Method for completing battery pack bottom test based on ejection impact ball head of linear motor

Abstract

The invention discloses a method for completing a battery pack bottom test based on a linear motor ejection impact ball head, and the method comprises the steps: placing a to-be-tested battery pack on a battery pack bottom ball strike test bench, and enabling a power device of a bottom impact test device to drive the impact ball head of the battery pack bottom ball strike test to impact the battery pack from the bottom of the to-be-tested battery pack; the power device is a linear motor, the impact ball head is installed at the head of the linear motor, the impact ball head is driven by the linear motor, the battery pack is impacted from the bottom of the battery pack according to the impact force and the impact mode required by the bottom ball strike test of the battery pack, and the bottom ball strike test of the battery pack to be tested is carried out. According to the invention, an impact ball head driving mode of a battery pack bottom ball impact test is changed into a linear motor driving mode so as to determine the speed and the energy impact direction designated position, and compared with the existing spring, pneumatic and other emission modes in the industry, the energy control precision is higher, the repeatability is good, the adjustment and control are convenient, and the operation is simple.

Description

Technical Field

[0001] The present invention relates to a method for testing components of an electric vehicle, and in particular to a method for bottom impact testing of a power battery pack of a new energy vehicle, belonging to the technical field of battery pack testing. Background Art

[0002] With the booming electric vehicle industry, the battery pack, the "heart" of an electric vehicle, has a significant impact on its performance and safety, directly impacting the vehicle's range, power, and overall user experience. Different battery pack types exhibit varying characteristics in the bottom ball impact test due to differences in design and structure.

[0003] The battery pack bottom ball impact test is an important method for evaluating the impact resistance of electric vehicle battery pack bottoms. This test simulates the impact that the battery pack bottom might experience when a vehicle encounters an obstacle (such as a speed bump or rock) while driving, comprehensively testing the battery pack's structural safety, internal cooling system, and electrical components. Existing test methods are typically conducted under specific environmental conditions (e.g., a temperature of 22°C ± 5°C and a relative humidity of 15% to 90%). A metal ball with a diameter of 150 mm is used to impact the battery pack bottom at a velocity of 1 ± 0.2 mm / s. The impact point is selected at the center of the battery pack bottom or within a 240 mm radius from the geometric center. The impact force is typically 110% of the vehicle's permissible gross mass, and the load is maintained for 60 seconds. After unloading, the battery pack is observed for signs of leakage, fire, or explosion, and internal electrolyte and coolant leaks are inspected. In order to generate sufficient impact kinetic energy, the current main means is to push the impact ball head through a spring, cylinder or electric cylinder, so that the impact ball head can achieve the required ball impact force when impacting the bottom of the battery pack; however, these impact test methods currently mentioned generally have the disadvantage that the impact test force is difficult to control and even more difficult to adjust. Therefore, when encountering different test requirements, it is difficult to respond in time. As the requirements for battery pack testing and inspection are strengthened, more and more various experiments are required. The original bottom test method can no longer meet the needs of existing requirements and needs to be adaptively improved.

[0004] The search did not find any technical solutions identical to the present invention, but only found some related technical solutions, mainly the following: Patent No. CN202420355559.5 discloses a battery pack bottom ball impact test device, including an impact platform, a power release member, and a power device. The power release member is pivotally connected to the impact platform to adjust the angle between the power release direction and the horizontal direction. The release end of the power release member is connected to an impact ball. The power device is mounted on the impact platform and is transmission-connected to the input end of the power release member. While the battery pack bottom ball impact test device provided in this patent application has the advantages of being able to simulate impact operations under complex working conditions and highly accurate impact test results, it still uses ordinary methods.

[0005] 2. Patent No. CN202310090755.4 discloses a method for impact testing the bottom of a new energy vehicle battery pack, comprising the following steps: lifting the test vehicle to a certain height and placing it in a Ready state; adjusting the height of the impact test mechanism and the lower surface of the battery pack; performing impact tests on each marked point one by one, while monitoring and observing changes in the battery pack temperature and vehicle electrical safety data; after all marked points are tested in accordance with technical requirements, the vehicle is lowered, and the tested vehicle is placed in an open area for more than 24 hours, while recording the battery pack temperature and electrical safety data in real time; measuring the deformation of the marked points on the test vehicle after it has been left to rest, removing the battery pack after the measurement, and performing a sealing test; and conducting tests and inspections on the remaining vehicles according to the above steps until all are completed. This application makes the bottom support safety test items and test areas of the battery pack of new energy electric vehicles more complete, and can also evaluate the sealing and water wading after impact.

[0006] 3. Patent No. CN202111472237.6 discloses a needle puncture and extrusion test bench for new energy vehicle battery packs, including a workbench and a battery pack, a test bench is fixedly installed on the top of the workbench, a hydraulic cylinder is fixedly installed on the bottom of the inner cavity of the workbench, a placement plate is fixedly installed on the telescopic end of the hydraulic cylinder, a sealing column is fixedly installed on the top of the placement plate, and a fixed platform is fixedly installed on the top of the test bench. The present invention drives the placement plate and the battery pack to move upward synchronously, so that the movement of the battery pack has an initial acceleration. When the needle puncture and extrusion plate punctures and extrudes the battery pack, the two collide, thereby simulating the impact force caused by a real car collision. At the same time, by providing an isolation plate to simulate the protective function of the battery box for the battery pack, the needle puncture and extrusion test results of the battery pack are more in line with reality, thereby improving the accuracy of the test.

[0007] Based on the analysis of the retrieved patents, we found that many companies have applied for relevant patents in this regard regarding the battery pack bottom test, but they are all different from the technical solutions proposed in this project, especially how to overcome the problems mentioned above. The existing technical solutions cannot solve them well, so the problems mentioned above still exist and it is necessary to solve them. Summary of the Invention

[0008] The technical problem to be solved by the present invention is: how to further improve the bottom impact test method based on the requirements of the existing power battery pack bottom impact test, so that the detection is more accurate and the impact energy is convenient to adjust; mainly in terms of the movement of the impact head and its control method, accurate detection and precise control can be achieved, and the impact energy can be adjusted.

[0009] In view of the above problems, the technical solution proposed by the present invention is: A method for completing a battery pack bottom test based on a linear motor ejection impact ball head, wherein the battery pack to be tested is placed on a battery pack bottom ball impact test bench, and a linear motor bottom impact test device driven by a linear motor is provided below the battery pack bottom ball impact test bench, at an impact point below the battery pack to be tested. The power device of the bottom impact test device drives the impact ball head of the battery pack bottom ball impact test to impact the battery pack to be tested from the bottom; the power device is a linear motor, and the impact ball head is installed at the head of the linear motor. The impact ball head is driven by the linear motor to impact the battery pack from the bottom according to the impact force and impact method required for the battery pack bottom ball impact test, thereby performing a bottom ball impact test on the battery pack to be tested.

[0010] Furthermore, the movement of the impact ball head is driven by a linear motor, and the impact ball head is installed on the impact ball head sliding track of the bottom impact test device. At the same time, a linear motor is also installed in the bottom impact test device, and the linear motor drives the impact ball head to perform accelerated movement from bottom to top along the impact ball head sliding track in a sliding impact manner, and ensures that the impact energy when the impact ball head contacts the bottom of the battery pack to be tested is the energy required by the test, thereby completing the battery pack bottom ball impact test of the battery pack to be tested.

[0011] Furthermore, the impact ball head is driven by a linear motor to perform acceleration motion from bottom to top along the sliding track in a sliding impact manner, and it is ensured that the impact energy when the impact ball head contacts the bottom of the battery pack to be tested is the energy required by the test. The linear motor stator track and the impact ball head sliding track are laid on the motion bracket of the linear motor bottom impact test device, and the linear motor stator track and the impact ball head sliding track are arranged parallel to each other on the motion bracket of the linear motor bottom impact test device, and then the linear motor mover is installed on the linear motor stator track, and a sliding block matching the impact ball head sliding track is installed on the impact ball head sliding track; and then An impact ball head connecting plate is provided on the linear motor mover and the sliding block, and the impact ball head connecting plate is respectively connected to the linear motor mover and the sliding block to form a whole, so that the sliding block and the linear motor mover move up and down together, and then the impact ball head is installed on the impact ball head connecting plate at a position on one side of the impact ball head sliding track, and the head of the impact ball head is facing upward; then, the linear motor control system is used to adjust the operating speed of the linear motor, and the linear motor is started. The linear motor mover will drive the impact ball head to move from bottom to top, and when it reaches the bottom of the battery pack to be tested and contacts with the bottom of the battery pack to be tested, it reaches the impact force required for the test, and the battery pack bottom ball impact test of the battery pack to be tested is carried out.

[0012] Furthermore, the linear motor track is laid on the linear motor bottom impact test device, and a moving bracket of the linear motor bottom impact test device is set between the two support frames of the ball impact test bench at the bottom of the battery pack. The linear motor stator track is arranged from top to bottom on the moving bracket, and the linear motor stator track constitutes the moving track of the linear motor mover. The linear motor mover is then buckled on the linear motor stator track. After power is turned on, the linear motor mover will move from bottom to top along the linear motor stator track to achieve bottom impact on the battery pack to be tested.

[0013] Furthermore, the linear motor stator track is a linear rail, which is arranged from the upper part of the motion bracket to the bottom of the motion bracket. The linear motor mover is buckled on the side of the linear motor stator track. The linear motor mover performs linear acceleration motion from the bottom of the motion bracket upward, driving the impact ball head to impact the bottom of the battery pack to be tested, and performing a battery pack bottom ball impact test on the battery pack to be tested.

[0014] Furthermore, the stator track of the linear motor is a composite track of a combination of a straight line and an arc line, which is formed by combining a straight line rail and an arc line to form a composite track with a combination of an arc line and a straight line.

[0015] Furthermore, the composite track comprises two sections of straight rails and one section of curved rail, and the two sections of straight rails are connected by the curved rail to form a composite track; wherein, one section is a vertical straight rail, which is arranged on the side of the moving bracket from the top to the bottom of the moving bracket, and the other section is a horizontal straight rail, which is horizontally arranged on the bottom platform of the moving bracket, and the two sections of straight rails are connected by a curved rail to form a composite track composed of straight lines and arcs; the linear motor mover is buckled on the composite track, and after power is turned on, the linear motor mover first performs initial acceleration through the horizontal linear rail of the composite track, and then turns through the curved rail, the linear motor mover changes from horizontal motion to vertical upward motion, and then performs secondary acceleration through the vertical linear rail, and performs linear acceleration motion from the bottom of the moving bracket upward, driving the impact ball head to impact the bottom of the battery pack to be tested, and performing a battery pack bottom ball impact test on the battery pack to be tested.

[0016] Furthermore, the curvature of the arc track must ensure that the movement of the linear motor mover is not obstructed, and the minimum arc radius is proportional to the length of the linear motor mover and the speed of the linear motor mover when passing through the arc track, as well as the mass of the linear motor mover and the impact ball head combination.

[0017] Furthermore, the minimum arc radius is not less than twice the length of the linear motor rotor.

[0018] Furthermore, the arc rail is formed by laying multiple arc-shaped stator coils under the arc-shaped track and combining them according to a determined curvature; the straight rail is also formed by laying multiple flat-wound stator coils under the straight track and combining them to form a straight rail, and then two straight rails and one arc rail are combined together to form a composite rail.

[0019] Furthermore, the linear motor bottom impact test device is a mobile impact device; when in use, the support frame of the bottom ball impact test bench is first raised by adjusting the bracket to leave enough height space under the test platform of the battery pack bottom ball impact test bench, and then the battery pack to be tested is placed on the test platform and fixed with the battery pack pressing tool; then the linear motor bottom impact test device is moved to the bottom of the test position with the impact test battery pack, and the linear motor on the linear motor bottom impact test device drives the impact ball head to move linearly from bottom to top to realize the battery pack bottom ball impact test of the battery pack to be tested; The linear motor is a permanent magnet synchronous linear motor. The stator coils of the linear motor are arranged from top to bottom on the moving bracket. The linear motor stator track for the linear motor is composed of multiple stator coils. The linear motor mover is then buckled on the linear motor stator track. The linear motor mover is made of permanent magnet material. After power is turned on, the linear motor mover will move from bottom to top along the linear motor stator track to achieve bottom impact on the battery pack to be tested. A laser alignment device is provided on the top of the moving bracket of the linear motor bottom impact test device. The operator uses the laser to determine the impact position to ensure that the target collision position and the launch point coincide.

[0020] Furthermore, the battery pack bottom ball impact test includes at least the following steps: 1) Raise the ball impact test stand at the bottom of the battery pack According to the space height required for the linear motor bottom impact test, adjust the test platform space height of the battery pack bottom ball impact test bench so that the space position height of the test platform bottom of the battery pack bottom ball impact test bench is sufficient for the operation of the linear motor; 2) Install the test battery pack on the test platform of the ball impact test bench at the bottom of the battery pack After adjusting the test platform height of the battery pack bottom ball impact test bench, lock the support frame of the battery pack bottom ball impact test bench with locking bolts, then use a crane to lift the battery pack to be tested onto the upper surface of the test platform of the battery pack bottom ball impact test bench, and secure it with a pressure plate type battery pack clamping fixture; 3) Arrangement of linear motor bottom impact test device The linear motor bottom impact test device is moved to the bottom of the battery pack bottom ball impact test bench test platform. The operator uses a laser to determine the impact position and aligns it with the test position on the bottom of the battery pack to be tested, ensuring that the target collision position and the launch point coincide with each other. The operator then installs the impact ball head on the upper head of the linear motor mover of the linear motor bottom impact test device, aligning the impact ball head with the test position on the bottom of the battery pack to be tested. 4) Conduct battery pack bottom impact test Start the linear motor. The linear motor actuator drives the impact ball head to accelerate and impact the test position of the battery pack to be tested in an electromagnetic catapult manner. Ensure that the speed and energy of the impact ball head when it contacts the test position at the bottom of the battery pack to be tested meet the requirements of the test standard, and the corresponding test data is recorded by the set detection sensor; 5) Evacuate after the test is completed After the back impact test of the battery pack to be tested is completed, the battery pack is unloaded and observed to see if there is any leakage, fire, explosion, etc., and the internal electrolyte and coolant leakage is checked; after the inspection is completed, the linear motor bottom impact test device is evacuated, and then the tooling of the battery pack to be tested is untied, and the battery pack to be tested is hoisted down to the ball impact test bench at the bottom of the battery pack, and the entire test is completed.

[0021] Beneficial Effects: This invention changes the driving mode of the impact ball head in the battery pack bottom ball impact test to a linear motor drive to determine the speed and energy to hit the specified position. Compared with the existing spring and pneumatic launch modes in the industry, it has higher energy control accuracy and good repeatability, is easy to adjust and control, and is simple to operate. It has the following advantages: 1. Use linear motor to accelerate the impact of the workpiece to set the speed and energy to hit the specified position. The energy accuracy is high. Compared with the spring, pneumatic and other launch modes in the industry, it can more accurately control the bottom impact test; 2. The linear motor is used as the driving device of the impact ball head, which is easy to adjust and control. By adjusting the voltage or frequency, or changing the secondary material, different speeds and electromagnetic thrusts can be obtained. The actual speed before the impact can be accurately tested with high accuracy. It is suitable for various test conditions. 3. The battery bottom test is carried out by electromagnetic ejection using a linear motor, which has high acceleration. This is a significant advantage of linear motor drive over other cylinders, hydraulic cylinders, or screw, synchronous belt and gear rack drives; 4. The double-track impact structure of the linear motor stator track and the impact ball head sliding track 9 can not only ensure the impact force, but also effectively protect the linear motor stator track from damage; 5. Using a composite magnetic track that combines straight lines and arcs, through secondary acceleration, this can not only effectively reduce the space height required by the test device, but also reduce the space of the entire test device at the bottom; 6. The lower end of the linear motor bottom impact test device is equipped with a fixed universal wheel, which is convenient for adjusting the focus impact position and has a good fixing effect; 7. A laser alignment device is installed at the front end of the linear motor bottom impact test device, so the operator can clearly and conveniently observe whether the target collision position coincides with the launch point. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a three-dimensional schematic diagram of the overall structure of the battery pack bottom ball impact test bench of the present invention; Figure 2 This is a schematic diagram of the front structure of the overall structure of the battery pack bottom ball impact test bench of the present invention; Figure 3 This is a schematic side view of the overall structure of the battery pack bottom ball impact test bench of the present invention; Figure 4 It is a disassembled three-dimensional schematic diagram of a three-dimensional schematic diagram of a linear motor bottom impact test device; Figure 5 This is a schematic diagram of the front structure of the linear motor bottom impact test device; Figure 6 This is a side structural diagram of the linear motor bottom impact test device; Figure 7 This is an enlarged structural diagram of the linear motor and impact ball head part of the linear motor bottom impact test device; Figure 8 This is a schematic diagram of the stator track structure of a linear motor according to the second embodiment of the present invention.

[0023] In the figure: 1. Battery pack to be tested; 2. Ball impact test bench for battery pack bottom; 201. Support frame; 202. Height adjustment bracket; 203. Test platform; 204. Battery pack pressing fixture; 3. Bottom impact test device; 4. Linear motor; 401. Linear motor stator track; 4011. Linear rail; 4012. Arc rail; 402. Linear motor mover; 5. Impact ball head; 6. Motion bracket; 7. Traveling wheel; 8. Locking support rod; 9. Impact ball head sliding track; 10. Sliding block; 11. Impact ball head connecting plate. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings: Example 1

[0025] like Figure 1 、 2As shown in Figure 3, a method for completing a battery pack bottom test based on a linear motor ejection impact ball head is provided. The battery pack 1 to be tested is placed on a battery pack bottom ball impact test bench 2, and a linear motor bottom impact test device 3 driven by a linear motor is provided below the battery pack bottom ball impact test bench 2, at the impact point below the battery pack 1 to be tested. The power device of the bottom impact test device 3 drives the impact ball head of the battery pack bottom ball impact test to impact the battery pack from the bottom of the battery pack to be tested; the power device is a linear motor 4, and the impact ball head 5 is installed at the head of the linear motor 4. The impact ball head 5 is driven by the linear motor 4 to impact the battery pack 1 to be tested from the bottom of the battery pack 1 according to the impact force and impact method required for the battery pack bottom ball impact test, so as to perform a bottom ball impact test on the battery pack to be tested.

[0026] Among them, the movement of the impact ball head driven by the linear motor is to first lift the support frame 201 of the bottom ball impact test bench 2 through the height adjustment bracket 202, so that sufficient height space is left under the test platform 203 of the battery pack bottom ball impact test bench, ensuring that the linear motor bottom impact test device 3 can be placed under the test platform 203 of the battery pack bottom ball impact test bench 2; after the height is adjusted, the support frame 201 and the height adjustment bracket 202 are fixed together with the "C" clamp 205 to form an integral height adjustment support frame; then the battery pack 1 to be tested is placed on the test platform 203, and is pressed and fixed with the battery pack pressing tool 204, and then the linear motor bottom impact test device 3 is placed on the test platform 203 with the impact test battery pack 1. Below the test position, the linear motor 4 on the linear motor bottom impact test device 3 drives the impact ball head 5 to perform a linear impact movement from bottom to top; and the linear motor 4 on the linear motor bottom impact test device 3 drives the impact ball head 5 to perform a linear impact movement from bottom to top by installing the impact ball head 5 on the impact ball head sliding track 9 of the bottom impact test device 3. At the same time, a linear motor 4 is also installed on the bottom impact test device 3, and the linear motor 4 drives the impact ball head 5 to perform an accelerated movement from bottom to top along the impact ball head sliding track 9 in a sliding impact manner, and ensures that the impact energy when the impact ball head contacts the bottom of the battery pack to be tested is the energy required by the test, thereby completing the battery pack bottom ball impact test of the battery pack to be tested.

[0027] like Figure 4-7As shown, the linear motor 4 on the linear motor bottom impact test device 3 drives the impact ball head 5 to perform a linear impact motion from bottom to top. The linear motor stator track 401 and the impact ball head sliding track 9 are laid on the linear motor bottom impact test device 3. The linear motor stator track 401 and the impact ball head sliding track 9 are arranged parallel to each other on the motion bracket 6 of the linear motor bottom impact test device 3; then the linear motor mover 402 is installed on the linear motor stator track 401, and a sliding block 10 matching the impact ball head sliding track is installed on the impact ball head sliding track 9; then the impact ball head connecting plates 11 are arranged on the linear motor mover and the sliding block, and 11 is respectively connected to the linear motor The motor 402 and the sliding block 10 are connected to form an integral unit, allowing the sliding block 10 and the linear motor mover 402 to move up and down together. The impact ball 5 is then mounted on the impact ball connecting plate 11, located on one side of the impact ball sliding track 9, via the impact ball bracket 12, with the impact ball 5 facing upward. The linear motor control system (not shown) then adjusts the linear motor's operating speed, starts the linear motor 4, and the linear motor mover 402 drives the impact ball 5 upward. Upon reaching the bottom of the battery pack 1 to be tested, the required impact force is achieved upon contact with the bottom 1, allowing the battery pack bottom impact test to be performed. This ensures the stability of the impact ball during impact and reduces the impact of the recoil of the impact test on the linear motor stator track.

[0028] Among them, the linear motor track is laid on the linear motor bottom impact test device 3, and the linear motor bottom impact test device 3 is set in the middle of the two support frames 201 of the ball impact test bench 2 at the bottom of the battery pack. The linear motor bottom impact test device 3 is a mobile device, which is only moved to the middle of the two support frames 201 of the ball impact test bench 2 at the bottom of the battery pack when doing the test; the linear motor bottom impact test device 3 includes a moving bracket 6, an impact ball head 5 and a linear motor 4; the bracket of the moving bracket 6 frame structure is upright installed on the bottom platform 15, and a back plate 14 is installed on the moving bracket 6. The linear motor stator track 401 is arranged on the back plate 14 from top to bottom, and the linear motor stator track 401 constitutes the motion track of the linear motor mover 402, and then the linear motor mover 402 is buckled on the linear motor stator track 401. After power is turned on, the linear motor mover 402 will move from bottom to top along the linear motor stator track to realize the bottom impact of the battery pack to be tested. In addition, a movable roller 16 and a fixed support rod 17 are provided under the bottom surface of the bottom platform 15. When the linear motor bottom impact test device 3 is moved to the middle position of the two support frames 201 by the movable roller 16, it is fixed by the fixed support rod 17 to prevent the linear motor bottom impact test device 3 from moving as a whole when the linear motor 4 drives the impact ball head 5 to perform an impact test.

[0029] The linear motor stator track 401 is a linear rail, which is arranged from the upper part of the motion bracket 6 to the bottom platform 602 of the motion bracket 6. The linear motor mover 402 is buckled on the side of the linear motor stator track 401. The linear motor mover 402 performs linear acceleration motion from the bottom of the motion bracket 6 upward, driving the impact ball head 5 to impact the bottom of the battery pack to be tested, and performing a battery pack bottom ball impact test on the battery pack to be tested.

[0030] The linear motor 4 is a permanent magnet synchronous linear motor. The linear motor stator track 401 is a linear motor stator coil 13 arranged from top to bottom on a moving bracket. The linear motor stator track 401 for the operation of the linear motor is composed of multiple stator coils 13. The linear motor mover 402 is then buckled onto the linear motor stator track 401. The linear motor mover 402 is made of permanent magnet material to constitute a permanent magnet linear motor. After power is turned on, the linear motor mover 402 will move from bottom to top along the linear motor stator track to achieve bottom impact on the battery pack to be tested.

[0031] Example 2 The principle of Example 2 is the same as that of Example 1, except that the specific structure of the example is different from that of Example 1. It is a method for completing the bottom test of the battery pack based on a linear motor ejecting impact ball head. The battery pack to be tested is placed on a battery pack bottom ball impact test bench, and the power device of the bottom impact test device drives the impact ball head of the battery pack bottom ball impact test to impact the battery pack from the bottom of the battery pack to be tested; the power device is a linear motor, and the impact ball head is installed on the head of the linear motor. The impact ball head is driven by the linear motor to impact the battery pack from the bottom of the battery pack according to the impact force and impact method required for the battery pack bottom ball impact test, so as to perform a bottom ball impact test on the battery pack to be tested.

[0032] Among them, the linear motor track is laid on the linear motor bottom impact test device, and a moving bracket of the linear motor bottom impact test device is set in the middle of the two support frames of the ball impact test bench at the bottom of the battery pack. The linear motor stator track is arranged from top to bottom on the moving bracket, and the linear motor stator track constitutes the moving track of the linear motor mover. The linear motor mover is then buckled on the linear motor stator track. After power is turned on, the linear motor mover will move from bottom to top along the linear motor stator track to achieve bottom impact on the battery pack to be tested.

[0033] The linear motor stator track 401 is a composite track composed of a straight line and an arc, which is formed by combining a straight line track 4011 and an arc track 4012 to form a composite track with an arc and a straight line.

[0034] The composite track comprises two sections of straight rails 4011 and one section of curved rail 4012, and the two sections of straight rails 4011 are connected by the curved rail 4012 to form a composite track; wherein, one section of the two sections of straight rails 4011 is a vertical straight rail, which is arranged on the side of the moving bracket from the top to the bottom of the moving bracket, and the other section is a horizontal straight rail, which is horizontally arranged on the bottom platform of the moving bracket. The two sections of straight rails are connected by a curved rail to form a composite track combining straight lines and arcs; the linear motor mover is buckled on the composite track. After power is turned on, the linear motor mover first performs initial acceleration through the horizontal linear rail of the composite track, and then turns through the curved rail. The linear motor mover changes from horizontal motion to vertical upward motion, and then performs secondary acceleration through the vertical linear rail, and performs linear acceleration motion from the bottom of the moving bracket upward, driving the impact ball head to impact the bottom of the battery pack to be tested, and performing a battery pack bottom ball impact test on the battery pack to be tested.

[0035] The curvature of the arc rail 4012 must ensure that the linear motor mover is not obstructed when passing through. The minimum arc radius is proportional to the length of the linear motor mover, the speed of the linear motor mover when passing through the arc rail, and the mass of the linear motor mover and the impact ball head combination.

[0036] The minimum arc radius of the arc rail 4012 is not less than twice the length of the linear motor mover 5; the length refers to the size of the arc rail 4012 along the direction of track travel.

[0037] The arc rail 4012 is formed by laying multiple arc stator coils 4013 under the arc track 4015 and combining them according to a determined curvature; the straight rail 4011 is also formed by laying multiple flat-wound stator coils 4014 under the straight track 4016, and then combining two straight rails 4011 and a arc rail to form a composite rail.

[0038] The rest is the same as that of the first embodiment.

[0039] It should be noted that the above-mentioned embodiments are only used to clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and the terms such as "upper", "lower", "front", "back", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be considered as the scope of the implementation of the present invention without substantially changing the technical content. At the same time, the structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] This invention changes the driving mode of the impact ball head in the battery pack bottom ball impact test to a linear motor drive to determine the speed and energy to hit the specified position. Compared with existing spring and pneumatic launch modes in the industry, it has higher energy control accuracy and good repeatability, is easy to adjust and control, and is simple to operate. It has the following advantages: 1. Use linear motor to accelerate the impact of the workpiece to set the speed and energy to hit the specified position. The energy accuracy is high. Compared with the spring, pneumatic and other launch modes in the industry, it can more accurately control the bottom impact test; 2. The linear motor is used as the driving device of the impact ball head, which is easy to adjust and control. By adjusting the voltage or frequency, or changing the secondary material, different speeds and electromagnetic thrusts can be obtained. The actual speed before the impact can be accurately tested with high accuracy. It is suitable for various test conditions. 3. The battery bottom test is carried out by electromagnetic ejection using a linear motor, which has high acceleration. This is a significant advantage of linear motor drive over other cylinders, hydraulic cylinders, or screw, synchronous belt and gear rack drives; 4. The double-track impact structure of the linear motor stator track and the impact ball head sliding track can not only ensure the impact force, but also effectively protect the linear motor stator track from damage; 5. Using a composite magnetic track that combines straight lines and arcs, through secondary acceleration, this can not only effectively reduce the space height required by the test device, but also reduce the space of the entire test device at the bottom; 6. A fixed universal wheel is arranged at the lower end of the linear motor bottom impact test device to facilitate adjustment of the focus impact position and achieve good fixing effect; 7. A laser alignment device is installed at the front end of the linear motor bottom impact test device, so the operator can clearly and conveniently observe whether the target collision position coincides with the launch point.

Claims

1. A method for completing a battery pack bottom test using a linear motor-ejected impact ball head. The method comprises placing a battery pack to be tested on a battery pack bottom impact test bench. A linear motor bottom impact test device driven by a linear motor is installed below the battery pack bottom impact test bench, at the impact point below the battery pack to be tested. The power device of the bottom impact test device drives the impact ball head of the battery pack bottom impact test to impact the battery pack from the bottom of the battery pack to be tested. The method is characterized by: The power device is a linear motor, and the impact ball head is installed on the head of the linear motor. The linear motor drives the impact ball head to move. According to the impact force and impact method required by the battery pack bottom ball impact test, the battery pack is impacted from the bottom of the battery pack to perform the battery pack bottom ball impact test on the battery pack to be tested.

2. The method for completing a battery pack bottom test based on a linear motor ejection impact ball head according to claim 1, characterized in that: The impact ball head is driven to move by a linear motor, and the impact ball head is installed on the sliding track of the bottom impact test device. At the same time, a linear motor is also installed in the bottom impact test device, and the linear motor drives the impact ball head to perform accelerated movement from bottom to top along the sliding track in a sliding impact manner, and ensures that the impact energy when the impact ball head contacts the bottom of the battery pack to be tested is the energy required by the test, thereby completing the battery pack bottom ball impact test of the battery pack to be tested.

3. The method for completing a battery pack bottom test based on a linear motor ejection impact ball head according to claim 2, characterized in that: The impact ball head is driven by a linear motor to perform acceleration movement from bottom to top along the sliding track in a sliding impact manner, and it is ensured that the impact energy when the impact ball head contacts the bottom of the battery pack to be tested is the energy required by the test. The linear motor stator track and the impact ball head sliding track are laid on the motion bracket of the linear motor bottom impact test device, and the linear motor stator track and the impact ball head sliding track are arranged parallel to each other on the motion bracket of the linear motor bottom impact test device, and then the linear motor mover is installed on the linear motor stator track, and a sliding block matching the impact ball head sliding track is installed on the impact ball head sliding track; then An impact ball head connecting plate is provided on the motor and the sliding block. The impact ball head connecting plate is respectively connected to the linear motor mover and the sliding block to form an integral body, so that the sliding block and the linear motor mover move up and down together. Then, the impact ball head is installed on the impact ball head connecting plate at a position on one side of the impact ball head sliding track, and the head of the impact ball head is facing upward; then, the linear motor control system is used to adjust the running speed of the linear motor, and the linear motor is started. The linear motor mover will drive the impact ball head to move from bottom to top, and when it reaches the bottom of the battery pack to be tested and contacts the bottom of the battery pack to be tested, the impact force required for the test is achieved, and the battery pack bottom ball impact test of the battery pack to be tested is carried out.

4. The method for completing a battery pack bottom test based on a linear motor ejection impact ball head according to claim 3, characterized in that: The linear motor track is laid on the linear motor bottom impact test device, and a moving bracket of the linear motor bottom impact test device is set between the two support frames of the ball impact test bench at the bottom of the battery pack. The linear motor stator track is arranged from top to bottom on the moving bracket, and the linear motor stator track constitutes the moving track of the linear motor mover. The linear motor mover is then buckled on the linear motor stator track. After power is turned on, the linear motor mover will move from bottom to top along the linear motor stator track to achieve bottom impact on the battery pack to be tested.

5. The method for completing a battery pack bottom test based on a linear motor ejection impact ball head according to claim 4, characterized in that: The linear motor stator track is a linear rail, which is arranged from the upper part of the motion bracket to the bottom of the motion bracket. The linear motor mover is buckled on the side of the linear motor stator track. The linear motor mover performs linear acceleration motion from the bottom of the motion bracket upward, driving the impact ball head to impact the bottom of the battery pack to be tested, and performing a battery pack bottom ball impact test on the battery pack to be tested.

6. The electromagnetic ejection battery pack bottom ball impact test method according to claim 4, characterized in that: The linear motor stator track is a composite track composed of a straight line and an arc line, which is formed by combining a straight line track and an arc line track to form a composite track with an arc line and a straight line shape.

7. The electromagnetic ejection battery pack bottom ball impact test method according to claim 6, characterized in that: The composite track comprises two sections of straight rails and one section of curved rail, and the two sections of straight rails are connected by the curved rail to form a composite track; wherein, one section is a vertical straight rail, which is arranged on the side of the moving bracket from the top to the bottom of the moving bracket, and the other section is a horizontal straight rail, which is horizontally arranged on the bottom platform of the moving bracket. The two sections of straight rails are connected by a curved rail to form a composite track combining straight lines and arcs; the linear motor mover is buckled on the composite track, and after power is turned on, the linear motor mover first performs preliminary acceleration through the horizontal linear rail of the composite track, and then turns through the curved rail, the linear motor mover changes from horizontal motion to vertical upward motion, and then performs secondary acceleration through the vertical linear rail, and performs linear acceleration motion from the bottom of the moving bracket upward, driving the impact ball head to impact the bottom of the battery pack to be tested, and performing a battery pack bottom ball impact test on the battery pack to be tested.

8. The electromagnetic ejection battery pack bottom ball impact test method according to claim 7, characterized in that: The curvature of the arc track must ensure that the linear motor mover is not obstructed when passing through. The minimum arc radius is proportional to the length of the linear motor mover, the speed of the linear motor mover when passing through the arc track, and the mass of the linear motor mover and the impact ball head combination.

9. The electromagnetic ejection battery pack bottom ball impact test method according to claim 8, characterized in that: The minimum arc radius is not less than twice the length of the linear motor rotor.

10. The electromagnetic ejection battery pack bottom ball impact test method according to claim 8, characterized in that: The arc rail is formed by laying multiple arc-shaped stator coils under the arc-shaped track and combining them according to a determined curvature; the straight rail is also formed by laying multiple flat-wound stator coils under the straight track and combining them to form a straight rail, and then combining two straight rails and a arc rail to form a composite rail.

11. The electromagnetic ejection battery pack bottom ball impact test method according to claim 1, characterized in that: The linear motor bottom impact test device is a mobile impact device. When in use, the support frame of the bottom ball impact test bench is first raised by adjusting the bracket to leave sufficient height space under the test platform of the battery pack bottom ball impact test bench. The battery pack to be tested is then placed on the test platform and fixed with a battery pack pressing tool. The linear motor bottom impact test device is then moved to the bottom of the test position with the impact test battery pack. The linear motor on the linear motor bottom impact test device drives the impact ball head to move linearly from bottom to top to achieve the battery pack bottom ball impact test of the battery pack to be tested. The linear motor is a permanent magnet synchronous linear motor. The stator coils of the linear motor are arranged from top to bottom on the moving bracket. The linear motor stator track for the operation of the linear motor is composed of multiple stator coils. The linear motor mover is then buckled on the linear motor stator track. The linear motor mover is made of permanent magnet material. After power is turned on, the linear motor mover will move from bottom to top along the linear motor stator track to achieve bottom impact on the battery pack to be tested. A laser alignment device is provided on the top of the moving bracket of the linear motor bottom impact test device. The operator uses the laser to determine the impact position to ensure that the target collision position and the launch point coincide.

12. The electromagnetic ejection battery pack bottom ball impact test method according to any one of claims 1 to 11, characterized in that: The battery pack bottom ball impact test comprises at least the following steps: 1) Raise the ball impact test stand at the bottom of the battery pack According to the space height required for the linear motor bottom impact test, adjust the test platform space height of the battery pack bottom ball impact test bench so that the space position height of the test platform bottom of the battery pack bottom ball impact test bench is sufficient for the operation of the linear motor; 2) Install the test battery pack on the test platform of the ball impact test bench at the bottom of the battery pack After adjusting the test platform height of the battery pack bottom ball impact test bench, lock the support frame of the battery pack bottom ball impact test bench with locking bolts, then use a crane to lift the test battery pack onto the upper surface of the test platform of the battery pack bottom ball impact test bench, and secure it with a pressure plate type battery pack clamping fixture; 3) Arrangement of linear motor bottom impact test device The linear motor bottom impact test device is moved to the bottom of the battery pack bottom ball impact test bench test platform. The operator uses a laser to determine the impact position and aligns it with the test position on the bottom of the battery pack to be tested, ensuring that the target collision position and the launch point coincide with each other. The operator then installs the impact ball head on the linear motor mover head of the linear motor bottom impact test device, aligning the impact ball head with the test position on the bottom of the battery pack to be tested. 4) Conduct battery pack bottom impact test Start the linear motor. The linear motor actuator drives the impact ball head to accelerate and impact the test position of the battery pack to be tested in an electromagnetic catapult manner. Ensure that the speed and energy of the impact ball head when it contacts the test position at the bottom of the battery pack to be tested meet the requirements of the test standard, and the corresponding test data is recorded by the set detection sensor; 5) Evacuate after the test is completed After the bottom impact test of the battery pack to be tested is completed, the battery pack is unloaded and observed to see if there is leakage, fire, explosion, etc., and whether there is leakage of electrolyte and coolant inside. After the inspection is completed, the linear motor bottom impact test device is evacuated, and then the tooling of the battery pack to be tested is untied, and the battery pack to be tested is hoisted down to the ball impact test bench at the bottom of the battery pack, and the entire test is completed.

Images