Battery pack air tightness detection system and method

Abstract

The invention discloses a battery pack airtightness detection system and method, and relates to the technical field of battery pack detection. The system specifically comprises a mechanical arm, helium detection equipment, a support, a sliding table, a controller and a visual mechanism, the mechanical arm is connected with the sliding table, the sliding table is slidably connected with the support, the visual mechanism is arranged on the mechanical arm, a driving mechanism is arranged between the sliding table and the support, and the visual mechanism, the driving mechanism and the mechanical arm are electrically connected with the controller. The helium detection equipment comprises a suction gun, and the suction gun is connected with the mechanical arm. The mechanical arm is arranged on the upper side of the to-be-detected battery pack, so that the moving stroke of the mechanical arm can be reduced, the moving amount of the mechanical arm during detection is reduced, the influence of the movement of the mechanical arm on helium emission is reduced, and the detection accuracy is improved.

Description

Technical Field

[0001] This invention relates to the field of battery pack testing technology, and specifically provides a battery pack airtightness testing system and method. Background Technology

[0002] The airtightness of a battery pack is a crucial indicator of its safety performance. A common method for airtightness testing is the helium detection method. This method involves filling the battery pack with helium gas and then transporting it to a relatively sealed testing chamber, isolating the chamber from the external gas. After the battery pack enters the testing chamber, the chamber door is closed, and gas samples are collected from the vicinity of structural components such as seams and joints in the battery pack's casing. The helium content in the collected gas samples is then analyzed. If the helium content exceeds a threshold, the battery's airtightness is considered unqualified; conversely, if the helium content is below the threshold or no helium is detected, the battery pack's airtightness is considered qualified.

[0003] As shown in the invention patent with publication number CN118032217A, a robotic arm moves a suction gun to collect gas samples around the battery pack. By analyzing the helium content in the collected gas samples, the gas content is used to determine whether the battery pack has an airtightness problem.

[0004] As shown in the aforementioned patent, the robotic arm is positioned on one side of the battery pack during testing. The connectors and other structural components of the battery pack are typically located on various sides, and the connecting seams on the battery pack's casing are also located on each side. When collecting gas samples, the robotic arm needs to sample the structural components and connecting seams. During its movement, the robotic arm also needs to sample the gas on the side it is currently positioned on. Frequent movement of the robotic arm causes gas flow within the testing chamber; the faster the movement, the more pronounced the gas flow. This gas flow can cause the diffusion of leaked helium from the battery pack, affecting testing accuracy. Therefore, in actual testing, after sampling one side of the battery pack, the robotic arm moves to the next side. When moving to each side, the structural components and connecting seams on each side need to be identified and calibrated to ensure accuracy. However, this frequent identification leads to low gas sampling efficiency and low testing efficiency. Summary of the Invention

[0005] This invention provides a battery pack airtightness testing system to solve the problem of low testing efficiency.

[0006] The technical solution of the present invention is as follows:

[0007] A battery pack airtightness testing system includes a robotic arm, a helium detector, a support, a slide, a controller, and a vision mechanism. The robotic arm is connected to the slide, the slide is slidably connected to the support, the vision mechanism is mounted on the robotic arm, and a drive mechanism is provided between the slide and the support. The vision mechanism, the drive mechanism, and the robotic arm are all electrically connected to the controller. The helium detector includes a suction gun, which is connected to the robotic arm. In this design, the robotic arm is positioned on the slide table, allowing it to be located on top of the battery pack during inspection. Compared to positioning the robotic arm on one side of the battery pack, this method reduces the distance between the robotic arm and both sides of the battery pack's end face. The robotic arm covers the entire battery pack, requiring less movement to inspect all sides. Positioning the robotic arm on one side necessitates moving it to at least the opposite side of the battery pack, resulting in a movement path longer than any side of the battery pack. In this design, the slide table's movement distance is necessarily shorter than the battery pack's length. Therefore, the slide table's movement range is less than one-third of that of a side-mounted robotic arm, significantly reducing the movement distance of both the slide table and the robotic arm. This reduces the impact of the robotic arm's movement on airflow, slows helium diffusion, and improves inspection accuracy. Furthermore, with the robotic arm positioned on top of the battery pack, the airflow generated during movement is away from the sides of the battery pack, minimizing its impact on helium diffusion on those sides. Therefore, during testing, the seams on each side of the battery pack casing are interconnected. During testing, the slide only needs to move back and forth along the support once, and with the help of the robotic arm, it can complete the inspection of the seams around the casing. Then, the structural components on each side are inspected separately. This inspection method can reduce the number of times the seams on each side are identified, thereby improving the inspection efficiency.

[0008] To prevent the rapid diffusion of leaked helium from the battery pack from affecting the test results, the battery pack testing is conducted inside a testing chamber. To prevent helium accumulation inside the testing chamber from affecting the results, an intake fan and an exhaust fan are installed. After each battery pack test is completed, the gas inside the testing chamber is exhausted through these fans. The intake fan is typically located at the bottom of the side wall of the testing chamber. When personnel walk outside or equipment moves, airflow may be generated, and this airflow may enter the testing chamber through the intake fan. To address the issue of outside air entering through the intake fan and affecting helium diffusion, a lifting device is used to lift the battery pack, the tray supporting the battery pack, or the trolley supporting the battery pack. In this design, during battery pack testing, the lifting device raises the battery pack off the ground. Even if a small amount of airflow enters the testing chamber from the intake fan, the higher height of the battery pack prevents this airflow from affecting helium diffusion, thus improving testing accuracy.

[0009] To address the issue of inaccurate battery pack positioning after lifting, leading to large adjustments in the robotic arm path and low inspection efficiency, the lifting unit includes a positioning pin. The tray has positioning holes that mate with the positioning pin, and the end of the positioning pin has a guide surface, which may be a conical or spherical surface. In this solution, when the tray is lifted, positioning holes are provided on the tray, and positioning pins are provided on the lifting unit. The positioning pins are inserted into the positioning holes, achieving precise positioning of the tray or trolley, thus ensuring accurate positioning of the battery pack. The guide surface at the end of the positioning pin allows it to exert force on the tray when inserted into the positioning holes, enabling the tray to move under the action of the positioning pin and automatically move to the accurate position. This allows each battery pack to be quickly and accurately positioned at the predetermined location, thereby improving inspection accuracy and efficiency.

[0010] The battery packs are very heavy, with some exceeding one ton. When the guide surface of the positioning pin acts on the positioning hole, the positioning pin experiences a large reaction force, which can easily lead to breakage or deformation of the positioning pin, or damage to the mechanism driving the positioning pin. Therefore, the lifting section also includes multiple universal bearings, each located at the top of the lifting section. The lifting section contacts and lifts the tray through these universal bearings. In this solution, the universal bearings contact the tray, allowing them to roll synchronously as the tray moves, significantly reducing the tray's movement resistance and solving the problems of breakage or deformation of the positioning pin due to excessive reaction force, as well as damage to the mechanism driving the positioning pin. The cooperation between the guide surface of the positioning pin and the universal bearings achieves automatic positioning of the battery pack at the lifting device. With the battery pack positioned correctly, the path adjustment of the robotic arm is reduced, improving detection efficiency.

[0011] To address the issue of excessive tray position misalignment and large misalignment between the positioning hole and the positioning pin, making it impossible to correct the tray position using the guide surface of the positioning pin, a guide surface is also provided at the end of the positioning hole near the positioning pin. In this solution, the guide surface on the positioning hole increases the mating area between the positioning pin and the positioning hole, thereby expanding the correction range for the tray position when the positioning pin and positioning hole are engaged. A larger correction range allows for successful positioning of the battery pack and tray on the first attempt, reducing rework and improving inspection efficiency.

[0012] In addition, the lifting part moves back and forth between two planes. When the bottom of the lifting part abuts against the plane, the supporting effect on the lifting part is stable, which can avoid the lifting part from shifting up and down during the detection process and solve the problem of inaccurate detection caused by the shaking of the battery pack or the trolley.

[0013] The robotic arm moves with the slide table. To address the issue of reduced detection accuracy due to decreased slide table movement precision, a guide rail is installed between the slide table and the frame. A sensor is mounted on one side of the guide rail and is electrically connected to the controller. This sensor is used to calibrate the position of the slide table. In this design, the sensor on one side of the guide rail can detect the position of the slide table, enabling its calibration and allowing the slide table and robotic arm to work together to move the suction gun to the accurate position.

[0014] To address the issue of larger non-target battery packs being transported to the testing chamber by a robotic arm, which can cause the suction gun to collide with the battery pack and break during feature acquisition by the vision mechanism, the testing system includes a position sensor electrically connected to the controller. This position sensor detects the battery pack's height; if it exceeds a set value, it indicates an incorrect battery pack model. In this case, the controller will not move the robotic arm, preventing collisions. If the incorrect battery pack is smaller, the robotic arm will also avoid collisions during movement. Simultaneously, the vision mechanism acquires the battery pack's features, identifying the incorrect model without any collisions.

[0015] This invention provides a method for detecting the airtightness of a battery pack, applicable to the aforementioned battery pack airtightness detection system, for detecting the airtightness of a battery pack, comprising the following steps:

[0016] S1. Fill the battery pack with helium at a specified pressure;

[0017] S2. The trolley transfers the helium-filled battery pack to the testing chamber via a tray. After the battery pack is transferred to the testing chamber, the door of the testing chamber is closed to prevent the airflow outside the testing chamber from affecting the airflow inside the testing chamber.

[0018] S3. The trolley moves the battery pack to the lifting device, which lifts the battery pack upward to the detection range of the robotic arm, and then corrects the position of the battery pack or tray.

[0019] S4. The slide table drives the robotic arm to move, causing the vision mechanism on the robotic arm to move around the battery pack. During the movement, the vision mechanism collects images of the battery surface and obtains the positions of the battery surface connection seams and structural components.

[0020] S5. After the controller determines the position of the battery pack based on the position of the connecting seam and structural components, it can determine whether the position of the battery pack has shifted, thereby adjusting the movement path of the robotic arm.

[0021] S6. After determining the movement path, the robotic arm moves along the designated path, and the suction gun collects gas samples during the movement.

[0022] S7. After the suction gun completes sampling along the path, the lifting device descends, and the trolley transports the battery pack out of the testing chamber.

[0023] In this solution, after the vision mechanism identifies the features on the battery pack surface, the position of the battery pack can be determined. The controller adjusts the movement path of the robotic arm and slide table to prevent the suction gun from colliding with the battery pack and causing damage during movement. Furthermore, it ensures that the suction gun is positioned accurately, with the distance between it and potential gas leaks, such as seams and structural components, not exceeding 4mm, thus ensuring accurate detection.

[0024] The slide table can also experience positional errors during operation. To address the issue of positional misalignment of the robotic arm and suction gun caused by these errors, step S4 involves calibrating a sensor to detect the slide table's position. In this solution, calibrating the sensor to detect the slide table's position ensures its accuracy. Since the robotic arm is mounted on the slide table, accurate slide table positioning ensures accurate robotic arm positioning, thereby ensuring accurate and reliable suction gun positioning during gas sampling and guaranteeing detection precision.

[0025] The beneficial effects of this invention are:

[0026] This invention improves detection accuracy by placing the robotic arm on top of the battery pack to be tested, thereby reducing the robotic arm's travel distance, minimizing its movement during testing, and reducing the impact of the robotic arm's activity on helium emission. Attached Figure Description

[0027] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the detection chamber of the present invention;

[0029] Figure 2 This is a schematic diagram of the internal structure of the various devices in the testing chamber of the present invention;

[0030] Figure 3 This is a schematic diagram of the support, slide, and robotic arm of the present invention;

[0031] Figure 4 This is a partial structural schematic diagram of one arrangement of the sensor between the slide and the bracket according to the present invention;

[0032] Figure 5 This is a schematic diagram of the lifting device of the present invention;

[0033] Figure 6 for Figure 5 Enlarged view of a portion of point A in the middle;

[0034] Figure 7 This is a cross-sectional view of the lifting device of the present invention;

[0035] Figure 8 for Figure 5 Enlarged view of section B in the middle.

[0036] In the above figures, the corresponding reference numerals are as follows:

[0037] 1. Testing chamber; 2. Pipeline; 3. Inlet fan; 4. Support; 5. Slide table; 6. Robotic arm; 7. Suction gun; 8. Vision mechanism; 9. Battery pack; 10. Cart; 11. Lifting device; 12. Shielding plate; 13. Frame; 14. Power unit; 15. Lifting unit; 16. Limiting unit; 17. Upright pole; 18. Position sensor; 19. Guide structure; 20. Universal bearing; 21. Telescopic mechanism; 22. Transmission block; 23. Roller; 24. Calibration sensor; 25. Positioning pin. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described in conjunction with the accompanying drawings and through specific embodiments of the present invention.

[0039] Example 1:

[0040] like Figure 1 and Figure 2 As shown, this embodiment provides a battery pack 9 airtightness testing system, including a testing chamber 1, a support 4, a slide table 5, a robotic arm 6, a helium detection device, and a vision mechanism 8. The support 4 is disposed within the testing chamber 1, the slide table 5 is slidably mounted on the support 4, the robotic arm 6 is mounted on the slide table 5, and the vision mechanism 8 is mounted on the robotic arm 6. The helium detection device includes a suction gun 7, which is used to collect gas samples. The gas samples collected by the suction gun 7 are transported to the helium detection device, which analyzes the helium content in the gas samples. The suction gun 7 is mounted on the robotic arm 6. The testing system is also equipped with a controller, and the robotic arm 6, the vision mechanism 8, and the helium detection device are electrically connected to the controller.

[0041] The testing chamber 1 is equipped with a door for the battery pack 9 to enter and exit. During the testing process, the door of the testing chamber 1 is kept closed to prevent the gas inside the testing chamber 1 from flowing due to external interference, thereby reducing the gas flow velocity inside the testing chamber 1 and preventing the rapid diffusion of leaked helium from the battery pack 9. With a low gas flow velocity inside the testing chamber 1, the leaked helium from the battery pack 9 will slowly diffuse from the leak point. This allows the suction gun 7 to accurately collect the leaked helium from the leak point when collecting air samples from easily leaking locations such as seams and structural components of the battery pack 9.

[0042] The top of the testing chamber 1 is equipped with an exhaust vent, which can house an exhaust fan. The bottom of the side of the testing chamber 1 is equipped with an air inlet, which is fitted with an air intake fan 3. After testing a battery pack 9, the exhaust fan and air intake fan 3 are activated to replace the air in the testing chamber 1, preventing any residual leaked helium from remaining inside and affecting testing accuracy. Multiple exhaust and air inlets can be installed. Each exhaust vent is equipped with a pipe 2 to transport the exhausted gas, preventing helium from remaining outside the testing chamber 1 and thus preventing the exhausted helium from entering the testing chamber 1 through the air intake fan.

[0043] like Figure 3 As shown, inside the testing chamber 1, the support 4 is constructed from profiles connected to each other by welding or fasteners. The support 4 can be connected to the inner side of the testing chamber 1, or, if a crossbeam is provided inside the testing chamber 1, the support 4 can be fixedly connected to the crossbeam by fasteners. The support 4 can also be a spatial three-dimensional frame fixedly connected to the ground. A guide rail is provided on the support 4, and a slider adapted to the guide rail is provided on the slide table 5, which is slidably connected to the guide rail. Therefore, through the cooperation of the guide rail and the slider, the slide table 5 and the support 4 can be slidably connected. The slide table 5 is equipped with a drive mechanism, and a transmission mechanism is also provided between the slide table 5 and the support 4. The drive mechanism and the transmission mechanism are connected, and the drive mechanism provides power for the movement of the slide table 5, making the movement of the slide table 5 on the support 4 controllable. The drive mechanism is electrically connected to the controller, enabling the slide table 5 to cooperate with the robotic arm 6, allowing the robotic arm 6 to move relative to the battery pack 9, thereby increasing the working range of the robotic arm 6 and enabling the robotic arm 6 to collect air samples from various locations on the battery pack 9.

[0044] The transmission mechanism between the slide 5 and the support 4 can be a gear and rack mechanism or a lead screw and nut mechanism. Taking the gear and rack mechanism as an example, the drive mechanism is located on the slide 5 and connected to the gear. The rack is located on the support 4 and is parallel to the guide rail. The gear and rack mesh. When the drive mechanism is working, the gear rotates, and with the cooperation of the gear and rack, the slide 5 slides relative to the support 4.

[0045] After the battery pack 9 enters the inspection chamber 1, its height is lower than that of the slide table 5. The robotic arm 6 is connected to the bottom of the slide table 5 and is suspended directly above the battery pack 9, allowing it to move the suction gun 7 to the top and sides of the battery pack 9. During operation, the robotic arm 6 moves the suction gun 7 from above the middle of the battery pack. The robotic arm 6 only needs to extend to the edge of the battery pack 9, allowing it to extend to both sides to inspect the width of the battery pack 9. Combined with the slide table 5 moving along the length of the battery pack 9, this allows for comprehensive inspection of the battery pack 9. When the robotic arm 6 is positioned on top of the battery pack 9, the distance between the robotic arm 6 and the two sides of the end face of the battery pack 9 is smaller. The robotic arm 6 covers the entire battery pack 9, and the moving distance required to complete the detection of all surfaces is smaller. If the robotic arm 6 is positioned on one side of the battery pack 9, then when the robotic arm 6 moves, it must be able to move to at least the opposite side of the battery pack 9, and the moving path is longer than the length of any side of the battery pack 9. However, in this application, the moving distance of the slide table 5 is necessarily shorter than the length of the battery pack 9. Therefore, the moving range of the slide table 5 is less than one-third of that of the side-mounted robotic arm 6, which significantly shortens the moving distance of the slide table 5 and the robotic arm 6, reduces the impact of the movement of the robotic arm 6 on the airflow, slows down the diffusion of helium, and improves the detection accuracy. Furthermore, since the robotic arm 6 is located on top of the battery pack, the airflow generated during its movement is away from the side of the battery pack 9, and has a low impact on the diffusion of helium on the side of the battery pack 9. Therefore, during the inspection, the connecting seams on each side of the battery pack 9 are interconnected. During the inspection, the slide 5 only needs to move back and forth along the bracket 4 once, and the robotic arm 6 can complete the inspection of the connecting seams by circling the battery pack 9. Then, the structural components on each side are inspected separately. This inspection method can reduce the number of times the connecting seams on each side are identified, thereby improving the inspection efficiency.

[0046] Furthermore, the robotic arm 6 is positioned directly above the battery pack 9. When the robotic arm 6 moves the suction gun 7 to both sides of the battery pack 9, the angle change of the suction gun 7 is smaller, which can reduce the angle change of the suction gun 7, thereby reducing the sampling error of the suction gun 7 and improving the accuracy of the detection.

[0047] Both the vision mechanism 8 and the suction gun 7 are located at the end of the robotic arm 6. The vision mechanism 8 is positioned to one side of the suction gun 7, and its field of vision covers the suction gun 7, allowing it to capture its position. When the suction gun 7 collects a gas sample, the robotic arm 6 moves it closer to the battery pack 9. At this point, the vision mechanism 8 captures an image of the battery pack 9. The battery pack 9 has seams in its casing, and the positions of structural components on the casing can be directly analyzed from the captured images. By obtaining the positional information of the seams and structural components on the battery pack from the images captured by the vision mechanism 8, the controller determines the movement path of the robotic arm 6 based on the positions of these components, preventing the suction gun 7 from colliding with the battery pack 9 and breaking due to path deviation. Because the vision mechanism 8 is positioned relative to the robotic arm 6, the positional information detected by the vision mechanism 8 is relative to the robotic arm 6, making the sampling position of the suction gun 7 more accurate when the robotic arm 6 moves it.

[0048] The vision unit 8 includes a 3D camera, which captures the positions of features on the battery pack to determine the position of the battery pack 9. Identifiable features on the battery pack can be structural components or seams.

[0049] Structural components refer to the high-voltage connectors, low-voltage signal plugs, liquid cooling system interfaces, explosion-proof valves, and safety valves installed on the battery pack 9. Connecting seams refer to the main weld seams of the battery pack 9's casing, the weld seams of the water-cooling plate, and the weld seams around bosses and openings on the shell.

[0050] Typically, structural components are located on the front and rear sides of the battery pack 9. Therefore, during inspection, the vision mechanism 8 captures images of the front and rear sides of the battery pack 9 to identify the positions of the structural components. By combining the positions of the structural components on both sides, it can determine whether the battery pack 9 is tilted vertically or horizontally, thus locating the battery pack 9. After the battery pack 9 is located, the controller can accurately control the movement of the robotic arm 6, causing the robotic arm 6 to move the suction gun 7 to collect gas samples from the structural components on that side. When the vision mechanism 8 captures images of the front side of the battery pack 9, the vision mechanism 8 is positioned diagonally above the battery pack 9, allowing it to simultaneously capture images of the top surface of the battery pack 9. In other words, the vision mechanism 8 can also simultaneously identify the top surface of the edges of the battery pack 9. When capturing images of each side, the features of the top surface can be combined with the features of the sides for reference, improving the accuracy of the determined position of the battery pack 9. After the structural components on the front side of the battery pack 9 are inspected, the controller can control the robotic arm 6 to move the suction gun 7 to the location of the connecting seam or structural component for inspection.

[0051] The controller can be an industrial computer or a PC.

[0052] Example 2:

[0053] like Figure 2 As shown, this embodiment 2 provides a battery pack 9 airtightness detection system. Unlike embodiment 1, this embodiment 2 also includes a lifting device 11.

[0054] The battery pack 9 is heavy, potentially exceeding one ton, and is typically transferred via a trolley 10 to the testing chamber 1. To facilitate unloading the battery pack 9 from the trolley 10, it is usually placed on a pallet, which is then mounted on the trolley 10. Before testing, the trolley 10 carries the pallet and battery pack 9 into the testing chamber 1. Upon reaching the lifting device 11, the trolley 10 stops, awaiting the lifting device 11 to lift the pallet.

[0055] A lifting device 11 is installed inside the testing chamber 1. The lifting device 11 is used to lift the battery pack 9, the tray, or the trolley 10. The purpose is to increase the height of the battery pack 9. A robotic arm 6 is positioned on top of the battery pack 9, lifting it upwards so that it is within the working range of the robotic arm 6. The advantage of this setup is that after testing, the lifting device 11 descends, causing the battery pack 9 or the tray to fall back onto the trolley 10, or causing the lifted trolley 10 to land. After the battery pack 9 descends, the trolley 10 can directly transport the battery pack 9 out of the testing chamber 1. The battery pack 9 will not interfere with the robotic arm 6 during movement, and the robotic arm 6 does not need to actively avoid the battery pack 9. The airtightness test of battery pack 9 is usually carried out in batches for the same type of battery pack 9. Therefore, when the battery pack 9 leaves the test chamber 1, the robotic arm 6 can directly return to the initial position of the test. After the next battery pack 9 enters the test chamber 1, it is lifted up by the lifting device 11. After the vision mechanism 8 identifies the position, the test can start immediately, thus improving the test efficiency.

[0056] Directly lifting the battery pack 9 may damage it, and after the battery pack 9 is lowered following detection, it may also collide with the trolley 10. Therefore, lifting the trolley 10 or using a pallet is preferable. However, since the trolley 10 itself has a large weight, lifting the pallet is a more preferred solution. Therefore, in the following description, the lifting pallet will be used as the standard.

[0057] like Figure 5 As shown, the lifting device 11 includes a frame 13, a power unit 14, and a lifting part 15. The lifting part 15 is movably connected to the frame 13. The power unit 14 is disposed on the frame 13 and connected to the lifting part 15. The power unit 14 is used to drive the lifting part 15 to move upward or downward. The lifting part 15 is used to contact the tray and is located under the tray. When the lifting part 15 moves upward under the action of the power unit 14, it lifts the tray upward, thereby raising the battery pack 9 and bringing it into the detection range of the robotic arm 6.

[0058] like Figure 8 As shown, the lifting part 15 also includes a positioning pin 25. A positioning power source is provided on the frame to drive the positioning pin 25. The positioning power source is connected to the positioning pin 25 for driving the positioning pin 25 to rise and fall vertically. In implementation, the positioning power source can be an electric cylinder or a pneumatic cylinder. During implementation, the bottom of the tray (on which the battery is placed) is also provided with positioning holes adapted to the positioning pin 25. Initially, the top of the positioning pin 25 is not higher than the top of the lifting part 15. The positioning pin 25 corresponds to the positioning hole at the bottom of the upper tray. When it is necessary to raise the height of the battery pack 9, the lifting part 15 lifts the tray upwards. When it is lifted to the predetermined height, the battery pack 9 on the tray simultaneously reaches the predetermined height to cooperate with the upper robotic arm 6. Then, the positioning power source drives the positioning pin 25 to extend upwards and insert into the corresponding positioning hole. This prevents the horizontal position of the tray from changing during the detection process, affecting the detection accuracy and precision, and also locks the tray to prevent it from slipping off the lifting part 15, effectively improving safety.

[0059] When the trolley 10 is loaded with the battery pack 9 and moves to the position of the lifting device 11, the positioning accuracy of the trolley 10 is obviously not as precise as the millimeter level as the detection accuracy. Therefore, after the trolley 10 stops, there will be a certain error in the horizontal position of the tray and the battery pack 9. Therefore, in a further embodiment, the top of the positioning pin 25 is provided with a guide surface, which includes a conical surface or a spherical surface. When there is a certain misalignment between the positioning pin 25 and the positioning hole, for example, a misalignment of 2mm, the guide surface of the positioning pin will contact the positioning hole, exerting a horizontal force on the positioning hole, driving the tray to move horizontally until the positioning pin 25 can be inserted into the positioning hole, thereby achieving the purpose of automatically correcting the horizontal position of the tray, ensuring that the battery on the tray can be more accurately positioned at the predetermined position, which is beneficial to improving the detection accuracy. Furthermore, the opening of the positioning hole is also constructed with a guide surface to cooperate with the positioning pin 25 to achieve a wider range of automatic correction of the horizontal position of the tray.

[0060] In a further embodiment, the lifting unit 15 may include a frame, rollers 23, and a universal bearing 20. The frame is constructed from profiles using fasteners or welding. The rollers 23 are located at the bottom of the frame, while the universal bearing 20 is located at the top of the frame. A guide rail is connected to the frame. The rollers 23 contact the transmission block 22 to reduce its movement resistance, while the universal bearing 20 contacts the pallet. The universal bearing 20 reduces the pallet's movement resistance, effectively solving the problems of the positioning pin 25 easily breaking and the positioning power easily burning out due to overload.

[0061] like Figure 6 and Figure 7As shown, the power unit 14 includes a telescopic mechanism 21 and at least two transmission blocks 22. The telescopic mechanism 21 is a pneumatic cylinder, hydraulic cylinder, or electric cylinder. The cylinder body of the telescopic mechanism 21 is connected to the frame 13, and the piston rod of the telescopic mechanism 21 is connected to the transmission blocks 22. Each transmission block 22 can be connected by a connecting rod, allowing each transmission block 22 to move synchronously. The connecting rods space the transmission blocks 22 apart, thus distributing each transmission block 22 at different positions on the frame 13, providing more uniform support for the lifting unit 15. If each transmission block 22 is driven by a different telescopic mechanism 21, an electric cylinder is preferred to ensure the movement accuracy of each transmission block 22.

[0062] The transmission block 22 includes two planes of different heights connected by an inclined surface. The two planes are a lower plane (located at a lower position) and a higher plane (located at a higher position). The bottom end of the lifting section 15 abuts against the transmission block 22. The telescopic mechanism 21 is horizontally mounted on the frame 13 and is used to push the transmission block 22 to move horizontally. When the transmission block 22 moves horizontally, taking the lifting section 15's upward movement as an example, the lifting section 15 will sequentially contact the lower plane, the inclined surface, and the higher plane. Since the lower and higher planes are at different heights, the height of the lifting section 15 changes when the roller 23 at the bottom of the lifting section 15 contacts different planes. In its initial position, the roller 23 is in contact with the transmission block 22 at the lower plane. When lifting is required, the transmission block 22 moves laterally under the action of the telescopic mechanism 21, and the roller 23 moves upward along the inclined surface, eventually reaching the higher plane of the transmission block 22. At this point, the battery pack 9 reaches a detectable position to cooperate with the robotic arm 6. In other words, the universal bearing 20 at the top of the lifting section 15 abuts against the tray. As the height of the lifting section 15 increases, the tray is lifted, allowing the battery pack 9 to reach the working range of the robotic arm 6. When the lifting section 15 is at its highest point, its bottom abuts against the plane of the transmission block 22, ensuring that the height of the lifting section 15 does not change, thus ensuring that the height of the battery pack 9 remains stable. The transmission block 22 moves laterally under the action of the telescopic mechanism 21. When the transmission block 22 moves, it applies a lateral force to the lifting section 15. To prevent the lateral movement of the lifting section 15 from causing inaccurate positioning of the battery pack 9, a guide structure 19 can be provided between the lifting section 15 and the frame 13. The guide structure 19 can include a guide rod and a guide hole. For example, the guide hole is provided in the frame 13, and the guide rod is provided in the lifting section 15. The guide rod is inserted into the guide hole to constrain the direction of movement of the lifting section 15. The axis of the guide hole is vertically set, so that the lifting section 15 can only move in the vertical direction. As an optional technical solution, the guide rod in the guide structure 19 can also be set on the frame 13, and the guide hole can be set on the lifting part 15. Alternatively, the lifting part 15 can be equipped with a sleeve, which is fitted onto the guide rod, and the sleeve serves the function of the guide hole. Similarly, the guide structure 19 can also adopt a guide rail slider assembly, with the guide rail set on the frame 13 and the slider set on the lifting part 15.

[0063] The transmission block 22 is a horizontally moving structural component. Through precision machining, the dimensions of each transmission block 22 can be made identical. Therefore, by moving at least two transmission blocks 22 laterally to push the lifting part 15 upward, the levelness of the lifting part 15 can be ensured, preventing it from tilting during upward movement. Preventing the lifting part 15 from tilting aims to prevent the tray from slipping off the universal bearing 20 or from significant displacement, thereby avoiding damage to the battery pack 9 from falling.

[0064] The trolley 10 is equipped with a power system and a position detection system, both of which are electrically connected to the controller. The position detection system can be a sensor, and a corresponding sensing structure, such as a sensing block, can be installed in the detection chamber. When the sensor detects the sensing block, its signal changes, and the controller stops the trolley 10 from moving. Then, it controls the lifting device to lift the tray on the trolley 10.

[0065] The robotic arm 6 returns to its initial position, meaning that the robotic arm 6 moves to the position where it begins to inspect the battery pack 9.

[0066] A position sensor 18 is installed inside the testing chamber 1 to detect the position of the battery pack 9. The position sensor 18 is electrically connected to the controller. When the position sensor 18 detects the position of the battery pack 9, it indicates that the battery pack 9 is of an incorrect model or is in the wrong position—that is, a non-target model battery pack 9 that does not correspond to the detected model. The lifting device will not lift the battery pack 9; instead, the trolley 10 will transport the battery pack 9 out of the testing chamber 1. The height of the position sensor 18 is set to correspond to the height of the battery pack 9. Under normal circumstances, after the trolley 10 stops, the detection area of ​​the position sensor 18 is slightly higher than the top of the battery pack 9, for example, 5mm or 10mm higher. Because the robotic arm 6 is mounted on the slide table 5, it is suspended above the battery pack 9, thus preventing interference between the robotic arm 6 and the position sensor 18.

[0067] The position sensor 18 can be installed on the side wall of the detection chamber 1 or on the lifting device 11. For example, uprights 17 can be installed on both sides of the frame 13 of the lifting device 11, and the position sensor 18 can be installed on the uprights 17 to detect the position of the battery pack 9. The position sensor 18 can be a common photoelectric position sensor 18, infrared position sensor 18, etc.

[0068] A limiting part 16 can be installed inside the detection chamber 1 to limit the movement of the trolley 10, stopping it at a designated position. After the trolley 10 stops at the designated position, the lifting device 11 lifts the tray, moving the battery pack 9 into the working range of the robotic arm 6. Once the battery pack 9 is in the working range of the robotic arm 6, it is also in a fixed position. The position of the battery pack 9 detected by the vision mechanism 8 is fixed, so the robotic arm 6 does not need to readjust its movement path, allowing it to move along a fixed path, reducing the adjustment time of the robotic arm 6 and improving detection efficiency.

[0069] The limiting part 16 includes a limiting block and a telescopic mechanism 21. The limiting block is a block-shaped, rod-shaped, or similar structure. The telescopic mechanism 21 is used to drive the limiting block to move. When a new trolley 10 enters the detection chamber 1, the telescopic mechanism 21 moves the limiting block onto the movement path of the trolley 10, stopping the trolley 10 in a fixed position. After the battery pack 9 is detected, the telescopic mechanism 21 causes the limiting block to move away, allowing the trolley 10 to move from the direction of the limiting block and leave the detection chamber 1. The trolley 10 leaving the detection chamber 1 will not obstruct or interfere with the trolley 10 entering the detection chamber 1, which can improve the entry and exit efficiency of the battery pack 9, thereby improving the detection efficiency.

[0070] As an optional solution, the limiting block can be rotatably connected to the ground or the frame 13. The limiting block can rotate onto or away from the travel path of the trolley 10. The telescopic mechanism 21 is used to drive the limiting block to move back and forth between the travel path of the trolley 10 and the area outside the travel path. The advantage of this rotating limiting block setting is that if the trolley 10 stops too far forward, the limiting block can push the trolley 10 to a suitable position, thus improving the stopping position accuracy of the trolley 10. Similarly, limiting parts 16 can be set on the front and rear sides of the lifting device respectively. With the combined action of the two limiting parts 16, the stopping position of the trolley 10 can be prevented from being too far forward or too far back.

[0071] like Figure 4As shown, the robotic arm 6 moves along with the slide table 5. A guide rail is provided between the slide table 5 and the support 4, and a calibration sensor 24 for detecting the position of the slide table 5 is provided on one side of the guide rail. When the slide table 5 passes the calibration sensor 24, the calibration sensor 24 detects the position of the slide table 5, and the controller calibrates the position of the slide table 5. The positional accuracy of the slide table 5 is calibrated during movement, thereby ensuring the accurate position of the robotic arm 6 and ensuring that the robotic arm 6 can move the suction gun 7 to the accurate position for sampling, thus improving the accuracy of detection. The calibration sensor 24 can be a photoelectric sensor or an infrared sensor. If a photoelectric sensor is used, the photoelectric sensor includes a receiver and a transmitter, which are provided on the support 4. A shielding plate 12 is provided on the slide table 5. When the shielding plate 12 passes between the receiver and the transmitter, the signal of the photoelectric sensor changes. The position of the slide table 5 can be determined by the position of the shielding plate 12, thereby calibrating the position of the slide table 5, and the controller can detect the positional accuracy of the slide table 5.

[0072] Because an intake fan 3 is located at the bottom of the side wall of the detection chamber 1, both the intake fan 3 and the exhaust fan are stopped during the detection process. After the detection is completed, the intake fan 3 and the exhaust fan are activated to replace the gas in the detection chamber 1. A pipe 2 is installed at the output end of the exhaust fan to guide the discharged gas to other locations for processing, preventing helium from being released near the detection chamber 1. Due to the presence of the intake fan 3, the bottom of the side wall of the detection chamber 1 remains connected to the outside, allowing for faster gas flow at the bottom of the detection chamber 1 compared to other locations within it. The lifting device 11 is used to lift the tray, raising the height of the battery pack 9 and placing it in a position with lower gas flow velocity, thus improving detection accuracy. The intake fan 3 is located at the bottom of the side wall to ensure that when replacing the air in the detection chamber 1, the air inside the chamber flows upwards as a whole, reducing gas residue. If the intake fan is located in the middle of the side wall, when the gas is replaced in the detection chamber 1, the gas enters the detection chamber 1 from the middle and does not flow from the middle to the top, resulting in a small gas flow at the bottom of the detection chamber 1 and easy helium residue. The lifting device 11 solves the problem of the intake fan 3 affecting the detection by raising the height of the battery pack 9.

[0073] Example 3:

[0074] This third embodiment provides a method for detecting the airtightness of a battery pack 9, which can be applied to the detection system of embodiment one or embodiment two for detecting the airtightness of the battery pack 9.

[0075] The battery pack airtightness testing method includes the following steps:

[0076] S1. Fill the battery pack 9 with helium at a specified pressure. When helium is filled into the battery pack 9 and the pressure inside the battery pack 9 is greater than atmospheric pressure, if there is a leak in the battery pack 9, the helium will leak out of the battery pack 9 from the leak.

[0077] S2. The trolley 10 transfers the helium-filled battery pack 9 to the detection chamber 1 via a tray. After the battery pack 9 is transferred to the detection chamber 1, the door of the detection chamber 1 is closed to prevent the airflow outside the detection chamber 1 from affecting the airflow inside the detection chamber 1. If there is a leak in the battery pack 9, the rapid spread of the leaked helium can be prevented by the isolation effect of the detection chamber 1, thus improving the detection accuracy.

[0078] S3. The trolley 10 moves the battery pack 9 to the lifting device 11, which lifts the battery pack 9 upwards. The lifting device 11 lifts the tray, raising the position of the battery pack 9 on the tray to the working range of the robotic arm, and then corrects the horizontal position of the battery pack 9 again, so that the battery pack 9 is positioned.

[0079] S4. The slide table 5 moves the robotic arm 6, causing the vision mechanism 8 on the robotic arm 6 to move around the battery pack 9. During the movement, the vision mechanism 8 acquires images of the battery surface, obtaining the positions of the connecting seams and structural components on the battery surface. Since the vision mechanism 8 cannot capture images of all sides and the top of the battery pack 9 at once, the slide table 5 and the robotic arm 6 work together to obtain images of all sides of the battery pack 9. From these images, the positions of features such as connecting seams and structural components are obtained, and the position of the battery pack 9 is determined based on these features. While the slide table 5 moves, the position of the slide table 5 is simultaneously detected using the calibration sensor 24. This means that the position of the slide table 5 is calibrated before each detection, ensuring the positional information of the robotic arm 6 and the vision mechanism 8. This prevents the suction gun 7 from colliding with the battery pack 9 when the robotic arm 6 moves the suction gun 7. It also ensures the accurate positioning of the suction gun 7, with the distance between it and connecting seams and structural components that may leak gas not exceeding 4mm, ensuring the accuracy of the detection.

[0080] S5. After the controller determines the position of the battery pack 9 based on the position of the connecting seam and structural components, it can determine whether the position of the battery pack 9 has deviated, thereby adjusting the movement path of the robotic arm 6 to prevent the suction gun 7 from colliding with the battery pack 9 due to positional deviation. Through the combined action of steps S5 and S4, the positions of the slide table 5 and the battery pack 9 are simultaneously detected, ensuring that the suction gun 7 will not collide with the battery pack 9 during movement.

[0081] S6. After determining the movement path, the robotic arm 6 moves along the designated path, and the suction gun 7 collects gas samples during the movement. When collecting gas samples, because the connecting seams of the battery pack 9's casing are interconnected, the robotic arm 6 detects the connecting seams all at once. The robotic arm 6 moves the suction gun 7 to the connecting seam, and then the slide table 5 drives the robotic arm 6 to circle the battery pack 9 once, thus completing the detection of the connecting seams. Only the position of the connecting seam needs to be identified on the initial side; it is not necessary to identify the position of the connecting seams on other sides, which improves detection efficiency. It should be noted that if the connecting seams on different sides of some battery pack 9 models are misaligned, the information about the connecting seams can be obtained in step S4, and therefore step S6 is not applicable.

[0082] S7. After the suction gun 7 completes sampling along the path, the lifting device 11 descends, and then the trolley 10 transports the battery pack 9 out of the testing chamber 1.

Claims

1. A battery pack airtightness testing system, characterized in that, The device includes a robotic arm, a helium detection device, a support, a slide table, a controller, and a vision mechanism. The robotic arm is connected to the slide table, and the slide table is slidably connected to the support. The vision mechanism is mounted on the robotic arm, and a drive mechanism is provided between the slide table and the support. The vision mechanism, drive mechanism, and robotic arm are all electrically connected to the controller. The helium detection device includes a suction gun, which is connected to the robotic arm.

2. The battery pack airtightness testing system according to claim 1, characterized in that, It also includes a lifting device for lifting the battery pack, the tray for carrying the battery pack, or the trolley for carrying the battery pack.

3. The battery pack airtightness testing system according to claim 2, characterized in that, The lifting device includes a frame, a lifting section and a power section. The power section is connected to the frame, and the lifting section is located on the upper side of the power section. The power section is used to push the lifting section to move upward.

4. The battery pack airtightness testing system according to claim 3, characterized in that, The lifting part includes a positioning pin, the tray is provided with a positioning hole adapted to the positioning pin, and the end of the positioning pin is provided with a guide surface, which includes a conical surface or a spherical surface.

5. The battery pack airtightness testing system according to claim 4, characterized in that, The lifting section also includes multiple universal bearings, each of which is located at the top of the lifting section. The lifting section contacts and lifts the tray through the universal bearings.

6. The battery pack airtightness testing system according to claim 4, characterized in that, The end of the positioning hole near the positioning pin is also provided with a guide surface.

7. The battery pack airtightness testing system according to claim 1, characterized in that, A guide rail is provided between the slide and the frame. A calibration sensor is provided on one side of the guide rail. The sensor is electrically connected to the controller and is used to calibrate the position of the slide.

8. The battery pack airtightness testing system according to claim 2, characterized in that, It also includes a position sensor for detecting the position of the battery pack, and the position sensor is electrically connected to the controller.

9. A method for detecting the airtightness of a battery pack, characterized in that, A battery pack airtightness testing system according to any one of claims 1-8, used for testing the airtightness of a battery pack, includes the following steps: S1. Fill the battery pack with helium at a specified pressure; S2. The trolley transfers the helium-filled battery pack to the testing chamber via a tray. After the battery pack is transferred to the testing chamber, the door of the testing chamber is closed to prevent the airflow outside the testing chamber from affecting the airflow inside the testing chamber. S3. The trolley moves the battery pack to the lifting device, which lifts the battery pack upward to the detection range of the robotic arm, and then corrects the position of the battery pack or tray. S4. The slide table drives the robotic arm to move, causing the vision mechanism on the robotic arm to move around the battery pack. During the movement, the vision mechanism collects images of the battery surface and obtains the positions of the battery surface connection seams and structural components. S5. After the controller determines the position of the battery pack based on the position of the connecting seam and structural components, it can determine whether the position of the battery pack has shifted, thereby adjusting the movement path of the robotic arm. S6. After determining the movement path, the robotic arm moves along the designated path, and the suction gun collects gas samples during the movement. S7. After the suction gun completes sampling along the path, the lifting device descends, and the trolley transports the battery pack out of the testing chamber.

10. A method for detecting the airtightness of a battery pack according to claim 9, characterized in that, In step S4, the position of the slide is detected by calibrating the sensor.

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