Winding needle capable of preventing core winding and core pulling and battery winding equipment

Abstract

The utility model relates to the technical field of battery production equipment, in particular to a winding needle for preventing a winding core from being pulled and battery winding equipment, and the winding needle is provided with a clamping surface for clamping a winding core diaphragm and / or a battery piece; a coating is arranged on the surface of the winding needle and used for reducing the friction coefficient between the winding needle and the winding core diaphragm and / or the battery piece. According to the utility model, a layer of DLC material is plated on the winding needle, so that the friction coefficient between the winding needle and the winding core diaphragm is reduced, and the wear resistance, corrosion resistance and the like of the winding needle are enhanced. The winding needle can be pulled out more easily after winding is completed, wrinkles or damage in a battery cell cannot be caused when the winding needle is pulled out, the conditions that a positive pole piece, a negative pole piece and a diaphragm are misplaced and the like are effectively avoided, and therefore the production efficiency of a lithium battery and the quality of the battery are effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery production equipment, in particular to a winding needle for preventing winding core from pulling out and a battery winding device. Background Art

[0002] In the lithium battery production process, after the positive and negative electrode sheets are cut, they need to be wound with a certain length and a separator by a winding machine to form a battery cell. After the battery is wound, the winding needle needs to be pulled out from the battery cell.

[0003] Chinese patent CN219435927U discloses a battery winding needle and a battery winding device, the winding needle includes: a connecting column; a transition column connected to the connecting column, the axis of the transition column coincides with the axis of the connecting column; a needle member connected to the connecting column, the length direction of the needle member is parallel to the axis of the transition column, the cross-sectional area of ​​the transition column is smaller than the cross-sectional area of ​​the connecting column, and the cross-sectional area of ​​the transition column is larger than the cross-sectional area of ​​the needle member. The connecting column can be connected to a driving mechanism for easy installation and use. The connecting column is connected to the needle member through the transition column, the needle member contacts the electrode sheet and the diaphragm, and the driving mechanism drives the connecting column to drive the needle member to rotate, so that the electrode sheet and the diaphragm are wound to form a battery cell.

[0004] In the prior art, due to the influence of static electricity on the diaphragm inside the battery cell, the friction between the diaphragm and the winding needle is relatively large. Therefore, when the winding needle is pulled out, the diaphragm will be pulled out, causing wrinkles inside the battery cell. In response to this situation, the method used on site is to manually smooth out the wrinkled part of the winding core, but this method has low working efficiency and may miss detections. Utility Model Content

[0005] In order to solve the above problems, the purpose of the utility model is to provide a winding needle and a battery winding device that can prevent the winding core from being pulled out.

[0006] The technical solution provided by the utility model is:

[0007] In a first aspect, a winding needle for preventing core pulling is provided, wherein the winding needle is provided with a clamping surface for clamping a winding core diaphragm and / or a battery cell; and a coating is provided on the surface of the winding needle, wherein the coating is used to reduce the friction coefficient between the winding needle and the winding core diaphragm and / or the battery cell.

[0008] As an optional technical solution of the first aspect, a connecting portion is provided at one end of the winding needle, and the connecting portion is used to connect to a driving mechanism; the driving mechanism is used to drive the winding needle holding the core diaphragm and / or battery cell to drive the core diaphragm and / or battery cell to be wound.

[0009] As an optional technical solution of the first aspect, the winding needle includes a first winding needle and a second winding needle; the first winding needle and the second winding needle are both connected to the connecting part; and the opposite surfaces of the first winding needle and the second winding needle constitute a clamping surface.

[0010] As an optional technical solution of the first aspect, the connecting part includes a first connecting part and a second connecting part, the first connecting part is connected to the first winding needle, and the second connecting part is connected to the second winding needle;

[0011] The first connecting part is connected to the second connecting part through a connecting assembly; when the first connecting part is connected to the second connecting part through the connecting assembly, the first winding needle and the second winding needle clamp the winding core diaphragm and / or the battery cell between the clamping surfaces.

[0012] Optionally, the first connecting portion and the second connecting portion are both provided with corresponding through holes; the connecting assembly includes a bolt passing through the through hole, and a nut is installed on the bolt.

[0013] Optionally, a first baffle is provided at the connection between the first connecting portion and the first winding needle; and a second baffle is provided at the connection between the second connecting portion and the second winding needle.

[0014] Further, the first connecting portion and the second connecting portion form a cylinder; the first baffle and the second baffle form a cylinder; the first winding needle and the second winding needle form a cylinder;

[0015] Among them, the ratio of the side arc length of the first connecting part to the side arc length of the second connecting part is X; the ratio of the side arc length of the first baffle to the side arc length of the second baffle is Y; the ratio of the side arc length of the first winding needle to the side arc length of the second winding needle is Z; among them, X=Y=Z>1.

[0016] Furthermore, in the side surfaces of the first winding needle and the second winding needle, the flat surface is a clamping surface, and the arc surface is provided with a plurality of air-avoiding grooves.

[0017] As an optional technical solution of the first aspect, the coating is a DLC coating, and the thickness of the DLC coating is 0.01-0.03 mm.

[0018] In a second aspect, a battery winding device includes a frame on which a driving mechanism is mounted;

[0019] It also includes the winding needle for preventing the core from pulling out in the first aspect or any one of the technical solutions of the first aspect, and the driving mechanism is used to drive the winding needle holding the winding core diaphragm and / or battery cell to drive the winding core diaphragm and / or battery cell to be wound up.

[0020] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects:

[0021] The utility model reduces the friction coefficient between the winding needle and the winding core diaphragm by coating a layer of DLC material on the winding needle, and enhances the wear resistance and corrosion resistance of the winding needle. After the winding is completed, the winding needle is easier to be pulled out, and the pulling out will not cause wrinkles or damage inside the battery core, effectively avoiding the misalignment of the positive and negative pole pieces and the diaphragm, thereby effectively improving the production efficiency of lithium batteries and the quality of batteries.

[0022] The utility model divides the two winding needles into a large and a small winding needle. When the winding needles are pulled out after the winding core is wound, the small winding needle is pulled out first to enlarge the internal space, and then the large winding needle is pulled out, thereby reducing the problem of internal wrinkles of the winding core caused by pulling out the winding needles after the winding is completed.

[0023] At the same time, the present application provides an air avoidance groove on the winding needle to reduce the friction between the winding needle and the diaphragm, so as to reduce the phenomenon of wrinkles inside the winding core when the winding needle is pulled out after the winding is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a three-dimensional diagram of a winding needle structure in one embodiment of the present application;

[0025] Figure 2 This is a schematic diagram of the first winding needle structure in one embodiment of the present application;

[0026] Figure 3 It is a side view of the winding needle structure in one embodiment of the present application.

[0027] Explanation of the symbols in the schematic diagram:

[0028] 101: First roll of needles;

[0029] 102: Avoidance slot;

[0030] 103: Second needle roll;

[0031] 201: first connecting portion;

[0032] 202: first baffle;

[0033] 203: through hole;

[0034] 204: second connecting portion;

[0035] 205: Second baffle. DETAILED DESCRIPTION

[0036] In order to further understand the content of the utility model, the utility model is described in detail in conjunction with the drawings and embodiments.

[0037] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of implementation. The change or adjustment of their relative relationship should also be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0038] In one embodiment, the present application provides a winding needle that prevents the winding core from pulling out, such as Figure 1 As shown, a clamping surface is provided on the winding needle, and the clamping surface is used to clamp the winding core diaphragm, or clamp the battery cell, or clamp the winding core diaphragm and the battery cell together.

[0039] In one embodiment, the core diaphragm is first clamped by the winding needle, and after the core diaphragm is wound around the winding needle for one or several turns, the battery sheet is then inserted for winding. In this embodiment, the winding needle is only used to clamp the core diaphragm.

[0040] In one embodiment, the core separator and the battery cell are clamped by the winding needles together, so that the core separator and the battery cell begin to be wound together.

[0041] In one embodiment, a coating is provided on the surface of the winding needle, and the coating is used to reduce the friction coefficient between the winding needle and the winding core separator and / or the battery cell. The coating reduces the friction coefficient, so that when the battery cell is wound and the winding needle is pulled out, the winding needle will not bring out the separator, so that no wrinkles will be generated inside the battery cell.

[0042] In this embodiment, the material of the coating can be selected from

[0043] In one embodiment, the coating is a DLC coating.

[0044] DLC (Diamond Like Carbon) is a type of amorphous carbon film with properties similar to diamond, high hardness, high resistivity, good optical properties, and unique tribological properties. The core of the DLC coating is composed of amorphous carbon. Unlike the crystal structure where atoms are systematically arranged, in amorphous carbon, they lack a consistent pattern. This unique atomic arrangement is the basis of the characteristics and advantages of the DLC coating.

[0045] DLC coating can significantly reduce friction, and its friction coefficient is lower than that of polytetrafluoroethylene. At the same time, because trifluorochloroethylene is a toxic chemical, and workers need to touch the winding needles during the battery winding production, trifluorochloroethylene is not suitable as a coating for winding needles.

[0046] In one embodiment, the DLC coating has a thickness of 0.01-0.03 mm, such as 0.02 mm.

[0047] The DLC coating reduces the friction coefficient between the winding needle and the winding core diaphragm, and also enhances the wear resistance and corrosion resistance of the winding needle. This makes it easier to pull out the winding needle after winding is completed, and it will not cause wrinkles or damage inside the battery cell when it is pulled out, effectively avoiding the misalignment of the positive and negative pole pieces and the diaphragm, thereby effectively improving the production efficiency and quality of lithium batteries.

[0048] The coating in this embodiment can be applied to other types of winding needles, and can also achieve the effect of reducing the core pulling of the battery cell.

[0049] In one embodiment, a connecting portion is provided at one end of the winding needle, and the connecting portion is used to connect with the driving mechanism. Usually, the connecting portion and the winding needle are both cylindrical, and the diameter of the connecting portion is larger than the diameter of the winding needle.

[0050] Since the diameter of the winding needle determines the inner diameter of the wound battery cell, when the inner diameter of the wound battery cell needs to be smaller, the diameter of the winding needle cannot be too large. Since the connecting part needs to be connected to the driving mechanism, the connecting part needs to have a high strength, so the diameter of the connecting part should not be too small.

[0051] When winding the battery cell, the connecting part is connected to the driving mechanism, and the driving mechanism drives the connecting part to drive the winding needle to rotate, so that the winding needle holding the winding core separator and / or battery cell drives the winding core separator and / or battery cell to be rolled up.

[0052] In one embodiment, if Figure 2-3 As shown, the winding needle includes a first winding needle 101 and a second winding needle 103, and the first winding needle 101 and the second winding needle 103 are both connected to the connecting portion. The opposing surfaces of the first winding needle 101 and the second winding needle 103 constitute a clamping surface. In this embodiment, the first winding needle 101 and the second winding needle 103 together constitute a winding needle, and the opposing surfaces of the first winding needle 101 and the second winding needle 103 clamp the winding core diaphragm and / or the battery cell, so that the rotating first winding needle 101 and the second winding needle 103 can drive the winding core diaphragm and / or the battery cell to be wound.

[0053] In one embodiment, the connecting portion includes a first connecting portion 201 and a second connecting portion 204 , wherein the first connecting portion 201 is connected to the first winding needle 101 , and the second connecting portion 204 is connected to the second winding needle 103 .

[0054] The first connecting part 201 and the second connecting part 204 are connected together by a connecting assembly. When the first connecting part 201 and the second connecting part 204 are connected by the connecting assembly, the first winding needle 101 and the second winding needle 103 clamp the winding core separator and / or the battery cell between the clamping surfaces.

[0055] In this embodiment, the first connection part 201 is connected to the second connection part 204 by a connection assembly. When the first connection part 201 is connected to the second connection part 204 by the connection assembly, the first winding needle 101 and the second winding needle 103 clamp the winding core diaphragm and / or the battery cell between the clamping surfaces. That is, the first connection part 201 and the second connection part 204 can be connected together by the connection assembly, so that the distance between the first winding needle 101 and the second winding needle 103 is sufficient to clamp the winding core diaphragm and / or the battery cell between the first winding needle 101 and the second winding needle 103.

[0056] In one embodiment, the first connection part 201 and the second connection part 204 are both provided with corresponding through holes 203. The connection assembly includes a bolt passing through the through hole 203, and a nut is installed on the bolt. When winding the battery cell, the first winding needle 101 and the second winding needle 103 are first clamped to the winding core diaphragm and / or the battery cell, and then the bolt is passed through the through hole 203, and then the nut is tightened, so that the first winding needle 101 and the second winding needle 103 clamp the winding core diaphragm and / or the battery cell.

[0057] By dividing the winding needle into the first winding needle 101 and the second winding needle 103, when the battery cell is wound, a part of the winding needles, such as the first winding needle 101, can be pulled out first to enlarge the internal space of the winding core, and then another part of the winding needles, such as the second winding needle, can be pulled out, thereby reducing the problem of internal wrinkles of the winding core caused by pulling out the winding needles after the winding is completed.

[0058] In one embodiment, a first baffle 202 is provided at the connection between the first connection part 201 and the first winding needle 101, and a second baffle 205 is provided at the connection between the second connection part 204 and the second winding needle 103. When the first connection part 201 and the second connection part 204 are connected through the connection assembly, the first baffle 202 and the second baffle 205 form a disc-shaped shielding part, which can prevent the wound battery cell from contacting other components such as the drive mechanism.

[0059] In this embodiment, the first connecting part 201, the first baffle 202 and the first winding needle 101 are integrally formed, and the second connecting part 204, the second baffle 205 and the second winding needle 103 are integrally formed. The connecting part, the baffle and the winding needle can be made of metal or alloy and then made by casting or other mechanical processing technology.

[0060] In one embodiment, when the first connecting part 201 and the second connecting part 204 are connected through the connecting assembly, the first connecting part 201 and the second connecting part 204 form a cylinder, the first baffle 202 and the second baffle 205 form a cylinder, and the first winding needle 101 and the second winding needle 103 form a cylinder.

[0061] The ratio of the arc length of the side of the first connecting portion 201 to the arc length of the side of the second connecting portion 204 is X, the ratio of the arc length of the side of the first baffle 202 to the arc length of the side of the second baffle 205 is Y, and the ratio of the arc length of the side of the first winding needle 101 to the arc length of the side of the second winding needle 103 is Z. X=Y=Z>1, and X, Y, and Z are all positive numbers, that is, the first winding needle 101 and the second winding needle 103 are different in size, and are a large and a small structure. In this embodiment, the first winding needle 101 is a larger winding needle, and the second winding needle 103 is a smaller winding needle.

[0062] By making the first winding needle 101 and the second winding needle 103 of different sizes, when the winding needles are pulled out after winding the core, the small winding needle is pulled out first to increase the internal space of the core, and then the large winding needle is pulled out, thereby reducing the problem of wrinkles inside the core caused by pulling out the winding needles after winding is completed.

[0063] In this embodiment, when the first winding needle 101 and the second winding needle 103 form a cylinder, the first winding needle 101 occupies about three fifths of the entire winding needle, and the second winding needle 103 occupies about two fifths of the entire winding needle. It should be noted that in this case, the clamping surfaces of the first winding needle 101 and the second winding needle 103 relative to each other are still planes.

[0064] In one embodiment, the plane of the side surfaces of the first winding needle 101 and the second winding needle 103 is a clamping surface, and the arc surface is provided with a plurality of air avoidance grooves 102. By providing the air avoidance grooves 102, the contact area between the winding needle and the winding core diaphragm can be reduced, thereby reducing friction.

[0065] It should be noted that the cross-sectional shape of the air-avoiding groove 102 may be rectangular, circular or other shapes, and the air-avoiding groove 102 may not necessarily be connected from one end of the first winding needle 101 and the second winding needle 103 to the other end, and the air-avoiding groove 102 may also be intermittently arranged on the arc surface of the first winding needle 101 and the second winding needle 103. Here, the air-avoiding groove 102 may also be irregularly arranged, and it is only necessary to reduce the contact area between the first winding needle 101 and the second winding needle 103 and the diaphragm.

[0066] In one embodiment, the present application also proposes a battery winding device, including a frame on which a driving mechanism is installed; and also includes a winding needle for preventing core pulling out in any of the above embodiments, wherein the driving mechanism is used to drive the winding needle holding the core diaphragm and / or battery cell to drive the core diaphragm and / or battery cell to be wound.

[0067] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A winding needle for preventing winding core from pulling out, the winding needle being provided with a clamping surface for clamping a winding core diaphragm and / or a battery cell; Features: The surface of the winding needle is provided with a coating, and the coating is used to reduce the friction coefficient between the winding needle and the winding core separator and / or the battery sheet.

2. The anti-winding core pulling winding needle according to claim 1, characterized in that: A connecting portion is provided at one end of the winding needle, and the connecting portion is used to connect with the driving mechanism; The driving mechanism is used to drive the winding needle holding the winding core diaphragm and / or the battery sheet to drive the winding core diaphragm and / or the battery sheet to be wound.

3. The anti-winding core pulling winding needle according to claim 2, characterized in that: The winding needle comprises a first winding needle (101) and a second winding needle (103); the first winding needle (101) and the second winding needle (103) are both connected to the connecting part; The opposing surfaces of the first winding needle (101) and the second winding needle (103) form a clamping surface.

4. The anti-winding core pulling winding needle according to claim 3, characterized in that: The connecting part comprises a first connecting part (201) and a second connecting part (204), the first connecting part (201) is connected to the first winding needle (101), and the second connecting part (204) is connected to the second winding needle (103); The first connection part (201) and the second connection part (204) are connected via a connection assembly; When the first connecting portion (201) and the second connecting portion (204) are connected via the connecting assembly, the first winding needle (101) and the second winding needle (103) clamp the winding core separator and / or the battery cell between the clamping surfaces.

5. The anti-winding core pulling winding needle according to claim 4, characterized in that: The first connecting portion (201) and the second connecting portion (204) are both provided with corresponding through holes (203); The connection assembly comprises a bolt passing through the through hole (203), and a nut is mounted on the bolt.

6. The anti-winding core pulling winding needle according to claim 4, characterized in that: A first baffle (202) is provided at the connection between the first connecting portion (201) and the first winding needle (101); and a second baffle (205) is provided at the connection between the second connecting portion (204) and the second winding needle (103).

7. The anti-winding core pulling winding needle according to claim 6, characterized in that: The first connecting portion (201) and the second connecting portion (204) form a cylinder; The first baffle (202) and the second baffle (205) form a cylinder; The first winding needle (101) and the second winding needle (103) form a cylinder; in, The ratio of the arc length of the side surface of the first connecting portion (201) to the arc length of the side surface of the second connecting portion (204) is X; The ratio of the side arc length of the first baffle (202) to the side arc length of the second baffle (205) is Y; The ratio of the side arc length of the first winding needle (101) to the side arc length of the second winding needle (103) is Z; X=Y=Z>1.

8. The anti-winding core pulling winding needle according to claim 7, characterized in that: On the side surfaces of the first winding needle (101) and the second winding needle (103), the plane surface is a clamping surface, and the arc-shaped surface is provided with a plurality of air-avoiding grooves (102).

9. The anti-winding core pulling winding needle according to any one of claims 1 to 8, characterized in that: The coating is a DLC coating, and the thickness of the DLC coating is 0.01-0.03 mm.

10. A battery winding device, comprising a frame, on which a driving mechanism is mounted; Features: It also includes the winding needle for preventing the core from being pulled out as described in claim 9, and the driving mechanism is used to drive the winding needle holding the winding core diaphragm and / or battery cell to drive the winding core diaphragm and / or battery cell to be wound up.

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