Laser cutting method and laser cutting device

Abstract

The application discloses a laser cutting method and a laser cutting device. The laser cutting method comprises the following steps: adjusting an initial workpiece to a first position; cutting the initial workpiece by a first laser to obtain a reserved workpiece; and melting and flattening bead particles on the reserved workpiece by a second laser. The cutting method can improve the yield of products.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery manufacturing, and more particularly to a laser cutting method and a cutting device. BACKGROUND

[0002] In related technologies, battery tab cutting is generally performed by cutting dies, but the cutting dies have high requirements for cutting tool adjustment accuracy, and the cutting tool is prone to wear during long-time cutting, which causes residual foil material filaments on the cut end face, and the filaments are prone to enter the product interior and pierce the protective film to form a short circuit of the battery cell, thereby reducing product yield.

[0003] Therefore, there is a need to provide a new technical solution to solve the above technical problems. SUMMARY

[0004] An object of the present application is to provide a new technical solution for a laser cutting method.

[0005] According to a first aspect of the present application, a laser cutting method is provided. The method comprises:

[0006] adjusting an initial workpiece to a first position;

[0007] cutting the initial workpiece by a first laser to obtain a reserved workpiece;

[0008] melting and flattening the fusion bead particles on the reserved workpiece by a second laser.

[0009] Optionally, after cutting the initial workpiece by the first laser to obtain the reserved workpiece, the reserved workpiece is adjusted to a second position, and then the fusion bead particles on the reserved workpiece are melted and flattened by the second laser.

[0010] Optionally, the adjusting of the initial workpiece to the first position comprises:

[0011] determining a cutting trajectory of the initial workpiece, and conveying the initial workpiece to a cutting position according to the cutting trajectory;

[0012] adjusting the position of the initial workpiece so that the cutting trajectory is the same as a preset trajectory of the first laser.

[0013] Optionally, the cutting of the initial workpiece by the first laser to obtain the reserved workpiece comprises:

[0014] the first laser melts or gasifies the initial workpiece, and blows off the molten metal or gas by a first inert gas.

[0015] Optionally, the pressure of the first inert gas is 0.5Mpa to 1Mpa.

[0016] Optionally, the melting and flattening of the bead particles on the retained workpiece by the second laser comprises: obtaining a bead particle region on the retained workpiece, and adjusting a running track of the second laser according to the bead particle region.

[0017] Optionally, the running track of the second laser is adjusted according to start and end points of the bead particle region.

[0018] Optionally, the melting and flattening of the bead particles on the retained workpiece by the second laser comprises: when the second laser melts the bead particles, a second inert gas is used to blow the molten metal evenly on the plane of the retained workpiece.

[0019] Optionally, the pressure of the second inert gas is 0.1 MPa to 0.5 MPa.

[0020] Optionally, the method further comprises: introducing a third inert gas into the cutting environment, so that the initial workpiece and / or the retained workpiece is in an oxygen-free environment.

[0021] Optionally, the size of the bead particles after the melting and flattening by the second laser is less than or equal to 60 μm.

[0022] Optionally, the cutting speed of the first laser and / or the melting and flattening speed of the second laser is 6 m / min to 15 m / min.

[0023] Optionally, the cutting speed is equal to the melting and flattening speed.

[0024] Optionally, the power of the second laser is less than the power of the first laser.

[0025] Optionally, the power of the first laser is 1500 W to 3000 W.

[0026] Optionally, the power of the second laser is 100 W to 800 W.

[0027] According to a second aspect of the present application, a laser cutting device is provided. The laser cutting device is applied to the laser cutting method described in the above embodiments.

[0028] One technical effect of the present application is that the cutting method of the present application can improve the yield of products.

[0029] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0031] Figure 1 is a flow chart of a laser cutting method according to one embodiment of the present application.

[0032] Figure 2 is a flow chart of a laser cutting method according to another embodiment of the present application.

[0033] Figure 3 is a flow chart of a laser cutting method according to another embodiment of the present application.

[0034] Figure 4 is a left view of an initial workpiece after first laser cutting according to one embodiment of the present application.

[0035] Figure 5 is a front view of an initial workpiece after first laser cutting according to another embodiment of the present application.

[0036] Figure 6 is a left view of a retained workpiece after second laser fusion flattening according to one embodiment of the present application.

[0037] Figure 7 is a partial structural schematic view of a laser cutting device according to one embodiment of the present application.

[0038] 1, retained workpiece; 2, scrap workpiece; 3, bead particles; 4, first laser device; 5, second laser device; 6, cell; 7, tab. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present application will now be described in detail with reference to the figures. It should be noted that the relative arrangements, numerical expressions, and values of components and steps set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0040] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the scope of the application its application or uses.

[0041] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, the techniques, methods, and devices should be considered part of the specification, if appropriate.

[0042] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0043] It should be noted that like numerals and letters refer to like items throughout the several views, as such, once an item is defined in one view, it should not need to be discussed further in subsequent views.

[0044] According to one embodiment of the present application, a laser cutting method is provided. As shown in Figures 1 to 7 the laser cutting method of the present application comprises: adjusting an initial workpiece to a first position; cutting the initial workpiece by a first laser to obtain a reserved workpiece 1; and melting the bead particles 3 on the reserved workpiece 1 by a second laser.

[0045] In this example, by cutting the initial workpiece by the first laser, the foil material filaments generated by hardware cutting can be avoided. Then by melting the bead particles 3 on the reserved workpiece 1 by the second laser, the problem that the bead particles 3 fall into the product and form a short circuit after falling off can be avoided, thereby reducing the product yield. And by the way of laser cutting, the cutting cost can be reduced.

[0046] In this example, the initial workpiece of the present application can be a tab 7 connected to a battery cell 6. By cutting the tab 7 by the first laser, and then melting the bead particles 3 on the surface of the tab 7 by the second laser, the problem that the bead particles 3 fall into the battery cell 6 and cause damage to the battery cell 6 can be avoided. Of course, the initial workpiece of the present application can also be other types of workpieces, which can be determined by those skilled in the art according to the actual situation, and are not specifically limited here.

[0047] As shown in Figure 1 In this example, the laser cutting method comprises:

[0048] S100, adjusting an initial workpiece to a first position. For example, the initial workpiece to be cut can be transported to a position corresponding to the first laser device 4 by driving a conveying mechanism, and the first laser device 4 can emit a first laser to cut the initial workpiece by laser.

[0049] S200, cutting the initial workpiece by a first laser to obtain a reserved workpiece 1.

[0050] In this example, after the initial workpiece is adjusted to the first position, the first laser device 4 emits the first laser and cuts the initial workpiece along a preset trajectory.

[0051] As shown in Figure 4 and Figure 5As shown, in this example, the distance between the cutting head of the first laser device 4 and the initial workpiece is less than or equal to 1 mm. The spot diameter of the cutting head of the first laser device 4 during cutting is less than or equal to 50 μm. The first laser cuts the initial workpiece along the cutting path of the initial workpiece. After cutting, a retained workpiece 1 is obtained, and the waste workpiece 2 is collected. Molten beads 3 are formed on the surface of the retained workpiece 1.

[0052] S300 , melting and leveling the molten bead particles 3 on the retained workpiece 1 by a second laser.

[0053] like Figure 6 As shown, the initial workpiece is cut by a first laser to obtain a retained workpiece 1. Then, the second laser can melt and flatten the molten bead particles 3 according to the running trajectory. The second laser device 5 emits a second laser to melt and flatten the molten bead particles. The spot of the cutting head of the second laser device 5 is located between 300 and 800. The cutting head of the second laser device 5 is 5mm to 10mm away from the retained workpiece, for example, it can be 6mm, 7mm, or 9mm, etc., and those skilled in the art can determine it according to actual conditions, and no specific limitation is given here.

[0054] In this example, since the first laser cuts the initial workpiece, molten beads are formed on the lower surface of the initial workpiece. Therefore, the second laser is located below the initial retained workpiece 1 to melt and smooth the molten beads on the lower surface of the retained workpiece 1.

[0055] In this example, the first laser and the second laser can be lasers emitted by the same laser device. The first laser is first emitted to cut the initial workpiece, and then the retained workpiece or the laser device is rotated so that the molten bead particles on the surface of the retained workpiece can correspond to the laser device. Then the laser device emits the second laser to melt and flatten the molten bead particles.

[0056] The cutting method of this application uses a first laser to cut the initial workpiece, thus avoiding the generation of foil strands due to metal cutting. A second laser is then used to melt and smooth the remaining molten beads 3 on the workpiece 1, preventing them from falling off and entering the product, causing short circuits and thus reducing product yield. Laser cutting also reduces cutting costs.

[0057] In one example, Figure 2 As shown, after the initial workpiece is cut by the first laser to obtain the retained workpiece 1, the retained workpiece is adjusted to a second position, and then the molten bead particles 3 on the retained workpiece 1 are melted and flattened by the second laser.

[0058] like Figure 2 As shown, the cutting method of the present application also includes:

[0059] S300, adjusting the reserved workpiece 1 to a second position. In this example, the molten bead particles 3 on the reserved workpiece 1 are fused flat by the second laser, as step S400.

[0060] In this example, after the first laser cutting is completed, the reserved workpiece 1 can be transported to the second position corresponding to the second laser device 5 by driving the conveying mechanism, and the second laser device 5 can emit the second laser to fuse and flatten the initial workpiece.

[0061] In one example, as shown in FIG. 1, the adjusting the initial workpiece to the first position includes: Figure 3

[0062] S110: determining a cutting trajectory of the initial workpiece, and transporting the initial workpiece to the cutting position according to the cutting trajectory. First, the cutting trajectory of the initial workpiece is determined, for example, the cutting trajectory can be marked. Then, the initial workpiece is transported to the position corresponding to the first laser device 4, i.e. the cutting position, and the initial workpiece is clamped and fixed by the clamp.

[0063] S120: adjusting the position of the initial workpiece so that the cutting trajectory is the same as the preset trajectory of the first laser. The position of the initial workpiece is adjusted according to the preset trajectory of the first laser, and the cutting trajectory of the initial workpiece is made the same as the preset trajectory of the first laser. At this time, the initial workpiece is located at the first position, so that the first laser can accurately cut the initial workpiece along the cutting trajectory, and the reserved workpiece 1 is obtained after cutting.

[0064] In this example, after the initial workpiece is transported to the position corresponding to the first laser device 4, the preset trajectory of the first laser can also be adjusted so that the preset trajectory of the first laser is the same as the cutting trajectory of the initial workpiece. The skilled person can determine according to the actual situation, which is not limited here.

[0065] In one example, as shown in FIG. 1, the cutting the initial workpiece by the first laser to obtain the reserved workpiece 1 includes: Figure 3

[0066] S210: the first laser fuses or gasifies the initial workpiece, and blows off the molten metal or gas by the first inert gas. The first laser can instantaneously fuse or gasify the initial workpiece, and the molten metal or gas is blown off by the high-pressure first inert gas to achieve the cutting effect. When the first inert gas blows off the molten metal, it is easy to quickly cool at the bottom of the reserved workpiece 1 to form large-size molten bead particles 3.

[0067] ​​In this example, the pressure of the first inert gas is 0.5 MPa to 1 MPa. For example, it can be 0.6 MPa, 0.7 MPa, 0.8 MPa, or 0.9 MPa, etc., as long as it can smoothly blow off the molten metal or gas. Through the above-mentioned range of the first inert gas pressure, the molten metal or gas can be stably and smoothly blown off. The cutting head of the first laser device 4 is provided with a nozzle, and the first inert gas can be sprayed from the nozzle towards the initial workpiece.

[0068] In this example, the initial workpiece can be aluminum or copper, etc. The first inert gas can be nitrogen. Those skilled in the art can select a suitable inert gas according to the specific material of the initial workpiece, which is not limited here.

[0069] As shown in Figure 3 , the first laser melts or vaporizes the initial workpiece, and the molten metal or gas is blown off by the first inert gas. The initial workpiece is obtained by cutting the initial workpiece by the first laser. Then, S300: adjusting the remaining workpiece to a second position.

[0070] In one example, as shown in Figure 3 , the melting and flattening of the molten bead particles 3 on the remaining workpiece 1 by the second laser includes:

[0071] S410: Obtain the molten bead particle area on the remaining workpiece 1. In this example, the molten bead particle area on the remaining workpiece 1 is obtained. After the remaining workpiece 1 is transported to a position corresponding to the second laser device 5, the remaining workpiece 1 is clamped and positioned by a clamp. Then, the molten bead particle area on the surface of the remaining workpiece 1 is obtained by a CCD (Charge-coupled Device, Charge-coupled Device) camera. That is, the molten bead particle area is surrounded by a plurality of molten bead particles 3.

[0072] S420: Adjust the running track of the second laser according to the molten bead particle area. The running track of the second laser is adjusted according to the molten bead particle area, so that the second laser can melt and flatten the molten bead particles in the molten bead particle area.

[0073] In this example, the running track of the second laser is adjusted according to the start and end points of the molten bead particle area. The start and end points of the molten bead particle area can be captured by the CCD camera to compensate and correct the running track of the second laser. Alternatively, the end face of the remaining workpiece 1 can also be positioned by vision to determine the running track of the second laser for melting and flattening the molten bead particle area.

[0074] In one example, as shown in Figure 3 , the melting and flattening of the molten bead particles 3 on the remaining workpiece 1 by the second laser further includes:

[0075] S430: While the second laser light melts the molten bead particles 3, a second inert gas is used to blow the molten metal evenly onto the surface of the retained workpiece 1. After the second laser light melts the molten bead particles 3, the second inert gas can be blown toward the molten metal, evenly spreading the molten metal across the surface of the retained workpiece 1. After cooling, the surface of the retained workpiece 1 remains flat and smooth, eliminating the risk of molten bead particles falling.

[0076] The pressure of the second inert gas is 0.1 MPa to 0.5 MPa. For example, it can be 0.2 MPa, 0.3 MPa, or 0.4 MPa. Those skilled in the art may determine this pressure based on actual circumstances, and this is not specifically limited here. The cutting head of the second laser device 5 is provided with a nozzle, through which the second inert gas can be ejected toward the retained workpiece 1.

[0077] In this example, the second inert gas may be nitrogen. Those skilled in the art may select a suitable inert gas according to the specific material of the initial workpiece, and no specific limitation is made here.

[0078] In this example, the size of the molten bead particles 3 after the second laser melting and flattening is less than or equal to 60 μm, thereby preventing the molten bead particles 3 from falling off.

[0079] In one example, the laser cutting method of the present application further includes introducing a third inert gas into the cutting environment to place the initial workpiece and / or the retained workpiece 1 in an oxygen-free environment.

[0080] The first laser device 4 and the second laser device 5 are located in a sealed cutting environment. Cutting of the initial workpiece and melting and leveling of the molten beads 3 of the retained workpiece 1 occur within the sealed environment. A third inert gas is introduced into the cutting environment to keep the initial workpiece and the retained workpiece 1 oxygen-free, preventing oxidation of the workpieces, which would further reduce their energy absorption and affect cutting and melting quality.

[0081] In this example, the third inert gas may be nitrogen. Those skilled in the art may select a suitable inert gas according to the specific material of the initial workpiece, and no specific limitation is made here.

[0082] Furthermore, 0.1 to 0.5 MPa nitrogen gas may be introduced into the cutting environment. For example, it may be 0.2 MPa, 0.3 MPa or 0.5 MPa, etc. Those skilled in the art may determine it according to the actual situation, and no specific limitation is made here.

[0083] In one example, the cutting speed of the first laser and / or the melting and leveling speed of the second laser are between 6 m / min and 15 m / min.

[0084] For example, the cutting speed of the first laser can be 7 m / min, 8 m / min, 10 m / min, 11 m / min, 13 m / min, or 14 m / min, etc. The melting and flattening speed of the second laser can also be 7 m / min, 8 m / min, 10 m / min, 11 m / min, 13 m / min, or 14 m / min, etc. The skilled in the art can determine according to the actual situation, and no specific limitation is made here.

[0085] In one example, the cutting speed is equal to the melting and flattening speed. The initial workpiece is cut by the first laser at the first position, and the remaining workpiece is melted and flattened by the second laser at the second position. By adjusting the cutting speed to be equal to the melting and flattening speed, the initial workpiece can be transported to the second position after cutting at the first position is completed, thereby improving the continuity of the machining process.

[0086] For example, the cutting speed and the melting and flattening speed can be set to 7 m / min, 8 m / min, 10 m / min, 11 m / min, 13 m / min, or 14 m / min, etc. The above range of values is used to improve the continuity of the machining process.

[0087] In one example, the power of the second laser is less than the power of the first laser. When the first laser cuts, the cutting volume is large and the energy required is large, so a high-power laser is used. When the second laser melts, the volume of the molten bead particles 3 is relatively small, and a smaller power laser can be used.

[0088] In this example, the power of the first laser is 1500 W to 3000 W. For example, the power of the first laser can be 1700 W, 2000 W, or 2500 W, etc. The skilled in the art can determine according to the actual situation, for example, the cutting speed of the first laser can be used to determine, and no specific limitation is made here.

[0089] In addition, the power of the second laser is 100 W to 800 W. For example, the power of the second laser can be 200 W, 400 W, 500 W, or 700 W, etc. The skilled in the art can determine according to the actual situation, for example, the cutting speed of the second laser can be used to determine, and no specific limitation is made here.

[0090] In one example, the first laser and the second laser of the present application can be pulse lasers or continuous lasers can also be used. For example, the laser cutting head is replaced by a galvanometer, and the laser device can use a CW laser, i.e., a continuous wave laser (Continuous Wave Laser). Or it can also be a QCW laser, i.e., a quasi-continuous wave laser (Quasi-Continuous Wave). The skilled in the art can determine according to the actual situation, and no limitation is made here.

[0091] According to another embodiment of the present application, a laser cutting device is provided, and the laser is applied to the laser cutting method described in the above embodiment. The laser cutting method includes: adjusting the initial workpiece to a first position; cutting the initial workpiece by a first laser to obtain a retained workpiece 1; adjusting the retained workpiece 1 to a second position; melting and leveling the molten bead particles 3 on the retained workpiece 1 by a second laser. Cutting the initial workpiece by the first laser can avoid foil material filaments generated by hardware cutting. Melting and leveling the molten bead particles 3 on the retained workpiece 1 by a second laser can prevent the molten bead particles 3 from falling off and entering the interior of the product to form a short circuit, thereby reducing the product yield. In addition, the cutting cost can be reduced by laser cutting.

[0092] In one example, Figure 7 As shown, the tab 7 is connected to the battery cell 6, and the laser cutting device is capable of cutting the tab 7. The laser cutting device includes a first laser device 4 and a second laser device 5. The first laser device 4 is used to emit a first laser, and the second laser device 5 is used to emit a second laser. The first laser device 4 and the second laser device 5 are respectively located on both sides of the tab 7. The first laser cutting device is located on one side of the tab 7 and is capable of cutting the tab 7. During cutting, molten bead particles 3 will be formed on the side of the tab 7 facing away from the first laser device 4. After the cutting is completed, the battery cell 6 is transported to the position corresponding to the second laser device 5. The second laser device 5 is located on the side of the tab 7 with the molten bead particles 3. The second laser device 5 is capable of melting and smoothing the molten bead particles 3 on the surface of the tab 7.

[0093] Alternatively, in this example, only one laser device can be provided, and the laser power can be adjusted to enable the laser device to emit either the first laser or the second laser. Specifically, the laser device first emits the first laser to cut the tab 7, forming molten beads 3 on the side of the tab 7 facing away from the laser device. After cutting, the battery cell 6 is flipped so that the side of the tab 7 with the molten beads 3 faces the laser device. The laser device then emits the second laser to melt and flatten the molten beads 3.

[0094] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0095] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A laser cutting method, characterized in that: include: adjusting the initial workpiece to a first position; cutting the initial workpiece by a first laser to obtain a retained workpiece; Melting and leveling the molten bead particles on the retained workpiece by a second laser; Melting and leveling the molten bead particles on the retained workpiece by a second laser comprises: When the second laser melts the molten bead particles, the molten metal is blown evenly onto the plane of the retained workpiece by a second inert gas; The size of the molten bead particles after the second laser melting and flattening is less than or equal to 60 μm.

2. The laser cutting method according to claim 1, characterized in that: After the initial workpiece is cut by the first laser to obtain a retained workpiece, the retained workpiece is adjusted to a second position, and then the molten bead particles on the retained workpiece are melted and leveled by the second laser.

3. The laser cutting method according to claim 1, wherein: The adjusting the initial workpiece to the first position comprises: determining a cutting trajectory of the initial workpiece, and transporting the initial workpiece to a cutting position according to the cutting trajectory; The position of the initial workpiece is adjusted so that the cutting trajectory is the same as the preset trajectory of the first laser.

4. The laser cutting method according to claim 1, wherein: Cutting the initial workpiece by the first laser to obtain a retained workpiece includes: The first laser melts or vaporizes the initial workpiece, and the molten metal or gas is blown away by the first inert gas.

5. The laser cutting method according to claim 4, characterized in that: The pressure of the first inert gas is 0.5 MPa to 1 MPa.

6. The laser cutting method according to claim 2, characterized in that: Melting and leveling the molten bead particles on the retained workpiece by a second laser comprises: Acquire a molten bead particle area on the retained workpiece; The running trajectory of the second laser is adjusted according to the molten bead particle area.

7. The laser cutting method according to claim 6, characterized in that: The running trajectory of the second laser is adjusted according to the starting and ending points of the molten bead particle area.

8. The laser cutting method according to claim 1, characterized in that: The pressure of the second inert gas is 0.1 MPa to 0.5 MPa.

9. The laser cutting method according to claim 1, wherein: The method further includes introducing a third inert gas into the cutting environment to place the initial workpiece and / or the retained workpiece in an oxygen-free environment.

10. The laser cutting method according to claim 1, wherein: The cutting speed of the first laser and / or the melting and leveling speed of the second laser are / is between 6 m / min and 15 m / min.

11. The laser cutting method according to claim 10, characterized in that: The cutting speed is equal to the melting and leveling speed.

12. The laser cutting method according to claim 1, wherein: The power of the second laser is smaller than the power of the first laser.

13. The laser cutting method according to claim 1, wherein: The power of the first laser is 1500W to 3000W.

14. The laser cutting method according to claim 1, wherein: The second laser power is 100W to 800W.

15. A laser cutting device, characterized in that: Applicable to the laser cutting method according to any one of claims 1 to 14.

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