Backpressure helium detection method and device

Abstract

The invention relates to the field of lithium battery manufacturing, and particularly discloses a backpressure helium detection method and device, and the method comprises the steps: controlling a gas nozzle to be attached to a sealing nail region of a to-be-detected battery, so as to form a sealed space; the sealing nail area is filled with helium through an air tap, so that the helium enters a cavity area between the sealing aluminum nail and the sealing rubber nail through micropores such as a welding seam pinhole and a sand hole; and the helium detection nozzle is controlled to carry out airtightness detection on the sealing nail area filled with the helium, that is, whether helium residues exist in the cavity area or not is detected to judge the airtightness condition of the battery, and then an airtightness detection result is obtained. According to the invention, the helium is directly filled into the sealing nail area through the air tap, then the airtightness detection is carried out by detecting whether the helium residue exists in the cavity area of the sealing nail, the detection operation is simple, and the detection efficiency and accuracy of the airtightness of the battery are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium battery manufacturing, and in particular relates to a back pressure helium detection method and device. Background Art

[0002] Lithium-ion batteries are gradually becoming an indispensable part of modern life due to their high capacity, long life and environmental protection. Whether used in large-scale energy storage systems, driving electric vehicles, or providing power for portable electronic products, lithium-ion batteries have demonstrated their unique advantages. Common lithium batteries are of various types, including blade batteries, square shell batteries, and cylindrical batteries. After the battery sealing nails are welded, the air tightness of the weld must be strictly tested to ensure its stable performance and safety and reliability.

[0003] The existing detection method is to first inject helium and insert glue nails into the sealing nail area of ​​the battery to be tested, then place the battery in a sealed cavity, evacuate the cavity, and after the vacuum value reaches the rated value, open the helium detection valve, connect the helium detector to the vacuum cavity, and determine whether the battery is leaking by detecting the helium concentration in the cavity. However, this detection method simply evaluates the air tightness of the battery by the residual amount of gas, and its detection results are not accurate when the gas is completely leaked; and, by combining the battery and the vacuum cavity to detect the air tightness of the battery, it is impossible to directly perform point-to-point air tightness detection on the battery body, which leads to insufficient accuracy of its air tightness detection results. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the present invention provides a back-pressure helium detection method and device.

[0005] In a first aspect, a back pressure helium detection method is provided, the back pressure helium detection method is applied to a back pressure helium detection device, the back pressure helium detection device is provided with a detection module, the detection module includes a helium detection nozzle for detecting air tightness of a sealing nail area of ​​a battery to be tested and a gas nozzle for filling and discharging gas; The back pressure helium detection method comprises: Controlling the air nozzle to fit the sealing pin area of ​​the battery to be tested to form a closed space; Filling the sealing nail area with helium through the gas nozzle to obtain a helium-filled sealing nail area; Purging the surface of the helium-filled sealing nail area to remove surface helium; The helium detection nozzle is controlled to perform airtightness detection on the helium-filled sealing nail area to obtain an airtightness detection result.

[0006] In some embodiments, before the helium is filled into the sealing nail area through the gas nozzle, the method further comprises: Filling nitrogen into the sealing nail area through the gas nozzle, and maintaining the pressure of the sealing nail area filled with nitrogen for a first time period; Obtaining a pressure drop value of the sealing pin area within a first time period, and comparing the pressure drop value with a first preset value; If the voltage drop value is greater than the first preset value, the battery to be tested is discharged; If the pressure drop value is less than or equal to the first preset value, the gas nozzle is controlled to fill the sealing nail area with helium.

[0007] In some embodiments, controlling the gas nozzle to fill the sealing nail area with helium includes: Performing a first vacuum on the sealing nail area filled with nitrogen through the gas nozzle to obtain a first vacuum sealing nail area; Helium is filled into the first vacuum sealing nail area through the gas nozzle so that the helium enters the cavity of the sealing nail area to obtain a helium-filled sealing nail area; the helium-filled sealing nail area is evacuated for a second time to obtain a second vacuum sealing nail area; the second vacuum sealing nail area is broken by vacuum to obtain a normal pressure sealing nail area.

[0008] In some embodiments, the detection module includes an air knife, and the step of blowing the surface of the helium-filled sealing nail area to remove the surface helium includes: The wind knife is controlled to purge nitrogen on the surface of the normal pressure sealing nail area to remove helium on the surface of the normal pressure sealing nail area.

[0009] In some embodiments, controlling the helium detection nozzle to perform airtightness detection on the helium-filled sealing nail area to obtain the airtightness detection result includes: Controlling the helium detection nozzle to fit the sealing pin area filled with helium to form a closed space; The air tightness test is performed on the sealing pin area through the helium test nozzle to obtain the air tightness test result.

[0010] In some embodiments, target values ​​of the first vacuuming and the second vacuuming are -50 KPa to -150 KPa.

[0011] In some embodiments, the first preset value ranges from 10-20 KPa.

[0012] In a second aspect, a back pressure helium detection device is provided, the device is used to perform the back pressure helium detection method described in any one of the above technical solutions, the device comprises a detection platform and a detection module, one side of the detection platform is provided with a detection part for placing a battery to be tested, and the detection module is provided on a side facing the detection part; The detection module includes a gas nozzle and a helium detection nozzle, and the gas nozzle and the helium detection nozzle are arranged at an interval. The gas nozzle is used to flexibly seal and close the sealing nail area of ​​the battery to be tested, and to fill or extract gas into the sealing nail area of ​​the battery to be tested. The helium detection nozzle is used to flexibly seal the sealing nail area of ​​the battery to be tested and detect air tightness.

[0013] In some embodiments, a solenoid valve control component is also included, wherein the gas nozzle is connected to a helium cylinder, a vacuum pump, and a nitrogen cylinder through a pipeline, and the solenoid valve control component is arranged on the pipeline to control the passage of the pipeline between the gas nozzle and the helium cylinder, the vacuum pump, and the nitrogen cylinder.

[0014] In some embodiments, it further comprises a feeding assembly and a discharging assembly, wherein the feeding assembly and the discharging assembly are respectively arranged on one side of the detection platform; The feeding assembly comprises a first moving module, a moving end of the first moving module is connected to a first transport member, and the battery to be tested is moved to the detection part through the first transport member; The discharge assembly comprises a second moving module, a moving end of the second moving module is transmission-connected with a second transport member, and the battery to be tested on the detection part is discharged through the second transport member.

[0015] In summary, the present invention has the following benefits: The present invention controls the gas nozzle to fit with the sealing nail area of ​​the battery to be tested to form a closed space; then, helium is filled into the sealing nail area through the gas nozzle, so that the helium enters the cavity area between the sealing aluminum nail and the sealing glue nail through micropores such as weld pinholes and sand holes; then the helium detection nozzle is controlled to perform airtightness detection on the sealing nail area after the helium is filled, that is, whether there is helium residual in the cavity area is detected to judge the airtightness of the battery, and accurate detection of the airtightness of the battery is achieved. In addition, the detection method is to directly control the helium detection nozzle to perform airtightness detection on the sealing nail area after the helium is filled, which is different from the prior art method of first placing the battery into the cavity and then performing airtightness detection in the form of a combination of the cavity and the battery, and effectively improves the accuracy of the battery airtightness detection result. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view of the sealing pin area in an embodiment of the present application.

[0017] Figure 2 It is a flow chart of the back pressure helium detection method in the embodiment of the present application.

[0018] Figure 3 It is a structural schematic diagram of the back pressure helium detection device in the embodiment of the present application.

[0019] Figure 4It is a front view of the back pressure helium detection device in the embodiment of the present application.

[0020] Figure 5 It is a schematic diagram of the structure of the gas nozzle in the embodiment of the present application.

[0021] Figure 6 It is a top view of the feed assembly and the discharge assembly in the embodiment of the present application.

[0022] Markings in the figure: 1. Testing table; 110. Testing department; 2. Detection module; 211. Helium detection nozzle; 221. Air nozzle; 222. Air pressure gauge; 230. Solenoid valve control assembly; 3. Feeding assembly; 310. First moving module; 320. First transporting member; 4. Discharging assembly; 410. Second moving module; 420. Second transporting member; 10. Cover plate; 20. Sealing aluminum nails; 30. Sealing glue nails; 40. Cavity area. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only partial embodiments of the present invention, not all embodiments.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1 Please see attached Figure 1-3, this embodiment provides a back pressure helium detection method, which is applied to a back pressure helium detection device. Usually, the battery to be tested needs to be injected through the battery injection hole, and the battery injection hole is welded and sealed by the battery sealing nail. The air tightness of the welding seal directly affects the reliability of the battery. Therefore, it is necessary to detect the air tightness of the weld after the battery sealing nail is welded by the back pressure helium detection method, and judge whether the air tightness of the battery is good by judging the air tightness of the weld. Among them, the battery to be tested can be a common battery such as a blade battery, a square shell battery, and a cylindrical battery. The battery injection hole includes an outer injection hole arranged on the surface of the cover plate and an inner injection hole opposite to the outer injection hole and arranged inside the battery. When the battery to be tested is sealed, the inner injection hole is first sealed with a sealing glue nail 30, and then the outer injection hole of the battery is sealed with a sealing aluminum nail 20. The injection hole on the surface of the cover plate is sealed by the sealing aluminum nail 20, wherein a cavity area 40 is formed between the sealing aluminum nail 20 and the sealing glue nail 30. The sealing nail area in this embodiment refers to the welding seam area formed between the sealing nail and the battery cover 10 and the sealing aluminum nail 20. The detection module includes a gas nozzle for charging and discharging gas into the battery to be tested. The gas nozzle can be a rubber head or other structure that can form a relatively sealed environment with the sealing nail area. After the gas nozzle is attached to the sealing nail area, it can realize operations such as filling or vacuuming the inside.

[0026] Back pressure helium inspection methods include: S110, first controlling the air nozzle to fit the sealing pin area of ​​the battery to be tested, so that the air nozzle and the sealing pin area form a closed space.

[0027] The air nozzle is controlled to fit directly with the sealing nail area, and the air nozzle can be moved to the sealing nail area by controlling the driving mechanism. The driving mechanism can be directly or indirectly driven by a cylinder, a motor, etc., so that the air nozzle can fit the sealing nail area and form a closed space with it as a whole.

[0028] The purpose of forming a closed space is to facilitate the formation of a vacuum environment between the single gas nozzle and the sealing pin area, and to prevent gas leakage or external gas from entering during gas filling or testing, thereby affecting the testing process. S120, filling the sealing nail area with helium through the gas nozzle to obtain a helium-filled sealing nail area.

[0029] After the air nozzle is controlled to fit the sealing nail area of ​​the battery to be tested to form a closed space, helium is filled into the sealing nail area through the air nozzle to obtain a helium-filled sealing nail area; wherein, helium is filled into the sealing nail area so that helium enters into the cavity area between the sealing aluminum nail and the sealing glue nail through micropores such as weld pinholes and sand holes. In the subsequent airtightness test, the airtightness of the battery will be judged by detecting the helium situation in the cavity area.

[0030] S130, purging the surface of the helium-filled sealing nail area to remove surface helium.

[0031] In order to ensure that the test results of the battery body are not interfered by the residual helium on the surface during the point-to-point airtightness test, thereby affecting the test results of the battery, the residual helium on the surface of the battery needs to be purged before the test, that is, the wind knife of the detection module is controlled to blow nitrogen on the surface of the helium-filled sealing nail area, thereby removing the residual gas on the surface of the helium-filled sealing nail area to ensure the cleanliness of the surface of the helium-filled sealing nail area.

[0032] S140, controlling the helium detection nozzle to perform airtightness detection on the helium-filled sealing nail area to obtain an airtightness detection result.

[0033] After the cavity of the sealing nail area is filled with helium and the helium on the surface of the sealing nail area is removed, the helium detection nozzle is controlled to fit the sealing nail area filled with helium to form a closed space; then, the sealing nail area is tested for air tightness by the helium detection nozzle, that is, whether there is helium residue in the cavity of the sealing nail area is detected to judge the air tightness of the battery, so as to achieve accurate detection of the air tightness of the battery; and, this detection method is to directly control the helium detection nozzle to perform air tightness detection on the sealing nail area after being filled with helium, which is different from the prior art method of first placing the battery into the cavity and then performing air tightness detection in the form of a combination of the cavity and the battery, and effectively improves the accuracy of the battery air tightness detection result.

[0034] In this embodiment, the air nozzle is controlled to fit with the sealing nail area of ​​the battery to be tested to form a closed space; then, helium is filled into the sealing nail area through the air nozzle, so that the helium enters the cavity area between the sealing aluminum nail and the sealing glue nail through micropores such as weld pinholes and sand holes; then the helium detection nozzle is controlled to perform an airtightness test on the sealing nail area after the helium is filled, that is, to detect whether there is helium residual in the cavity area and then judge the airtightness of the battery, thereby realizing accurate detection of the airtightness of the battery. Moreover, this detection method is to directly control the helium detection nozzle to perform an airtightness test on the sealing nail area after the helium is filled, which is different from the prior art method of first placing the battery into the cavity and then performing an airtightness test in the form of a combination of the cavity and the battery, and effectively improves the accuracy of the battery airtightness test result.

[0035] In some embodiments, before the helium is filled into the sealing nail area through the gas nozzle, the method further comprises: S121, filling the sealing nail area with nitrogen through the air nozzle, and maintaining the pressure of the sealing nail area filled with nitrogen for a first time period.

[0036] In the process of filling the sealing nail area with nitrogen, the air nozzle can be controlled by a manual or electromagnetic valve or other driving device to fill the sealing nail area with nitrogen. The time for filling nitrogen is 2-5 seconds, preferably 2-3 seconds. After 2-3 seconds, the nitrogen filling is stopped, and the sealing nail area filled with nitrogen is kept under pressure for a first time. Specifically, the first time is a preset time value, which can be 2-7 seconds, preferably 2-4 seconds. Of course, the specific time value can be determined according to actual needs.

[0037] In some cases, when nitrogen is filled into the sealing nail area through the gas nozzle, the gas nozzle can be first connected to an external nitrogen bottle or nitrogen pipeline, and an air pump can be used to fill the nitrogen into the sealing nail area, or a nitrogen bottle with a certain internal pressure can be used to fill nitrogen through the gas nozzle. The specific nitrogen filling method can be determined according to actual conditions.

[0038] S122, obtaining a pressure drop value of the sealing pin area within a first time period, and comparing the pressure drop value with a first preset value.

[0039] During the pressure maintenance process, the pressure drop value of the sealing nail area is recorded. The pressure drop value is the difference between the pressure value detected when the sealing nail area is just filled with nitrogen through the air nozzle and the pressure value detected after the first period of time. This process can be observed manually using instruments such as a barometer, or the pressure drop value can be automatically recorded and judged by the instrument. The obtained pressure drop value is compared with the first preset value, and it is determined whether to perform the helium detection process on the battery to be tested based on the size of the pressure drop value.

[0040] Exemplarily, the range of the first preset value is 10-20Kpa, preferably 15-17Kpa. Selecting this data as the first preset value can accurately determine whether there is a large leak in the airtightness, so as to prevent useless helium inspection processes for batteries with poor airtightness, thereby saving time for helium inspection of the battery. Of course, the first preset value can be determined according to actual conditions, for example, different values ​​are set for the airtightness requirements of different sealing nail areas, and the present invention does not limit the specific value of the first preset value.

[0041] S123: If the voltage drop value is greater than the first preset value, the battery to be tested is discharged.

[0042] When the pressure drop value is greater than the first preset value, it means that the airtightness of the sealing nail area of ​​the battery to be tested is poor. If you insist on completing the subsequent testing steps, it will not only waste testing time but also waste testing resources. Therefore, when it has been preliminarily proved that the airtightness of the sealing nail area of ​​the battery to be tested is poor, the battery to be tested with poor airtightness is directly discharged, thereby saving time for helium testing of the battery and improving detection efficiency.

[0043] In some embodiments, the discharging method can be implemented by using a conventional discharging mechanism, which is not limited in this application.

[0044] S124, if the pressure drop value is less than or equal to the first preset value, control the gas nozzle to fill the sealing pin area with helium.

[0045] When the pressure drop value is less than or equal to the first preset value, it indicates that the air tightness of the sealing nail area of ​​the battery to be tested is initially good, and further helium testing can be performed on the air tightness to further ensure the accuracy of the test.

[0046] In some embodiments, the gas nozzle for filling helium is the same as the gas nozzle for filling nitrogen; that is, the gas nozzle can be connected to the nitrogen bottle and the helium bottle at the same time, and an electromagnetic valve is provided between the gas nozzle and the nitrogen bottle and the helium bottle. After the large leak detection operation of filling the sealing nail area with nitrogen and maintaining the pressure for the first time is completed, the connection between the gas nozzle and the nitrogen bottle can be closed by controlling the electromagnetic valve, and the sealing nail area can be filled with helium after the connection between the gas nozzle and the helium bottle is opened, so that the switching between nitrogen filling and helium filling can be completed through the same gas nozzle.

[0047] The process of controlling the air nozzle to fill the sealing pin area with helium includes: S210, performing a first vacuuming on the sealing nail area filled with nitrogen through a gas nozzle to obtain a first vacuum sealing nail area; S220, filling helium into the first vacuum sealing nail region through a gas nozzle so that the helium enters the cavity of the sealing nail region to obtain a helium-filled sealing nail region; S230, evacuating the sealing nail area for the second time to obtain a second vacuum sealing nail area; S240, breaking the vacuum in the second vacuum sealing nail region to obtain a normal pressure sealing nail region.

[0048] Specifically, the sealing nail area filled with nitrogen is evacuated for the first time to obtain a first vacuum sealing nail area. At this time, the air nozzle can be connected to an external vacuum pump or other equipment to control the vacuum pump and use the air nozzle to evacuate the sealing nail area so that its internal pressure reaches the first target value, which can be -50Kpa to -150Kpa, preferably -95Kpa; the sealing nail area is evacuated to generate a large pressure difference inside and outside the sealing nail area, which is conducive to the subsequent helium filling of the battery. When the helium enters the cavity area of ​​the sealing nail area more easily. It can be understood that the specific value of the first target value can be determined according to actual conditions.

[0049] When the internal pressure between the air nozzle and the sealing nail area reaches the first target value, turn off the vacuum pump to end the vacuuming operation, and fill the sealing nail area with helium through the air nozzle. The time for filling helium is 50-80 seconds, preferably 55, 60 or 65 seconds, so that the helium can smoothly enter the cavity area, and maintain the pressure at 300-400Kpa, so that the helium enters the cavity area in the sealing nail area to obtain a helium-filled sealing nail area. After the helium filling time is up, the sealing nail area is vacuumed for the second time to obtain a second vacuum sealing nail area. The second vacuuming is performed until the pressure reaches the second target value, which can be -50Kpa to -150Kpa. Preferably, the first target value and the second target value are consistent, for example, -95Kpa. Of course, the first target value and the second target value may also be different, which can be determined according to actual conditions.

[0050] The second vacuuming can remove the helium on the surface of the sealing nail area and the residual helium in the trachea, preventing the external helium from affecting the test results during the test. Subsequently, the second vacuum sealing nail area is de-vacuumed until the air pressure returns to normal pressure, obtaining a normal pressure sealing nail area, and the air nozzle can be removed later.

[0051] It can be understood that the first vacuum sealing nail area, the helium sealing nail area, the second vacuum sealing nail area and the normal pressure sealing nail area are the names of the same sealing nail area at different stages. The gas nozzle can be the same gas nozzle, so that one gas nozzle can complete the operations of nitrogen filling, helium filling and vacuuming at the same time, which not only improves the test efficiency and reduces the complexity of the equipment, but also reduces the movement of the battery to be tested, and improves the accuracy of the subsequent helium inspection process.

[0052] In some embodiments, the detection module includes an air knife, and after obtaining the normal pressure sealing nail area, it also includes controlling the air knife to blow nitrogen on the surface of the normal pressure sealing nail area. By blowing nitrogen on the surface of the normal pressure sealing nail area, the helium on the surface of the normal pressure sealing nail area can be removed, thereby avoiding the helium on the surface of the normal pressure sealing nail area affecting the helium detection results and improving the accuracy of the detection.

[0053] In some embodiments, controlling the helium detection nozzle to perform airtightness detection on the helium-filled sealing nail area to obtain airtightness detection results includes: controlling the helium detection nozzle to fit the sealing nail area after helium is filled and purged to form a closed space; performing airtightness detection on the sealing nail area through the helium detection nozzle to obtain airtightness detection results. The helium atomic leakage rate of the sealing nail area is determined by connecting the helium detection nozzle to a helium detector, thereby determining the airtightness of the sealing nail area.

[0054] Among them, the helium detector is connected to the sealing pin area through the helium detection nozzle, and the detection time is 2-6 seconds, which is compared with the second preset value. The second preset value is the helium atomic leakage rate value set according to the airtightness requirements of the product. Exemplarily, the second preset value is 9.9E-07 Pa*m3 / s. The helium atomic leakage rate detected by the helium detector is less than or equal to this value for qualified products. It can be understood that different processes have different requirements for airtightness, which may cause the second preset value to be different, and it is set specifically according to the process requirements.

[0055] Illustratively, the airtightness detection principle of this embodiment is that high-pressure helium is filled into the battery sealing nail area through a gas nozzle, and the helium enters the cavity area between the sealing aluminum nail and the sealing glue nail through micropores such as weld pinholes and sand holes. The helium on the surface of the sealing aluminum nail is removed by vacuuming, nitrogen blowing, etc. After the helium detection nozzle presses the sealing nail area, it is connected to the leak detector to determine the airtightness of the battery by detecting whether there is any helium residual in the cavity area.

[0056] In some embodiments, the gas nozzle for filling helium is the same as the gas nozzle for filling nitrogen. Using the same gas nozzle can reduce maintenance and usage costs and reduce the complexity of equipment use. The helium detection nozzle does not participate in the filling and deflation process, which prevents other gases from remaining in the air pipe during the helium detection nozzle detection and affecting the detection effect, thereby improving the accuracy of the detection.

[0057] Example 2 This embodiment provides a back pressure helium detection device, such as Figure 4-6 As shown, the detection module 2 includes a gas nozzle 221 and a helium detection nozzle 211, and the gas nozzle 221 and the helium detection nozzle 211 are arranged at an interval from each other. The gas nozzle 221 is used to movably seal and close the sealing nail area of ​​the battery to be tested, and to fill and discharge gas into the sealing nail area of ​​the battery to be tested, and the helium detection nozzle 211 is used to movably seal the sealing nail area of ​​the battery to be tested and perform airtightness detection.

[0058] Among them, the detection part 110 is arranged at the end of the detection platform 1. The detection part 110 can be a groove at the end of the detection platform 1, and the groove is adapted to the battery to be tested; or the battery to be tested can be fixed by setting a limit block at the end of the detection platform 1, and the specific design method is not specifically limited in this embodiment. Among them, the detection module 2 is arranged opposite to the detection part 110, and the detection module 2 is used to perform airtightness detection on the battery. For the convenience of explanation, a rack is introduced, the detection platform 1 is arranged at the bottom of the rack, and the detection module 2 is arranged at the top of the rack.

[0059] The gas nozzle 221 can be connected to external gas charging and discharging equipment through a pipeline, such as a vacuum pump, a helium cylinder, a nitrogen cylinder, etc., to realize the gas charging and discharging function. During use, the gas nozzle 221 is pressed to the sealing nail area to form a separate sealed space between the gas nozzle 221 and the sealing nail area, and the gas nozzle 221 is used to charge and discharge the sealing nail area. The helium detection nozzle 211 is used to perform helium detection on the sealing nail area. Among them, a helium detector is connected to the helium detection nozzle 211 through a pipeline. When in use, the helium detection nozzle 211 is pressed to the sealing nail area to form a separate sealed space between the helium detection nozzle 211 and the sealing nail area to perform helium detection. Among them, the gas nozzle 221 performs all inflation and deflation operations, and the helium detection nozzle 211 does not perform vacuum operations. This setting can keep the helium detection nozzle 211 clean and avoid gas residue during the inflation and deflation process, which affects the detection results.

[0060] In this embodiment, a gas nozzle 221 and a helium detection nozzle 211 are provided. The gas nozzle 221 and the helium detection nozzle 211 are installed above the detection part 110. The gas nozzle 221 and the helium detection nozzle 211 can be directly attached to the sealing nail area of ​​the battery to be tested to form a closed space. At the same time, by inflating and deflating the gas nozzle 221, the sealing nail area of ​​the battery to be tested can be filled with detection gas, and the detection gas on the surface of the sealing nail area of ​​the battery to be tested can be discharged and removed in time. By additionally providing the helium detection nozzle 211, the sealing nail area of ​​the battery to be tested after being charged and deflated can be re-sealed, and then the sealing nail area of ​​the battery to be tested after being charged and deflated can be gas detected by an external detection device, so as to detect whether there is a weld in the sealing nail area of ​​the battery to be tested, and then detect its airtightness. In this way, the gas nozzle 221 performs the gas charging and discharging operations, and the helium detection nozzle 211 performs the detection operation, which can prevent the helium detection nozzle 211 from being introduced with gas and from being contaminated by gas, thereby greatly improving the detection accuracy during detection. The structure is simple and the operation is easy, and the sealing nail area of ​​the battery to be tested can be detected in time, which can improve the detection accuracy and efficiency.

[0061] In another embodiment, the device may further include a solenoid valve control component 230, the gas nozzle 221 is connected to the helium cylinder, the vacuum pump and the nitrogen cylinder respectively through pipelines, and the solenoid valve control component 230 is arranged on the pipeline to control the gating of the pipelines between the gas nozzle and the helium cylinder, the vacuum pump and the nitrogen cylinder. During use, if nitrogen filling is required, the pipeline between the gas nozzle 221 and the nitrogen cylinder is connected through the solenoid valve control component, and the pipeline between the vacuum pump and the nitrogen cylinder is closed, so as to realize nitrogen filling using the gas nozzle 221. If a vacuum operation is required later, the pipeline between the gas nozzle 221 and the nitrogen cylinder is closed, and the connection between the gas nozzle 221 and the vacuum pump is opened to realize the switching of the function of the gas nozzle 221.

[0062] The detection module 2 may further include a pressure gauge 222, which is connected to the air nozzle 221 through a pipeline. The pressure gauge 222 can be provided to intuitively observe the air pressure changes during the detection process.

[0063] In order to realize the movement of the gas nozzle 221 and the helium detection nozzle 211, the gas nozzle 221 and the helium detection nozzle 211 can be respectively connected with a driving cylinder, and the driving cylinder drives the gas nozzle 221 and the helium detection nozzle 211 to move toward the detection part 110. During use, the battery to be tested is placed in the detection part 110 by means of a moving fixture or the like. Under the action of the driving cylinder, the gas nozzle 221 is tightly fitted with the sealing pin area of ​​the battery to be tested, and forms a sealed space with the sealing pin area and its weld.

[0064] In one application mode, the solenoid valve control component 230 controls the pipeline of the nitrogen bottle to open, and fills nitrogen into the sealing nail area and its weld for 2-5 seconds through the gas nozzle 221, and then closes the pipeline of the nitrogen bottle to maintain the pressure for 2-5 seconds. The pressure drop value is observed through the pressure gauge 222 connected to the gas nozzle 221, and then the pressure drop value is compared with the preset value. If the pressure drop value is greater than 15Kpa, the battery to be tested is a defective product and is discharged. If the pressure drop value is less than or equal to 15Kpa, it is tested by nitrogen and the next testing process is carried out.

[0065] The solenoid valve control component 230 controls the opening of the vacuum pump pipeline, and vacuumizes the sealing nail area through the air nozzle 221 until it reaches the target value of -95Kpa, and then closes the vacuum pump pipeline to generate a pressure difference between the inside and outside, so that helium can enter the cavity area 40 more easily. The solenoid valve control component 230 controls the helium pipeline to open, and fills the sealing nail area with helium through the air nozzle 221 for 60 seconds. The helium pressure is maintained at 300-400Kpa. After the helium filling time is up, the helium pipeline is closed. At this time, the vacuum pump pipeline is opened, and the sealing nail area is vacuumed through the air nozzle 221 to reach the target value of -95Kpa, and the helium on the surface of the sealing nail area and the helium remaining in the air pipe are removed to prevent it from affecting the test data. Under the ideal model, if the battery leaks, after high-pressure helium filling, the helium has entered the cavity area inside the sealing nail area. Then the vacuum breaker valve is opened, and the driving cylinder of the air nozzle 221 is retracted normally to prevent damage to parts due to large internal and external pressure differences and violent retraction of the driving cylinder.

[0066] Then, the battery is transplanted to the bottom of the helium detection nozzle 211, and the driving cylinder of the helium detection nozzle 211 is extended. The helium detection nozzle 211 is close to the battery sealing nail area, forming a sealed space with the sealing nail area. The sealing nail area is evacuated to reach the leak detection pressure set by the helium detector, and then the helium detector is connected. The battery is helium tested, and the helium detector is connected to the test battery to output the leakage rate value of helium atoms, which is compared with the set value for judgment. The detection time is 3s. After the helium test is completed, the helium test valve is closed and the vacuum breaking valve is opened until the pressure gauge 222 returns to the normal pressure value. The driving cylinder of the helium detection nozzle 211 is retracted to complete the detection process.

[0067] Example 3 The difference between this embodiment and Example 2 is that this embodiment further optimizes the back pressure helium detection device of Example 2. Figure 6 , including a feed assembly 3, a discharge assembly 4 and a back-pressure helium detection device, wherein the feed assembly 3 and the discharge assembly 4 are respectively arranged on one side of the back-pressure helium detection device; the feed assembly 3 is used to load the battery to be tested, and the feed assembly 3 includes a first moving module 310, and a first transporting member 320 is transmission-connected to the moving end of the first moving module 310, so that the first transporting member 320 moves the battery to be tested to the detection part. Exemplarily, the first moving module 310 includes a guide rail, which is arranged along the direction of the back-pressure helium detection device, and a moving block is arranged on the guide rail. The first transporting member 320 is arranged on the moving block. The first transporting member 320 can be a manipulator, a material picking clamp, etc. The manipulator clamps the battery to be tested, moves along the guide rail direction through the moving block, and places the battery to be tested on the detection part to complete the loading.

[0068] The discharge assembly 4 includes a second moving module 410, and a second transporting member 420 is transmission-connected to the mobile end of the second moving module 410, and the battery to be tested on the detection part is discharged through the second transporting member 420. Exemplarily, the second moving module 410 includes a guide rail and a slider, and the second transporting member 420 is a manipulator, which is arranged on the slider, and the manipulator moves the tested battery from the detection part to the unloading position, thereby improving the efficiency of battery detection.

[0069] In some embodiments, a barcode scanning module for scanning the battery to be tested is further provided on one side of the feed assembly 3. The barcode scanning module is provided on one side of the feed assembly 3 to scan the battery to be tested. When the barcode scanning fails, the first transport member 320 can place the battery to be tested that fails the barcode scanning on the NG tray.

[0070] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0072] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0073] In the present invention, unless otherwise clearly specified and limited, a first feature being above or below a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, a first feature being above, above, and above a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being below, below, and below a second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0074] Although the present invention is described in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and changes according to the above content. Therefore, all such substitutions, improvements and changes are included in the spirit and scope of the appended claims.

Claims

1. A back pressure helium detection method, characterized in that: The back pressure helium detection method is applied to a back pressure helium detection device, wherein the back pressure helium detection device is provided with a detection module, wherein the detection module comprises a helium detection nozzle for detecting the air tightness of the sealing nail area of ​​the battery to be tested and a gas nozzle for filling and discharging gas; The back pressure helium detection method comprises: Controlling the air nozzle to fit the sealing pin area of ​​the battery to be tested to form a closed space; Filling the sealing nail area with helium through the gas nozzle to obtain a helium-filled sealing nail area; Purging the surface of the helium-filled sealing nail area to remove surface helium; The helium detection nozzle is controlled to perform airtightness detection on the helium-filled sealing nail area to obtain an airtightness detection result.

2. The back pressure helium detection method according to claim 1, characterized in that: Before the helium is filled into the sealing nail area through the gas nozzle, the method further comprises: Filling nitrogen into the sealing nail area through the gas nozzle, and maintaining the pressure of the sealing nail area filled with nitrogen for a first time period; Obtaining a pressure drop value of the sealing pin area within a first time period, and comparing the pressure drop value with a first preset value; If the voltage drop value is greater than the first preset value, the battery to be tested is discharged; If the pressure drop value is less than or equal to the first preset value, the gas nozzle is controlled to fill the sealing nail area with helium.

3. The back pressure helium detection method according to claim 2, characterized in that: The step of controlling the gas nozzle to fill the sealing nail area with helium includes: Performing a first vacuum on the sealing nail area filled with nitrogen through the gas nozzle to obtain a first vacuum sealing nail area; Filling helium into the first vacuum sealing nail region through the gas nozzle so that the helium enters the cavity of the sealing nail region to obtain a helium-filled sealing nail region; The helium-filled sealing nail area is evacuated for the second time to obtain a second vacuum sealing nail area; The second vacuum sealing nail region is subjected to a vacuum breaking process to obtain a normal pressure sealing nail region.

4. The back pressure helium detection method according to claim 3, characterized in that: The detection module includes an air knife, and the surface of the helium-filled sealing nail area is purged to remove the surface helium, including: The wind knife is controlled to purge nitrogen on the surface of the normal pressure sealing nail area to remove helium on the surface of the normal pressure sealing nail area.

5. The back pressure helium detection method according to claim 1, characterized in that: The controlling the helium detection nozzle to perform airtightness detection on the helium-filled sealing nail area to obtain the airtightness detection result includes: Controlling the helium detection nozzle to fit the sealing pin area filled with helium to form a closed space; The air tightness test is performed on the sealing pin area through the helium test nozzle to obtain the air tightness test result.

6. The back pressure helium detection method according to claim 3, characterized in that: The target values ​​of the first vacuuming and the second vacuuming are -50Kpa to -150Kpa.

7. The back pressure helium detection method according to claim 1, characterized in that: The first preset value range is 10-20Kpa.

8. A back pressure helium detection device, characterized in that: The device is used to perform the back pressure helium detection method according to any one of claims 1 to 7, and the device comprises a detection platform and a detection module, one side of the detection platform is provided with a detection part for placing the battery to be tested, and the detection module is arranged on a side facing the detection part; The detection module includes a gas nozzle and a helium detection nozzle, and the gas nozzle and the helium detection nozzle are arranged at an interval. The gas nozzle is used to flexibly seal and close the sealing nail area of ​​the battery to be tested, and to fill or extract gas into the sealing nail area of ​​the battery to be tested. The helium detection nozzle is used to flexibly seal the sealing nail area of ​​the battery to be tested and detect air tightness.

9. The back pressure helium detection device according to claim 8, characterized in that: It also includes an electromagnetic valve control component, the gas nozzle is connected to the helium cylinder, the vacuum pump and the nitrogen cylinder through a pipeline, and the electromagnetic valve control component is arranged on the pipeline to control the selection of the pipeline between the gas nozzle and the helium cylinder, the vacuum pump and the nitrogen cylinder.

10. The back pressure helium detection device according to claim 8, characterized in that: It also includes a feeding assembly and a discharging assembly, wherein the feeding assembly and the discharging assembly are respectively arranged on one side of the detection platform; The feeding assembly comprises a first moving module, a moving end of the first moving module is connected to a first transport member, and the battery to be tested is moved to the detection part through the first transport member; The discharge assembly comprises a second moving module, a moving end of the second moving module is transmission-connected with a second transport member, and the battery to be tested on the detection part is discharged through the second transport member.

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