CN114888897B

CN114888897B - Diaphragm cutting method

Info

Publication number: CN114888897B
Application number: CN202210431961.2A
Authority: CN
Inventors: 黄承玉; 曹杰; 余招宇; 曹辉
Original assignee: Rept Battero Energy Co Ltd
Current assignee: Rept Battero Energy Co Ltd
Priority date: 2022-04-22
Filing date: 2022-04-22
Publication date: 2024-03-19
Anticipated expiration: 2042-04-22
Also published as: CN114888897A

Abstract

The invention relates to a membrane cutting method, which comprises the following steps: pre-cutting the edge of the membrane in a pre-cutting station along the running direction perpendicular to the membrane so that the edge of the membrane forms an opening; the film is entirely cut at the cutting station in a direction perpendicular to the running direction of the film. According to the membrane cutting method, the edges of the membrane are pre-cut, and the opening formed in the edges of the membrane can release edge warping stress of the membrane caused by expansion and the like, so that edge cutting burrs and edge expansion defects can be obviously reduced.

Description

Diaphragm cutting method

Technical Field

The invention relates to the technical field of cutting, in particular to a membrane cutting method.

Background

At present, a battery cell consists of a positive plate, a negative plate and a diaphragm, wherein the positive plate, the negative plate and the diaphragm are wound, formed and accommodated in a steel shell, and before the battery cell is prepared, the positive plate, the negative plate and the diaphragm are respectively prepared at different stations and are required to be cut into rated sizes, and the battery cell is prepared after lamination and winding processes.

In the related art, the general cutting technology is to use a cutting knife to cut after the film is forced to be stretched, but the edge stretching of the cutting technology is not removed, and the cutting problems such as cutting burrs are not improved fundamentally.

Therefore, there is a need for a new method of cutting a film to overcome the above-mentioned problems.

Disclosure of Invention

The embodiment of the invention provides a diaphragm cutting method, which aims to solve the problem that cutting problems such as cutting burrs are not improved fundamentally in a cutting mode of using a cutting knife for cutting after the diaphragm is forced to be stretched in the related art.

In a first aspect, a method for cutting a film is provided, comprising the steps of: pre-cutting the edge of the membrane in a pre-cutting station along the running direction perpendicular to the membrane so that the edge of the membrane forms an opening; the film is entirely cut at the cutting station in a direction perpendicular to the running direction of the film.

In some embodiments, after the pre-cutting station pre-cuts the edge of the film sheet in a direction perpendicular to the running direction of the film sheet to form the opening on the edge of the film sheet, the method further comprises: the film sheet is driven to move around the flattening roller to a cutting station.

In some embodiments, the central angle of the contact surface of the film sheet with the flattening roller is greater than or equal to 60 °.

In some embodiments, the surface of the nip roll has a spiral pattern with a depth of less than 1.5 times the thickness of the film sheet.

In some embodiments, the pre-cutting station is provided with a first upper knife and a first lower knife, the first upper knife is a bevel knife, and the first lower knife is a straight knife.

In some embodiments, the cutting station is provided with a second upper blade and a second lower blade, both of which are straight blades.

In some embodiments, the blade profile of the second upper blade is serrated.

In some embodiments, after the cutting station cuts the web entirely in a direction perpendicular to the running direction of the web, further comprising: the membrane is clamped using two opposing clamping rollers.

In some embodiments, one of the opposing nip rollers is a fixed roller and the other opposing nip roller is a movable roller, and the opposing nip roller controls its travel and compression force via an air cylinder or motor.

In some embodiments, the roughness of the two opposing nip rollers is different.

The technical scheme provided by the invention has the beneficial effects that:

the embodiment of the invention provides a diaphragm cutting method, because the edge of the diaphragm is pre-cut, the opening formed at the edge of the diaphragm can release the edge warping stress of the diaphragm caused by extension and the like, so that edge cutting burrs and edge extension defects can be obviously reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic flow chart of a method for cutting a film according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a cutting process of a film according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a pre-cut station provided in an embodiment of the present invention;

FIG. 4 is a schematic side view of a pre-cutting station according to an embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view of a cutting station provided in an embodiment of the present invention;

fig. 6 is a schematic side view of a cutting station according to an embodiment of the present invention.

In the figure:

1. a pre-cutting station; 11. a first upper cutter; 12. a first lower cutter;

2. a cutting station; 21. a second upper cutter; 22. a second lower cutter;

3. a membrane; 4. a flattening roller; 5. oppositely clamping the passing roller; 6. a clamping plate; 7. horizontally passing through rollers.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The embodiment of the invention provides a diaphragm cutting method, which can solve the problem that cutting problems such as cutting burrs are not improved fundamentally in a cutting mode of using a cutting knife after forcibly extending a diaphragm in the related art.

Referring to fig. 1, a method for cutting a film according to an embodiment of the present invention may include the following steps:

s1: the edges of the film web 3 are precut in a precut station 1 in a direction perpendicular to the running direction of the film web 3, so that the edges of the film web 3 form an opening.

In this embodiment, with the running direction of the film 3 being the longitudinal direction, the running direction perpendicular to the film 3 is the transverse direction, in the pre-cutting station 1, the pre-cutting knife may be disposed on two opposite sides of the transverse direction of the film 3, and pre-cutting is performed on the edges of the film 3 on two opposite sides of the film 3 to form an opening, where the length of the single-side pre-cutting of the film 3 is preferably less than 5mm.

S2: the web 3 is cut completely in the cutting station 2 in a direction perpendicular to the running direction of the web 3. That is to say that the film 3 is cut in its entirety after the pre-cutting, the cutting position at the cutting station 2 preferably coincides with the cutting position at the pre-cutting station 1, although the cutting position at the cutting station 2 may also deviate slightly from the cutting position at the pre-cutting station 1 during the actual cutting.

In this embodiment, since the edge of the film 3 is pre-cut at the pre-cutting station 1, an opening can be formed at the edge of the film 3, the opening can release the edge warping stress of the film 3 caused by expansion and other reasons, and then the subsequent cutting process is performed, so that edge cutting burrs and edge expansion defects can be obviously reduced.

In some embodiments, referring to fig. 2, after the pre-cutting station 1 pre-cuts the edge of the film sheet 3 in the direction perpendicular to the running direction of the film sheet 3, the method may further include: the driving film web 3 moves around the flattening roller 4 to the cutting station 2. That is, a flattening roller 4 is arranged between the pre-cutting station 1 and the cutting station 2, the film 3 is flattened by the flattening roller 4 and then moves to the cutting station 2 for integral cutting after being pre-cut, and the flattening roller 4 can be made of alloy, carbon fiber and other materials; the flattening roller 4 is beneficial to releasing transverse stress of the pre-cut membrane 3, ensuring that the edge of the warped edge and the main body of the membrane 3 do not generate extension, fold and the like, and the flattening roller 4 is further beneficial to plasticity of the membrane 3 and improves the transverse rigidity of the membrane 3; the surface of the flattening roller 4 should meet the roughness requirements.

In some alternative embodiments, the running track of the film 3 may be a straight line or an oblique line, the selected track may be determined according to the space and the processing requirement, and the central angle of the contact surface of the film 3 and the flattening roller 4 may be greater than or equal to 60 °. That is, the contact surface of the film 3 and the flattening roller 4 is in a circular arc shape, and the central angle of the circular arc is not smaller than 60 degrees, so that the flattening roller 4 can be ensured to exhibit good flattening effect.

Preferably, the flattening roller 4 is preferably a driven roller, the surface of the flattening roller 4 can be provided with a spiral pattern, the depth and the width of the spiral pattern are selected according to application products and processing, the depth of the spiral pattern is preferably smaller than 1.5 times of the thickness of the membrane 3, the width is not particularly required, and further, the spiral angle of the spiral pattern is determined according to application products and processing. The material of the flattening roller 4 can be selected from alloy, carbon fiber and other materials, and the special material of the spiral pattern on the surface of the roller body of the flattening roller 4 can be inconsistent with the roller body, and the material selection is determined according to the application product and the processing.

In some embodiments, referring to fig. 3 and fig. 4, the pre-cutting station 1 may be provided with a first upper blade 11 and a first lower blade 12, where the first upper blade 11 is an oblique blade, the first lower blade 12 is a straight blade, and the first upper blade 11 and the first lower blade 12 need to be cut in a matched manner; further, the edge type of the first upper cutter 11 and the first lower cutter 12 can be opposite single edge, double edge, saw tooth or the like, and the selection is determined according to the application product and the processing; furthermore, the pre-cutting action of the pre-cutting station 1 can adopt the action design that the first upper knife 11 actively cuts the first lower knife 12 and passively cuts the first lower knife 12, or the action design that the first upper knife 11 and the first lower knife 12 actively cut the first lower knife, and the pre-cutting action is selected according to the application product and the processing; the materials of the first upper cutter 11 and the first lower cutter 12 can be alloy, ceramic and other materials, and the materials are selected according to the application products and processing; in this embodiment, the first upper blade 11 is more favorable to forming the opening of the membrane 3 by adopting the inclined blade, and the inclined blade is better as the opening is formed at the edge of the membrane 3 at the pre-cutting station 1. More specifically, the first upper blade 11 is a triangle-like oblique blade, a single blade type, and the first lower blade 12 is a parallel straight blade, a single blade type and a single blade direction opposite to the first upper blade 11, so as to increase the shearing force of cutting the membrane 3.

In some alternative embodiments, referring to fig. 5 and 6, the cutting station 2 may be provided with a second upper blade 21 and a second lower blade 22, where the second upper blade 21 and the second lower blade 22 are both straight blades, and the straight blades are in the shape of cutters. In this embodiment, at the cutting station 2, the second upper blade 21 and the second lower blade 22 need to be matched for cutting; further, the edge type of the second upper cutter 21 and the second lower cutter 22 can be opposite single edge, double edge, saw tooth, etc., and the selection is determined according to the application product and the processing; the further cutting action of the cutting station 2 can adopt the action design that the second upper knife 21 actively cuts the second lower knife 22 and the second upper knife 21 and the second lower knife 22 actively cut the second lower knife 22, and the cutting action is selected according to the application product and the processing; the materials of the second upper cutter 21 and the second lower cutter 22 can be alloy, ceramic and other materials, and the materials are selected according to the application products and processing. In this embodiment, the second upper blade 21 and the second lower blade 22 are straight blades, which is beneficial to reducing burrs during the whole cutting process of the film 3.

Preferably, the blade shape of the second upper blade 21 is a saw tooth shape, the cutting effect of the saw tooth shape of the second upper blade 21 is relatively good, and the phenomenon that the film 3 is draped or the film 3 breaks is basically avoided. The number and the size of the saw teeth of the second upper blade 21 are selected according to the thickness of the material of the membrane 3.

In some embodiments, referring to fig. 2, after the cutting station 2 cuts the whole of the film sheet 3 in the running direction perpendicular to the film sheet 3, it may further include: the membrane 3 is clamped by two opposite clamping passing rollers 5; two opposing nip rollers 5 provide traction to the film web 3, drawing the film web 3 into motion.

A horizontal roller 7 is further arranged before the pre-cutting station 1, the film 3 can be moved to the pre-cutting station 1 by bypassing the horizontal roller 7, and the horizontal roller 7 can play a role of pulling the film 3.

Further, referring to fig. 2, a clamping plate 6 may be further disposed between the cutting station 2 and the flattening roller 4, where the clamping plate 6 may clamp the film 3 and pull and move the film 3 between the pre-cutting station 1 and the cutting station 2, so as to ensure that the film 3 can smoothly move to the cutting station 2.

Further, one of the opposite clamping passing rollers 5 is preferably a fixed passing roller, the other opposite clamping passing roller 5 is a movable passing roller, and the opposite clamping passing roller 5 controls the stroke and extrusion force thereof through an air cylinder or a motor, so that the two opposite clamping passing rollers 5 can clamp films 3 with different thicknesses, and the adjustment of the extrusion force can be realized. The two opposite clamping passing rollers 5 meet the requirement of relative parallelism, the opposite clamping passing rollers 5 can be made of alloy, carbon fiber and other materials, the surface roughness can be made of mirror surface standard (Ra1.0 or more) or roughness standard (Ra1.0 or more), and the roughness is selected according to application products and processing; the two opposing nip rollers 5 may be of different materials, the choice of material being dependent on the application and the process.

Further, when the two opposite clamping rollers 5 are selected, the roughness of the two opposite clamping rollers can be different, and the different roughness of the two sides can provide stable and reliable traction.

In the description of the present invention, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present invention. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

It should be noted that in the present invention, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is only a specific embodiment of the invention to enable those skilled in the art to understand or practice the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended 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 method of cutting a web, comprising the steps of:

pre-cutting the edge of the membrane (3) along the running direction perpendicular to the membrane (3) at a pre-cutting station (1) to form an opening on the edge of the membrane (3);

cutting all the films (3) along the running direction perpendicular to the films (3) at a cutting station (2);

after the pre-cutting station (1) pre-cuts the edge of the film (3) along the running direction perpendicular to the film (3) so that the edge of the film (3) forms an opening, the device further comprises: the film (3) is driven to move to the cutting station (2) by bypassing the flattening roller (4).

2. The film cutting method as claimed in claim 1, wherein: the central angle of the contact surface of the film (3) and the flattening roller (4) is larger than or equal to 60 degrees.

3. The film cutting method as claimed in claim 1, wherein:

the surface of the flattening roller (4) is provided with a spiral pattern, and the depth of the spiral pattern is smaller than 1.5 times of the thickness of the membrane (3).

4. The film cutting method as claimed in claim 1, wherein:

the pre-cutting station (1) is provided with a first upper cutter (11) and a first lower cutter (12), the first upper cutter (11) is an inclined cutter, and the first lower cutter (12) is a straight cutter.

5. The film cutting method as claimed in claim 1, wherein:

the cutting station (2) is provided with a second upper cutter (21) and a second lower cutter (22), and the second upper cutter (21) and the second lower cutter (22) are straight cutters.

6. The method of cutting a web as recited in claim 5 wherein: the blade shape of the second upper knife (21) is saw-tooth-shaped.

7. The film cutting method as claimed in claim 1, wherein: after the cutting station (2) cuts the whole film (3) along the running direction perpendicular to the film (3), the device further comprises:

the membrane (3) is clamped using two opposing clamping rollers (5).

8. The method of cutting a web as recited in claim 7 wherein:

one of the opposite clamping passing rollers (5) is a fixed passing roller, the other opposite clamping passing roller (5) is a movable passing roller, and the travel and extrusion force of the opposite clamping passing roller (5) are controlled by an air cylinder or a motor.

9. The method of cutting a web as recited in claim 7 wherein:

the roughness of the two opposite clamping passing rollers (5) is different.