A method and device for cutting a soft-pack battery shell

Abstract

The present invention discloses a cutting method and a cutting device for a soft-pack battery shell. The cutting method comprises the following steps: obtaining a target length L of the soft-pack battery shell; M , the average length L of n first shells cut before the first shell is cut a According to the average length L a and the target length L M , control the first cutter assembly to move from the cutting position of the cut first shell to the target cutting position of the to-be-cut first shell, and cut the to-be-cut first shell to obtain the cut first shell. The present invention is based on the average length L of the first n cut first shells. a and target length L M , timely adjust the target cutting position of the first cutter assembly, and cut the first shell to be cut, so that the length value L of each first shell after cutting b Compared to the average length L of the cut first shell a Closer to target length L M , to achieve the effect of improving the length consistency of soft-pack batteries, thereby improving the cycle life and safety performance of the batteries.

Description

Technical Field

[0001] The present invention relates to the field of soft-pack battery production, and in particular to a cutting method and a cutting device for a soft-pack battery shell. Background Art

[0002] With the rapid development of consumer electronics, energy storage and electric vehicles, the demand for soft-pack batteries is also increasing, and the requirements for various aspects of soft-pack batteries are also getting higher and higher. In soft-pack batteries, the length consistency of the battery has an important impact on the performance and safety of the battery. Poor length consistency may cause uneven pressure distribution when the battery is assembled into a module, affecting the electrochemical state of the battery, and further affecting the battery's cycle life and safety performance. Summary of the invention

[0003] The embodiments of the present invention provide a method and a device for cutting a soft-pack battery shell to improve the consistency of the length of the soft-pack battery, thereby achieving the effect of improving the cycle life and safety performance of the shell battery.

[0004] Specifically, the present invention provides a method for cutting a soft-pack battery shell, the cutting method comprising the following steps: Get the target length L of the soft pack battery shell M , the average length L of the n cut first shells in the length direction of the soft pack battery before the first shell is cut a The first shell to be cut is a battery shell formed by an aluminum-plastic film that is punched and folded in half; According to the average length L a and the target length L M , control the first cutter assembly to move from the cutting position of the cut first shell to the target cutting position of the to-be-cut first shell, and cut the to-be-cut first shell to obtain the cut first shell; the cut first shell is used to load the bare battery cell.

[0005] Optionally, the average length L a and the target length L M , in the step of controlling the first cutter assembly to move from a cutting position where the first shell has been cut to a target cutting position where the first shell is to be cut: The distance moved by the first cutter assembly is ∆L=k*(L M -L a ); Wherein, k is the adjustment coefficient, 0.6≤k≤0.9.

[0006] Optional, 8≤n≤64.

[0007] Optionally, the cutting method further includes the following steps: Obtaining the actual length L of the second shell; the second shell is the shell of a semi-finished soft-pack battery obtained by cutting the first shell, loading the bare battery cell, and completing the top and side sealing; According to the actual length L of the second housing and the target length L of the soft pack battery housing M , determine whether the second shell needs to be cut; When the second shell needs to be cut, the second cutter assembly is controlled to move from the cutting position where the second shell has been cut to the target cutting position where the second shell is to be cut, and the second shell to be cut is cut.

[0008] Optionally, the step of determining whether the second shell needs to be cut includes: If the actual length L is less than the target length L M , there is no need to cut the second shell; If the actual length L is equal to the target length L M If the difference is between 0 and X, the second shell needs to be cut; If the actual length L is equal to the target length L M If the difference is greater than X, manual re-judgment is performed to determine whether the second shell needs to be cut; Among them, 0.2mm≤X≤0.5mm.

[0009] The present invention also provides a cutting device, comprising: A first positioning fixture, the first positioning fixture is used to fix the first shell to be cut; A cutting assembly, the cutting assembly comprising a first cutting knife assembly for cutting the first shell to be cut; A driving assembly, wherein the cutting assembly is arranged at an output end of the driving assembly, and the driving assembly is used to drive the cutting assembly to move in a direction close to or away from the first positioning fixture; A controller, the controller being communicatively connected to the cutting assembly and the driving assembly respectively; A host computer, wherein a machine executable program is stored in the host computer, and when the machine executable program is executed by the controller, it is used to implement any of the above cutting methods; A CCD detector is used to detect the length of the shell, and the CCD detector is communicatively connected with the host computer.

[0010] Optionally, the cutting device further comprises a base and a frame, the base is provided with a slide rail, and the frame is slidably arranged on the slide rail; the driving assembly is fixedly arranged on the base, and the driving end of the driving assembly is connected to the frame; the cutting assembly is arranged on the frame.

[0011] Optionally, the driving assembly includes a first servo motor and a first lead screw, the first servo motor is fixedly mounted on the base, the first servo motor is communicatively connected to the controller; the first lead screw is connected to the output end of the first servo motor, and the frame is screwed to the first lead screw.

[0012] Optionally, the cutting assembly includes a second servo motor, a second lead screw and a first cutter assembly, the second servo motor is fixedly arranged on the frame, the second servo motor is communicatively connected to the controller; the second lead screw is connected to the output end of the first servo motor; The first cutter assembly includes a first movable cutter and a first fixed cutter; the first movable cutter is screwed to the second lead screw; the first fixed cutter is detachably connected to the frame, and the blade of the first fixed cutter and the blade of the first movable cutter are arranged opposite to each other.

[0013] Optionally, the cutting device further includes a second positioning fixture for fixing the semi-finished soft-pack battery; the cutting assembly further includes a second cutting knife assembly for cutting the second shell; One of the first cutter assembly and the second cutter assembly is installed on the output end of the driving assembly; The second cutter assembly includes a second movable cutter and a second fixed cutter; When the second cutter assembly is mounted on the output end of the drive assembly (200): The driving assembly (200) is used to drive the cutting assembly (100) to move in a direction approaching or moving away from the second positioning fixture; the second movable cutter is screwed to the second lead screw; the second fixed knife is detachably connected to the frame, and the blade of the second fixed knife and the blade of the second movable cutter are arranged opposite to each other.

[0014] Optionally, the cutting device further comprises a dust removal assembly, wherein the dust removal assembly is arranged below the cutting assembly and is used for collecting debris.

[0015] The beneficial effects of the present invention are: The average length L of the first n cut first shells of the present invention a and target length L M , timely adjust the target cutting position of the first cutter assembly, and cut the first shell to be cut, so that the length value L of each first shell after cutting b Compared to the average length L of the cut first shell a Closer to target length L M The length consistency of the battery obtained by encapsulating the bare battery cell in the first shell obtained by the modified cutting method is good, so as to improve the cycle life and safety performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0017] Figure 1 is a schematic structural diagram of a cutting device in one embodiment of the present invention; Figure 2 is a schematic structural diagram of a cutting device in one embodiment of the present invention; Figure 3 is a schematic partial structural diagram of a cutting device in one embodiment of the present invention; Figure 4 It is a schematic structural diagram of a soft-pack battery to be cut in one embodiment of the present invention.

[0018] In the figure: 100, cutting assembly, 110, first movable cutter, 111, make way slot, 120, second servo motor, 130, second lead screw, 140, first fixed knife, 150, second movable cutter, 151, first make way slot, 160, second fixed knife, 161, second make way slot, 200, driving assembly, 210, first servo motor, 220, first lead screw, 300, base, 310, slide rail, 400, rack, 500, dust removal assembly, 600, first shell to be cut, 601, punching area, 610, pole ear, 620, second shell, 621, unsealed area, 622, top edge sealing, 623, side edge sealing, 630, pole ear glue. DETAILED DESCRIPTION

[0019] In order to make the technical problems, technical solutions and beneficial effects solved by 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.

[0020] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be glue injection inside two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] The present invention provides a method for cutting a soft-pack battery shell, the method comprising the following steps: Get the target length L of the soft pack battery shell M , the average length L of the n cut first shells in the length direction of the soft pack battery before the first shell is cut a The first shell to be cut is a battery shell formed by an aluminum-plastic film that is punched and folded in half; According to the average length L a and the target length L M , control the first cutter assembly to move from the cutting position of the cut first shell to the target cutting position of the to-be-cut first shell, and cut the to-be-cut first shell to obtain the cut first shell; the cut first shell is used to load the bare battery cell.

[0023] The length of the soft-pack battery depends on the length of the soft-pack battery shell, that is, the consistency of the battery length depends on the consistency of the length of the soft-pack battery shell after the soft-pack battery is packaged. a and target length L M , timely adjust the target cutting position of the first cutter assembly, and cut the first shell to be cut, so that the length value L of each first shell after cutting b Compared to the average length L of the cut first shell a Closer to target length L M The length consistency of the battery obtained by encapsulating the bare battery cell in the first shell obtained by the modified cutting method is good, so as to improve the cycle life and safety performance of the battery.

[0024] In one embodiment of the present invention, the distance ∆L moved by the first cutter assembly = k*(L M -L a ), where k is the adjustment coefficient, 0.6≤k≤0.9.

[0025] In the embodiment of the present invention, the target length L M With the average length L aThe difference ∆L is adjusted according to a certain ratio, which can reduce the impact of a sudden change in the length of the first shell to be cut on the length value L of the subsequent shells after cutting. b The influence of k on the length consistency of the cut first shell is improved, thereby improving the length consistency of the soft-pack battery shell. If the value of k is too small, then when the length of a first shell to be cut suddenly changes during the production process, the length value L of the subsequent first shell to be cut after being cut will be changed. b The adjustment is not timely enough, resulting in poor consistency in the length of the cut first shell, which in turn leads to poor consistency in the length of the soft-pack battery shell; if the value of k is too large, then in the production process, after a sudden change in the length of a first shell to be cut, although the length value L of the first shell to be cut can be adjusted in time b , but the length L of the first shell to be cut is b The influence of is too great, which easily leads to poor consistency in the length of the cut first shell, and further leads to poor consistency in the length of the soft-pack battery shell.

[0026] Furthermore, 8≤n≤64. When n is too small, if the length of a first shell to be cut suddenly changes during the production process, the length value L of the subsequent first shell to be cut after cutting is changed. b The impact is large, which may easily lead to the length L of the first shell that has been cut later. b A large deviation occurs, reducing the consistency of the length of the cut first shell; if the value of n is too large, after a sudden change in the length of a first shell to be cut during the production process, the length value L of the subsequent first shell to be cut after being cut b The impact is too small to adjust the length L of the first shell to be cut in time. b , resulting in poor consistency in the length of the cut first shell.

[0027] When preparing a soft-pack battery, the aluminum-plastic film is first punched and cut into multiple aluminum-plastic film sheets. The aluminum-plastic film sheets are folded in half to obtain the first shell to be cut, and then the cut first shell is cut according to the above-mentioned soft-pack battery shell cutting method to obtain the cut first shell. Then the bare battery cell is placed in the cut first shell (or first shell), and the two layers of laminated aluminum-plastic film and the ear glue between the two layers of aluminum-plastic film are heat-sealed on the top of the first shell through the heated head, and the two layers of laminated aluminum-plastic film are heat-sealed on the side of the first shell to form a semi-finished soft-pack battery. The shell of the semi-finished soft-pack battery is the second shell to ensure the sealing of the top and sides of the battery. The semi-finished soft-pack battery undergoes Hipot testing & coding, liquid injection, sealing, formation, secondary sealing, capacity division and other processes to form a finished soft-pack battery.

[0028] Due to process errors such as misalignment of the aluminum-plastic film during the cutting process, a first shell with a sudden change in length may be produced; and in the top and side sealing process (i.e., top sealing and side sealing), the length of the semi-finished soft-pack battery may also change due to problems such as misalignment of the aluminum-plastic film. Among them, the semi-finished soft-pack battery whose length exceeds the size specification requirements will still exceed the size specification after being prepared into a finished soft-pack battery. Considering the assembly requirements of downstream processors, it will generally be scrapped, increasing production costs.

[0029] Based on this, the present invention further provides a method for cutting a soft-pack battery shell, the cutting method comprising the following steps: Obtaining the actual length L of the second shell; the second shell is the shell of the soft-pack battery obtained by cutting the first shell, inserting the bare battery cell and completing the top and side sealing; According to the actual length L of the second shell and the target length L of the second shell M , determine whether the second shell needs to be cut; When the second shell needs to be cut, the second cutter assembly is controlled to move from the cutting position where the second shell has been cut to the target cutting position where the second shell is to be cut, and the second shell to be cut is cut.

[0030] The length of the soft pack battery depends on the length of the second housing 620. The target length L of the second housing is M The consistency of the length of the soft-pack battery depends on the consistency of the length of the second shell 620. M The second shell of the semi-finished soft-pack battery whose length exceeds the size specification is cut so that the length value of each semi-finished soft-pack battery after cutting is closer to the target length L M , so as to improve the length consistency of soft-pack batteries, thereby improving the cycle life and safety performance of the batteries. Furthermore, since the semi-finished soft-pack batteries whose length exceeds the size specification requirements are cut again, the proportion of scrapped soft-pack batteries is reduced, thereby reducing costs.

[0031] In one embodiment of the present invention, the step of determining whether the second housing needs to be cut includes: If the actual length L is less than the target length L M , there is no need to cut the second shell; If the actual length L is equal to the target length L M If the difference is between 0 and X, the second shell needs to be cut; If the actual length L is equal to the target length L M If the difference is greater than X, manual re-judgment is performed to determine whether the second shell needs to be cut; Among them, 0.2mm≤X≤0.5mm.

[0032] Due to the limitation of the semi-finished soft-pack battery, the length of the second housing 620 is less than the target length L M The difference is relatively small and does not affect subsequent use. No cutting is performed. The semi-finished soft-pack battery is processed through post-processing (liquid injection, formation, capacity division, etc.) to obtain a finished soft-pack battery. Therefore, it is only necessary to make the actual length L greater than the target length L. M The second shell of the semi-finished soft-pack battery is cut. Through this screening step, the semi-finished soft-pack batteries whose length exceeds the size specification requirements are screened out and cut again, which reduces the proportion of scrapped soft-pack batteries and reduces costs.

[0033] Furthermore, since the second shells 620 are cut by the same device, the difference between the second shells 620 is small, so the actual length L of the soft pack battery is different from the target length L. M The difference is usually less than X. If the actual length L of the soft pack battery is different from the target length L M If the difference is greater than X, manual re-judgment is performed to avoid errors caused by interference from other factors.

[0034] like Figure 4 As shown, the top sealing and side sealing processes form a top sealing edge 622 and a side sealing edge 623 on the first shell to obtain a second shell 620, thereby sealing the bare battery cell. In order to prevent the top seal head from scalding the tab glue 630 at high temperature, there needs to be a certain distance between the upper edge of the top seal head and the edge of one end of the tab 610 of the soft-pack battery, and the distance is controlled to be 0.2~1.0mm; that is, an unsealed area 621 is formed on the second shell 620, which is partially located on the side of the top seal edge 622 away from the pit area 601 (the bare battery cell is placed in the pit area 601). If the actual length L of the second shell to be cut is greater than the target length L M , cutting is performed in the unsealed area 621 , which can control the length of the second shell and avoid losing the top sealing edge 622 .

[0035] like Figure 1 As shown, the present invention also provides a cutting device, comprising: A first positioning fixture, which is used to fix the first shell (i.e., the aluminum-plastic film) to be cut; A cutting assembly 100, wherein the cutting assembly 100 comprises a first cutting knife assembly for cutting the first shell to be cut; A driving assembly 200, wherein the cutting assembly 100 is disposed at an output end of the driving assembly 200, and the driving assembly 200 is used to drive the cutting assembly 100 to move in a direction close to or away from a first positioning fixture; A controller, the controller being communicatively connected to the cutting assembly 100 and the driving assembly 200 respectively; A host computer, wherein a machine executable program is stored in the host computer, and when the machine executable program is executed by the controller, it is used to implement the cutting method described in any of the above embodiments; A CCD detector is used to detect the length of the shell, and the CCD detector is communicatively connected with the host computer.

[0036] When applied, the host computer initializes and loads the soft-pack battery shell length setting parameters (including the target length L of the soft-pack battery shell M , the position parameters of the first cutter 110 and the specification parameters of the CCD detector); then the host computer sends the soft pack battery shell length setting parameters to the controller, and the controller controls the cutting component 100 to cut the aluminum-plastic film after the pitting into multiple first shells according to the cutting method of the soft pack battery shell. And the length value L of the cut first shell is obtained through the CCD detector b , and the length value L b Transmitted to the host computer to calculate the average length L of the n cut shells before the shell to be cut a .

[0037] At the same time, the bare battery cell is placed in the first shell, and the aluminum-plastic film and the ear glue at the head of the soft-pack battery are heat-sealed by heating the head to ensure the sealing of the top of the battery; the aluminum-plastic film on the side is heat-sealed to ensure the sealing of the side of the battery, forming a semi-finished soft-pack battery. The CCD detector obtains the actual length L of the second shell of the semi-finished soft-pack battery, and transmits the actual length L to the host computer, which determines the actual length L and the target length L. M The relationship between the difference and X, if the actual length L and the target length L M If the difference between the actual length L and the target length L is less than 0, no processing is done and the semi-finished soft-pack battery can enter the next process; M If the difference between the actual length L and the target length L is greater than 0 and less than X, the controller controls the cutting assembly 100 to perform secondary cutting according to the cutting method of the soft-pack battery; M If the difference is greater than X, manual re-judgment is performed.

[0038] Specifically, the cutting device further comprises a base 300 and a frame 400, wherein the base 300 is provided with a slide rail 310, and the frame 400 is slidably arranged on the slide rail 310; the driving assembly 200 is fixedly arranged on the base 300, and the driving end of the driving assembly 200 is connected to the frame 400; the cutting assembly 100 is arranged on the frame 400. The driving assembly 200 comprises a first servo motor 210 and a first lead screw 220, wherein the first servo motor 210 is fixedly arranged on the base 300, and the first servo motor 210 is communicatively connected to the controller; the first lead screw 220 is connected to the output end of the first servo motor 210, and the frame 400 is screwed to the first lead screw 220. The cutting assembly 100 includes a second servo motor 120, a second lead screw 130 and a first cutter assembly, wherein the second servo motor 120 is fixedly arranged on the frame 400, and the second servo motor 120 is communicatively connected to the controller; one end of the second lead screw 130 is connected to the output end of the first servo motor 210; the first cutter assembly includes a first movable cutter 110 and a first fixed knife 140, and the first movable cutter 110 is screwed to the second lead screw 130; the first fixed knife 140 is detachably connected to the frame 400, and the blade of the first fixed knife 140 and the blade of the first movable cutter 110 are arranged opposite to each other.

[0039] After the controller obtains the cutting instruction sent by the host computer, the controller controls the first servo motor 210 to rotate, so as to push the frame 400 to move along the slide rail 310 through the first lead screw 220, until the first movable cutter 110 on the frame 400 reaches the target cutting position. Then the controller controls the second servo motor 120 to rotate, so as to drive the first movable cutter 110 to move through the second lead screw 130, until the blade of the first fixed knife 140 contacts the blade of the first movable cutter 110, and the aluminum-plastic film is cut off to obtain the battery shell 620. The purpose of selecting the servo motor as the power source is that the positioning accuracy of the servo motor can reach within 0.002mm, so the aluminum-plastic film can be accurately cut to improve the consistency of the length of the first shell. The frame 400 and the drive assembly 200 are both rigidly connected to ensure the stability and accuracy of the cutting device.

[0040] like Figure 2 , Figure 3 As shown, in one embodiment of the present invention, the cutting device further includes a second positioning fixture for fixing the semi-finished soft-pack battery; the cutting assembly further includes a second cutter assembly, and the second cutter assembly is used to cut the second shell; the second cutter assembly includes a second movable cutter 150 and a second fixed cutter 160; Either the first cutter assembly or the second cutter assembly is installed on the output end of the drive assembly 200; when the first cutter assembly is installed on the output end of the drive assembly 200, the specific installation method is the same as the above embodiment. When the second cutter assembly needs to be installed, the first cutter assembly is first removed; When the second cutter assembly is installed on the output end of the driving assembly 200: The driving assembly 200 is used to drive the cutting assembly 100 to move in a direction close to or away from the second positioning fixture; the second movable cutter 150 is screwed to the second lead screw 130; the second fixed knife 160 is detachably connected to the frame 400, and the blade of the second fixed knife 160 and the blade of the second movable cutter 150 are arranged opposite to each other. After the cutting device cuts the aluminum-plastic film, the first movable cutter 110, the first fixed knife 140 and the first positioning fixture are removed, and the second positioning fixture, the second fixed knife 160 and the second movable cutter 150 are installed, so that the blade of the second fixed knife 160 and the blade of the second movable cutter 150 are opposite to each other, and the second shell 620 can be cut.

[0041] like Figure 2 , Figure 3 As shown, in one embodiment of the present invention, there are at least two cutting devices. One cutting device is as follows: Figure 1 As shown, the cutting device is provided with a first positioning fixture and a first cutting knife assembly. The specific structure of the cutting device is shown in the above embodiment. Another cutting device is as shown in FIG. Figure 2 As shown, the cutting device is provided with a second positioning fixture and a second cutting knife assembly. The specific structure of the cutting device refers to the above embodiment.

[0042] When the shell is top-sealed, in order to avoid the top-sealing head from scalding the ear glue 630 at high temperature, the distance between the upper edge of the top-sealing head and the edge of one end of the second shell with the ear 610 needs to be controlled within 0.2-1.0 mm; that is, an unsealed area 621 is formed on the second shell 620, which is partially located on the side of the top-sealing edge 622 away from the punching area 601. If the actual length L of the uncut second shell 620 is greater than the target length L M , then cutting in the unsealed area 621 can control the length of the second shell and avoid loss of the top seal; at the same time, in order to ensure the sealing of the tab glue 630 and the second shell 620 at the tab 610, the width of the tab glue 630 needs to be greater than the width of the tab 610; preferably, the width of the tab glue 630 minus the width of the tab 610 ≥ 2 mm. Figure 3As shown, in order to prevent the second movable cutter 150 from damaging the tab 610, an embodiment of the present invention is provided with a first clearance groove 151 for avoiding the tab 610 on the second housing on the blade of the second movable cutter 150, the difference between the width of the first clearance groove 151 and the width of the tab 610 is 0-2mm, and the depth of the first clearance groove 151 is greater than 5cm. Similarly, a second clearance groove 161 for avoiding the tab 610 on the second housing is provided on the blade of the second fixed knife 160, the difference between the width of the second clearance groove 161 and the width of the tab 610 is 0-2mm, and the depth of the second clearance groove 161 is greater than 5cm. The second clearance groove 161 is provided in a one-to-one correspondence with the first clearance groove 151.

[0043] Furthermore, if Figure 3 As shown, the cutting device further comprises a dust removal assembly 500, which is arranged below the cutting assembly 100 and is used to collect debris. The dust removal assembly 500 can adopt a negative pressure adsorption method to promptly take away the cut aluminum-plastic film debris.

[0044] Verification of different models: Example 1 A cutting device with only one first positioning fixture is selected to cut the aluminum-plastic film. The CCD detector obtains the length value L of the cut first shell. b , and the length value L b The data is transmitted to the host computer, which calculates the average length L of the 16 first shells that have been cut before the first shell to be cut. a , and control the moving distance of the first movable cutter 110 to be ∆L=0.6*(L M -L a ), and then cut the first shell 600 to be cut in the first positioning fixture to obtain a cut first shell. Repeat the cutting to obtain 500 cut first shells.

[0045] Example 2 Compared with Example 1, Example 2 is different in that the number of first positioning fixtures in the cutting device is 2; Example 3 Compared with Example 1, Example 3 differs in that the number of first positioning fixtures in the cutting device is 8.

[0046] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the first movable cutter at a fixed cutting position directly cuts the aluminum-plastic film of the first housing 600 to be cut in the first positioning fixture. The cutting is repeated to obtain 500 soft-pack battery housings.

[0047] Comparative Example 2 Compared with Comparative Example 1, Comparative Example 2 differs in that the number of first positioning fixtures in the cutting device is 2; Comparative Example 3 The difference between Comparative Example 3 and Comparative Example 1 is that the number of the first positioning fixtures in the cutting device is 8.

[0048] Obtain and calculate the length L of 500 cut first shells in each embodiment and comparative example b The length average value Mean1 长 , calculate the length mean Mean1 长 With target length L M The difference D is calculated, and then the length L of the 500 cut first shells is calculated. b The mean square error Sigma. The data is shown in Table 1: Table 1 Cutting data table of Examples 1-3 and Comparative Examples 1-3 As can be seen from Table 1, by the method for cutting the soft-pack battery shell provided by the present invention, the position of the first movable cutter 110 is adjusted in real time during the continuous production process when each first shell is cut, so that the length value L of the first shell is b Closer to target length L M , so the length average value Mean1 of each embodiment 长 With target length L M The difference D and the mean square error Sigma are better than the corresponding control examples, achieving the effect of improving the consistency of length, which is sufficient to show that the cutting method provided by the present invention is applicable to the cutting devices of various models. Moreover, for models with a large number of clamps, the cutting method of the soft-pack battery shell provided by the present invention improves the consistency of the length of the first shell to a greater extent.

[0049] Based on this, a cutting device with 8 first positioning fixtures was selected for the experiment: Example 4 Get the length L of the cut first shell b , and the length value L b The data is transmitted to the host computer, which calculates the average length L of the 16 shells that have been cut before the shell to be cut. a , and control the moving distance of the first movable cutter 110 to be ∆L=0.6*(L M -L a ), and then cut the first shell 600 to be cut in the first positioning fixture to obtain a cut first shell. Repeat the cutting to obtain 500 first shells.

[0050] The difference between Examples 5 to 14 and Example 4 is only that n or k is changed, and each first shell in Comparative Example 4 is directly cut by the first movable cutter 110 at a fixed cutting position. The condition variables and test data of Examples 5 to 14 and Comparative Example 4 are shown in Table 2: Table 2 Cutting data table of Examples 4 to 14 and Comparative Example 4 From the test results in Table 2, we can see that: By comparing the test results of Examples 4 to 14 and Comparative Example 4, it can be seen that the method for cutting the soft-pack battery shell of the present invention adjusts the position of the first movable cutter 110 when each first shell is cut in real time during the continuous production process, so that the length value L of each first shell is b Closer to target length L M , so the length average value Mean1 of each embodiment 长 , and the mean square error Sigma are both better than those of comparative example 4, achieving the effect of improving the consistency of length.

[0051] Comparing the test results of Examples 4 to 9, it can be seen that the value of n between 8 and 64 has a better effect. When n1 is 4, if the length of a first shell suddenly changes during the production process, the length value L of the first shell after subsequent cutting will be affected. b The influence is large, so the average value of the length of the 500 first shells is Mean1 长 With target length L M The difference D and the mean square error Sigma are large, and the consistency of length is poor; when n is 128, a sudden change in the length of a first shell during the production process has an impact on the length value L of the first shell after subsequent cutting. b The effect is too small to change the length L of the first shell to be cut later by adjusting the target cutting position of the first movable cutter 110 in time. b , resulting in the length mean Mean1 of the 500 first shells 长 With target length L M The difference D and mean square error Sigma are large, and the consistency of length is poor.

[0052] By comparing the test results of Example 7, Example 10 to Example 14, it can be seen that the value of k between 0.6 and 0.9 has a better effect. When k is lower than 0.6, after a sudden change in the length of a first shell during the production process, the adjustment of the target cutting position of the first movable cutter 110 when the subsequent first shell is cut is not timely enough, so it is difficult to timely adjust the length value L of the subsequent first shell after cutting. b , resulting in 500 first shells being cut to a length L b Sigma 注When k is higher than 0.9, after a sudden change in the length of a first shell during the production process, the length value L of the subsequent first shell after cutting can be adjusted in time. b , but the length L of the first shell after cutting b The influence is too great, so the length value L after the 500 first shells are cut b Sigma 注 Larger, less consistent in length.

[0053] Embodiment 15 By adopting the cutting method of the soft-pack battery shell provided by the above embodiment, after the aluminum-plastic film is cut into a first shell, the bare battery cell is placed in the first shell, and the aluminum-plastic film and the ear glue at the head of the first shell are heat-sealed by heating the head to ensure the sealing of the top of the battery; the aluminum-plastic film on the side is heat-sealed to ensure the sealing of the side of the battery, and a semi-finished soft-pack battery is formed at the same time; due to process errors such as misalignment of the aluminum-plastic film during the cutting process, a first shell with a length exceeding the size specification will be generated; and the length of the semi-finished soft-pack battery may also change due to process errors during the top and side sealing process, among which the semi-finished soft-pack battery with a length exceeding the size specification requirements will still exceed the size specification after being prepared into a soft-pack battery. Considering the assembly requirements of downstream processors, it is generally scrapped, increasing production costs.

[0054] Therefore, the CCD detector obtains the actual length L of the second shell 620 of the semi-finished soft-pack battery to be cut, and transmits the actual length L to the host computer, which determines whether the actual length L is greater than the target length L. M , the actual length L is less than the target length L M The semi-finished soft-pack battery is not processed; the actual length L is greater than the target length L M The semi-finished soft-pack battery is then judged by the host computer between the actual length L and the target length L M Is the difference less than X (X=0.2mm)? If so, move the semi-finished soft-pack battery to be cut into the second positioning fixture. The upper computer determines the actual length L and the target length L. M The difference of controls the second movable cutter 150 to move and cut the second housing 620 of the semi-finished soft-pack battery in the second positioning fixture to obtain a cut semi-finished soft-pack battery. Repeat the cutting to obtain 2000 cut semi-finished soft-pack batteries.

[0055] The difference between Examples 16 to 19 and Example 15 is only the change of X. In Comparative Example 5, each second shell is directly cut by the second movable cutter 150 at a fixed cutting position.

[0056] Statistics of defective shells in various embodiments and comparative examples (the length of the shell after cutting still exceeds the target length L M ) and calculate the defective rate, defective rate = number of defective shells / 2000*100%. At the same time, measure the effective top seal width of each second shell, and then calculate the average value Mean2 of the effective top seal width of 2000 second shells in each embodiment and comparative example. 宽 .

[0057] The condition variables and test data of Examples 15 to 19 and Comparative Example 5 are shown in Table 3: Table 3 Cutting data table of Examples 15 to 19 and Comparative Example 5 From the test results in Table 3, we can see that: By comparing the test results of Examples 15 to 19 and Comparative Example 5, it can be seen that the cutting method of the soft-pack battery of the present invention is used for each length exceeding the target length L during the continuous production process. M The target cutting position of the semi-finished soft-pack battery is adjusted in real time, so that the length value L of each semi-finished soft-pack battery after cutting b Closer to target length L M Therefore, the defective rate of the semi-finished soft-pack batteries in each embodiment is much lower than that in comparative example 5; that is, according to the cutting method of the present invention, the length of the semi-finished soft-pack batteries exceeding the target length L M Cutting the soft-pack batteries can reduce the number of scrapped soft-pack batteries and reduce costs.

[0058] However, as the value of X increases, the average value of the effective top seal width of 2000 semi-finished soft-pack batteries in each embodiment is 宽 The reason may be that, due to the large X value, when the actual length L of a certain soft-pack battery is large during the production process, it is easy to affect the distance moved by the second movable cutter 150 when the subsequent semi-finished soft-pack battery is cut, so that the aluminum-plastic film cut off of the semi-finished soft-pack battery is longer, and part of the top sealing edge 622 is cut off, so that the effective top sealing width of the semi-finished soft-pack battery is reduced. In order to ensure the sealing effect of the soft-pack battery, the width of the top sealing edge 622 (effective top sealing width) should be greater than 1mm, so it is better that the X value is less than or equal to 0.5mm.

[0059] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for cutting a soft pack battery shell, characterized in that: The cutting method comprises the following steps: Get the target length L of the soft pack battery shell M , the average length L of the n cut first shells in the length direction of the soft pack battery before the first shell is cut a The first shell to be cut is a battery shell formed by an aluminum-plastic film that is punched and folded in half; According to the average length L a and the target length L M , controlling the first cutter assembly to move from a cutting position where the first shell has been cut to a target cutting position where the first shell is to be cut, and cutting the first shell to be cut to obtain the cut first shell; The cut first shell is used to house the bare battery cell.

2. The cutting method according to claim 1, characterized in that: According to the average length L a and the target length L M , in the step of controlling the first cutter assembly to move from a cutting position where the first shell has been cut to a target cutting position where the first shell is to be cut: The distance moved by the first cutter assembly is ∆L=k*(L M -L a ); Wherein, k is the adjustment coefficient, 0.6≤k≤0.

9.

3. The cutting method according to claim 1, characterized in that: 8≤n≤64。 4. The cutting method according to any one of claims 1 to 3, characterized in that: The following steps are also included: Obtaining the actual length L of the second shell; the second shell is the shell of a semi-finished soft-pack battery obtained by cutting the first shell, loading the bare battery cell, and completing the top and side sealing; According to the actual length L of the second housing and the target length L of the soft pack battery housing M , determine whether the second shell needs to be cut; When the second shell needs to be cut, the second cutter assembly is controlled to move from the cutting position where the second shell has been cut to the target cutting position where the second shell is to be cut, and the second shell to be cut is cut.

5. The cutting method according to claim 4, characterized in that: The step of determining whether the second housing needs to be cut includes: If the actual length L is less than the target length L M , there is no need to cut the second shell; If the actual length L is equal to the target length L M If the difference is between 0 and X, the second shell needs to be cut; If the actual length L is equal to the target length L M If the difference is greater than X, manual re-judgment is performed to determine whether the second shell needs to be cut; Among them, 0.2mm≤X≤0.5mm.

6. A cutting device, characterized in that: include: A first positioning fixture, the first positioning fixture is used to fix the first shell to be cut; A cutting assembly (100), the cutting assembly (100) comprising a first cutting knife assembly for cutting the first shell to be cut; a driving component (200), wherein the cutting component (100) is arranged at an output end of the driving component (200), and the driving component (200) is used to drive the cutting component (100) to move in a direction approaching or moving away from the first positioning fixture; a controller, the controller being communicatively connected to the cutting component (100) and the driving component (200) respectively; A host computer, wherein a machine executable program is stored in the host computer, and when the machine executable program is executed by the controller, it is used to implement the cutting method according to any one of claims 1 to 5; A CCD detector is used to detect the length of the shell, and the CCD detector is communicatively connected with the host computer.

7. The cutting device according to claim 6, characterized in that: The cutting device further comprises a base (300) and a frame (400); a slide rail (310) is arranged on the base (300), and the frame (400) is slidably arranged on the slide rail (310); the driving component (200) is fixedly arranged on the base (300), and a driving end of the driving component (200) is connected to the frame (400); and the cutting component (100) is arranged on the frame (400).

8. The cutting device according to claim 7, characterized in that: The driving assembly (200) comprises a first servo motor (210) and a first lead screw (220); the first servo motor (210) is fixedly arranged on the base (300); the first servo motor (210) is communicatively connected to the controller; the first lead screw (220) is connected to an output end of the first servo motor (210); and the frame (400) is screwed to the first lead screw (220); The cutting assembly (100) comprises a second servo motor (120), a second lead screw (130) and a first cutter assembly, wherein the second servo motor (120) is fixedly arranged on the frame (400), and the second servo motor (120) is communicatively connected to the controller; the second lead screw (130) is connected to the output end of the first servo motor (210); The first cutter assembly comprises a first movable cutter (110) and a first fixed cutter (140); the first movable cutter (110) is screwed to the second lead screw (130); the first fixed cutter (140) is detachably connected to the frame (400), and the blade of the first fixed cutter (140) and the blade of the first movable cutter (110) are arranged opposite to each other.

9. The cutting device according to claim 8, characterized in that: The cutting device also includes a second positioning fixture for fixing the semi-finished soft-pack battery; The cutting assembly (100) further comprises a second cutting knife assembly for cutting the second shell; Either the first cutter assembly or the second cutter assembly is installed on the output end of the drive assembly (200); The second cutting knife assembly comprises a second movable cutting knife (150) and a second fixed knife (160); When the second cutter assembly is mounted on the output end of the drive assembly (200): The driving assembly (200) is used to drive the cutting assembly (100) to move in a direction approaching or moving away from the second positioning fixture; the second movable cutter (150) is screwed to the second lead screw (130); the second fixed knife (160) is detachably connected to the frame (400), and the blade of the second fixed knife (160) and the blade of the second movable cutter (150) are arranged opposite to each other.

10. The cutting device according to claim 6, characterized in that: The cutting device further comprises a dust removal component (500), wherein the dust removal component (500) is arranged below the cutting component (100) and is used to collect debris.

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