Downsizing method of high-speed helium detection device of 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 airtightness detection of battery cells, and particularly to a method for miniaturizing a high-speed helium detection device for cylindrical battery cells.

Background Art

[0002] The production tact (ppm) of the production line of cylindrical battery cells is extremely fast, and usually can reach 100 ppm, 150 ppm, and even 200 ppm. That is, 100, 150, and even 200 are produced per minute, but the helium measurement test time for a single battery cell requires 20 seconds or more. Therefore, in the industry, a large number of test chambers are usually provided in a vacuum helium detection device to perform an initial inspection on a plurality of grouped battery cells. In this process, the larger the number of battery cells that can be detected simultaneously by one detection device, the smaller the number of facilities required for the initial inspection, and the smaller the installation area of the detection device. However, for a vacuum helium detection device with a plurality of chambers installed in this way, even if an NG is detected, it is impossible to know which specific NG battery cell it is. Therefore, when an NG is detected, it is necessary to extract and inspect each battery cell in the entire group one by one to accurately find the NG battery cell. In this process, the larger the number of battery cells that can be inspected simultaneously by the detection device, the larger the facilities required for single-cycle extraction inspection, and the larger the installation area of the extraction inspection facilities. When designing the production line of cylindrical battery cells, it is necessary to balance the NG rate of the product and the number of test chambers of the detection device.

[0003] As can be understood, since the NG rate of the product objectively exists based on the actual situation of the production line and can be calculated from production data, if the NG rate is large and the number of test channels in the detection device is also large, the corresponding area of the sampling inspection facility will become larger, the installation area of the facility cannot be controlled, and it is disadvantageous for improving production efficiency. When the NG rate fluctuates until it exceeds the design capacity of the equipment, an overload stack will occur, seriously affecting the operation of the production line. Therefore, on the premise that the NG rate is determined, the number of test chambers of the detection device needs to be rationally allocated based on the actual production situation, so that the overall installation area of the equipment can be reduced. Nevertheless, the conventional helium detection method of initially inspecting and sampling and inspecting one by one for each group still requires a certain installation area.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In view of the problems of the prior art, an object of the present invention is 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 improve the efficiency of helium detection.

Means for Solving the Problems

[0005] The method for miniaturizing a high-speed helium detection device for cylindrical battery cells according to the present invention includes screening out NG products by detecting the battery cells to be detected before liquid injection, and the method includes the following steps. Initial inspection of battery cells: Use the first detection unit to perform airtightness inspection on the battery cells to be detected one by one at the first leakage rate, convey and discharge the battery cells to be detected with a leakage rate greater than the first leakage rate to the NG discharge line, and group the battery cells to be detected with a leakage rate less than or equal to the first leakage rate and then convey and supply them to the second detection unit. Initial inspection of battery cells: After initial inspection and grouping at the second leakage rate using the second detection unit, helium detection is performed on the battery cells to be detected. If the leakage rate of the battery cell is greater than the second leakage rate, the battery cells to be detected for the entire group are transported to the third detection unit. If the leakage rate of the battery cell is less than or equal to the second leakage rate, the battery cells to be detected for the entire group are discharged. Extraction inspection of battery cells: Using the third detection unit, helium detection is performed one by one on the battery cells to be detected at the third leakage rate. The detected battery cells with a leakage rate greater than the third leakage rate are transported to the NG discharge line for discharge, and the detected battery cells with a leakage rate 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 volume V of the battery cell, and the detection time length t, and the calculation formula is as shown in (Equation 1).

Equation

[0007] Furthermore, all of the first leakage rate, the second leakage rate, and the third leakage rate are calibration values.

[0008] Furthermore, when calibrating the first leakage rate with the third leakage rate, the volume V of the battery cell is the same as 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 provided with a helium detection device, a first lower cavity, and a second lower cavity. Test chambers for accommodating the battery cells to be detected are respectively provided in the first lower cavity and the second lower cavity. When either one of the first lower cavity and the second lower cavity inputs or discharges a product, the upper cavity is used to perform helium detection on the other one of the first lower cavity and the second lower cavity.

[0011] Furthermore, the second detection unit further includes a second chamber, a slide rail assembly, and a slide unit. The slide rail assembly is accommodated in the second chamber and fixedly attached to the second chamber integrally. The slide unit is slidably disposed on the slide rail assembly. The first lower cavity and the second lower cavity are disposed on the slide unit and are slidable relative to the upper cavity or 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 a first chamber, the third detection unit is provided in a third chamber. The first chamber, the second chamber, and the third chamber are integrally installed in a helium detection assembly. A transport belt for transporting and inputting / discharging products among the first chamber, the second chamber, and the third chamber is installed in the helium detection assembly.

Advantages of the Invention

[0015] The method for miniaturizing the high-speed helium detection device of the cylindrical battery cell of the present invention is to add initial inspection steps of the battery cell before the initial inspection of the battery cell and the extraction inspection of the battery cell, so as to screen out NG battery cells with a large leakage rate in advance, thereby reducing the number of battery cells waiting for inspection entering the initial inspection and extraction inspection stations of the battery cell, and reducing the installation area required for the extraction inspection station. The present invention also realizes high-speed tact helium detection and product loading / unloading by means of two cavities that can alternately perform product loading / unloading and helium detection, shortens the waiting time of the mechanical operation during the initial inspection of the battery cell, effectively improves the efficiency of helium detection, and further improves the overall working efficiency of the production line.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0017] In order to describe in more detail the technical means and effects adopted by the present invention to achieve a predetermined invention purpose, the present invention will be described in detail below in connection with the drawings and more preferred embodiments.

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

[0019] As shown in FIG. 1, the method for miniaturizing a high-speed helium detection device for a cylindrical battery cell according to the present invention selects NG products by detecting a battery cell to be detected before liquid injection. The method includes the following steps.

[0020] In step S1, airtightness detection is performed one by one on the battery cells to be detected using the first detection unit at a first leakage rate.

[0021] In step S2, the battery cells to be detected with a leakage rate greater than the first leakage rate are conveyed to the NG discharge line and discharged. After grouping the battery cells to be detected with a leakage rate less than or equal to the first leakage rate, they are conveyed to and input into the second detection unit.

[0022] Specifically, both step S1 and step S2 belong to the initial inspection steps of the battery cells. The first detection unit in step S1 is not a helium detection device but an airtightness detection unit having a vacuum tank. When detecting airtightness, the first detection unit does not need to execute complex detection steps corresponding to helium detection and only detects the change in pressure difference, so the cost of the instrument for the preliminary detection step of the battery cells is low. In this embodiment, the first detection unit is installed in the first chamber, and a plurality of test chambers are installed in the first chamber, which can perform airtightness detection on all the battery cells to be detected in the test chamber simultaneously. Even when NG is detected, the test chamber where the NG battery cell is located can be accurately detected. The first detection unit installed in this way can quickly and accurately find the NG battery cells in the set of battery cells to be detected, realizing finding the NG battery cells in advance before helium detection, thereby reducing the number of NG battery cells among the battery cells waiting for detection in the initial inspection of the battery cells and the extraction inspection of the battery cells.

[0023] For ease of understanding, during the initial inspection of battery cells, a set of battery cells to be detected contains 20 battery cells, and during the initial inspection of battery cells, it is only possible to know that there is a defective battery cell among these 20 battery cells to be detected, and it is not possible to detect which specific one among the 20 is the defective battery cell. When it is detected that there is a defective battery cell among a set of battery cells to be detected during the initial inspection of battery cells, it means that all of these 20 battery cells need to be subjected to extraction inspection. If a specific defective battery cell can be detected in advance, at least the extraction inspection process for 20 battery cells can be omitted, significantly improving the production efficiency of the production line and at the same time significantly improving the load capacity of the defective rate of the entire production line. The leakage rate of the battery cells in step S2 is calculated by the same formula based on the pressure change amount ΔP, the volume V of the battery cells, and the detection time length t. That is, the calculation formula is as shown in (Equation 2).

Number

[0024] From the above calculation formula, when the volume V and detection time length t of the battery cell are fixed, the leakage rate Q of the battery cell is positively correlated with the pressure change amount ΔP. The larger the pressure change amount ΔP is, the larger the leakage rate Q of the battery cell becomes. However, when the leakage rate Q of the battery cell exceeds the first leakage rate, this battery cell is surely a NG cell, which means that it is necessary to convey it to the NG discharge line and perform subsequent production operations. After grouping the detection target battery cells with a leakage rate of the battery cell below the first leakage rate, when conveying and inputting them to the second detection unit, if the number of the grouped detection target battery cells is smaller than the number of chambers for the initial inspection of the battery cells in a single cycle of the second detection unit, wait for the completion of the initial inspection of the battery cells in the first detection unit of the next batch, take the normal battery cells from them to make up the quantity, and ensure the initial inspection efficiency of the battery cells in the second detection unit in the subsequent steps. In this embodiment, the first leakage rate is a standard value, but it is also calculated according to the calculation formula of the leakage rate of the battery cell during its calculation. When performing calibration calculation, if the pressure change amount ΔP is set to 200 Pa, the volume V of the battery cell is set to 20 ml, and the detection time length t is set to 30 s, the first leakage rate is 1.33E-4 Pa.m 3 / s.

[0025] In step S3, using the second detection unit, helium detection is performed on the detection target battery cells after initial inspection and grouping at the second leakage rate.

[0026] In step S4, if the leakage rate of the battery cell is greater than the second leakage rate, the entire group of the detection target battery cells is conveyed to the third detection unit. If the leakage rate of the battery cell is less than or equal to the second leakage rate, the entire group of the detection target battery cells is discharged.

[0027] Refer to FIGS. 2 to 4 together. Specifically, both step S3 and step S4 belong to the initial inspection steps of the battery cell. 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 the slide unit 3 are housed in the second chamber 1 and fixedly integrated with the second chamber 1. The slide unit 3 is slidably installed on the slide rail assembly 2 and driven by a cylinder. The first lower cavity 5 and the second lower cavity 6 are installed on the slide unit 3 and slide in the slide rail assembly 2 together with the slide unit 3, so as to slide relative to the upper cavity 4 or be 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, an exhaust valve group, a vacuum breaking valve, etc. Test chambers for accommodating the battery cells to be detected are respectively provided in the first lower cavity 5 and the second lower cavity 6. When either one of the first lower cavity 5 and the second lower cavity 6 inputs or discharges products, the upper cavity 4 can perform helium detection on the other of the first lower cavity 5 and the second lower cavity 6. Also, in this embodiment, the second leakage rate is a standard value, and it is also calculated by the calculation formula of the leakage rate of the battery cell during its calculation. However, since the helium detection in step S3 is to perform helium detection simultaneously in a multi-test chamber, when the second leakage rate in step S4 performs calibration calculation, some of its parameters, that is, the volume V of the battery cell and the pressure change amount ΔP, are both different from the parameters during the calibration calculation of the first leakage rate, and the two cannot be directly compared. 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 of the first detection unit is equal to the number of test chambers in the first lower cavity 5 and the number of test chambers in the second lower cavity 6. This is because the appearance of NG battery cells cannot be avoided during the initial inspection of the battery cells.In the aforementioned step S2, when the number of battery cells to be detected after grouping is smaller than the number of battery cells in a single cycle of the second detection unit, that is, smaller than the number of test chambers in the first lower cavity 5, it is necessary to take out the normal battery cells among them to supplement the quantity after the initial inspection of the next batch of battery cells. Therefore, in order to further improve the working efficiency of the production line and facilitate the supplementation of the insufficient battery cells to be detected, the number of test chambers of the first detection unit used for the initial inspection cannot be set to be smaller than the number of test chambers in the first lower cavity 5.

[0028] When performing the initial inspection of battery cells using the second detection unit in the present invention, first, the battery cells to be detected are put into the test chambers in the first lower cavity 5 and the second lower cavity 6. After filling the battery cells to be detected, the second lower cavity 6 is controlled to slide to the corresponding position of the upper cavity 4, and the upper cavity 4 is controlled to perform helium detection on the second lower cavity 6. When this operation is completed, the first lower cavity 5 is slid to the corresponding position of the upper cavity 4, the second lower cavity 6 is controlled to move away from the helium detection position, the upper cavity 4 is controlled to perform helium detection on the first lower cavity 5, and corresponding operations are executed on the battery cells to be detected therein based on the helium detection result of the second lower cavity 6, that is, the battery cells to be detected are conveyed to the third detection unit or discharged. Then, the battery cells to be detected are put into the second lower cavity 6 for supplementation. After all the battery cells to be detected in the second lower cavity 6 are replaced and supplemented, the helium detection operation of the first lower cavity 5 is also completed. Thereafter, the second lower cavity 6 is controlled to slide to the corresponding position of the upper cavity 4, and thus circulates back and forth. The second detection unit in the present invention realizes high-speed tact helium detection and product input / output through two cavities that can alternately perform product input / output and helium detection, shortens the waiting time of the mechanical operation during the initial inspection of battery cells, and effectively improves the efficiency of helium detection.

[0029] In step S5, helium detection is performed one by one on the battery cells to be detected at a third leakage rate using a third detection unit.

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

[0031] Specifically, steps S5 and S6 belong to the extraction inspection step of the battery cells. The third detection unit in step S5 is a helium detection device for extraction inspection. The third detection unit is installed in a third chamber, and a plurality of 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, the second chamber 1, and the third chamber are integrally installed in the helium detection assembly. A transport belt for transporting and loading / discharging products among the first chamber, the second chamber 1, and the third chamber is installed in the helium detection assembly. The helium detection assembly of the present invention conveniently and consistently installs three stations through the integrally installed first chamber, second chamber 1, and third chamber, which is quick and convenient during the loading / discharging of products and the transportation of the battery cells to be detected, and improves the overall production efficiency of the production line. The third leakage rate in step S6 is a calibration value, and it is also calculated by (Equation 2) during its calculation. In this embodiment, the number of test chambers of the third detection unit is equal to the number of test chambers of the first detection unit used in the initial inspection and is also equal to the number of test chambers of the first lower cavity 5. During the calibration calculation, 1.0E-06 Pa·m is used as the third leakage rate. 3Take / s. In the aforementioned step S4, some parameters in the second leakage rate, namely, the volume V of the battery cell and the pressure change amount ΔP, are both different from those during the calculation of the first leakage rate. However, the third leakage rate in step S6 has partial parameters during the calibration calculation, that is, the volume V of the battery cell and the pressure change amount ΔP are also different from some parameters in the second leakage rate (i.e., the volume V of the battery cell and the pressure change amount ΔP). Therefore, the second leakage rate cannot be directly compared with the third leakage rate. However, in this embodiment, since the volume V of the battery cell and the detection time length t in the first leakage rate are the same as the volume V of the battery cell and the detection time length t in the third leakage rate, the two can be compared. The leakage rate of the NG battery cells screened out during the initial inspection of the battery cells actually lies between the first leakage rate and the third leakage rate. When designing the scale of the production line of the battery cells, by adjusting the first leakage rate, the second leakage rate, and the third leakage rate, the scale of the initial inspection station, the initial inspection station, and the extraction inspection station of the production line of the cylindrical battery cells can be adjusted, and at the same time, the load capacity of the NG rate of the entire production line can be significantly improved.

[0032] As described above, the method for miniaturizing the high-speed helium detection device for cylindrical battery cells of the present invention adds an initial inspection step of the battery cells before the initial inspection of the battery cells and the extraction inspection of the battery cells, thereby screening out in advance the NG battery cells with a large leakage rate, further reducing the battery cells waiting for detection entering the initial inspection of the battery cells and the extraction inspection of the battery cells, and reducing the required equipment area of the extraction inspection station. The present invention also realizes high-speed tact helium detection and product input / output by means of two cavities that can alternately perform product input / output and helium detection, shortens the waiting time of the mechanical operation during the initial inspection of the battery cells, effectively improves the efficiency of helium detection, and further improves the overall working efficiency of the production line.

[0033] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician proficient in this technical field can easily conceive of changes or substitutions within the technical scope disclosed by the present invention, and all those obtained by these changes or substitutions should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope of the claims.

Claims

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

2. The leakage rate Q of the battery cell is calculated from the pressure change amount ΔP, the volume V of the battery cell, and the detection time length t, and the calculation formula is as shown in (Equation 3). [0030] 2. The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell according to claim 1.

3. 3. The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell according to claim 2, wherein the first leakage rate, the second leakage rate, and the third leakage rate are all calibrated values.

4. 4. The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell according to claim 3, wherein when the first leakage rate and the third leakage rate are calibrated, the volume V of the battery cell is equal to the detection time length t.

5. 5. The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell according to claim 4, wherein the first leakage rate is greater than the third leakage rate.

6. 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 test target battery cell, 2. The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell as described in claim 1, wherein the upper cavity (4) is used to perform helium detection for the other of the first lower cavity (5) and the second lower cavity (6) when either one of the first lower cavity (5) and the second lower cavity (6) is inputting or discharging a product.

7. 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), The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell as described in claim 6, characterized in that 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).

8. 7. The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell as claimed in claim 6, wherein 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).

9. The method for miniaturizing a rapid helium detection device for cylindrical battery cells as claimed in claim 6, 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).

10. the first detection unit is provided in the first chamber, and the third detection unit is provided in the third chamber; the first chamber, the second chamber (1) and the third chamber are integrally installed in a helium detection assembly; The method for miniaturizing a high-speed helium detection device for a cylindrical battery cell according to claim 7, characterized in that 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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