Cylindrical roll core hot-pressing device and hot-pressing method thereof

Abstract

The invention relates to a cylindrical roll core hot-pressing device and a hot-pressing method thereof, and the cylindrical roll core hot-pressing device comprises a fixed rotating part which is used for fixing a cylindrical roll core and driving the cylindrical roll core to rotate; the hot-pressing rotating part can rotate and is used for performing contact heating on the cylindrical roll core; and the adjusting mechanism is used for driving the fixed rotating part and the hot-pressing rotating part to be close to or far away from each other so as to adjust the pressure between the cylindrical roll core and the hot-pressing rotating part. The cylindrical roll core coated with the diaphragm after being wound is fixed through the fixed rotating part, the cylindrical roll core is driven to rotate through the fixed rotating part, the cylindrical roll core is subjected to contact heating through the hot-pressing rotating part, and then the pressure between the cylindrical roll core and the hot-pressing rotating part is adjusted through the adjusting mechanism, so that the cylindrical roll core is heated and pressurized; therefore, hot pressing of the cylindrical roll core with the coated diaphragm is realized, the coated diaphragm can be applied to the cylindrical battery, and the cycle performance and the structural stability performance of the cylindrical battery are finally improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a cylindrical core hot pressing device and a hot pressing method thereof. Background Art

[0002] Cylindrical lithium-ion batteries are suitable for series-parallel combination due to their standardized size, high production efficiency, low manufacturing cost, good consistency, etc., and are an important application branch of lithium-ion batteries. The structure of cylindrical batteries mainly includes shell, cap, positive electrode, negative electrode, diaphragm, electrolyte, PTC element, gasket, safety valve, etc. These components work together to ensure that the battery can work safely and effectively.

[0003] In the field of lithium batteries, the coated diaphragm is to apply one or more layers of glue on the base film of the diaphragm. The glue has a certain viscosity. After the coated diaphragm is hot-pressed with the pole piece in the battery cell, it can ensure close and uniform contact between the diaphragm and the pole piece, inhibit gas production, inhibit lithium dendrites, improve battery hardness, and ensure battery cycle and safety. Square batteries can be directly hot-pressed with flat plates. Conventional square battery glue-coated diaphragm hot-pressing processes are as follows: Figure 1 , place the square battery cell 1' (wound core or stacked core) in the middle of the hot pressing plate 2', and use the high temperature (70-120℃) and pressure (0.1-1Mpa) generated by electric heating to use the glue on the surface of the glue-coated diaphragm to produce adhesion with the electrode, thereby exerting the role of the glue-coated diaphragm.

[0004] However, due to the cylindrical shape of cylindrical batteries, there is currently no hot pressing method that can meet the requirements of coating diaphragms for cylindrical batteries, which results in the inability to apply coated diaphragms to cylindrical batteries, limiting the performance improvement of cylindrical batteries. In addition, the current hot pressing plate generally uses ordinary electric heating, which has slow heat conduction and gradually transfers heat from the outside to the inside. During the heat transfer process, the viscosity consistency between each layer of the pole piece and the coated diaphragm is poor. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a cylindrical core hot pressing device and a hot pressing method thereof, so as to realize the hot pressing of the cylindrical core with a coated diaphragm after winding, so that the coated diaphragm can be applied to cylindrical batteries to improve the cycle performance and structural stability of the cylindrical batteries.

[0006] To achieve the above object, the present invention adopts the following technical solutions: The present invention first provides a cylindrical core hot pressing device, wherein the cylindrical core is a cylindrical core with a coated diaphragm after winding, and the cylindrical core hot pressing device comprises: A fixed rotating member, which is used to fix the cylindrical winding core and drive the cylindrical winding core to rotate; A hot pressing rotating member, which is rotatable and used for surface contact heating of the cylindrical winding core; and The regulating mechanism is used to drive the fixed rotating part and the hot pressing rotating part to move closer to or farther from each other so as to regulate the pressure between the cylindrical winding core and the hot pressing rotating part.

[0007] The present invention fixes the wound cylindrical core with a coated diaphragm by a fixed rotating part and drives the cylindrical core to rotate by the fixed rotating part, performs contact heating on the cylindrical core by a hot pressing rotating part, and then adjusts the pressure between the cylindrical core and the hot pressing rotating part by an adjusting mechanism to heat and pressurize the cylindrical core, thereby realizing hot pressing of the cylindrical core with the coated diaphragm, so that the coated diaphragm can be applied to cylindrical batteries, and finally improves the cycle performance and structural stability performance of the cylindrical batteries.

[0008] As a further improvement of the above scheme of the present invention, the fixed rotating part includes an inflatable shaft and a driving mechanism for driving the inflatable shaft to rotate, and a far-infrared electric heating tube is arranged in the inflatable shaft.

[0009] As a further improvement of the above scheme of the present invention, the driving mechanism 1 includes two brackets 1, a driving motor 1, a transmission belt and a pulley 2; the two ends of the air shaft are rotatably mounted on the two brackets 1 respectively and one end of the air shaft is fixed with a pulley 1, the driving motor 1 is mounted on one of the brackets 1 and its output end is fixed with a pulley 2, and the transmission belt is sleeved on the pulley 1 and the pulley 2; And / or, the heating temperature of the far-infrared electric heating tube 1 is 70-130°C, preferably 100°C.

[0010] As a further improvement of the above-mentioned scheme of the present invention, the hot pressing rotating part includes a hot pressing roller and two driving mechanisms for driving the hot pressing roller to rotate; the hot pressing roller includes a roller body parallel to the cylindrical winding core, and a plurality of mounting holes are opened circumferentially through the roller body, and two far-infrared electric heating tubes are installed in each of the mounting holes.

[0011] As a further improvement of the above-mentioned scheme of the present invention, the second driving mechanism includes a transmission shaft and a second driving motor. The transmission shaft is inserted into the roller body and is fixed to the roller body. Both ends of the transmission shaft are rotatably mounted on two brackets two respectively, and one end of the transmission shaft is transmission-connected to the second driving motor.

[0012] As a further improvement of the above solution of the present invention, the heating temperature of the far-infrared electric heating tube 2 is 70-120°C, preferably 85°C.

[0013] As a further improvement of the above solution of the present invention, a plurality of mounting holes are evenly distributed circumferentially on the hot pressing roller, and the outer diameter of the hot pressing roller is 1-5 times, preferably 2 times, the outer diameter of the cylindrical winding core.

[0014] The present invention also provides a cylindrical core hot pressing method, which uses the cylindrical core hot pressing device as described above, and comprises the following steps: S1. Fix the cylindrical core set on the fixed rotating member; S2. The hot pressing rotating member is in contact with the cylindrical winding core and the fixed rotating member drives the cylindrical winding core and the hot pressing rotating member to rotate synchronously; S3. The adjustment mechanism drives the fixed rotating part and the hot pressing rotating part to move closer to each other so that the pressure between the hot pressing rotating part and the cylindrical winding core F Gradually increase until the number of turns of the cylindrical winding core reaches n Then the adjustment mechanism drives the fixed rotating part and the hot pressing rotating part to move away from each other so that the pressure between the hot pressing rotating part and the cylindrical winding core F Gradually decrease until the number of turns of the cylindrical winding core reaches N circle, the hot pressing is finished; among them, n , N are positive integers and n Less than N .

[0015] As a further improvement of the above solution of the present invention, in step S3, when the cylindrical winding core rotates a number of times, n When the hot pressing rotating part and the cylindrical winding core are F Reaching the maximum value is F max , when the cylindrical winding core rotates ≤ n When the pressure between the hot pressing rotating part and the cylindrical winding core is controlled to ,in x is a positive integer and 0 <x≤n ; When the cylindrical core rotates the number of times> n When the pressure between the hot pressing rotating part and the cylindrical winding core is controlled to ,in y is a positive integer and n <y≤N .

[0016] As a further improvement of the above solution of the present invention, the rotation speed of the cylindrical winding core is 1 turn / min-20 turns / min, preferably, the rotation speed of the cylindrical winding core is 6 turns / min; and / or, 0.5MPa≤ F max ≤5MPa. Preferably, F max =2MPa; and / or, 2≤ N ≤50, preferably 5≤ N ≤20.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention fixes the wound cylindrical core with a coated diaphragm by a fixed rotating part and drives the cylindrical core to rotate by the fixed rotating part, performs contact heating on the cylindrical core by a hot pressing rotating part, and then adjusts the pressure between the cylindrical core and the hot pressing rotating part by an adjusting mechanism to heat and pressurize the cylindrical core, thereby realizing hot pressing of the cylindrical core with a coated diaphragm, so that the coated diaphragm can be applied to cylindrical batteries, and finally improves the cycle performance and structural stability performance of the cylindrical batteries.

[0018] 2. The present invention arranges a far-infrared electric heating tube in the air shaft of the fixed rotating part, so that heating can be performed from the pole piece inside the cylindrical winding core from the inside to the outside, with high heating efficiency, good heating consistency, and improved hot pressing effect.

[0019] 3. The hot pressing rotating part of the present invention also adopts far infrared heating, which has high heating efficiency and good heating consistency.

[0020] 4. The present invention sets the outer diameter of the hot pressing roller to 1-5 times the outer diameter of the cylindrical winding core, thereby ensuring good contact between the hot pressing roller and the cylindrical winding core, improving the heating effect, and also ensuring that the cylindrical winding core does not deform.

[0021] 5. When the cylindrical core is hot-pressed, the pressure between the hot roller and the cylindrical core is controlled to gradually increase and then gradually decrease, which can ensure that the cylindrical core does not deform and the diaphragm inside the cylindrical core does not wrinkle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of an existing flat plate hot pressing device; Figure 2 A schematic structural diagram of a cylindrical core hot pressing device provided in an embodiment of the present invention.

[0023] Reference numerals: 1', square battery cell; 2', hot pressing flat plate; 1. Fixed rotating part; 2. Cylindrical winding core; 3. Hot pressing roller; 3-1. Roller body; 3-2. Far infrared electric heating tube 2; 4. Transmission shaft. DETAILED DESCRIPTION

[0024] For ease of understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0026] Reference Figure 2 The present embodiment proposes a hot pressing device for a cylindrical core 2, which is used to realize hot pressing of the cylindrical core 2. The cylindrical core 2 is a cylindrical core with a coated diaphragm after winding, and includes a fixed rotating part, a hot pressing rotating part and an adjusting mechanism (not shown).

[0027] The fixed rotating member is used to fix the cylindrical winding core 2 and drive the cylindrical winding core 2 to rotate. The fixed rotating member includes an inflatable shaft 1 and a driving mechanism 1.

[0028] The working principle of the inflatable shaft 1 is based on the effect of gas pressure. The gas is provided to the inflatable shaft 1 through a compressed air system or other gas source. The gas enters the inflation pipeline inside the inflatable shaft 1 through a pipeline. As the gas is injected, the pressure inside the inflatable shaft 1 gradually increases, and the surface of the inflatable shaft 1 can expand. The cylindrical core 2 is subjected to a radial pressure from the inside to the outside, so that it is fixedly mounted on the inflatable shaft 1. After deflation, the surface part of the inflatable shaft 1 retracts rapidly, and the cylindrical core 2 can be removed. In this embodiment, a far-infrared electric heating tube 1 is arranged inside the inflatable shaft. The heating temperature of the far-infrared electric heating tube 1 is 70-130°C. In this embodiment, the heating temperature of the far-infrared electric heating tube 2 3-2 is controlled at 100°C.

[0029] In this embodiment, a driving mechanism 1 (not shown) is used to realize the rotation of the inflatable shaft 1, thereby driving the cylindrical winding core 2 to rotate. Specifically, the driving mechanism 1 includes two brackets 1, a driving motor 1, a transmission belt and a pulley 2. The two ends of the inflatable shaft 1 are rotatably mounted on the two brackets 1 respectively, and one end of the inflatable shaft 1 is fixed with a pulley 1, a driving motor 1 is mounted on one of the brackets 1 and its output end is fixed with a pulley 2, and the transmission belt is mounted on the pulley 1 and the pulley 2. Once the driving motor is started, the inflatable shaft 1 can be driven to rotate through the transmission belt. In order to facilitate the disassembly and assembly of the cylindrical winding core 2, the inflatable shaft 1 and a bracket 1 are connected in a detachable manner.

[0030] The hot pressing rotating member is used for contact heating of the cylindrical winding core 2. In this embodiment, the hot pressing rotating member includes a hot pressing roller and a second driving mechanism.

[0031] The hot pressing roller 3 includes a hollow roller body 3-1, and a plurality of mounting holes are evenly opened on the roller body 3-1 in the circumferential direction, and a far-infrared electric heating tube 2 3-2 is arranged in each mounting hole. The outer diameter of the roller body 3-1 and the number of the far-infrared electric heating tubes 2 3-2 can be reasonably designed according to the size of the cylindrical core 2 that needs to be heated. The larger the diameter of the hot pressing roller 3, the larger the contact surface between the roller surface and the core, and the faster the core is heated, but the degree of deformation caused by the extrusion of the core will also be greater; the smaller the radius of the hot pressing roller 3, the slower the heating speed, but the shape of the core can be effectively maintained; therefore, the outer diameter of the hot pressing roller 3 is controlled to be 1-5 times the outer diameter of the cylindrical core 2. In this embodiment, the outer diameter of the hot pressing roller 3 is twice the outer diameter of the cylindrical core 2, the outer diameter of the roller body 3-1 is, and the number of the far-infrared electric heating tubes 2 3-2 is 12. The heating temperature of the far-infrared electric heating tube 2 3 - 2 is 70-120° C. In this embodiment, the heating temperature of the far-infrared electric heating tube 2 3 - 2 is controlled at 85° C.

[0032] In this embodiment, the driving mechanism 2 (not shown) is used to realize the rotation of the hot pressing roller 3. Specifically, the driving mechanism 2 includes two brackets 2, a transmission shaft 4 and a driving motor 2. The transmission shaft 4 is inserted into the roller body 3-1 and the transmission shaft 4 is fixed to the roller body 3-1. The two ends of the transmission shaft 4 are rotatably installed on the two brackets 2, and one end of the transmission shaft 4 is connected to the driving motor 2. When the driving motor 2 is started, the transmission shaft 4 can be driven to rotate, and the transmission shaft 4 drives the hot pressing roller 3 to rotate.

[0033] The adjustment mechanism is used to drive the hot pressing roller 3 and the air shaft 1 to move closer to or farther from each other. By adjusting the distance between the hot pressing roller 3 and the air shaft 1, the pressure between the hot pressing roller 3 and the cylindrical core 2 can be adjusted to achieve hot pressing of the cylindrical core 2. In this embodiment, the adjustment mechanism can adopt a screw transmission mechanism, which includes a base, a drive motor 3, a screw, a moving block 1 and a moving block 2. The drive motor 3 is installed on the base, one end of the screw is connected to the drive motor 3 in a transmission manner, and the screw is provided with two threaded segments with opposite spiral directions. The moving block 1 and the moving block 2 are both slidably installed on the base, and the moving block 1 and the moving block 2 are respectively threadedly connected with the two threaded segments of the screw. The moving block 1 is fixedly connected to the two brackets 1, and the moving block 2 is fixedly connected to the two brackets 2. The drive motor 2 drives the screw to rotate, and the screw drives the moving block 1 and the moving block 2 to move closer to or farther from each other, thereby driving the air shaft 1 and the hot pressing roller 3 to move closer to or farther from each other.

[0034] Based on the above cylindrical core 2 hot pressing device, this embodiment further provides a cylindrical core 2 hot pressing method, and the specific steps are as follows: S1. The cylindrical core 2 is mounted on the inflatable shaft 1, and the inflatable shaft 1 is inflated to fix the cylindrical core 2; S2. The hot pressing roller 3 is in contact with the cylindrical core 2, the motor drive mechanism drives the air shaft 1 to rotate, and the transmission mechanism drives the hot pressing roller 3 to rotate, so that the cylindrical core 2 and the hot pressing roller 3 rotate synchronously; S3. The regulating mechanism drives the air shaft 1 and the heat pressing roller 3 to move closer to each other so that the pressure between the heat pressing roller 3 and the cylindrical winding core 2 F Gradually increase until the number of revolutions of the cylindrical winding core 2 reaches n Then the adjustment mechanism drives the air shaft 1 and the hot pressing roller 3 to move away from each other so that the pressure between the hot pressing roller 3 and the cylindrical winding core 2 F Gradually decrease until the number of revolutions of the cylindrical winding core 2 reaches N circle, the hot pressing is finished; among them, n , N are positive integers and n Less than N When the cylindrical core 2 rotates the number of times n When the circle is turned, the pressure between the hot pressing roller 3 and the cylindrical winding core 2 F Reaching the maximum value is F max , when the number of turns of cylindrical core 2 is ≤ n When the pressure between the hot pressing roller 3 and the cylindrical winding core 2 is controlled to ,in x is a positive integer and 0 <x≤n ; When the cylindrical core 2 rotates the number of times> n When the pressure between the hot pressing roller 3 and the cylindrical winding core 2 is controlled to ,in y is a positive integer and n <y≤N .

[0035] Control the speed of the cylindrical core 2 to be 1 turn / min-20 turns / min. The total number of turns of the cylindrical core 2 is N Controlled at: 2 ≤ N ≤50. In this embodiment, the rotation speed of the cylindrical winding core 2 is 6 turns / min, and the total number of rotations is controlled at 5≤ N ≤20. Control the maximum pressure between the hot pressing roller 3 and the cylindrical winding core 2 F max Meet: 0.5MPa≤ F max ≤5MPa, as proved by a large number of experimental data, is preferred F max =2MPa is the best.

[0036] The present invention is described in detail below in conjunction with specific hot pressing embodiments. Example Preparation of cylindrical core 2: Model cylindrical 18650, capacity 2500mAh, nominal voltage 3.6V, positive electrode ternary NCM622, negative electrode artificial graphite; positive electrode sheet length 605mm, width 57mm, surface density 450g / m 2 ; Negative electrode sheet length 649mm, width 58mm, surface density 114g / m 2 ; The diaphragm PE wet method is 7+2+1+1um, of which 7μm is the base film, 2μm is the ceramic layer, and the outermost sides of the diaphragm are 1um PVDF coating layers; the above positive and negative electrode sheets and diaphragms are wound into a cylindrical core 2 using a 4mm winding needle, and the diameter of the cylindrical core 2 is 17.4mm.

[0037] An inflatable shaft 1 is selected, which has a diameter of 3mm when not inflated and can expand to a maximum diameter of 4.5mm after inflation. The diameter of the far-infrared electric heating tube 1 in the inflatable shaft 1 is 1.5mm, and the heating temperature is 100°C; the hot pressing roller 3 is twice the diameter of the winding core, which is 34.8mm. The diameter of the far-infrared electric heating tube 2 3-2 in the hot pressing roller 3 is 2mm. There are 14 far-infrared electric heating tubes 3-2, which are evenly distributed on the outside of the hot pressing roller 3 in a ring shape. The heating temperature of the far-infrared electric heating tube 2 3-2 is 85°C.

[0038] During hot pressing, the wound cylindrical core 2 is placed on the inflatable shaft 1, and the cylindrical core 2 is fixed after inflation. Then the surface of the hot pressing roller 3 contacts and presses the surface of the core. The adjustment mechanism drives the inflatable shaft 1 to press down and the hot pressing roller 3 to press up, and controls the rotation speed of the cylindrical core 2 to 6 turns / min. While rotating synchronously, the pressure is gradually increased; the pressure gradually increases with each turn of the cylindrical core 2. Set the maximum pressure between the hot pressing roller 3 and the cylindrical core 2 F max =2MPa, set N=9, n=6. When the cylindrical winding core 2 of this embodiment is hot-pressed, the pressure of each turn of the cylindrical winding core 2 is as shown in Table 1.

[0039] Table 1

[0040] Through the above hot pressing, the diameter of the cylindrical winding core of this embodiment becomes 17.26 mm after hot pressing. The battery after hot pressing is shelled, grooved, spot welded, baked, injected, capped, left to stand, formed, divided, and self-discharged to obtain a finished 18650 battery cell.

[0041] Comparative Example Cylindrical core preparation: Model cylindrical 18650, capacity 2500mAh, nominal voltage 3.6V, positive electrode ternary NCM622, negative electrode artificial graphite; positive electrode sheet length 605mm, width 57mm, surface density 450g / m 2 ; Negative electrode sheet length 649mm, width 58mm, surface density 114g / m2 ; The diaphragm PE wet method is 7+2+1+1um, of which 7μm is the base film, 2μm is the ceramic layer, and the outermost sides of the diaphragm are 1um PVDF coating layers; the above positive and negative electrodes and diaphragms are wound into a cylindrical core using a 4mm winding needle; the core diameter is 17.4mm.

[0042] The cylindrical core is rolled without hot pressing, and is directly put into the shell, grooved, spot welded, baked, liquid injected, capped, left to stand, formed, capacity divided, and self-discharged to obtain the finished 18650 battery cell.

[0043] Test Case The battery cells prepared in the embodiment and the comparative example were subjected to a cycle test at 1C 100% DOD and a vibration test according to the national standard GB38031-2020. The test results are shown in Table 2.

[0044] Table 2

[0045] It can be seen from the results in Table 2 that since the cylindrical winding core of the embodiment was hot pressed, the diameter was reduced by 0.14 mm after hot pressing, and the embodiment had a significant improvement in 1C cycle compared with the comparative example; the battery cells of the embodiment and the comparative example both passed the national standard vibration test, but the pole piece of the embodiment had no displacement relative to the diaphragm, while the pole piece of the comparative example had displacement with the diaphragm, and the structural stability of the embodiment was better.

[0046] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is considered to be "fixed to" another component, it may be directly fixed on the other component or there may be a central component at the same time.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0048] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A cylindrical core hot pressing device, characterized in that: The cylindrical winding core (2) is a cylindrical winding core having a coated diaphragm after winding, and the cylindrical winding core hot pressing device comprises: A fixed rotating member, used to fix the cylindrical winding core (2) and drive the cylindrical winding core (2) to rotate; A hot pressing rotating member, which is capable of rotating and is used to contact heat the cylindrical winding core (2); and The regulating mechanism is used to drive the fixed rotating part and the hot pressing rotating part to move closer to or farther from each other so as to regulate the pressure between the cylindrical winding core (2) and the hot pressing rotating part.

2. The cylindrical core hot pressing device according to claim 1, characterized in that: The fixed rotating part comprises an inflatable shaft (1) and a driving mechanism for driving the inflatable shaft (1) to rotate, and a far-infrared electric heating tube is arranged in the inflatable shaft (1).

3. The cylindrical core hot pressing device according to claim 2, characterized in that: The driving mechanism comprises two brackets, a driving motor, a transmission belt and a pulley; the two ends of the air shaft (1) are rotatably mounted on the two brackets and one end of the air shaft (1) is fixed with a pulley; the driving motor is mounted on one of the brackets and its output end is fixed with a pulley; the transmission belt is sleeved on the pulleys one and two; And / or, the heating temperature of the far-infrared electric heating tube 1 is 70-130°C.

4. The cylindrical core hot pressing device according to claim 1, characterized in that: The hot pressing rotating member comprises a hot pressing roller (3) and a driving mechanism for driving the hot pressing roller (3) to rotate; the hot pressing roller (3) comprises a roller body (3-1) parallel to the cylindrical winding core (2), a plurality of mounting holes are circumferentially penetrated on the roller body (3-1), and two far-infrared electric heating tubes (3-2) are installed in each of the mounting holes.

5. The cylindrical core hot pressing device according to claim 4, characterized in that: The second driving mechanism comprises a transmission shaft (4) and a second driving motor; the transmission shaft (4) is inserted into the roller body (3-1) and the transmission shaft (4) is fixed to the roller body (3-1); both ends of the transmission shaft (4) are rotatably mounted on two second brackets respectively, and one end of the transmission shaft (4) is transmission-connected to the second driving motor.

6. The cylindrical core hot pressing device according to claim 4, characterized in that: The heating temperature of the far-infrared electric heating tube 2 (3-2) is 70-120°C.

7. The cylindrical core hot pressing device according to claim 4, characterized in that: The plurality of mounting holes are evenly distributed circumferentially on the hot pressing roller (3), and the outer diameter of the hot pressing roller (3) is 1 to 5 times the outer diameter of the cylindrical winding core (2).

8. A method for hot pressing a cylindrical core, characterized in that: It adopts the cylindrical core hot pressing device as described in any one of claims 1 to 7, which includes the following steps: S1. The cylindrical core (2) is fixed to the fixed rotating member; S2. The hot pressing rotating member contacts the cylindrical winding core (2) and the fixed rotating member drives the cylindrical winding core (2) and the hot pressing rotating member to rotate synchronously; S3. The adjustment mechanism drives the fixed rotating member and the hot pressing rotating member to move closer to each other so that the pressure between the hot pressing rotating member and the cylindrical winding core (2) F Gradually increase until the cylindrical winding core (2) rotates a number of times n The adjusting mechanism then drives the fixed rotating part and the hot pressing rotating part to move away from each other so that the pressure between the hot pressing rotating part and the cylindrical winding core (2) is F Gradually decrease until the cylindrical winding core (2) rotates a number of times N circle, the hot pressing is finished; among them, n , N are positive integers and n Less than N .

9. The cylindrical core hot pressing method according to claim 8, characterized in that: In step S3, when the cylindrical winding core (2) rotates a number of times n When the hot pressing rotating part and the cylindrical winding core (2) are F Reaching the maximum value is F max , when the cylindrical winding core (2) rotates ≤ n When the pressure between the hot pressing rotating part and the cylindrical winding core (2) is controlled to be ,in 0<x≤ n ; When the cylindrical winding core (2) rotates a number of times> n When the pressure between the hot pressing rotating part and the cylindrical winding core (2) is controlled to be ,in n <y≤N .

10. The cylindrical core hot pressing method according to claim 9, characterized in that: The rotation speed of the cylindrical winding core (2) is 1 turn / min to 20 turns / min; and / or, 0.5MPa≤ F max ≤5MPa; and / or, 2≤ N ≤50.

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