Bottom test bench for power battery pack

Abstract

A power battery pack bottom test bed comprises a test bed support, a test bed plate and a battery pack bottom ball strike test device. The test bed plate is installed on the test bed support, a tool clamp is arranged on the test bed plate, and a to-be-detected battery pack is installed on the test bed plate through the tool clamp; a battery pack bottom ball strike test device is arranged between the test bed bracket and below the test bed plate; the battery pack bottom ball strike test device is a test impact device driven by a linear motor, an impact ball head is installed at the head of the linear motor rotor and moves together with the linear motor rotor, the impact ball head is driven by the linear motor, the battery pack is impacted from the bottom of the battery pack, and a bottom ball strike test of the battery pack to be tested is carried out. The linear motor is adopted for driving so as to determine the speed and the energy collision direction designated position, and compared with existing spring and pneumatic launching modes in the industry, the energy control precision is higher, repeatability is good, adjustment and control are convenient, and operation is easy.

Description

Technical Field

[0001] The present invention relates to an electric vehicle component detection and testing device, in particular to a device for bottom impact testing of a power battery pack of a new energy vehicle, belonging to the technical field of battery pack detection. 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 ball impact test on the bottom of the battery pack is an important means of evaluating the impact resistance of the bottom of the battery pack of electric vehicles. This test simulates the impact that the bottom of the battery pack may receive when the vehicle encounters obstacles (such as speed bumps, stones) during driving, and comprehensively tests the structural safety, internal cooling system, electrical components, etc. of the battery pack. The existing test method is usually carried out under specific environmental conditions (such as temperature 22℃±5℃, relative humidity 15%-90%), using a metal ball impact head with a diameter of 150mm to impact the bottom of the battery pack at a speed of 1±0.2mm / s. The impact point is selected at the center of the bottom of the battery pack or within a radius of 240mm from the geometric center. The ball impact force is usually 110% of the vehicle's allowable gross mass, and the load is continuously applied for 60 seconds. After unloading, observe whether the battery pack has leakage, fire, explosion, etc., and check whether there is leakage of electrolyte and coolant inside. 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, including 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 placed in an open area for more than 24 hours after the test, 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 fixedly installed on the top of the workbench, a hydraulic cylinder fixedly installed on the bottom of the inner cavity of the workbench, a placement plate fixedly installed on the telescopic end of the hydraulic cylinder, a sealing column fixedly installed on the top of the placement plate, and a fixed platform 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 device in accordance with the requirements of the existing power battery pack bottom impact test, so that its 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 is adjustable.

[0009] In view of the above problems, the technical solution proposed by the present invention is: A power battery pack bottom test bench comprises a test bench bracket, a test bench plate and a battery pack bottom ball impact test device; the test bench plate is mounted on the test bench bracket, a tooling fixture is provided on the test bench plate, and the battery pack to be tested is mounted on the test bench plate through the tooling fixture; a battery pack bottom ball impact test device is provided between the test bench brackets and below the test bench plate; the battery pack bottom ball impact test device is a test impact device driven by a linear motor, the impact ball head is mounted on the head of the linear motor mover and moves together with the linear motor, and 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, so as to perform a bottom ball impact test on the battery pack to be tested.

[0010] Furthermore, the test bench bracket is a combined bracket, including a main bracket and a secondary bracket, the main bracket is mounted on the secondary bracket, and the main bracket and the secondary bracket are connected and fixed by locking bolts. Preferably, a C-type clamp is selected to fasten the main bracket and the secondary bracket together.

[0011] Furthermore, the sub-bracket is a height-adjustable bracket, which includes an X-shaped support arm, a base and an upper support plate, and the X-shaped support arm is arranged between the base and the support plate; the height of the sub-bracket is adjusted by adjusting the height of the X-shaped support arm to ensure that there is enough space under the test bench for the ball impact test device at the bottom of the battery pack.

[0012] Furthermore, the battery pack bottom ball impact test device is a mobile device, including a movable base plate, a linear motor bracket is installed on the movable base plate, the linear motor is vertically installed on the linear motor bracket, the impact ball head is installed on the head of the linear motor mover, and moves together with the linear motor mover, and moves up and down with the linear motor mover; universal wheels and fixed support rods are installed under the movable base plate, and the entire battery pack bottom ball impact test device is moved by the universal wheels, and is locked and fixed by the fixed support rod after moving into place.

[0013] Furthermore, the linear motor bracket is a tower-shaped frame structure, and a fixed backplate is arranged in the middle of the linear motor bracket of the tower-shaped frame structure; on the fixed backplate, the linear motor stator track and the impact ball head sliding track are arranged in parallel from top to bottom; the linear motor stator track and the impact ball head sliding track are arranged parallel to each other on the fixed backplate of the linear motor bracket, 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; the linear motor mover and the sliding block are connected together by the impact ball head connecting plate to form a whole, so that the sliding block and the linear motor mover move up and down together; on the impact ball head connecting plate, the impact ball head is installed at a position on one side of the impact ball head sliding track, and the head of the impact ball head is facing upward, and the impact ball head moves up and down together with the linear motor mover.

[0014] 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 linear motor stator track. The linear motor mover is connected to the impact ball head through the impact ball head connecting plate. 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.

[0015] Furthermore, the stator track of the linear motor is a stator composite track that is a combination of straight lines and arcs, which is formed by combining a straight rail and an arc rail to form a stator composite track with a combination of arcs and straight lines.

[0016] Furthermore, the stator composite track comprises two sections of linear rails and one section of curved rail, the two sections of linear rails are connected by the curved rail to form a stator composite track; wherein, one section is a vertical linear rail, which is arranged on the side of the motion bracket from the upper part to the lower part of the motion bracket, and the other section is a horizontal linear rail, which is horizontally arranged on the bottom platform of the motion bracket. The two sections of linear rails are connected by a curved rail to form a stator composite track of a combination of straight lines and arcs; at the same time, an impact ball head sliding track of the same structure is provided in parallel with the stator composite track; the linear motor mover is buckled on the stator composite track, and the impact ball head slides A slider is buckled on the track, and the linear motor mover and the slider are connected by an impact ball head connecting plate. The impact ball head is installed on the impact ball head connecting plate through a mounting seat, forming an impact ball head movement form of a dual-track structure in which the linear motor mover and the impact ball head move together; after power is turned on, the linear motor mover first undergoes initial acceleration through the horizontal linear rail of the stator composite track, and then turns through the arc rail, and the linear motor mover changes from horizontal movement to vertical upward movement, and then undergoes secondary acceleration through the vertical linear rail, performing linear acceleration movement upward from the bottom of the motion bracket, 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.

[0017] Furthermore, the curvature of the arc track must ensure that the movement of the linear motor mover is unobstructed, and 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.

[0018] Furthermore, the minimum arc radius is not less than twice the length of the linear motor mover in the moving direction.

[0019] Furthermore, the arc track is composed of a plurality of single-piece arc linear motor stators, and the arc track is formed according to the determined arc combination.

[0020] Furthermore, the linear motor is a permanent magnet synchronous linear motor, and the stator track of the linear motor is arranged from top to bottom on the moving bracket, and the stator magnetic track is laid on the stator coil. The linear motor stator track for the operation of the linear motor is composed of a combination of multiple stator coils and stator magnetic tracks, and then the linear motor mover is buckled on the linear motor stator track, and 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.

[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 composite magnetic track is used and the secondary acceleration is performed, which 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; 5. The linear motor and the impact ball head sliding track dual-track motion structure is adopted. Although the linear motor mover and the impact ball head move together, the forces are separated by a dual-track structure of the impact ball head motion form. This can not only ensure the impact force of the impact ball head during impact, but also effectively prevent the impact force from damaging the linear motor stator track. 6. The lower end of the battery pack bottom ball impact test device is arranged with fixed universal wheels and fixed support rods, which are convenient for adjusting the focus impact position and have a good fixing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a three-dimensional schematic diagram of a battery pack bottom ball impact test bench according to the present invention; Figure 2 This is a schematic diagram of the front structure of the battery pack bottom ball impact test bench of the present invention; Figure 3 It is a side structural schematic diagram of the battery pack bottom ball impact test bench of the present invention; Figure 4 This is a disassembled diagram of a three-dimensional schematic diagram of a linear motor bottom impact test device; Figure 5 This is a schematic diagram of the combined structure of the linear motor stator track and the impact ball head sliding track; Figure 6 This is a schematic diagram of the combined structure of the linear motor stator track and the impact ball head sliding track from another direction; Figure 7 This is a schematic diagram of the overall top-down perspective structure of the linear motor bottom impact test device; Figure 8 This is a schematic diagram of the bottom three-dimensional structure of the linear motor bottom impact test device; Figure 9 This is a schematic diagram of the principle structure of the linear motor stator track of Example 2.

[0023] Figure: 1. Test bench bracket; 101. Main bracket; 102. Auxiliary bracket; 1021. X-shaped support arm; 1022. Base; 1023. Upper support plate; 103. Locking bolt; 2. Test bench plate; 3. Battery pack bottom ball impact test device; 301. Mobile base plate; 302. Linear motor bracket; 3021. Fixed back plate; 303. Universal wheel; 304. Fixed support rod; 305. Impact ball head connecting plate; 4. Fixture; 5. Battery pack to be tested; 6. Linear motor; 601. Linear motor mover; 602. Linear motor stator track; 6021. Linear rail; 6022. Curved rail; 6023. Stator coil; 6024. Stator magnetic track; 6025. Curved stator coil; 6026. Curved stator magnetic track; 603. Stator coil; 604. Stator magnetic track; 605. Anti-accidental triggering safety device; 7. Impact ball head; 701. Impact ball head sliding track; 702. Sliding block; 703. Impact ball head support. DETAILED DESCRIPTION

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

[0025] like Figure 1 、 2 As shown in Figure 3, a power battery pack bottom test bench, a power battery pack bottom test bench, includes a test bench bracket 1, a test bench plate 2 and a battery pack bottom ball impact test device 3; the test bench plate 2 is installed on the test bench bracket 1, and a tooling fixture 4 is provided on the test bench plate 2. The battery pack 5 to be tested is installed on the test bench plate 2 through the tooling fixture 4; the test bench bracket 1 is a double bracket, and a battery pack bottom ball impact test device 3 is provided between the two test bench brackets 1 and below the test bench plate 2; the battery pack bottom ball impact test device 3 is a test impact device driven by a linear motor, which is driven by a linear motor 6 to perform impact motion, and an impact ball head 7 is installed on the head of the linear motor 6 and moves together with the linear motor 6. The impact ball head 7 is driven by the linear motor 6 to impact the battery pack 6 to be tested from the battery pack 6 to be tested 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 6 to be tested.

[0026] The test bench bracket 1 is a combined bracket, including a main bracket 101 and a sub-bracket 102. The main bracket 101 is mounted on the sub-bracket 102, and the main bracket 101 and the sub-bracket 102 are connected and fixed by locking bolts 103. Preferably, a C-type clamp is selected to fasten the main bracket 101 and the sub-bracket 102 together.

[0027] The sub-bracket 102 is a height-adjustable bracket, which includes an X-shaped support arm 1021, a base 1022 and an upper support plate 1023. The X-shaped support arm 1021 is arranged between the base 1022 and the support plate 1023; the height of the sub-bracket 102 is adjusted by adjusting the height of the X-shaped support arm 1021 to ensure that there is enough space under the test bench for the ball impact test device at the bottom of the battery pack.

[0028] The battery pack bottom ball impact test device 3 is a mobile device, including a movable base plate 301, a linear motor bracket 302 is installed on the movable base plate 301, the linear motor 6 is vertically installed on the linear motor bracket 302, the impact ball head 7 is installed at the head of the linear motor mover 601, and moves together with the linear motor mover 601, and moves up and down with the linear motor mover 601; universal wheels 303 and fixed support rods 304 are installed under the movable base plate 301, the entire battery pack bottom ball impact test device is moved by the universal wheels 303, and after moving into place, it is locked and fixed by the fixed support rod 304, so that the entire battery pack bottom ball impact test device 3 is in a locked and fixed state.

[0029] The linear motor bracket 302 is a tower-shaped frame structure, and a fixed back plate 3021 is provided in the middle of the linear motor bracket 302 of the tower-shaped frame structure; on the fixed back plate 3021, the linear motor stator track 602 and the impact ball head sliding track 701 are arranged in parallel from top to bottom; the linear motor stator track 602 and the impact ball head sliding track 701 are arranged parallel to each other on the fixed back plate 3021 of the linear motor bracket 302, the linear motor mover 601 is installed on the linear motor stator track 602, and the impact ball head sliding track 701 is installed in parallel with the linear motor mover 601. The impact ball head sliding track matches the sliding block 702; the linear motor mover 601 and the sliding block 702 are connected together through the impact ball head connecting plate 305 to form a whole, so that the sliding block 702 moves up and down together with the linear motor mover 601; on the impact ball head connecting plate 305, the impact ball head 7 is installed at a position on the side of the impact ball head sliding track 701, and the impact ball head 7 is installed on the impact ball head connecting plate 305 through the impact ball head support 703, and the head of the impact ball head 7 is facing upward, and the impact ball head 7 moves up and down together with the linear motor mover 601.

[0030] Moreover, the linear motor stator track 602 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 601 is buckled on the linear motor stator track 602. The linear motor mover 601 is connected to the impact ball head 7 through the impact ball head connecting plate 305. The linear motor mover 601 performs linear acceleration motion upward from the bottom of the motion bracket 302, driving the impact ball head 7 to impact the bottom of the battery pack to be tested 5, and performing a battery pack bottom ball impact test on the battery pack to be tested.

[0031] The linear motor 6 is a permanent magnet synchronous linear motor. The linear motor stator track 602 is constructed by distributing the linear motor's stator coils 603 from top to bottom on the fixed backplate 3021 of the motion bracket 302. A stator magnetic track 604 is laid on the stator coils 603. The combination of multiple stator coils 603 and the stator magnetic track 604 forms the linear motor stator track 602 for the linear motor's operation. The linear motor mover 601, made of permanent magnet material, is then buckled onto the linear motor stator track 602. When energized, the linear motor mover 601 moves from bottom to top along the linear motor stator track 602, impacting the bottom of the battery pack under test. Preferably, electromagnetic ejection is used for impact.

[0032] In addition, an anti-mis-triggering safety device 605 is provided at the linear motor stator track launch port of the linear motor bottom impact test device 3. Preferably, the anti-mis-triggering safety device 605 is a proximity switch light, which prevents the impact ball head 7 from falling out through electromechanical linkage.

[0033] The testing method of this power battery pack bottom test bench is as follows: the battery pack 5 to be tested is placed on the test bench plate 2 and fixed with a fixture 4, and then the battery pack bottom ball impact test device 3 is moved to the impact point position under the battery pack 1 to be tested, and after accurate positioning by laser measurement, it is locked and fixed by the fixed support rod 304; then the linear motor 6 is started, and the linear motor 6 will drive the impact ball head 7 to slide upward along the impact ball head sliding track 701 to eject and impact, and the impact ball head 7 impacts 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 the bottom ball impact test of the battery pack to be tested. Example 2

[0034] 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 power battery pack bottom test bench, comprising a test bench bracket, a test bench plate and a battery pack bottom ball impact test device; the test bench plate is installed on the test bench bracket, and a tooling fixture is provided on the test bench plate, and the battery pack to be tested is installed on the test bench plate through the tooling fixture; a battery pack bottom ball impact test device is provided between the test bench brackets and below the test bench plate; the battery pack bottom ball impact test device is a test impact device driven by a linear motor, and the impact ball head is installed on the head of the linear motor mover and moves together with the linear motor mover. 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, and a bottom ball impact test of the battery pack to be tested is performed.

[0035] The linear motor stator track 602 is a stator composite track composed of a straight line and an arc, as shown in the attached figure. Figure 9As shown, the straight rail 6021 and the arc rail 6022 are combined together to form a stator composite track with a combination of arc and straight shapes.

[0036] The stator composite track includes two sections of linear rails 6021 and one section of curved rail 6022. The two sections of linear rails 6021 are connected by the curved rail 6022 to form a stator composite track. One section is a vertical linear rail 6021, which is arranged on the side of the motion bracket from the top to the bottom of the motion bracket. The other section is a horizontal linear rail 6021, which is horizontally arranged on the bottom platform of the motion bracket. The two sections of linear rails 6021 are connected by a curved rail 6022 to form a stator composite track that is a combination of straight lines and arcs. At the same time, an impact ball head sliding track of the same structure is provided in parallel with the stator composite track. The linear motor mover is buckled on the stator On the stator composite track, a slider is buckled on the impact ball head sliding track, the linear motor mover and the slider are connected by an impact ball head connecting plate, and the impact ball head is installed on the impact ball head connecting plate through a mounting seat, forming a dual-track structure of impact ball head movement in which the linear motor mover and the impact ball head move together; after power is turned on, the linear motor mover first performs initial acceleration through the horizontal linear rail 6021 of the stator composite track, and then turns through the arc rail 6022, and the linear motor mover changes from horizontal movement to vertical upward movement, and then performs secondary acceleration through the vertical linear rail 6021, performing linear acceleration movement 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.

[0037] The curvature of the arc rail 6022 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 impact ball head combination.

[0038] The minimum arc radius of the arc rail 6022 is not less than twice the length of the linear motor mover in the traveling direction.

[0039] The linear rail 6021 is the same as that in the first embodiment. The stator coils 6023 of the linear motor are arranged from top to bottom on the back plate of the moving bracket 301 and on the moving base plate 301, and the stator magnetic rail 6024 is laid on the stator coil 6023. The linear rail 6021 of the linear motor stator track for the linear motor operation is composed of a plurality of stator coils 6023 and the stator magnetic rail 6024. The arc rail 6022 is composed of an arc stator coil 6025 and an arc stator magnetic rail 6026. The arc-shaped stator magnetic rail 6026 is combined to form the arc-shaped rail 6022 of the linear motor stator track for the operation of the linear motor; the linear motor mover 601 is then buckled on the linear motor stator rail 602, and the linear motor mover 601 is made of permanent magnetic material; after power is turned on, the linear motor mover will first perform horizontal acceleration motion along the linear rail 6021 on the movable base plate 301, and then turn along the arc-shaped rail 6022, and then perform a second acceleration motion from bottom to top along the linear rail 6021 on the moving bracket 301, so as to realize the bottom impact of the battery pack to be tested.

[0040] The rest is the same as that of the first embodiment.

[0041] 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.

[0042] 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 composite magnetic track is used and the secondary acceleration is performed, which 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; 5. The linear motor and the impact ball head sliding track dual-track motion structure is adopted. Although the linear motor mover and the impact ball head move together, the forces are separated by a dual-track structure of the impact ball head motion form. This can not only ensure the impact force of the impact ball head during impact, but also effectively prevent the impact force from damaging the linear motor stator track. 6. An anti-mis-triggering safety device is installed at the linear motor stator track launch port of the linear motor bottom impact test device. The proximity switch light can reliably avoid the safety risks caused by misoperation through electromechanical linkage. 7. The lower end of the ball impact test device at the bottom of the battery pack is equipped with fixed universal wheels, which is convenient for adjusting the focus impact position and has a good fixing effect.

Claims

1. A power battery pack bottom test bench, comprising a test bench bracket, a test bench plate and a battery pack bottom ball impact test device; the test bench plate is installed on the test bench bracket, and a tooling fixture is provided on the test bench plate, and the battery pack to be tested is installed on the test bench plate through the tooling fixture; a battery pack bottom ball impact test device is provided between the test bench brackets and below the test bench plate; the battery pack bottom ball impact test device is a test impact device driven by a linear motor, the impact ball head is installed on the head of the linear motor mover and moves together with the linear motor, and 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.

2. The power battery pack bottom test bench according to claim 1, characterized in that: The test bench bracket is a combined bracket, including a main bracket and a sub-bracket. The main bracket is installed on the sub-bracket, and the main bracket and the sub-bracket are connected and fixed by locking bolts.

3. The power battery pack bottom test bench according to claim 2, characterized in that: The sub-bracket is a height-adjustable bracket, which includes an X-shaped support arm, a base and an upper support plate. The X-shaped support arm is arranged between the base and the support plate. The height of the sub-bracket is adjusted by adjusting the height of the X-shaped support arm to ensure that there is enough space under the test bench for the ball impact test device at the bottom of the battery pack.

4. The power battery pack bottom test bench according to claim 1, characterized in that: The battery pack bottom ball impact test device is a mobile device, including a mobile base plate, a linear motor bracket is installed on the mobile base plate, the linear motor is vertically installed on the linear motor bracket, the impact ball head is installed on the head of the linear motor mover, and moves together with the linear motor mover, and moves up and down with the linear motor mover; universal wheels and fixed support rods are installed under the mobile base plate, and the entire battery pack bottom ball impact test device is moved by the universal wheels, and is locked and fixed by the fixed support rod after moving into place.

5. The power battery pack bottom test bench according to claim 4, characterized in that: The linear motor bracket is a tower-type frame structure, and a fixed backplate is arranged in the middle of the linear motor bracket of the tower-type frame structure; on the fixed backplate, a linear motor stator track and an impact ball head sliding track are arranged in parallel from top to bottom; the linear motor stator track and the impact ball head sliding track are arranged parallel to each other on the fixed backplate of the linear motor bracket, 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; the linear motor mover and the sliding block are connected together by the impact ball head connecting plate to form a whole, so that the sliding block and the linear motor mover move up and down together; on the impact ball head connecting plate, an impact ball head is installed at a position on one side of the impact ball head sliding track, and the impact ball head head is facing upward, and the impact ball head moves up and down together with the linear motor mover, forming an impact ball head movement form of a double-track structure in which the linear motor mover and the impact ball head move together.

6. The electromagnetic ejection battery pack bottom ball impact test method according to claim 5, 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 linear motor stator track. The linear motor mover is connected to the impact ball head through the impact ball head connecting plate. 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.

7. The electromagnetic ejection battery pack bottom ball impact test method according to claim 5, characterized in that: The stator track of the linear motor is a stator composite track that is a combination 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 stator composite track with a combination of an arc line and a straight line.

8. The electromagnetic ejection battery pack bottom ball impact test method according to claim 7, characterized in that: The stator composite track comprises two sections of linear rails and one section of curved rail, and the two sections of linear rails are connected by the curved rail to form a stator composite track; wherein, one section is a vertical linear rail, which is arranged on the side of the motion bracket from the upper part to the lower part of the motion bracket, and the other section is a horizontal linear rail, which is horizontally arranged on the bottom platform of the motion bracket. The two sections of linear rails are connected by a curved rail to form a stator composite track combining straight lines and curved lines; at the same time, an impact ball head sliding track of the same structure is arranged parallel to the stator composite track; the linear motor mover is buckled on the stator composite track, and a slider is buckled on the impact ball head sliding track, and the linear motor mover and the slider are connected by an impact ball head connecting plate, and the impact ball head is mounted on the impact ball head connecting plate through a mounting seat, forming an impact ball head motion form of a dual-track structure in which the linear motor mover and the impact ball head move together.

9. The electromagnetic ejection battery pack bottom ball impact test method according to claim 8, 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.

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

11. The electromagnetic ejection battery pack bottom ball impact test method according to claim 5, characterized in that: The linear motor stator track is a linear motor stator coil arranged from top to bottom on a moving bracket, a stator magnetic track is laid on the stator coil, and a plurality of stator coils and stator magnetic tracks are combined to form a linear motor stator track for the operation of the linear motor. The linear motor mover is then buckled and mounted on the linear motor stator track, and the linear motor mover is made of permanent magnetic 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.

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