A method for laser cutting to effectively avoid empty coating areas

Abstract

The present invention discloses a method for effectively avoiding an empty coating area by laser cutting, wherein the pole piece is transmitted through a belt with the center of the roller as the reference, and before laser cutting, a pole piece correction actuator is provided to correct the pole piece horizontally before cutting, a lower negative pressure area is provided on the surface of the belt, a cutting support plate is movably provided on the pole piece, a step is provided at one end of the cutting support plate facing the pole piece coating area, and an empty avoiding area is formed between the step and the pole piece coating area, an upper negative pressure area is provided at the bottom of the cutting support plate, and the pole piece is tensioned in combination with the lower negative pressure area during cutting, and the empty foil area of ​​the pole piece is cut into pole ears and waste materials by scanning the laser cutting area with a laser, and the cutting support plate is driven to move horizontally on the pole piece by a cutting support plate moving servo mechanism to adjust the spacing between the empty avoiding line of the cutting support plate and the coating line of the pole piece coating area, and adjust the width of the pole piece. The present invention can avoid cutting jitter, maintain cutting stability, reduce burr generation, improve cutting quality, and reduce the occurrence of phenomena such as broken belts and polluted pole pieces.

Description

Technical Field

[0001] The invention relates to the technical field of laser processing, and in particular to a method for laser cutting an effective air-avoiding coating area. Background Art

[0002] As we all know, lithium battery cells have very high requirements for the quality of pole pieces and tabs. Laser cutting is widely used as a common way to form tabs. Laser cutting of lithium battery pole pieces produces tabs. Generally, the edge of the pole piece is an empty foil area (the cathode is aluminum foil and the anode is copper foil), and the middle of the pole piece is a coating area (with continuous coating and intermittent coating, single-sided coating and double-sided coating processes, in which the coatings of the anode and cathode are different, the cathode can have an extra layer of AT9, etc., and the thickness also has a certain range of variation, and the coating thickness is several times that of the foil). In special cases, adhesive tape will appear on the front and back of the coating area, which is mostly used for splicing or marking NG pole pieces. When laser cutting is performed using the traditional laser cutting method, there is relative scratching between the cutting pallet and the pole piece coating area, resulting in the coating of the pole piece falling off and contaminating the pole piece, or the pole piece empty foil area shaking, resulting in cutting defocus, increasing burrs and joints; in particular, when there is adhesive tape on the pole piece, when passing through the cutting pallet, the tape will directly scratch the cutting pallet, causing adverse consequences such as shaking and tape breakage. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for laser cutting to effectively avoid empty coating areas.

[0004] The technical solution of the present invention is as follows:

[0005] A method for laser cutting to effectively avoid empty coating areas, wherein the pole piece is transmitted through a belt with the center of a roller as a reference, and before laser cutting, a pole piece correction actuator is provided to perform horizontal correction on the pole piece before cutting, a lower negative pressure area is provided on the surface of the belt, a cutting pallet is movably provided on the pole piece, a step is provided at one end of the cutting pallet facing the pole piece coating area, an empty foil area is formed between the step and the pole piece coating area, an upper negative pressure area is provided at the bottom of the cutting pallet, and the pole piece is tensioned in combination with the lower negative pressure area during cutting, and a laser is used to scan the laser cutting area to cut the empty foil area of ​​the pole piece into pole ears and waste, and the cutting pallet is driven by a cutting pallet moving servo mechanism to move horizontally on the pole piece to adjust the spacing between the empty foil line of the cutting pallet and the coating line of the pole piece coating area and to adjust the width of the pole piece.

[0006] Furthermore, the pole piece deviation correction actuator detects the deviation range T1 of the coating line of the pole piece coating area through a deviation correction sensor. The pole piece deviation correction actuator performs deviation correction based on the virtual center line, and the effective deviation correction range is J.

[0007] Furthermore, the spacing between the air avoidance line of the cutting pallet and the coating line of the electrode coating area is maintained at a safe distance S1.

[0008] Furthermore, the safety distance S1>N*T2 / 2, wherein N is the safety factor, N≥1, T2 is the actual fluctuation value of the coating line of the electrode coating area based on the virtual center line, and T2=T1 / 2+J / 2.

[0009] Furthermore, a closed-loop sensor is provided after laser cutting to detect the current actual position T3 of the coating line in the electrode coating area, and the data is quickly fed back to the cutting pallet movement servo mechanism for closed-loop control of the cutting pallet for horizontal adjustment dynamic compensation X1, so as to dynamically maintain the actual distance S2 between the coating line in the electrode coating area and the avoidance line of the cutting pallet close to the safe distance S1, S2=S1+T3+X1.

[0010] Furthermore, the clearance height of the step K1>K2Max+K3Max, wherein K2Max is the maximum thickness of the single-sided coating area of ​​the electrode, and K3Max is the maximum thickness of the adhesive paper on the coating area.

[0011] Furthermore, a pole-supporting ear is protrudingly provided on one side of the cutting support plate facing the laser cutting area.

[0012] Compared with the prior art, the beneficial effect of the present invention lies in: the present invention provides a method for effectively avoiding the empty coating area in laser cutting, the pole piece is guided by the center of the roller as the reference, and a pole piece correction actuator is provided before laser cutting to correct the pole piece before cutting, the cutting pallet has a negative pressure area to suck the upper area of ​​the empty foil tightly, and at the same time, the lower area of ​​the empty foil area is sucked tightly by the negative pressure area of ​​the belt, and the foil area is tensioned up and down, and the laser scans the laser cutting area to cut the empty foil area into pole ears and waste materials, and by adopting a stepped cutting pallet, an empty avoidance area is formed between the step and the pole piece coating area, and under the action of the empty avoidance area, relative scratching with the cutting pallet can be avoided, resulting in the coating of the pole piece falling off and contaminating the pole piece or the empty foil area of ​​the pole piece shaking, resulting in cutting defocus, increasing burrs and linkage, and when there is adhesive tape on the pole piece, when passing through the cutting pallet, it can be avoided that the tape directly scratches the pallet, causing shaking, broken tape and other adverse consequences. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 is a flow chart of the method of the present invention;

[0015] Figure 2 It is a top view of the working principle of the present invention;

[0016] Figure 3 It is a front view of the working principle of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] In order to illustrate the technical solution of the present invention, a specific embodiment is provided below for illustration.

[0019] Example

[0020] See also Figures 1 to 3 This embodiment provides a method for laser cutting an effective air-avoiding coating area, comprising:

[0021] The pole piece is transmitted through the belt (threading and walking) based on the center of the roller;

[0022] Before laser cutting, a pole piece deviation correction actuator is used to perform horizontal deviation correction on the pole piece before cutting. The pole piece deviation correction actuator detects the deviation range T1 (constant, i.e., the actual coating deviation range of the incoming material coating line based on the center or both sides of the pole piece) of the coating line in the pole piece coating area through a deviation correction sensor.

[0023] The pole piece deviation correction actuator performs deviation correction based on the virtual center line, and the effective deviation correction range is J (which can be regarded as a constant, that is, after the pole piece deviation correction actuator corrects the pole piece to a stable tape run, the overall fluctuation range of the pole piece at both ends based on the virtual center line is mainly aligned with the center of the roller, and is generally also affected by the installation accuracy of the mechanical structure such as the roller, and the process quality of the pole piece itself);

[0024] A cutting support plate is movably provided on the electrode, and a step is provided at one end of the cutting support plate facing the electrode coating area, and an air avoidance area is formed between the step and the electrode coating area, which is used to avoid the electrode single-sided coating area and tape. In particular, the AT9+ coating area (part of the cathode electrode) can be avoided. The air avoidance height K1 (constant) of the step is greater than K2Max+K3Max, where K2Max is the maximum thickness of the electrode single-sided coating area, and K3Max is the maximum thickness of the adhesive tape on the coating area;

[0025] The cutting pallet is driven by the cutting pallet moving servo mechanism to move horizontally on the pole piece, so as to adjust the distance between the avoidance line of the cutting pallet and the coating line of the pole piece coating area and adjust the width of the pole piece;

[0026] The distance between the air avoidance line of the cutting pallet and the coating line of the electrode coating area is maintained at a safe distance S1 (constant), which is used to control the horizontal air avoidance distance of the coating. It should not be too large, otherwise the electrode may be wrinkled and the empty foil area may shake. It should not be too small, otherwise the actual air avoidance failure may occur, the coating may be scratched, etc. It needs to be set according to the actual production process debugging situation and gradually verified. Usually, the safe distance S1>N*T2 / 2 is taken, where N is the safety factor, N≥1, and T2 is the actual fluctuation value of the coating line of the electrode coating area based on the virtual center line, T2=T1 / 2+J / 2;

[0027] A lower negative pressure area is provided on the surface of the belt, and an upper negative pressure area is provided at the bottom of the cutting support plate. The upper negative pressure area and the lower negative pressure area work together to tension the pole piece during cutting. A pole-supporting ear is provided on the side of the cutting support plate facing the laser cutting area, which can support part of the pole ear and reduce the shaking during the cutting process.

[0028] The empty foil area of ​​the pole piece is cut into pole ears and waste by scanning the laser in the laser cutting area;

[0029] After laser cutting, a closed-loop sensor is set to detect the current actual position T3 (with the virtual center line as 0) of the coating line (or AT9 boundary line) in the electrode coating area, and quickly feed back the data to the cutting pallet moving servo mechanism for closed-loop control of the cutting pallet for horizontal adjustment dynamic compensation X1 (that is, according to the current coating line position data measured by the closed-loop sensor, the cutting pallet moving servo mechanism is quickly fed back for closed-loop, with positive and negative feedback), dynamically maintaining the actual distance S2 between the coating line in the electrode coating area and the avoidance line of the cutting pallet to a safe distance S1 (S2 = S1 + T3 + X1), that is, after the tape deviation After the accumulated fluctuation of the difference and coating deviation, the real-time and actual distance between the coating line in the coating area of ​​the pole piece and the avoidance line of the cutting pallet is theoretically S2≥S1 (under special circumstances, the edge of the pole piece is damaged or there is a serpentine mutation, etc., S2 may be less than S1, but the probability is small, so it is excluded here and not discussed), and the situation of S2=S1 is the best, that is, the dynamic value of S2 is maintained to change towards S1 through the compensation value X1, and S2 is controlled within a reasonable fluctuation range, which is conducive to avoiding cutting jitter, maintaining cutting stability, reducing burr generation, improving cutting quality, and reducing the occurrence of phenomena such as broken belts and contaminated pole pieces.

[0030] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for laser cutting an effective free-space coating area, characterized in that: The pole piece is transmitted through the belt with the center of the roller as the reference. Before laser cutting, a pole piece correction actuator is provided to correct the pole piece horizontally before cutting. A lower negative pressure area is provided on the surface of the belt. A cutting pallet is movably provided on the pole piece. A step is provided at one end of the cutting pallet facing the pole piece coating area. An air avoidance area is formed between the step and the pole piece coating area. An upper negative pressure area is provided at the bottom of the cutting pallet. During cutting, the pole piece is tensioned in combination with the lower negative pressure area. The empty foil area of ​​the pole piece is cut into pole ears and waste materials by scanning the laser cutting area with a laser. The cutting pallet is driven to move horizontally on the pole piece by a cutting pallet moving servo mechanism to adjust the spacing between the air avoidance line of the cutting pallet and the coating line of the pole piece coating area and adjust the width of the pole piece. Wherein, the pole piece deviation correction actuator detects the deviation range T1 of the coating line of the pole piece coating area through the deviation correction sensor, and the pole piece deviation correction actuator performs deviation correction based on the virtual center line, and the effective deviation correction range is J. The spacing between the avoidance line of the cutting pallet and the coating line of the pole piece coating area is maintained at a safe distance S1, and the safe distance S1>N*T2 / 2, wherein N is the safety factor, N≥1, and T2 is the actual fluctuation value of the coating line of the pole piece coating area based on the virtual center line, T2=T1 / 2+J / 2; After laser cutting, a closed-loop sensor is set to detect the current actual position T3 of the coating line in the electrode coating area, and quickly feed back the data to the cutting pallet moving servo mechanism to close the loop to control the cutting pallet to perform horizontal adjustment dynamic compensation X1, and dynamically maintain the actual distance S2 between the coating line in the electrode coating area and the avoidance line of the cutting pallet to the safe distance S1, S2=S1+T3+X1; The clearance height of the step is K1>K2Max+K3Max, wherein K2Max is the maximum thickness of the single-sided coating area of ​​the electrode, and K3Max is the maximum thickness of the adhesive paper on the coating area.

2. A method for laser cutting an effective air-avoiding coating area according to claim 1, characterized in that: A pole-supporting ear portion is protrudingly provided on one side of the cutting support plate facing the laser cutting area.

Images