued and / or a prompt is given through a human-computer interaction interface.

[0015] In some embodiments, before formally starting the diaphragm production process, a diaphragm reference sample that meets the quality standards is obtained through trial production, and the target thickness range of the casting is determined based on the casting thickness distribution data recorded by the first thickness gauge.

[0016] In some embodiments, during the online production control stage, thickness data change curves with production time as the horizontal axis are drawn based on the thickness data collected by the first thickness gauge and the second thickness gauge; the target thickness range of the casting is corrected based on the changing trend of the thickness change curve corresponding to the second thickness gauge; and the opening of the die lip is adjusted in real time based on the changing trend of the thickness data change curve corresponding to the first thickness gauge.

[0017] In some embodiments, the driving mechanism includes an X-axis moving module, a Y-axis moving module and a Z-axis moving module, the Z-axis moving module is arranged on the Y-axis moving module for realizing movement in the Z-axis direction, the Y-axis moving module is arranged on the X-axis moving module for realizing movement in the Y-axis direction, the X-axis moving module is used to realize movement in the X-axis direction, and the twisting assembly is arranged on the Z-axis moving module.

[0018] In some embodiments, the X-axis moving module, the Y-axis moving module, and the Z-axis moving module are moved by a ball screw nut pair.

[0019] In some embodiments, the screwing assembly includes a socket for engaging an existing fine-tuning bolt, and a motor for rotating the socket after the fine-tuning bolt has been engaged by the socket.

[0020] In some embodiments, a position detection device is further included, and the position detection device is used to detect the position of the screwing assembly.

[0021] The present invention also provides a lithium battery separator casting sheet forming method, comprising the following steps:

[0022] Preset the target thickness of the casting sheet and the diaphragm, and divide the casting sheet and the diaphragm into a plurality of transverse sections in the transverse direction, wherein the transverse sections correspond to the fine-tuning bolts;

[0023] The thickness of each transverse section of the casting sheet and the diaphragm is measured by a first thickness gauge and a second thickness gauge respectively;

[0024] Correct the time delay of obtaining the casting thickness data and the diaphragm thickness data according to the speed of the mechanical flow;

[0025] Compare the diaphragm thickness with the diaphragm target thickness, and correct the casting target thickness according to the comparison result;

[0026] The thickness of the casting is compared with the target thickness of the casting, and the opening of the die lip is adjusted according to the comparison result so that the thickness of any lateral section of the casting is stabilized within the corresponding target range of the casting.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention can correct the target thickness of the casting sheet in real time according to the data of the first thickness gauge and the second thickness gauge, and automatically control the opening of the die lip according to the target thickness of the casting sheet. Since an engineering and digital control method is adopted to replace the manual control of the die lip opening of the die head, the adjustment result of the die lip opening can be obtained in a short time, eliminating the phenomenon of low control accuracy, long time consumption and large waste of the die lip, and can achieve stable output of high consistency diaphragm products. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The preferred implementation modes will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0030] Figure 1 It is a structural schematic diagram of the lithium battery separator casting sheet forming device of the present invention.

[0031] Figure 2 It is a structural schematic diagram of a die lip opening control device of a lithium battery diaphragm casting sheet forming device of the present invention.

[0032] Figure 3 yes Figure 2 Schematic diagram of the structure of the mobile module.

[0033] Description of Figure Numbers:

[0034] Die head 1; fine-tuning bolt 11; chilled roller 2; first thickness gauge 3; second thickness gauge 4; controller 5; drive mechanism 6; frame 61; X-axis moving module 62; Y-axis moving module 63; Z-axis moving module 64; support seat 65; screwing assembly 7; sleeve 71; motor 72; stepper motor 81; screw nut seat 82; linear guide rail 83; guide rail slider 84. DETAILED DESCRIPTION

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0036] Please refer to the instruction manual Figures 1 to 3 , a lithium battery diaphragm casting sheet forming system proposed in one embodiment of the present invention comprises a die head 1, a chilling roller 2, a first thickness gauge 3, a second thickness gauge 4 and a die lip opening control device. The die head 1 is used to extrude and shape the melt flowing out of the extruder side. The die head 1 has a cavity, and the bottom of the cavity is provided with a fixed die lip and a movable die lip in opposite positions. The fixed die lip and the movable die lip cooperate to form an extrusion slit. The high-temperature melt in the die head 1 cavity can flow out through the extrusion slit, and after forming a sheet, it flows from the die head 1 side to the chilling roller 2 side. The chilling roller 2 is used to cool the sheet, so that the temperature of the high-temperature sheet is quickly reduced to below the glass transition temperature, and the sheet is transformed from a viscous flow state to an amorphous solid casting sheet to avoid crystallization affecting subsequent stretching. After the casting sheet is stretched, extracted, dried and other processes, it finally forms a diaphragm product.

[0037] In this embodiment, a plurality of fine-tuning bolts 11 are provided on the outer side of the movable die lip, and the plurality of fine-tuning bolts 11 are spaced apart along the length direction of the movable die lip, and are used to adjust the gap of the extrusion slot. It should be noted that the transverse direction described in this embodiment refers to the length direction of the extrusion slot. In this embodiment, the sheet, the cast sheet and the diaphragm can be divided into a plurality of transverse intervals along the transverse direction, and the transverse intervals have a corresponding relationship with the fine-tuning bolts 11. By rotating the fine-tuning bolts 11, the gap at the corresponding position of the extrusion slot can be increased or decreased, thereby adjusting the thickness of the sheet, the cast sheet and the final diaphragm. The first thickness gauge 3 and the second thickness gauge 4 can move back and forth in the transverse direction, and the first thickness gauge 3 is used to measure the thickness of each transverse interval of the cast sheet, and the second thickness gauge 4 is used to measure the thickness of each transverse interval of the diaphragm. The structure for driving the first thickness gauge 3 and the second thickness gauge 4 is not limited in this embodiment. For example, the first thickness gauge 3 and the second thickness gauge 4 are driven to perform linear motion by structures such as linear guides. The die lip opening control device in this embodiment controls the fine-tuning bolt 11 based on the data collected by the first thickness gauge 3 and the second thickness gauge 4 to adjust the thickness of the sheet in the transverse section.

[0038] Before the diaphragm production process is officially started, a target thickness reference system needs to be established: obtain diaphragm reference samples that meet the quality standards through trial production, and determine the target thickness range of the cast sheet based on the cast sheet thickness distribution data recorded by the first thickness gauge 3. In this embodiment, the system synchronously collects the thickness data of the first thickness gauge 3 (cast sheet detection) and the second thickness gauge 4 (diaphragm finished product detection) according to the preset sampling period, and establishes a thickness data change curve based on this, and compares the real-time data with the target thickness. When the measured thickness of any detection point deviates from the target interval (maximum threshold setting value +8%, minimum threshold setting value -5%), the system automatically activates the sound and light alarm and / or prompts through the human-computer interaction interface. The thickness data change curve is a curve drawn based on the thickness data collected by the first thickness gauge 3 and the second thickness gauge 4 with the production time as the horizontal axis, and the target thickness range includes the maximum threshold and the minimum threshold. Exemplarily, when any thickness data on the thickness data change curve of the diaphragm exceeds the maximum threshold, a sound alarm and / or a prompt can be given through the human-computer interaction interface. For example, if the variation curve of the diaphragm thickness data is always maintained near the minimum threshold, it indicates that the production process is normal. However, the present invention is not limited thereto. In some embodiments of the present invention, the diaphragm and casting sheet thickness data exceeding the maximum threshold or being less than the minimum threshold can be set as alarm / prompt conditions at the same time.

[0039] In the online production control stage, a thickness data change curve of each transverse section of the casting sheet with the production time as the horizontal axis is drawn according to the thickness data collected by the first thickness gauge 3, and the gap of the extrusion slot corresponding to each transverse section of the casting sheet is reset according to the change trend of the thickness data change curve of each transverse section of the casting sheet. For example, when the thickness data within a period of time on the thickness data change curve of a certain transverse section of the casting sheet exceeds the minimum threshold value and the slope of the curve within the time period exceeds a certain threshold value, it means that the thickness data changes drastically within the time period, and the opening of the die lip can be automatically adjusted to ensure that the thickness of any transverse section of the casting sheet is stable within the corresponding target range.

[0040] After the sheet is formed into a cast sheet, it needs to go through at least stretching, extraction, drying and other steps, and the factors affecting the final diaphragm thickness include the stretching multiples of each transverse section of the cast sheet, so even if the thickness of the cast sheet is stable within the preset target range, when the temperature of a certain transverse section of the cast sheet changes or the stretching multiple changes, it will still affect the thickness of the final diaphragm. Therefore, in this embodiment, the system also draws a thickness data change curve of each transverse section of the diaphragm with production time as the transverse direction based on the thickness data collected by the second thickness gauge 4, and resets the target thickness of the cast sheet according to the change trend of the thickness data change curve, and adjusts the gap of the extrusion slit corresponding to each transverse section of the cast sheet according to the reset target thickness of the cast sheet. For example, when the thickness data within a period of time on the thickness data change curve of a certain transverse interval of the diaphragm exceeds the minimum threshold and the slope of the curve within this time period exceeds a certain threshold, it means that the diaphragm thickness data changes dramatically within this time period, the stretching multiple of the casting has changed, and the originally set target thickness range of the casting can no longer meet the actual needs. The target thickness of the casting can be corrected based on the relationship between the actual thickness of the casting and the actual thickness of the diaphragm during this time period, and the opening of the die lip can be adjusted according to the corrected target thickness of the casting to ensure that the thickness of each transverse interval of the casting is stable within the corrected target range of the casting.

[0041] It can be understood that the thickness of the diaphragm is jointly determined by the thickness of the casting and the subsequent stretching process. The greater the stretching multiple of the casting, the smaller the thickness of the finished diaphragm. During the biaxial stretching process, the thickness of the casting will be significantly reduced by longitudinal (MD) and transverse (TD) stretching. The thickness conversion relationship between the casting and the diaphragm is T_final = T_cast / (MD_ratio×TD_ratio), where T_final is the thickness of the diaphragm, T_cast is the thickness of the casting, and MD_ratio and TD_ratio are the longitudinal and transverse stretching ratios, respectively. For example, the thickness of the casting is 100μm. After longitudinal stretching 3 times and transverse stretching 5 times, the thickness of the finished diaphragm is about 100 / (3×5)=6.67μm. Therefore, based on the actual thickness of the diaphragm and the casting, the stretching multiple of any transverse interval of the casting can be determined, and the target thickness of the casting can be corrected according to the stretching multiple to ensure that the thickness of the finished diaphragm is always maintained within the preset range.

[0042] In this embodiment, a first thickness gauge 3 is configured at the upstream end of the mechanical flow direction of the production line, and a second thickness gauge 4 is set at the downstream end, and there is a predetermined distance between the two thickness gauges. Due to the time lag effect in the transmission process of the cast sheet, in order to match the data collected by the first thickness gauge 3 and the second thickness gauge 4, it is necessary to perform time series processing on the thickness data collected by the first thickness gauge 3 and the second thickness gauge 4. As a time series processing, the time delay (time lag) can be appropriately corrected according to the speed of the mechanical flow. Specifically, the distance between the first thickness gauge 3 and the second thickness gauge 4 is determined in advance, and the time delay for obtaining the cast sheet thickness data and the diaphragm thickness data is corrected according to the speed of the mechanical flow, and the data is stored. In this way, the thickness data of the first thickness gauge 3 and the second thickness gauge 4 can correspond to each other respectively, and the time delay can be corrected.

[0043] In this embodiment, the target thickness of the casting sheet can be corrected in real time according to the data of the first thickness gauge 3 and the second thickness gauge 4, and the opening of the die lip can be automatically controlled according to the target thickness of the casting sheet, thereby achieving uniform thickness of the diaphragm. In addition, the adjustment of the die lip opening is based on the target thickness of the casting sheet. Since the distance between the die head 1 and the first thickness gauge 3 is short, the adjustment result of the die lip opening can be obtained in a short time, which helps to reduce the waste of raw materials.

[0044] In this embodiment, the die lip opening control device includes a controller 5, a driving mechanism 6 and a twisting assembly 7. The twisting assembly 7 is connected to the driving mechanism 6. The controller 5 signal is connected to the driving mechanism 6 and the twisting assembly 7. The controller 5 is used to control the opening and closing of the driving mechanism 6 and the twisting assembly 7.

[0045] For details, please refer to the attached Figure 1The screwing assembly 7 is connected to the driving mechanism 6, and the controller 5 controls the driving mechanism 6 to drive the screwing assembly 7 to move to the fine-tuning bolt 11. The fine-tuning bolt 11 is screwed by the screwing assembly 7 to make the die lip opening reach the expected value.

[0046] The driving mechanism 6 includes an X-axis moving module 62, a Y-axis moving module 63 and a Z-axis moving module 64. For ease of explanation, a right-handed XYZ orthogonal coordinate system based on the gravity direction is set, with the length direction of the extrusion slot as the X-axis direction, the Y-axis direction perpendicular to the X-axis direction in the horizontal plane as the Y-axis direction, and the direction perpendicular to the horizontal plane as the Z-axis direction.

[0047] The X-axis moving module 62 is used to realize the linear motion of the X-axis. The X-axis moving module 62 can be installed on the ground, for example, in the form of existing tracks and track wheels; the X-axis moving module 62 can also be suspended above the ground, for example, it can be suspended on the ceiling indoors, using the existing overhead crane structure. Therefore, the X-axis moving module 62 can be arranged according to needs or according to the structure of the site. At the same time, the X-axis moving module 62 can use existing equipment, such as a crane, a combined structure of tracks and track wheels, a gear rack, a gear chain, a pulley system, and a combination of a steel cable winch and a motor at both ends of the support seat 65 to pull along the X-axis to achieve movement. The support seat 65 is connected to the X-axis moving module 62, and is driven by the X-axis moving module 62 to realize the movement of the support seat 65 in the X-axis direction; the support seat 65 can be used as a mounting seat for parts, and the structure can be set as needed.

[0048] The Y-axis moving module 63 is used to realize the movement in the Y-axis direction. The Y-axis moving module 63 is movably connected to the support seat 65, so that the support seat 65 drives the Y-axis moving module 63 to move in the X-axis direction, realizing the position change of the Y-axis moving module 63 in the X-axis direction. The Y-axis moving module 63 can also adopt existing equipment such as existing ball screw nut pair, gear rack, gear chain, cylinder, hydraulic cylinder and pulley system.

[0049] The Z-axis moving module 64 is used to realize movement in the Z-axis direction. The Z-axis moving module 64 is connected to the Y-axis moving module 63, so that the Y-axis moving module 63 drives the Z-axis moving module 64 to move, realizing the position change of the Z-axis moving module 64 in the Y-axis direction.

[0050] As an example, the X-axis moving module 62 is connected to the frame 61, the Y-axis moving module 63 is arranged at the moving end of the X-axis moving module 62, the Z-axis moving module 64 is arranged at the moving end of the Y-axis moving module 63, and the twisting component 7 is arranged at the moving end of the Z-axis moving module 64, that is, the X-axis moving module 62, the Y-axis moving module 63 and the Z-axis moving module 64 are connected in series with the twisting component 7, so that the twisting component 7 can be used in conjunction with the X-axis moving module 62, the Y-axis moving module 63 and the Z-axis moving module 64 to achieve movement in the X-axis, Y-axis and Z-axis directions.

[0051] In this embodiment, the X-axis moving module 62, the Y-axis moving module 63 and the Z-axis moving module 64 can adopt the same structural design, all of which include a stepper motor 81, a coupling, a ball screw, a screw nut seat 82, a linear guide 83 and a guide slider 84, wherein the output end of the stepper motor 81 is rigidly connected to the ball screw in a direct drive manner through the coupling, and the ball screw passes through the screw nut seat 82 and cooperates with its thread, so that the screw nut seat 82 can perform precise reciprocating motion along the axis of the ball screw when the stepper motor 81 is driven. The linear guide 83 extends along the axial direction of the ball screw, and the guide slider 84 is fixedly installed on the screw nut seat 82. The guide slider 84 and the linear guide 83 are slidably matched, and the two cooperate to form a double guide limit mechanism to ensure that the composite motion trajectory of the screw nut seat 82 and the guide slider 84 is strictly controlled, and its movable stroke is limited to the mechanical range formed by the bearing seats on both sides of the ball screw. Therefore, in this embodiment, a hierarchical stacking assembly mode is adopted between the moving modules. The Y-axis moving module 63 is integrally installed on the screw nut seat of the X-axis moving module 62, and the Z-axis moving module 64 is further mounted on the top of the screw nut seat of the Y-axis moving module 63, so that precise displacement control in three-dimensional space is achieved through three-axis linkage.

[0052] The screwing assembly 7 is connected to the Z-axis moving module 64, so that the Z-axis moving module 64 drives the screwing assembly 7 to move in the Z-axis direction, realizing the position change of the screwing assembly 7 in the Z-axis. Finally, the position of the screwing assembly 7 is adjusted by the position change of the X-axis moving module 62, the Y-axis moving module, and the Z-axis moving module 64, and the position adjustment is realized. Since all of them are controlled by automatic control, the position of the screwing assembly 7 can be accurately adjusted, and finally when the screwing assembly 7 is used to rotate the fine-tuning bolt 11, the precision of the alignment with the fine-tuning bolt 11 is realized.

[0053] The screwing assembly 7 includes a sleeve 71 for engaging the fine-tuning bolt 11, and a motor 72 for rotating the sleeve 71 after the fine-tuning bolt 11 has been engaged by the sleeve 71. The sleeve 71 has a cavity that matches the shape of the head of the fine-tuning bolt, and the axial direction of the sleeve 71 is preferably parallel to the axial direction of the fine-tuning bolt 11. In addition, the screwing assembly 7 also includes a position detection device, which is used to detect the position of the screwing assembly 7. The movement trajectory of the screwing assembly 7 can be pre-set according to the installation position of different fine-tuning bolts 11. When in use, after determining the fine-tuning bolt 11 that needs to be adjusted, the controller 5 controls the driving mechanism 6 to drive the screwing assembly 7 to move, and the position detection device checks whether the screwing assembly 7 moves in place. After the screwing assembly 7 is aligned with the adjustment bolt, a feedback signal is given to the controller 5. After the controller 5 determines that the screwing assembly 7 has moved in place, the screwing assembly 7 can proceed to the next step. In this embodiment, the position detection device can be a position sensor, a visual detection device, etc., which is not limited here.

[0054] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A lithium battery diaphragm casting device, characterized in that: include: A die head, including a plurality of fine-tuning bolts for adjusting the die lip opening; Chilled rollers, used to cool the sheet into cast sheets; The first thickness gauge is used to measure the thickness of each transverse section of the casting; The second thickness gauge is used to measure the thickness of each lateral section of the diaphragm; A die lip opening control device comprises a controller and a twisting assembly, wherein the controller is preset with target thicknesses of a diaphragm and a cast sheet, and the controller is used to correct the target thickness of the cast sheet according to a comparison result between the actual thickness of the diaphragm and the target thickness, and to control the twisting assembly to rotate a fine-tuning bolt according to the corrected target thickness of the cast sheet, so that the thickness of the cast sheet is stabilized within the corrected target thickness range of the cast sheet.

2. The lithium battery separator casting sheet forming device according to claim 1, characterized in that: When the thickness data within a period of time on the thickness data change curve of a certain transverse interval of the diaphragm exceeds the minimum threshold and the slope of the curve within this time period exceeds a certain threshold, the target thickness of the casting is corrected based on the relationship between the actual thickness of the casting and the actual thickness of the diaphragm in this time period.

3. The lithium battery separator casting sheet forming device according to claim 1, characterized in that: When the thickness data within a period of time on the thickness data change curve of a certain transverse section of the casting exceeds the minimum threshold and the slope of the curve within this time period exceeds a certain threshold, the controller controls the screwing component to rotate the fine-tuning bolt to stabilize the thickness of any transverse section of the casting within the corresponding target range.

4. The lithium battery separator casting sheet forming device according to claim 1, characterized in that: Also includes: At each preset time interval, the thickness data of the casting sheet and the diaphragm are read from the first thickness gauge and the second thickness gauge; The thickness data of the casting sheet and the diaphragm are compared with a preset target thickness data range, and when any of the thickness data exceeds the target thickness range, a sound alarm is issued and / or a prompt is given through a human-computer interaction interface.

5. The lithium battery separator casting sheet forming device according to claim 1, characterized in that: Also includes: Before officially starting the diaphragm production process, a diaphragm reference sample that meets the quality standards is obtained through trial production, and the target thickness range of the casting is determined based on the casting thickness distribution data recorded by the first thickness gauge.

6. The lithium battery separator casting sheet forming device according to claim 1, characterized in that: Also includes: In the online production control stage, thickness data variation curves with production time as the horizontal axis are drawn according to the thickness data collected by the first thickness gauge and the second thickness gauge; The target thickness range of the casting sheet is corrected according to the changing trend of the thickness change curve corresponding to the second thickness gauge; and the opening of the die lip is adjusted in real time according to the changing trend of the thickness data change curve corresponding to the first thickness gauge.

7. The lithium battery separator casting sheet forming device according to claim 1, characterized in that: Also includes: The driving mechanism includes an X-axis moving module, a Y-axis moving module and a Z-axis moving module. The Z-axis moving module is arranged on the Y-axis moving module for realizing movement in the Z-axis direction. The Y-axis moving module is arranged on the X-axis moving module for realizing movement in the Y-axis direction. The X-axis moving module is used to realize movement in the X-axis direction. The twisting assembly is arranged on the Z-axis moving module.

8. The lithium battery separator casting sheet forming device according to claim 1, characterized in that: The screwing assembly includes a socket for engaging an existing fine-tuning bolt, and a motor for rotating the socket after the fine-tuning bolt has been engaged by the socket.

9. The lithium battery separator casting sheet forming device according to claim 1, characterized in that: It also includes a position detection device, which is used to detect the position of the screwing component.

10. A method for forming a lithium battery separator casting sheet, characterized in that: The forming device according to any one of claims 1 to 9 is used, comprising the following steps: Preset the target thickness of the casting sheet and the diaphragm, and divide the casting sheet and the diaphragm into a plurality of transverse sections in the transverse direction, wherein the transverse sections correspond to the fine-tuning bolts; The thickness of each transverse section of the casting sheet and the diaphragm is measured by a first thickness gauge and a second thickness gauge respectively; Correct the time delay of obtaining the casting thickness data and the diaphragm thickness data according to the speed of the mechanical flow; Compare the diaphragm thickness with the diaphragm target thickness, and correct the casting target thickness according to the comparison result; The thickness of the casting is compared with the target thickness of the casting, and the opening of the die lip is adjusted according to the comparison result so that the thickness of any lateral section of the casting is stabilized within the corresponding target thickness range of the casting.

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