Method and system for battery case sealing inspection
By combining rough inspection and fine inspection in the sealing inspection of the battery case, the leakage point is located using the sensor device to solve the problem of insufficient fast and reliable inspection in the prior art, and efficient sealing inspection is achieved.
Patent Information
- Application Number
- CN202380051312.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-08-12
- Filing Date
- 2023-07-20
- Publication Date
- 2025-02-07
AI Technical Summary
The prior art is difficult to quickly and reliably check the sealing properties of the battery housing, especially in the case of different sealing materials, shapes and types.
By performing a rough inspection to measure the total gas leakage amount, fine inspection parameters are preset based on the results, and the leakage point is positioned in a predetermined area using a sensor device.
A fast and reliable battery housing sealing inspection is achieved, and the leakage point can be effectively located, suitable for different types of sealing materials and shapes.
Smart Images
Figure CN119404086A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method and a system for checking the sealing property of a battery casing. Background Art
[0002] When producing power batteries for motor vehicles, it is usually necessary to check the sealing of the corresponding battery housing, for example, to reliably prevent the outflow or inflow of the medium. Here, the sealing check is generally only carried out when the battery housing is already closed. In addition, the manufactured battery housing can have different sealing materials, sealing shapes and sealing types. These factors may lead to a certain inspection method not being suitable for all possible leakage types. In addition, it is ideal in principle to be able to perform such a sealing check very quickly and reliably at the same time. Summary of the invention
[0003] The object of the present invention is to realize a battery housing leak-tightness test which is as reliable and efficient as possible.
[0004] This object is achieved by the subject matter of the independent claim. Further possible embodiments of the invention are disclosed in the dependent claims, the description and the drawings.
[0005] In the method for checking the sealing of a battery housing according to the present invention, the following steps are performed: a rough check on the sealing of the battery housing is performed, and the total gas leakage is determined by measuring the total amount of gas that escapes from the battery housing; at least one parameter for a detailed check on the sealing of the battery housing is pre-set based on the rough check result to locate the leak on the battery housing; a detailed check is performed to locate at least one leak on the battery housing, and at least a predetermined area of the battery housing is checked with the help of a sensor device according to the at least one set parameter to check where the gas escapes from the battery housing in the area.
[0006] The battery housing can be, in particular, a battery housing for a traction battery of an electric vehicle. However, it can also be another type of battery housing. The rough check can also be understood as a rough tightness check. The rough check can be performed, for example, in the form of a pressure check, a pressure difference check or a mass flow check. Therefore, the total leakage is determined in the rough check. This means that it is necessary to check whether the battery housing is leaking and to what extent. This does not involve locating possible leaks in the battery housing. In the rough check, only how much gas has escaped from the battery housing in total is first determined. During the execution of the method, it can be particularly provided that the battery housing is sealed.
[0007] At least one parameter of the detailed inspection of the battery housing tightness is pre-set based on the results of the rough inspection to locate leaks on the battery housing. For example, standard values can be stored for the detailed inspection. If, for example, no obvious leak is detected during the rough inspection, it can also be provided during the method that the standard value can be directly kept unchanged. If, however, an obvious leak is detected within the scope of the rough inspection, it can be provided that the standard value or at least one standard value or parameter for the detailed inspection is adjusted based on the rough inspection. For example, it can be provided that from about 10 -5 mbar l / s or more is considered as a significant leak. However, other set values may also be specified, and a significant leak is considered when the set value is exceeded, for example, 10 -2 or 10 -3 mbar l / s.
[0008] The detailed inspection is performed after the rough inspection to locate at least one leak on the battery housing. In the detailed inspection, at least at a predetermined area of the battery housing, a sensor device (also referred to as a sniffer probe) is used to detect where in the area the gas escapes from the battery housing, especially a closed battery housing, according to at least one predetermined parameter. The detailed inspection is therefore intended to accurately locate the point of leak, i.e. the leak point. By presetting at least one detailed inspection parameter based on the rough inspection result, the detailed inspection can be performed particularly efficiently on the one hand and very reliably on the other hand. The present invention is based in particular on the recognition that for the detailed inspection it is necessary to distinguish whether a larger or smaller total leakage has been detected during the rough inspection. Therefore, in the present invention, the detailed inspection is parameterized so that the detection can be performed particularly quickly on the one hand and always very reliably on the other hand based on the total leakage determined during the rough inspection.
[0009] The leak (if any) is therefore located during the detailed inspection. Leaks can also be referred to as leak points, which are, for example, in the form of leaks, openings, gaps, holes, etc., through which, for example, air or other media can enter the battery housing or flow out of the battery housing. For the detailed inspection, as described above, at least one area is predefined, and the area is detected using a sensor device, in particular with the aid of a sniffer probe. The area can, for example, include welds, joints, bolted connections or other connection points, where leaks may occur. The method of the present invention therefore provides for a combination of rough inspection and detailed inspection to check the tightness of the battery housing. By coordinating the detailed inspection with the rough inspection results or by performing appropriate parameter settings, the battery housing tightness inspection can be performed both reliably and quickly.
[0010] A possible design of the present invention provides that the greater the total leakage determined, the greater the movement speed of the sensor device along the area to be inspected during the detailed inspection of the battery housing. Correspondingly, it can also be provided that the smaller the total leakage determined during the rough inspection, the smaller the movement speed of the sensor device along the area to be inspected during the detailed inspection of the battery housing. Therefore, if, for example, a significant leak is detected, the movement speed of the sniffer probe can be significantly increased for the detailed inspection, which can also be called a sniffing test, to locate the significant leak. Here, the present invention is based on the following recognition: Since a significant leak causes enough gas to escape from the battery housing, it can be detected even when the movement speed of the sniffer probe or the sensor device is relatively high. As a result, a possible significant leak can be located particularly quickly, so that less gas needs to be added to the battery housing, and the gas previously discharged from the battery housing may also be less, so that the degree of gas contamination of the measurement environment is greatly reduced.
[0011] Another possible design of the present invention provides that the greater the total leakage determined, the greater the distance between the sensor device and the area to be inspected of the battery housing during the detailed inspection is set. Correspondingly, it can also be provided that the smaller the total leakage determined during the rough inspection, the smaller the distance between the sensor device and the area to be inspected of the battery housing during the detailed inspection is set. If the distance between the sensor device (especially in the form of the sniffer probe) and the area to be inspected of the battery housing is selected to be larger, it is possible to prevent or relatively reliably prevent the sensor device from colliding with the battery housing during the detailed inspection. The battery housing can have various shapes, protrusions, etc. in the area to be inspected, and these features may make it difficult for the sensor device to inspect the battery housing without collision. Here, the present invention is based on the following understanding: For example, in the case of a large total leakage, it can be assumed that even if the distance between the sensor device and the area to be inspected of the battery housing during the detailed inspection is large, the leak can still be reliably located. The distance of the sensor device is therefore adjusted according to the total leakage determined during the rough inspection.
[0012] Another possible embodiment of the invention provides that the gas comprises a test gas, for example in the form of helium, a nitrogen-hydrogen mixture, or a refrigerant, wherein the sensor device is designed to detect the test gas. The sensor device can, for example, comprise a gas detector, a mass spectrometer, etc. The test gas can be detected very reliably during the detailed inspection, so that any leaks, i.e., leaks, can be identified very reliably during the detailed inspection.
[0013] Another possible embodiment of the invention provides for using 5% to 20% of the test gas with respect to the total volume of the battery housing. Thus, a relatively low test gas concentration is used, but due to the implementation of the method, this concentration is still sufficient to reliably determine any leaks, i.e. leaks, on the battery housing during a close inspection.
[0014] Another possible embodiment of the invention provides that the gas is temperature-controlled relative to the environment, wherein the sensor device comprises a temperature sensor. For example, the gas can be cooled or heated before being used for a leak test in a rough test and a subsequent fine test. Since the gas is temperature-controlled relative to the environment (i.e. the test environment in which the battery housing is arranged) and this is done before the actual rough test and fine test are carried out, the temperature-controlled gas can be detected very reliably, so that any leaks can be detected during the fine test.
[0015] In another possible embodiment of the invention, it is provided that the greater the total volume of the battery housing, the greater the temperature difference between the gas and the environment is selected. The invention is based on the recognition that the temperature difference required for a reliable leak test is related to the size of the volume to be tested. In particular, the temperature of the tempered gas should not be allowed to converge too quickly with the ambient temperature, so that the tempered gas can be easily tracked during a detailed test and thus leaks can be located.
[0016] Another possible embodiment of the invention provides that the greater the test pressure exerted by the pressurized gas on the battery housing, the smaller the temperature difference between the gas and the environment is selected. In this regard, the invention is based on the recognition that the gas cooling effect caused by the pressure relief is pressure-dependent. By adjusting the temperature difference between the gas and the environment as a function of the test pressure, it can be ensured that, in particular during a close inspection, the temperature difference between the gas and the environment remains sufficiently large to allow any leaks on the battery housing to be determined very reliably.
[0017] Another possible embodiment of the invention provides that the battery housing is not evacuated before the rough test. This can be achieved in that the gas contains the test gas and / or the gas is appropriately temperature-controlled relative to the environment. Since the evacuation before the rough test is omitted, a step that may be required during the tightness test of the battery housing is avoided. As a result, the method can be carried out particularly simply and with less effort.
[0018] The system for checking the tightness of a battery housing according to the invention is designed to carry out the method according to the invention or a possible embodiment of the method according to the invention. The system comprises in particular a device designed to carry out the method. In particular, the system can have a detection device for carrying out a rough inspection, the sensor device for carrying out a fine inspection, and a control device set up to pre-set at least one fine inspection parameter depending on the result of the rough inspection.
[0019] Further advantages, features and details of the invention can be obtained from the following description of possible embodiments in conjunction with the accompanying drawings. The features and feature combinations mentioned above in the specification and the features and feature combinations shown separately in the following description of the drawings and / or in the drawings can be used not only in the combination indicated in each case, but also in other combinations or alone without exceeding the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The attached drawings are shown in the single figure ( Figure 1 ) shows a schematic illustration of a battery housing to be tested for leak tightness. DETAILED DESCRIPTION
[0021] Figure 1 A battery housing 10 is shown very schematically. The battery housing 10 can be, for example, the housing of a traction battery of an electric vehicle. However, the battery housing 10 can also be any other battery housing. Also shown schematically is a system 12 designed for checking the tightness of the battery housing 10. The system 12 comprises a detection device 14 for performing a rough check, a sensor device 16 for performing a fine check (which can be a sniffer probe or include such a sniffer probe), and a control device 18 which is set up for presetting or changing at least one fine check parameter as a function of the rough check result. The method for checking the tightness of the battery housing 10 will be explained in detail below.
[0022] First, the sealing of the battery housing 10 is roughly checked by means of the detection device 14. Here, the total leakage of gas introduced into the battery housing 10 is determined in the following manner, that is, how much gas escapes from the closed battery housing 10, for example, and leaks out to the outside. Based on the rough inspection result, the control device 18 pre-sets at least one parameter for the detailed inspection of the sealing of the battery housing 10, which is used to locate the possible leakage (i.e., leakage) on the battery housing 10. Then, a detailed inspection is performed with the help of the sensor device 16. The purpose of the detailed inspection is to locate at least one leakage on the battery housing 10, i.e., the leakage point. During the detailed inspection, the sensor device 16 (which can be a sniffer probe, for example) moves along the area 20 to be inspected where the leakage (i.e., leakage point) may exist according to at least one parameter previously set. The leakage can generally refer to leakage, opening, seam, hole, etc., through which air can enter the battery housing 10 or flow out of it. The area 20 to be inspected during the detailed inspection can, for example, have weld seams, joints, bolt connection points or other connection points. In particular, these locations may be particularly prone to leakage.
[0023] For example, the greater the total leakage determined during the rough inspection, the greater the movement speed v of the sensor device 16 along the area 20 to be inspected during the detailed inspection of the battery housing 10. Conversely, the smaller the total leakage determined, the smaller the movement speed v can be set.
[0024] It can also be provided that the greater the total leakage determined, the greater the distance h between the sensor device 16 and the region 20 to be inspected during the detailed inspection is set, and vice versa.
[0025] The gas used can be, for example, a test gas, a nitrogen-hydrogen mixture, a refrigerant, etc. In this case, the sensor device 16 is designed to detect the test gas. For this purpose, the sensor device 16 can have, for example, a gas detector, a mass spectrometer, etc. With respect to the total volume of the battery housing 10, it can be provided that the test gas concentration is in the range of 5% to 20%.
[0026] The gas used can also be, for example, ambient air, which is temperature-controlled relative to the environment, wherein the sensor device 16 in this case has a temperature sensor. In this case, the gas, which can be, in particular, ambient air, can be cooled or heated accordingly before the rough test, for example, so that the temperature difference is large enough so that the sensor device 16 can also reliably detect the temperature-controlled air escaping from the area 20 of the battery housing 10 during the detailed test, for example, in order to locate any leaks.
[0027] It can be provided that the temperature difference between the gas used (for example in the form of ambient air) and the environment is selected to be greater, the greater the total volume of the battery housing 10. This ensures that even in the case of a large volume of the battery housing 10, for example, the temperature-conditioned gas can still maintain a sufficiently large temperature difference for a sufficiently long time, so that during a detailed inspection, the gas used can be reliably detected based on the temperature difference, and any leaks in the battery housing 10 can be determined and localized.
[0028] It can also be provided that the temperature difference between the gas and the environment is selected to be smaller the greater the test pressure exerted by the pressurized gas on the battery housing 10. This makes it possible to ensure, depending on the pressure, that the temperature difference of the gas is still sufficient to reliably detect the gas even during the detailed inspection, so that any leaks in the area 20 of the battery housing 10 can also be reliably detected by means of the sensor device 16.
[0029] In addition, it can also be provided that the battery housing 10 is not evacuated before the rough inspection. This can be achieved by using a gas containing a test gas and / or by temperature control of the gas, so that the battery housing 10 does not need to be evacuated before the rough inspection.
[0030] Overall, the method or system 12 allows a particularly reliable and rapid test of the tightness of the battery housing 10 .
[0031] Reference numerals list 10Battery housing 12 Systems 14 Detection device 16 sensor devices 18 Control Devices 20 Areas h distance vMovement Speed
Claims
1. A method for checking the sealing property of a battery housing (10), comprising the following steps: - a rough check of the tightness of the battery housing (10), wherein the total leakage of gas is determined by measuring the total amount of gas escaping from the battery housing (10); - based on the rough inspection result, presetting at least one parameter for detailed inspection of the sealing of the battery housing (10) to locate the leakage on the battery housing (10); - performing the scrutiny to locate at least one leak on the battery housing (10), during which the scrutiny is checked at least in a predetermined area (20) of the battery housing (10) by means of a sensor device (16) (sniffer probe), according to the at least one set parameter, where in the area (20) the gas escapes from the battery housing (10).
2. The method according to claim 1, characterized in that The greater the total leakage determined, the higher the speed (v) of movement of the sensor device (16) along the region (20) of the battery housing (10) to be inspected during the scrutiny is set.
3. The method according to claim 1 or 2, characterized in that: The greater the total leakage determined, the greater the distance (h) between the sensor device (16) and the region (20) of the battery housing (10) to be detected during the scrutiny is set.
4. The method according to one of the preceding claims, characterized in that The gas comprises a test gas, and the sensor device (16) is designed to detect the test gas.
5. The method according to claim 4, characterized in that A test gas is used at 5% to 20% of the total volume of the battery housing (10).
6. The method according to one of the preceding claims, characterized in that The gas is temperature-controlled relative to the environment, wherein the sensor device (16) comprises a temperature sensor.
7. The method according to claim 6, characterized in that The greater the total volume of the battery housing (10), the greater the temperature difference between the gas and the environment is selected to be.
8. The method according to claim 6 or 7, characterized in that: The greater the detection pressure applied by the pressurized gas to the battery housing (10), the smaller the temperature difference between the gas and the environment is selected.
9. The method according to one of claims 4 to 8, characterized in that The battery housing (10) is not evacuated before the rough inspection.
10. A system (12) for checking the leak tightness of a battery housing (10), designed to carry out the method according to any of the preceding claims.