Miniaturization of a high-speed helium detection device for cylindrical battery cells

Abstract

To provide a downsizing method of a high-speed helium detection device of cylindrical battery cells.SOLUTION: A downsizing method includes a step of performing detection on detection target battery cells before liquid injection to screen out NG products. The method according to the present invention performs an additional initial inspection on the battery cells before a conventional initial inspection and a sampling inspection so that NG battery cells each having a large leakage rate can be screened out in advance, thereby reducing the number of battery cells to be inspected entering the conventional initial inspection and a sampling inspection station for the battery cells, and reducing an equipment area occupied by the sampling inspection station. Further, the method can achieve fast-paced helium detection and loading / unloading through two cavities that can perform helium detection, loading and unloading alternately, shortening waiting time for mechanical actions during the conventional initial inspection, improving the efficiency of the helium inspection, and further enhancing overall work efficiency of a production line.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technical field of battery cell airtightness detection, and more particularly to a method for miniaturizing a high-speed helium detection device for cylindrical battery cells. [Background technology]

[0002] Cylindrical battery cell production lines have extremely fast production takt times (ppm), typically reaching 100 ppm, 150 ppm, and even 200 ppm. That is, they produce 100, 150, or even 200 cells per minute, but the helium measurement test time for a single cell takes more than 20 seconds. Therefore, the industry typically installs multiple test chambers within a vacuum helium detection system to perform initial testing on a group of multiple battery cells. In this process, the more battery cells a single detection system can simultaneously test, the less equipment is required for initial testing and the smaller the installation area of ​​the detection system. However, even if a multi-chamber vacuum helium detection system detects a non-conforming battery cell, it is unable to identify the specific non-conforming battery cell. Therefore, once a non-conforming battery cell is detected, each battery cell in the group must be randomly inspected one by one to accurately identify the non-conforming battery cell. In this process, the more battery cells a detection system can simultaneously inspect, the larger the equipment required for single-cycle sampling testing and the larger the installation area of ​​the sampling inspection system. When designing a production line for cylindrical battery cells, it is necessary to find a balance between the product NG rate and the number of test chambers for the detection equipment.

[0003] As can be seen, the NG rate of a product is objectively determined based on the actual conditions of the production line and can be calculated from production data. Therefore, if the NG rate is high and the test channels in the detection device are large, the required area for random inspection equipment will be larger, making it difficult to control the equipment's installation area and adversely affecting production efficiency. If the NG rate fluctuates beyond the equipment's design capacity, overload stacking will occur, seriously affecting the operation of the production line. Therefore, assuming the NG rate is determined, the number of test chambers in the detection device should be rationally adjusted based on the actual production situation, thereby reducing the overall equipment installation area. However, the traditional helium detection method of initial inspection in groups and random inspection of each group still requires a considerable amount of installation space. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the problems of the prior art, the present invention aims to provide a method for miniaturizing a high-speed helium detection device for cylindrical battery cells, which can reduce the installation area of ​​the detection equipment and increase the efficiency of helium detection. [Means for solving the problem]

[0005] The method for miniaturizing a high-speed helium detection device for cylindrical battery cells according to the present invention includes screening out defective products by detecting the target battery cells before injection of helium, and the method includes the following steps. Initial inspection of battery cells: Using a first detection unit, an airtightness test is performed on each of the target battery cells at a first leakage rate, and the target battery cells whose leakage rate is greater than the first leakage rate are transported to the NG discharge line and discharged, and the target battery cells whose leakage rate is less than or equal to the first leakage rate are grouped and then transported to the second detection unit and supplied. Initial inspection of battery cells: Using the second detection unit, helium detection is performed on the battery cells to be detected after initial inspection and grouping at the second leakage rate, and if the leakage rate of the battery cells is greater than the second leakage rate, the entire group of battery cells to be detected is transported to the third detection unit, and if the leakage rate of the battery cells is less than or equal to the second leakage rate, the entire group of battery cells to be detected is discharged. Random inspection of battery cells: Using a third detection unit, helium detection is performed on the target battery cells one by one at a third leakage rate, and detected battery cells whose leakage rate is greater than the third leakage rate are transported to the NG discharge line and discharged, and detected battery cells whose leakage rate is less than or equal to the third leakage rate are discharged.

[0006] Furthermore, the battery cell leakage rate Q is calculated from the pressure change amount ΔP, the battery cell volume V, and the detection time length t, and is calculated using the following formula (Equation 1).

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[0007] Furthermore, the first leak rate, the second leak rate, and the third leak rate are all calibrated values.

[0008] Furthermore, when the first leakage rate is calibrated with the third leakage rate, the volume V of the battery cell is equal to the detection time length t.

[0009] Furthermore, the first leakage rate is greater than the third leakage rate.

[0010] Furthermore, the second detection unit includes an upper cavity in which a helium detection device is provided, a first lower cavity, and a second lower cavity, and the first lower cavity and the second lower cavity are each provided with a test chamber for accommodating the battery cell to be detected; The upper cavity is used to perform helium detection for the other of the first lower cavity and the second lower cavity when either the first lower cavity or the second lower cavity is inputting or outputting a product.

[0011] Furthermore, the second detection unit further includes a second chamber, a slide rail assembly, and a slide unit, wherein the slide rail assembly is housed within the second chamber and is fixed integrally with the second chamber, the slide unit is slidably disposed on the slide rail assembly, and the first lower cavity and the second lower cavity are disposed on the slide unit and are slidable relative to the upper cavity or are stationary relative to the upper cavity.

[0012] Furthermore, the number of test chambers in the first lower cavity is the same as the number of test chambers in the second lower cavity.

[0013] Furthermore, the number of test chambers in the first detection unit is greater than or equal to the number of test chambers in the first lower cavity.

[0014] Furthermore, the first detection unit is provided in the first chamber, the third detection unit is provided in the third chamber, the first chamber, the second chamber, and the third chamber are collectively installed in a helium detection assembly, and a transport belt is installed in the helium detection assembly for transporting and loading / unloading products between the first chamber, the second chamber, and the third chamber. [Effects of the Invention]

[0015] The method for miniaturizing a high-speed helium detection device for cylindrical battery cells of the present invention adds an initial battery cell inspection step before the initial battery cell inspection and random battery cell inspection, thereby filtering out non-conforming battery cells with high leakage rates in advance, thereby reducing the number of battery cells waiting to be inspected at the initial battery cell inspection and random battery cell inspection station and reducing the installation area required for the random battery cell inspection station.The present invention also achieves high-speed helium detection and product loading / unloading by using two cavities that can alternate between product loading / unloading and helium detection, thereby shortening the waiting time for machine operation during initial battery cell inspection, effectively improving the efficiency of helium detection and further improving the overall work efficiency of the production line. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic diagram of a miniaturization method for a high-speed helium detection device for a cylindrical battery cell provided by the present invention. [Figure 2] FIG. 2 is a schematic diagram of a second detection unit according to the present invention. [Figure 3] FIG. 3 is a plan view of a second detection unit according to the present invention. [Figure 4] FIG. 3 is a side view of a second detection unit according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described in detail with reference to the drawings and preferred embodiments in order to more fully describe the technical means and effects employed by the present invention to achieve the intended inventive objectives.

[0018] The terms "first," "second," "third," "fourth," etc. in the present specification and claims are not used to describe any particular order or priority, but are used to distinguish between similar objects.

[0019] As shown in Figure 1, the method for miniaturizing a high-speed helium detection device for cylindrical battery cells according to the present invention detects target battery cells before injection of helium and sorts out defective products. The method includes the following steps.

[0020] In step S1, the first detection unit is used to perform airtightness detection on the target battery cells one by one at a first leakage rate.

[0021] In step S2, the battery cells to be detected whose leakage rate is greater than the first leakage rate are transported to the NG discharge line and discharged, and the battery cells to be detected whose leakage rate is equal to or less than the first leakage rate are grouped and then transported to and inserted into the second detection unit.

[0022] Specifically, steps S1 and S2 are both part of the initial battery cell inspection process. The first detection unit in step S1 is not a helium detection device but an airtightness detection unit with a vacuum tank. The first detection unit detects only changes in pressure difference during airtightness detection, eliminating the need for complex helium detection steps. This reduces the cost of the equipment required for the preliminary battery cell inspection process. In this embodiment, the first detection unit is installed in a first chamber, which contains multiple test chambers. This allows simultaneous airtightness detection for all target battery cells within the test chambers. Even if a non-compliant battery cell is detected, the test chamber containing the non-compliant battery cell can be accurately identified. The first detection unit installed in this manner can quickly and accurately identify non-compliant battery cells in the target battery cell set, enabling pre-detection of non-compliant battery cells before helium detection. This reduces the number of non-compliant battery cells among the target battery cells undergoing initial inspection and random inspection.

[0023] For ease of understanding, suppose a set of 20 test cells contains 20 test cells during initial battery cell testing. The initial battery cell testing can only determine whether there is a defective battery cell among the 20 test cells, but cannot identify which of the 20 cells is defective. If a defective battery cell is detected during initial battery cell testing, it means that all 20 battery cells require random testing. If the defective battery cell can be detected in advance, the random testing process for at least 20 battery cells can be omitted, significantly improving the production efficiency of the production line and significantly improving the overall defective rate load capacity of the production line. The battery cell leakage rate in step S2 is calculated using the same formula based on the pressure change ΔP, the battery cell volume V, and the detection time t. That is, the calculation formula is as follows:

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[0024] The above formula shows that for a fixed battery cell volume V and detection time t, the battery cell leakage rate Q is positively correlated with the pressure change ΔP. The larger the pressure change ΔP, the greater the battery cell leakage rate Q. However, if the battery cell leakage rate Q exceeds the first leakage rate, the battery cell is deemed a defective cell and must be transported to the defective discharge line for subsequent production operations. When target battery cells with leakage rates equal to or less than the first leakage rate are grouped and transported to the second detection unit, if the number of target battery cells after grouping is less than the number of chambers for the initial inspection of single-cycle battery cells in the second detection unit, the next batch of battery cells must be inspected until the first detection unit completes the initial inspection, and then normal battery cells among them are selected to supplement the number, ensuring the efficiency of the initial inspection of battery cells by the second detection unit in the subsequent step. In this embodiment, the first leakage rate is a standard value, but its calculation is still based on the battery cell leakage rate calculation formula. When performing the calibration calculation, if the pressure change ΔP is 200 Pa, the battery cell volume V is 20 ml, and the detection time length t is 30 s, the first leak rate is 1.33E-4 Pa.m 3 / s.

[0025] In step S3, the second detection unit is used to perform helium detection at a second leakage rate on the battery cells to be detected after the initial inspection and grouping.

[0026] In step S4, if the leakage rate of the battery cells is greater than the second leakage rate, the entire group of battery cells to be detected is transported to a third detection unit, and if the leakage rate of the battery cells is less than or equal to the second leakage rate, the entire group of battery cells to be detected is discharged.

[0027] Please also refer to Figures 2 to 4. Specifically, steps S3 and S4 are both initial battery cell inspection steps. The second detection unit in step S3 includes a second chamber 1, a slide rail assembly 2, a slide unit 3, an upper cavity 4, a first lower cavity 5, and a second lower cavity 6. The slide rail assembly 2 and slide unit 3 are housed in the second chamber 1 and fixedly attached to the second chamber 1. The slide unit 3 is slidably installed in the slide rail assembly 2 and driven by a cylinder. The first lower cavity 5 and the second lower cavity 6 are installed in the slide unit 3 and slide together with the slide unit 3 on the slide rail assembly 2, thereby sliding relative to the upper cavity 4 or remaining stationary relative to the upper cavity 4. A helium detection device is installed in the upper cavity 4. The helium detection device includes at least a filling mechanism, a bleed valve group, a vacuum breaker valve, etc. The first lower cavity 5 and the second lower cavity 6 each have a test chamber for accommodating a battery cell to be inspected. The upper cavity 4 can perform helium detection for either the first lower cavity 5 or the second lower cavity 6 when either one of the first lower cavity 5 and the second lower cavity 6 is loading or unloading a product. In this embodiment, the second leakage rate is a standard value and is calculated using a battery cell leakage rate calculation formula. However, because helium detection in step S3 is performed simultaneously in multiple test chambers, when the second leakage rate is calibrated in step S4, some parameters, i.e., the battery cell volume V and the pressure change ΔP, differ from those used in the calibration calculation of the first leakage rate, making the two calculations indirectly comparable. In this embodiment, the number of test chambers in the first lower cavity 5 is the same as the number of test chambers in the second lower cavity 6. The number of test chambers in the first detection unit is equal to the number of test chambers in the first lower cavity 5 and the second lower cavity 6. This is because the occurrence of defective battery cells is inevitable during initial battery cell testing.In the aforementioned step S2, if the number of battery cells to be detected after grouping is smaller than the number of single-cycle battery cells in the second detection unit, i.e., smaller than the number of test chambers in the first lower cavity 5, it is necessary to supplement the quantity by taking normal battery cells from the next batch of battery cells after initial inspection. Therefore, in order to further improve the working efficiency of the production line and make it easier to supplement the missing battery cells to be detected, the number of test chambers in the first detection unit used for initial inspection cannot be set smaller than the number of test chambers in the first lower cavity 5.

[0028] When using the second detection unit of the present invention to perform an initial battery cell inspection, the test cells are first inserted into the test chambers in the first lower cavity 5 and the second lower cavity 6. After the test cells are fully loaded, the second lower cavity 6 is controlled to slide to the corresponding position in the upper cavity 4, and the upper cavity 4 is controlled to perform helium detection for the second lower cavity 6. After this operation is completed, the first lower cavity 5 is slid to the corresponding position in the upper cavity 4, and the second lower cavity 6 is controlled to move away from the helium detection position, and the upper cavity 4 is controlled to perform helium detection for the first lower cavity 5. Based on the helium detection result for the second lower cavity 6, a corresponding operation is performed on the test cells, i.e., the test cells are transferred to the third detection unit or ejected. Then, the test cells are inserted into the second lower cavity 6 to replenish them. After all the battery cells to be detected in the second lower cavity 6 have been replaced and replenished, the helium detection operation in the first lower cavity 5 is also completed. Then, the second lower cavity 6 is controlled to slide to a corresponding position in the upper cavity 4, circulating back and forth in this manner. The second detection unit of the present invention has two cavities that can alternately perform product loading / unloading and helium detection, thereby achieving high-speed helium detection and product loading / unloading, shortening the waiting time for mechanical operation during initial battery cell inspection and effectively improving helium detection efficiency.

[0029] In step S5, helium detection is performed on each of the target battery cells at a third leakage rate using the third detection unit.

[0030] In step S6, detected battery cells whose leakage rate is greater than the third leakage rate are transported to the NG discharge line and discharged, and detected battery cells whose leakage rate is less than or equal to the third leakage rate are discharged.

[0031] Specifically, steps S5 and S6 are battery cell sampling inspection steps. The third detection unit in step S5 is a helium detection device for sampling inspection. The third detection unit is installed in the third chamber, and multiple test chambers are installed in the third chamber. In this embodiment, the number of test chambers in the third chamber is the same as the number of test chambers in either the first lower cavity 5 or the second lower cavity 6. The first chamber, second chamber 1, and third chamber are installed in a stacked arrangement in the helium detection assembly. A transport belt is installed in the helium detection assembly for transporting and loading / unloading products between the first chamber, second chamber 1, and third chamber. The helium detection assembly of the present invention conveniently and consistently installs three stations through the stacked first chamber, second chamber 1, and third chamber, which enables fast and convenient loading / unloading of products and transport of battery cells to be tested, thereby improving the overall production efficiency of the production line. The third leakage rate in step S6 is a calibration value and is calculated using Equation 2. In this embodiment, the number of test chambers in the third detection unit is equal to the number of test chambers in the first detection unit used for the initial inspection, and is also equal to the number of test chambers in the first lower cavity 5. During the calibration calculation, the third leak rate is set to 1.0E-06 Pa m 3 / s. Note that in step S4 described above, some parameters for the second leakage rate, i.e., the battery cell volume V and the pressure change ΔP, are different from those used when calculating the first leakage rate. However, in step S6, some of the parameters for the third leakage rate, i.e., the battery cell volume V and the pressure change ΔP, are also different from some of the parameters for the second leakage rate (i.e., the battery cell volume V and the pressure change ΔP), so the second leakage rate cannot be directly compared with the third leakage rate. However, in this embodiment, the battery cell volume V and detection time t for the first leakage rate are the same as those for the third leakage rate, so the two can be compared. The leakage rate of defective battery cells filtered out during the initial battery cell inspection actually lies between the first leakage rate and the third leakage rate. When designing the scale of a battery cell production line, adjusting the first leakage rate, the second leakage rate, and the third leakage rate allows the scale of the initial inspection station, the initial inspection station, and the random inspection station of the cylindrical battery cell production line to be adjusted, and the NG rate load capacity of the entire production line can also be significantly improved.

[0032] "The present invention's method for miniaturizing a high-speed helium detection device for cylindrical battery cells adds an initial battery cell inspection step before the initial battery cell inspection and battery cell random inspection, thereby filtering out defective battery cells with high leakage rates and reducing the number of battery cells waiting for detection during the initial battery cell inspection and battery cell random inspection, thereby reducing the equipment space required for the random inspection station. The present invention also uses two cavities that can alternate between product loading / unloading and helium detection, enabling high-speed helium detection and product loading / unloading, shortening the waiting time for machine operation during the initial battery cell inspection and effectively improving the efficiency of helium detection, thereby further improving the overall work efficiency of the production line."

[0033] The above are only specific embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily think of modifications or substitutions within the technical scope disclosed in the present invention, and any results obtained by these modifications or substitutions should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be governed by the claims.

Claims

1. A method for miniaturizing a high-speed helium detection device for cylindrical battery cells, comprising: detecting a target battery cell before injection of helium to thereby select a defective product; an initial battery cell inspection step of using a first detection unit to perform an airtightness inspection on each of the target battery cells at a first leakage rate, transporting the target battery cells whose leakage rate is greater than the first leakage rate to an NG discharge line and discharging them, and grouping the target battery cells whose leakage rate is less than or equal to the first leakage rate and transporting them to a second detection unit for supply; an initial inspection step of the battery cells, in which helium detection is performed on the target battery cells after initial inspection and grouping at a second leakage rate using the second detection unit, and if the leakage rate of the battery cells is greater than the second leakage rate, the target battery cells of the entire group are transported to a third detection unit, and if the leakage rate of the battery cells is less than or equal to the second leakage rate, the target battery cells of the entire group are discharged; a sampling inspection step of detecting helium in each of the target battery cells at a third leakage rate using the third detection unit, transporting and discharging detected battery cells whose leakage rate is greater than the third leakage rate to an NG discharge line, and discharging detected battery cells whose leakage rate is less than or equal to the third leakage rate.

2. The second detection unit includes an upper cavity (4) in which a helium detection device is provided, a first lower cavity (5) and a second lower cavity (6), The first lower cavity (5) and the second lower cavity (6) each have a test chamber for accommodating the battery cell to be detected; 2. The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell according to claim 1, wherein the upper cavity (4) is used to perform helium detection for the first lower cavity (5) or the second lower cavity (6) when either one of the first lower cavity (5) or the second lower cavity (6) is inputting or outputting a product.

3. The second detection unit further includes a second chamber (1), a slide rail assembly (2), and a slide unit (3); The slide rail assembly (2) is housed within the second chamber (1) and is fixed integrally with the second chamber (1); The slide unit (3) is slidably disposed on the slide rail assembly (2), 3. The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell according to claim 2, wherein the first lower cavity (5) and the second lower cavity (6) are arranged on the slide unit (3) and are slidable relative to the upper cavity (4) or are stationary relative to the upper cavity (4).

4. A method for miniaturizing a high-speed helium detection device for a cylindrical battery cell as described in Claim 2, characterized in that the number of test chambers in the first lower cavity (5) is the same as the number of test chambers in the second lower cavity (6).

5. A method for miniaturizing a high-speed helium detection device for cylindrical battery cells as described in Claim 2, characterized in that the number of test chambers in the first detection unit is greater than or equal to the number of test chambers in the first lower cavity (5).

6. The first detection unit is provided in a first chamber, and the third detection unit is provided in a third chamber; the first chamber, the second chamber (1) and the third chamber are collectively installed in a helium detection assembly; 4. The method for miniaturizing a high-speed helium detection device for cylindrical battery cells according to claim 3, wherein a transport belt is installed in the helium detection assembly for transporting and loading / unloading products between the first chamber, the second chamber (1), and the third chamber.

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