A battery pack fire simulation test device

Abstract

The present invention discloses a battery pack fire simulation test device, which relates to the technical field of test devices and includes a test bench; further including: a positioning component installed inside the test bench, used to fix the battery pack to be tested; a mechanism simulation component, used to simulate the situation of external impact on the battery pack; a loading component, used to store potential energy for the mechanism simulation component; a water tank, which contains water and is used to extinguish the battery pack on fire after the test is completed; and a release component. The present invention implements the bottom impact test requirements newly added in the new national standard by setting a mechanism simulation component to impact the battery pack. The specific implementation of the test is not conducive to direct drive of the hydraulic system. Instead, when the positioning component fixes the battery pack, the loading component is first used to store energy for the mechanism simulation component, and the potential energy is released to impact when the dual-axis moving module sends the mechanism simulation component to the impact position. The spring structure has higher corrosion resistance and reduces maintenance costs.

Description

Technical Field

[0001] The present invention relates to the technical field of test devices, and in particular to a battery pack fire simulation test device. Background Art

[0002] New energy vehicles are in the stage of large-scale promotion and application worldwide. Among them, pure electric vehicles are the core technology route, and their safety is directly related to public acceptance and industrial development. However, the lithium-ion battery system of pure electric vehicles is prone to spontaneous combustion and even explosion accidents under thermal runaway conditions. According to industry statistics, most new energy vehicle fires are caused by thermal runaway of the battery pack. Such accidents not only increase consumers' safety concerns about electric vehicles, but also pose a significant threat to social public safety. It is necessary to propose special test equipment to simulate the causes of fire in order to optimize protection design.

[0003] Battery pack fire simulation tests encompass multiple research areas, including simulation of thermal runaway triggering mechanisms, fire behavior and thermal diffusion dynamics, verification of fire extinguishing and flame retardant systems, multi-physics field coupled failure analysis, and environmental adaptability and secondary disaster research. Thermal runaway triggering mechanisms are key to preventing fires. The battery packs of pure electric vehicles are typically located at the bottom of the vehicle, making them vulnerable to intrusion by foreign objects on the road or impacts from underbody collisions. These impacts can mechanically deform the battery pack casing, squeezing the internal cells and causing rupture of the cell's diaphragm and a short circuit between the positive and negative electrodes. The Joule heat released by the short circuit triggers thermal runaway in the cells, releasing flammable gases and high-temperature electrolytes that further diffuse into adjacent modules, triggering a chain reaction of thermal runaway, thermal diffusion, and vehicle spontaneous combustion.

[0004] To address these risks, GB38031-2025, "Safety Requirements for Power Batteries for Electric Vehicles," has added a mandatory bottom impact test, requiring the battery pack to withstand a 30mm diameter steel ball impact with an energy of 150J (simulating a 50km / h vehicle speed) without leakage, fire, or explosion, and to pass a two-hour thermal runaway monitoring (temperature ≤ 60°C). A search also revealed a Chinese patent with publication number CN216979257U that proposes a fire simulation test device. This device uses a hydraulic lift mechanism to push an impact head to simulate a bottom impact, reproducing the deformation and thermal runaway process of the battery pack after impact, providing an experimental basis for protective design.

[0005] However, since this scheme uses a hydraulic lifting device to directly drive the impact head for testing, the hydraulic system has weak impact resistance: the reaction force at the moment of impact causes the hydraulic cylinder to withstand a peak pressure twice the rated value (>60MPa), causing the sealing ring to burst and the pipe joints to loosen, thereby reducing the overall life of the test device; there is a risk of battery leakage during the test, and the fluorine-containing electrolyte leaked after the battery casing ruptures is highly corrosive, and direct contact with the hydraulic cylinder piston rod may cause surface coating failure and metal corrosion; in addition, the flame temperature of the battery thermal runaway eruption exceeds 1000℃, and the hydraulic oil pipe is prone to aging and bursting at high temperature, causing damage. At the same time, the ignition point of traditional mineral hydraulic oil is only 180℃, which poses a risk of combustion. Summary of the Invention

[0006] The object of the present invention is to provide a battery pack fire simulation test device to solve the problems raised in the above background technology.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A battery pack fire simulation test device comprises a test bench; further comprising: a positioning component installed inside the test bench and used to fix the battery pack to be tested; a mechanism simulation component for simulating external impact on the battery pack; a loading component for storing potential energy for the mechanism simulation component; a water tank containing water for extinguishing the battery pack in the event of fire after the test is completed; a release component arranged on the top of the test bench and used to release the battery pack in the event of fire, causing the battery pack to fall into the water tank; a two-axis movable module for controlling the movement of the mechanism simulation component to the position at the bottom of the battery pack to be impacted; a thermal feedback component for sensing abnormal heating and driving the release component to operate; the mechanism simulation component comprises a movable platform fixedly connected to the movable end of the two-axis movable module, the top and bottom of the movable platform respectively having an ejection groove and a clearance groove, a pressure rod slidably connected to one side of the inner wall of the ejection groove, the top of the pressure rod fixedly connected to the impact head, the end of the pressure rod away from the impact head extends into the interior of the clearance groove and is fixedly connected to a limit block, and the position of the pressure rod located in the ejection groove is covered with an energy storage spring.

[0009] By adopting the above technical solution, a mechanism simulation component is set up to impact the battery pack, thereby realizing the bottom impact test requirements newly added in the new national standard. The specific implementation of the test is not conducive to direct drive of the hydraulic system. Instead, when the positioning component fixes the battery pack, the loading component is first used to store energy for the mechanism simulation component, and then the potential energy is released to impact when the dual-axis moving module sends the mechanism simulation component to the impact position. The spring structure has higher corrosion resistance and lower replacement cost.

[0010] A further improvement of the technical solution of the present invention is that: the loading component includes a mounting groove symmetrically opened inside the ejection groove, a clamping block is slidably connected between the inner walls of the mounting groove, a locking spring is fixedly connected between the clamping block and one side of the inner wall of the mounting groove, and mounting cylinders are symmetrically fixedly connected on both sides of the movable platform, a sliding rod is slidably connected to one side of the inner wall of the mounting groove, one end of the sliding rod is fixedly connected to the clamping block, and the end away from the clamping block extends to the interior of the mounting cylinder and is fixedly connected to an iron block, an electromagnet is fixedly connected to one side of the inner wall of the mounting cylinder, the clamping block is configured as a wedge block, and a clamping groove is opened on the side wall of the impact head, and the clamping groove surrounds the periphery of the impact head; a hydraulic cylinder is fixedly installed inside the test bench, and a pressure plate is fixedly connected to the end of the piston rod of the hydraulic cylinder.

[0011] The above technical solution is adopted, and the mobile platform is controlled to move to the bottom of the hydraulic cylinder through the dual-axis mobile module, and then the hydraulic cylinder is controlled to work, pushing the pressure plate downward, and pushing the impact head downward, so that the energy storage spring is compressed until the card block is facing the card slot (the locking spring is in a compressed state when the card block is not facing the card slot), the locking spring rebounds and resets, and the card block is ejected into the card slot, and then the piston rod of the hydraulic cylinder is controlled to retract to complete the energy storage; during the test, the electromagnet is energized and generates magnetic force to attract the iron block, so that the iron block moves quickly in the direction close to the electromagnet, squeezing the locking spring, and driving the card block to move through the sliding rod until the card block leaves the card slot. At this time, the impact head is no longer bound, and the potential energy of the energy storage spring is released, pushing the impact head out and hitting the bottom of the battery pack.

[0012] A further improvement of the technical solution of the present invention is that: the positioning component includes a mounting frame, the mounting frame is fixedly connected to the inside of the test bench, four guide rods are slidably connected to the top of the inner side of the mounting frame, the bottom of the guide rods is fixedly connected to the bracket, the tops of the guide rods all extend to the top of the mounting frame and are fixedly connected to the limiting head, two racks are symmetrically fixedly connected on both sides of the top of the bracket, a lifting shaft is rotatably connected between the inner sides of the upper part of the test bench, two gears are symmetrically fixedly connected to the outside of the lifting shaft, the gears are meshed with the racks, and a motor for driving the lifting shaft to rotate is fixedly installed on the top of the test bench.

[0013] The above technical solution simplifies the fixing process of the battery pack, facilitates the preparatory operations before the test, and thus improves the test efficiency. Specifically, when placing the battery pack, the bracket is at a convenient operating height. The battery pack is placed on the bracket, and then the motor is controlled to drive the lifting shaft to rotate, which in turn drives the two gears to rotate and makes the two racks move upward, thereby lifting the battery pack upward until the top of the battery pack contacts the top of the inner side of the mounting frame to fix the battery pack. At the same time, the lifting and fixing of the battery pack are completed, which facilitates the actual operation.

[0014] A further improvement of the technical solution of the present invention is that the above-mentioned release component includes a side plate fixedly connected to the top of the test bench, one side of the side plate is rotatably connected to the first synchronous wheel, the outside of the lifting shaft is fixedly connected to the second synchronous wheel, a first spline groove is provided on the central axis of the first synchronous wheel, a side of the side plate close to the first synchronous wheel is fixedly connected to the first piston cylinder, a first piston plate is slidably connected between the inner walls of the first piston cylinder, a linkage rod is slidably connected to one side of the first piston cylinder, one end of the linkage rod extends to the interior of the first piston cylinder and is fixedly connected to the first piston plate, and the linkage rod is away from the first piston cylinder One end of the plug plate is fixedly connected to a movable plate, and a reset spring is sleeved on the part of the linkage rod located in the first piston cylinder. A transmission shaft is rotatably connected to the upper part of the movable plate, and both ends of the transmission shaft are fixedly connected to a spline shaft, and the output end of the motor is fixedly connected to a transmission sleeve, and a second spline groove is provided at the end of the transmission sleeve away from the motor, and the two spline shafts correspond to the first spline groove and the second spline groove one by one and are plug-fitted; an air inlet pipe, an air outlet pipe and a drive pipe are provided on the first piston cylinder, and a one-way valve is provided inside the air inlet pipe, the air outlet pipe and the drive pipe; the diameter of the air outlet pipe is smaller than that of the air inlet pipe and the drive pipe.

[0015] By adopting the above technical solution and providing a release component, the battery pack can be released after the fire becomes larger until the thermal feedback component is activated, causing the battery pack to fall into the pool of water, thereby extinguishing the fire on the battery pack and preventing it from burning the main structure of the test device. This improves the pertinence of the test equipment and the efficiency of conducting this special (fire mechanism) test, while also improving safety.

[0016] A further improvement of the technical solution of the present invention is that: the thermal feedback component includes several feedback cylinders, the inner walls of the feedback cylinders are slidably connected with a second piston plate, the mouth of the feedback cylinder is connected with a stud by a screw, the stud is made of copper and one end located in the feedback cylinder is a hollow structure, and a thermal expansion block is fixedly connected inside the hollow structure, the volume of the thermal expansion block increases when the temperature rises, one end of the thermal expansion block is fixedly connected to a pressure block, a tension spring is fixedly connected between the second piston plate and the top wall of the feedback cylinder, and a lock ring is fixedly connected to the side away from the tension spring, and a lock seat is fixedly connected to one side of the inner wall of the feedback cylinder, and the inner wall of the lock seat A locking block is slidingly connected between the locking block and the inner wall of the lock seat, and a locking spring is fixedly connected between the locking block and the inner wall of the lock seat. The two corners of the locking block away from the locking spring are both oblique angles, and the side length of the locking block close to the second piston plate is smaller than the side length away from the second piston plate; the top of the mounting frame is equidistantly provided with a number of through holes corresponding to the feedback cylinders, and the inner walls of the through holes are provided with threads. The feedback cylinder is connected to the inside of the through hole through a stud and the internal thread of the through hole. The internal structure of the feedback cylinder can be maintained by unscrewing the stud. An input pipe and an output pipe are provided on the feedback cylinder. A one-way valve is provided inside the input pipe and the output pipe, and the air inlet pipe is connected to the output pipe.

[0017] The above technical solution is adopted by opening several through holes on the mounting frame and installing thermal feedback components on the through holes. Each thermal feedback component serves as an external heat collection point, and heat collection is achieved through heat conduction. When the battery pack continues to heat up and transmits heat to the thermal expansion block through the copper stud, it expands in volume and pushes the pressure block to move and squeeze the bevel at the lower part of the lock hole, so that the lock block automatically retracts into the lock seat until the lock block is completely disengaged from the lock ring. At this time, the second piston plate moves rapidly and discharges air into the first piston cylinder through the output pipe to prompt the battery pack to be automatically released.

[0018] A further improvement of the technical solution of the present invention is that an air pump is fixedly installed on the top of the test bench, the output end of the air pump is connected to the input pipe, and the diameter of the input pipe is larger than that of the output pipe.

[0019] By adopting the above technical solution, an air pump is set up, which can be used to blow air and inject it into the feedback cylinder through the input pipe. Since the diameter of the input pipe is larger than the output pipe, the air pressure inside the feedback cylinder continues to increase during the operation of the air pump, thereby pushing the second piston plate to move, causing the tension spring to extend. During the process, the lock ring contacts the bevel on the upper part of the locking block, causing the locking block to automatically retract into the lock seat until the locking block is completely facing the inside of the lock ring. At this time, the locking block is inserted into the lock ring to complete the locking. After turning off the air pump, the tension spring pulls back the second piston plate and the lock ring, so that the lock ring and the lock block are pressed tightly.

[0020] A further improvement of the technical solution of the present invention is that: a buffer spring is sleeved on the part of the pressure rod located in the give way groove, the top of the buffer spring is fixedly connected to the top of the give way groove, the give way groove includes a narrow mouth portion arranged at the upper part and a wide mouth portion arranged at the lower part, and a transition portion is arranged between the narrow mouth portion and the wide mouth portion, the cross-sectional shape of the narrow mouth portion matches the cross-sectional shape of the limit block, and a deceleration hole connected to the outside is opened on the narrow mouth portion.

[0021] By adopting the above technical solution and setting a buffer spring, the limit block will enter the narrow mouth when it exceeds its movement range. During this process, the movement of the limit block will be restricted by the air pressure inside the narrow mouth, which can produce a damping effect. At the same time, the buffer spring is contacted to provide a reverse force, causing the limit block to gradually slow down until it stops moving, and then rebound until it resets.

[0022] A further improvement of the technical solution of the present invention is that the diameter of the ejection groove is larger than the impact head, a guide ring is fixedly connected to the outside of the impact head, and the bottom of the guide ring is set to be rounded.

[0023] By adopting the above technical solution, a guide ring with a larger outer diameter is provided on the outside of the impact head. The guide ring is flush with one side of the slot. When the card block leaves the slot, the slot must be moved to the outside of the guide ring. During the ejection process of the impact head, only this part of the guide ring and the card block generate contact friction. Therefore, the wear of the impact head during the ejection process can be reduced, and the accuracy of the test results is improved.

[0024] Due to the adoption of the above technical solution, the present invention has the following technical advancements compared to the prior art:

[0025] 1. The present invention provides a battery pack fire simulation test device, which realizes the bottom impact test requirements newly added in the new national standard by setting a mechanism simulation component to impact the battery pack. The specific implementation of the test is not conducive to direct drive of the hydraulic system. Instead, when the positioning component fixes the battery pack, the loading component is first used to store energy for the mechanism simulation component, and then the potential energy is released to impact when the dual-axis moving module sends the mechanism simulation component to the impact position. The spring structure has higher corrosion resistance and reduces maintenance costs.

[0026] 2. The present invention provides a battery pack fire simulation test device, which simplifies the battery pack fixing process, facilitates pre-test preparation operations, and thus improves test efficiency. Specifically, when placing the battery pack, the bracket is at a convenient operating height. The battery pack is placed on the bracket, and then the motor is controlled to drive the lifting shaft to rotate, which in turn drives the two gears to rotate and makes the two racks move upward, thereby lifting the battery pack upward until the top of the battery pack contacts the top of the inner side of the mounting frame to fix the battery pack. At the same time, the lifting and fixing of the battery pack are completed, which facilitates actual operation.

[0027] 3. The present invention provides a battery pack fire simulation test device. By providing a release component, the battery pack can be released after the fire becomes larger until the thermal feedback component is activated, causing the battery pack to fall into a pool of water, thereby extinguishing the fire on the battery pack and preventing it from burning the main structure of the test device. This improves the pertinence of the test equipment and the efficiency of conducting this special (fire mechanism) test, while also improving safety.

[0028] 4. The present invention provides a battery pack fire simulation test device, which is constructed by opening a plurality of through holes on a mounting frame and installing thermal feedback components on the through holes. Each thermal feedback component serves as an external heat collection point, and heat collection is achieved by heat conduction. When the battery pack continues to generate heat and transmits it to the thermal expansion block through a copper stud, the heat expands in volume and pushes the pressing block to move and squeeze the bevel at the lower part of the lock hole, causing the lock block to automatically retract into the lock seat until the lock block is completely disengaged from the lock ring. At this time, the second piston plate moves rapidly and discharges air into the first piston cylinder through the output pipe to promote the release of the battery pack.

[0029] 5. The present invention provides a battery pack fire simulation test device. A guide ring with a larger outer diameter is provided on the outside of the impact head. The guide ring is flush with one side of the slot. When the card block leaves the slot, the slot must be moved to the outside of the guide ring. During the ejection of the impact head, only this part of the guide ring and the card block generate contact friction. Therefore, the wear of the impact head during the ejection process can be reduced, and the accuracy of the test results is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic structural diagram of the present invention from a first perspective;

[0032] Figure 2 This is a schematic structural diagram of the second viewing angle of the present invention as a whole;

[0033] Figure 3 This is a schematic structural diagram of the present invention from a third viewing angle;

[0034] Figure 4 It is a structural diagram of the mechanism simulation component of the present invention;

[0035] Figure 5 Schematic diagram of the split structure of the spline shaft, the first spline groove and the second spline groove of the present invention;

[0036] Figure 6 Schematic diagram of the installation structure of the feedback tube and the mounting bracket of the present invention;

[0037] Figure 7 This is a schematic diagram of the split structure of the feedback tube and the mounting bracket of the present invention;

[0038] Figure 8 Schematic diagram of the three-dimensional structure of the thermal feedback component of the present invention;

[0039] Figure 9 This is a schematic diagram of the state of the thermal feedback component during the operation of the present invention;

[0040] Figure 10 It is a schematic structural diagram of the release component of the present invention;

[0041] Figure 11 Schematic diagram of the structure of the bracket of the present invention;

[0042] Figure 12 For the present invention Figure 10 Enlarged view of point A in the middle.

[0043] In the figure: 1. Test bench; 2. Water tank; 3. Mounting frame; 4. Biaxial moving module; 5. Moving platform; 6. Hydraulic cylinder; 7. Pressure plate; 8. Pressure rod; 9. Impact head; 10. Limit block; 11. Energy storage spring; 12. Mounting slot; 13. Mounting cylinder; 14. Electromagnet; 15. Ejector slot; 16. Iron block; 17. Sliding rod; 18. Block; 19. Locking spring; 20. Slot; 21. Buffer spring; 22. Deceleration hole; 23. Guide ring; 24. Through hole; 25. Feedback cylinder; 26. Stud; 27. Second piston plate; 28. Tension spring; 29. ​​Gap slot; 30. Lock ring; 31. Lock seat ;32. Locking block;33. Locking spring;34. Thermal expansion block;35. Pressure block;36. Motor;37. Transmission sleeve;38. First piston cylinder;39. First piston plate;40. Inlet pipe;41. Outlet pipe;42. Return spring;43. Movable plate;44. Transmission shaft;45. Spline shaft;46. First synchronous wheel;47. Lifting shaft;48. Second synchronous wheel;49. First spline groove;50. Second spline groove;51. Linkage rod;52. Output pipe;53. Input pipe;54. Air pump;55. Drive pipe;56. Guide rod;57. Bracket;58. Rack;59. Gear;60. Side plate. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below with reference to the embodiments.

[0045] Example 1

[0046] like Figure 1 、 Figure 3 and Figure 4As shown, the present invention provides a battery pack fire simulation test device, including a test bench 1; further comprising: a positioning component installed inside the test bench 1, used to fix the battery pack to be tested; a mechanism simulation component, used to simulate the situation of external impact on the battery pack; a loading component, used to store potential energy for the mechanism simulation component; a water pool 2, which contains water and is used to extinguish the battery pack on fire after the test is completed; a release component, which is arranged on the top of the test bench 1, used to release the battery pack when a fire occurs, causing the battery pack to fall into the water pool 2; a dual-axis moving module 4, including two linear modules with mutually perpendicular moving paths, one of which is installed on the slider of the other linear module , which can be moved to a certain position in the plane as needed, and is used to control the mechanism simulation component to move to the part of the bottom of the battery pack that needs to be impacted; a thermal feedback component is used to sense abnormal heat and drive the release component to move; the mechanism simulation component includes a mobile platform 5 fixedly connected to the movable end of the dual-axis mobile module 4, and the top and bottom of the mobile platform 5 are respectively provided with an ejection groove 15 and a clearance groove 29. A pressure rod 8 is slidably connected to one side of the inner wall of the ejection groove 15, and the top of the pressure rod 8 is fixedly connected to the impact head 9. The end of the pressure rod 8 away from the impact head 9 extends to the inside of the clearance groove 29 and is fixedly connected to the limiting block 10. The pressure rod 8 is located at the ejection groove 15 and is covered with an energy storage spring 11.

[0047] The battery pack has an internal monitoring system. For battery packs without a monitoring system, an external monitoring system is used to receive battery pack status information, including internal temperature abnormality monitoring.

[0048] In this embodiment, a mechanism simulation component is provided to impact the battery pack, thereby achieving the bottom impact test requirements newly added in the new national standard. However, the specific implementation of the test is not conducive to direct drive of the hydraulic system. Instead, when the positioning component fixes the battery pack, the loading component is first used to store energy for the mechanism simulation component. When the dual-axis moving module 4 moves the mechanism simulation component to the impact position, the potential energy is released to impact. The spring structure has higher corrosion resistance and lower replacement cost.

[0049] Specifically, by pressing the impact head 9 downward, the pressure rod 8 and the limit block 10 are pushed to move, the energy storage spring 11 is squeezed to accumulate elastic potential energy, and the impact head 9 is released after the impact head 9 moves to the position where it needs to be impacted, thereby simulating an external impact action. The structure that performs the impact action is composed of the impact head 9, the pressure rod 8, the limit block 10 and the energy storage spring 11, and the driving structure is not directly involved, thereby avoiding the influence of the reaction force on the life of the driving structure.

[0050] It should be noted that when the impact head 9 contacts the battery pack, the energy storage spring 11 has already exceeded its normal state and has a small amount of stretch (inertia). After the impact, the energy storage spring 11 no longer provides elastic force to the impact head 9. The impact head 9 is completely impacted by inertia. After the impact, the battery pack is deformed, and there is no upward supporting force under the impact head 9, so it will not continue to press against the battery pack.

[0051] The impact head 9 is hemispherical with a diameter of 30 mm, a mass of 10 kg, and is made of 45# steel.

[0052] The impact energy of the impact head 9 is about 150J±3J;

[0053] The impact location and number are the three bottom protection risk points provided by the manufacturer as the impact location (covering the front, middle, and rear of the battery);

[0054] After the impact operation is completed, observe at the test ambient temperature for 2 hours.

[0055] like Figure 2 、 Figure 3 and Figure 4 As shown, the loading component includes a mounting groove 12 symmetrically opened inside the ejection groove 15, and a block 18 is slidably connected between the inner walls of the mounting groove 12, and a locking spring 19 is fixedly connected between the block 18 and one side of the inner wall of the mounting groove 12. The two sides of the mobile platform 5 are symmetrically fixedly connected with the mounting cylinder 13, and a slide rod 17 is slidably connected to one side of the inner wall of the mounting groove 12. One end of the slide rod 17 is fixedly connected to the block 18, and the end away from the block 18 extends to the interior of the mounting cylinder 13 and is fixedly connected to the iron block 16. One side of the inner wall of the mounting cylinder 13 is fixedly connected with an electromagnet 14, and the block 18 is set as a wedge. The side wall of the impact head 9 is provided with a slot 20, and the slot 20 surrounds the periphery of the impact head 9; a hydraulic cylinder 6 is fixedly installed inside the test bench 1, and the end of the piston rod of the hydraulic cylinder 6 is fixedly connected to the pressure plate 7.

[0056] In this embodiment, during loading, the mobile platform 5 is controlled by the dual-axis mobile module 4 to move to the bottom of the hydraulic cylinder 6, and then the hydraulic cylinder 6 is controlled to work, pushing the pressure plate 7 downward and pushing the impact head 9 downward, compressing the energy storage spring 11 until the block 18 is facing the slot 20 (the locking spring 19 is in a compressed state when the block 18 is not facing the slot 20), the locking spring 19 rebounds and resets, and pops the block 18 into the slot 20, and then the piston rod of the hydraulic cylinder 6 is controlled to retract to complete the energy storage; during the test, the electromagnet 14 is energized and generates magnetic force to attract the iron block 16, so that the iron block 16 moves quickly in the direction close to the electromagnet 14, squeezing the locking spring 19, and driving the block 18 to move through the slide rod 17 until the block 18 leaves the slot 20. At this time, the impact head 9 is no longer bound, and the potential energy of the energy storage spring 11 is released, pushing the impact head 9 out and hitting the bottom of the battery pack.

[0057] like Figure 2 、 Figure 3 and Figure 11 As shown, preferably, the positioning component includes a mounting frame 3, which is fixedly connected to the inside of the test bench 1, and four guide rods 56 are slidably connected to the top of the inner side of the mounting frame 3, and the bottom of the guide rod 56 is fixedly connected to a bracket 57. The tops of the guide rods 56 extend to the top of the mounting frame 3 and are fixedly connected to the limiting head. Two racks 58 are symmetrically fixedly connected on both sides of the top of the bracket 57. A lifting shaft 47 is rotatably connected between the inner sides of the upper part of the test bench 1, and two gears 59 are symmetrically fixedly connected to the outside of the lifting shaft 47. The gears 59 are meshed with the racks 58, and a motor 36 for driving the lifting shaft 47 to rotate is fixedly installed on the top of the test bench 1.

[0058] During the operation, the battery pack must not only be fixed but also lifted to a height that is convenient for collision. Since the battery pack itself is large, it should not be placed too high. In addition, the test requires multiple groups of control tests. The battery pack should be easy to disassemble and assemble, and the operation process should not be too complicated.

[0059] In this embodiment, by simplifying the fixing process of the battery pack, the preparatory operations before the test are facilitated, thereby improving the test efficiency; specifically, when placing the battery pack, the bracket 57 is at a height that is convenient for operation, the battery pack is placed on the bracket 57, and then the motor 36 is controlled to work, driving the lifting shaft 47 to rotate, and then driving the two gears 59 to rotate, and making the two racks 58 move upward, thereby lifting the battery pack upward until the top of the battery pack contacts the top of the inner side of the mounting frame 3 to fix the battery pack, and at the same time completing the lifting and fixing of the battery pack, facilitating actual operation.

[0060] Example 2

[0061] like Figure 5 、 Figure 10 and Figure 12As shown, on the basis of Example 1, the present invention provides a technical solution: preferably, the releasing component includes a side plate 60 fixedly connected to the top of the test bench 1, one side of the side plate 60 is rotatably connected to the first synchronous wheel 46, the outside of the lifting shaft 47 is fixedly connected to the second synchronous wheel 48, the central axis of the first synchronous wheel 46 is provided with a first spline groove 49, the side of the side plate 60 close to the first synchronous wheel 46 is fixedly connected to the first piston cylinder 38, the first piston plate 39 is slidably connected between the inner walls of the first piston cylinder 38, and a linkage rod 51 is slidably connected to one side of the first piston cylinder 38, one end of the linkage rod 51 extends to the interior of the first piston cylinder 38 and is fixedly connected to the first piston plate 39, and the linkage rod 51 is away from the first piston plate 39. One end of 9 is fixedly connected to a movable plate 43, and a reset spring 42 is sleeved on the part of the linkage rod 51 located in the first piston cylinder 38. A transmission shaft 44 is rotatably connected to the upper end of the movable plate 43, and both ends of the transmission shaft 44 are fixedly connected to a spline shaft 45. The output end of the motor 36 is fixedly connected to the transmission sleeve 37, and a second spline groove 50 is provided at the end of the transmission sleeve 37 away from the motor 36. The two spline shafts 45 correspond to the first spline groove 49 and the second spline groove 50 respectively and are plug-fitted; an air inlet pipe 40, an air outlet pipe 41 and a drive pipe 55 are provided on the first piston cylinder 38, and a one-way valve is provided inside the air inlet pipe 40, the air outlet pipe 41 and the drive pipe 55; the diameter of the air outlet pipe 41 is smaller than that of the air inlet pipe 40 and the drive pipe 55.

[0062] Since this program aims to study the causes of simulated fires, specifically the impact of external impacts on battery fires, in order to conduct the above research in a targeted manner and prevent the fire from increasing and causing damage to the entire device, it is necessary to separate the battery pack and extinguish the fire after the fire has increased (the test objective has been achieved once the fire has occurred);

[0063] In this embodiment, by providing a release component, the battery pack can be released after the fire grows larger until the thermal feedback component is activated, causing the battery pack to fall into the water pool 2, thereby extinguishing the fire on the battery pack and preventing it from burning the main structure of the test device. Specifically, when a temperature abnormality occurs, the thermal feedback component is used to inflate the drive tube 55, and air enters the first piston cylinder 38 through the drive tube 55. The one-way valves inside the drive tube 55 and the air inlet pipe 40 both conduct air from the outside to the first piston cylinder 38, while the one-way valve inside the air outlet pipe 41 conducts air only from the first piston cylinder 38 to the outside. During the process of injecting air into the first piston cylinder 38 through the drive tube 55, some air is discharged through the air outlet pipe 41. However, because the diameter of the air outlet pipe 41 is smaller than that of the drive tube 55, the air pressure inside the first piston cylinder 38 gradually increases. The air pressure pushes the first piston plate 39 to move, squeezing the return spring 42, and driving the movable plate 43 to move through the linkage rod 51, while driving the transmission shaft 44 and the spline shaft 45 to move to the side away from the first synchronous wheel 46 until the spline shaft 45 is disengaged from the first spline groove 49. At this time, the first synchronous wheel 46 is no longer constrained by the output end of the motor 36 and can rotate freely, so that the rack 58 moves downward under the action of the gravity of the battery pack and the bracket 57 until it falls into the pool 2 and is supported by the bottom of the pool 2. The pool 2 contains water for extinguishing open flames. The above-mentioned rack 58 drives the gear 59 and the lifting shaft 47 to rotate during the downward process.

[0064] After the bracket 57 and the battery pack have fallen to the bottom of the pool 2 for a period of time, the mounting bracket 3 is no longer in contact with the battery pack, and the thermal feedback component no longer senses heat (its interior gradually resets), and no longer provides positive pressure to the first piston cylinder 38. The positive pressure inside the first piston cylinder 38 continues to slowly dissipate from the air outlet pipe 41 until the air pressure is insufficient to support the elastic force of the reset spring 42. At this time, the first piston plate 39 is pushed to slowly reset, and drives the transmission shaft 44 and the spline shaft 45 to reset until the spline shaft 45 is inserted into the first spline groove 49 again (there is a high probability that the spline shaft 45 is not facing the first spline groove 49. During the above process, the motor 36 is controlled to work at the same time. When the spline shaft 45 faces the first spline groove 49, the spline shaft 45 naturally inserts into the first spline groove 49). The bracket 57 can be lifted up again by controlling the motor 36 (the initial state is the same. The motor 36 can drive the first synchronous wheel 46 to rotate, and drive the second synchronous wheel 48 to rotate through the synchronous belt, and further drive the lifting shaft 47 to rotate).

[0065] Example 3

[0066] like Figure 6 、 Figure 7 and Figure 8As shown, on the basis of Example 2, the present invention provides a technical solution: preferably, the thermal feedback component includes a plurality of feedback cylinders 25, and a second piston plate 27 is slidably connected between the inner walls of the feedback cylinder 25. A stud 26 is connected to the mouth of the feedback cylinder 25 by a screw. The stud 26 is made of copper and one end of the stud 26 is located in the feedback cylinder 25. The hollow structure is fixedly connected to a thermal expansion block 34. The volume of the thermal expansion block 34 increases when the temperature rises. A pressure block 35 is fixedly connected to one end of the thermal expansion block 34. A tension spring 28 is fixedly connected between the second piston plate 27 and the top wall of the feedback cylinder 25, and a lock ring 30 is fixedly connected to the side away from the tension spring 28. A lock seat 31 is fixedly connected to one side of the inner wall of the feedback cylinder 25. The inner wall of the lock seat 31 A locking block 32 is slidingly connected between the locking block 32 and the inner wall of the lock seat 31. A locking spring 33 is fixedly connected between the locking block 32 and the inner wall of the lock seat 31. The two corners of the locking block 32 away from the locking spring 33 are both oblique angles, and the side length of the locking block 32 close to the second piston plate 27 is smaller than the side length away from the second piston plate 27; the top of the mounting frame 3 is equidistantly provided with a plurality of through holes 24 corresponding to the feedback tube 25, and the inner wall of the through hole 24 is provided with a thread. The feedback tube 25 is connected to the inside of the through hole 24 through a stud 26 and the internal thread of the through hole 24. The internal structure of the feedback tube 25 can be maintained by unscrewing the stud 26. An input pipe 53 and an output pipe 52 are provided on the feedback tube 25. Both the input pipe 53 and the output pipe 52 are provided with a one-way valve, and the intake pipe 40 is connected to the output pipe 52.

[0067] It should be noted that in the normal state (the state in which the locking block 32 is inserted into the locking ring 30 ), the tension spring 28 is in an extended state;

[0068] In this embodiment, a plurality of through holes 24 are provided on the mounting frame 3, and thermal feedback components are installed on the through holes 24. Each thermal feedback component serves as an external heat collection point, and heat collection is achieved by heat conduction. Figure 9 As shown, the initial state is shown on the left in the figure. When the battery pack continues to heat up and transmits it to the heat expansion block 34 through the copper stud 26, it expands in volume and pushes the pressing block 35 to squeeze the bevel at the bottom of the lock hole, so that the lock block 32 automatically retracts into the lock seat 31 (the process squeezes the locking spring 33 to compress it) until the bottom of the bevel of the lock seat 31 and the lock block 32 no longer contacts the inside of the lock ring 30. This state is referred to Figure 9 In the state shown in the second left middle, the beveled portion of the bevel is in contact with the inside of the lock ring 30, and the lock ring 30 and the second piston plate 27 themselves tend to be pulled by the tension spring 28. In this state, the tension spring 28 pulls the second piston plate 27 and the lock ring 30 to move, further retracting the lock block 32 into the lock seat 31 until the lock block 32 is completely separated from the lock ring 30. Figure 9As shown in the middle right, at this time, the second piston plate 27 moves quickly, exhausting air into the first piston cylinder 38 through the output pipe 52 to promote the release of the battery pack.

[0069] like Figure 3 、 Figure 8 and Figure 9 As shown, preferably, an air pump 54 is fixedly installed on the top of the test bench 1 , and the output end of the air pump 54 is connected to the input pipe 53 , and the diameter of the input pipe 53 is larger than that of the output pipe 52 .

[0070] Since the device in the scheme needs to be tested repeatedly, the thermal feedback component needs to be easy to reset after operation;

[0071] In this embodiment, by providing an air pump 54, air can be blown by the air pump 54 and injected into the feedback cylinder 25 through the input pipe 53. Since the diameter of the input pipe 53 is larger than that of the output pipe 52, the air pressure inside the feedback cylinder 25 increases continuously during the operation of the air pump 54, thereby pushing the second piston plate 27 to move, causing the tension spring 28 to extend. During this process, the lock ring 30 contacts the bevel on the upper part of the locking block, causing the locking block 32 to automatically retract into the lock seat 31 until the lock block 32 is completely opposite to the inside of the lock ring 30. At this time, the lock block 32 is inserted into the lock ring 30 (under the rebound action of the locking spring 33), completing the locking. After the air pump 54 is turned off, the tension spring 28 pulls the second piston plate 27 and the lock ring 30 back, so that the lock ring 30 and the lock block 32 are tightly pressed against each other.

[0072] During the above process, part of the air is discharged into the first piston cylinder 38 through the output pipe 52, thereby causing the spline shaft 45 to temporarily separate from the first spline groove 49. The inflation process using the air pump 54 is a reset operation that occurs after the thermal feedback component is actuated. In this state, the bracket 57 itself is in the water pool 2. Therefore, the operation of the air pump 54 occurs after the thermal feedback component is actuated.

[0073] It should be noted that since a one-way valve is provided inside each output tube 52 , when one feedback cylinder 25 is actuated, it does not affect other feedback cylinders 25 , and the air in the feedback cylinder 25 (which can be regarded as a signal) is only transmitted to the first piston cylinder 38 .

[0074] In addition, the battery pack itself has a monitoring system (or an external monitoring system, such as multiple temperature sensors installed on the inside of the mounting frame 3), and the monitoring system and the air pump 54 are electrically connected to the external controller; the monitoring system can monitor the thermal information of the battery pack. When thermal anomalies continue to occur, even if the above-mentioned thermal feedback component does not collect the ignition signal, it can still control the air pump 54 to work by transmitting the signal to the external controller, so that the spline shaft 45 is actively disengaged from the first spline groove 49, and the battery pack is released into the water pool 2.

[0075] Example 4

[0076] like Figure 4 As shown, on the basis of Example 3, the present invention provides a technical solution: preferably, the portion of the pressure rod 8 located in the give way groove 29 is sleeved with a buffer spring 21, and the top of the buffer spring 21 is fixedly connected to the top of the give way groove 29, and the give way groove 29 includes a narrow mouth portion arranged at the upper part and a wide mouth portion arranged at the lower part, and a transition portion is provided between the narrow mouth portion and the wide mouth portion, the cross-sectional shape of the narrow mouth portion matches the cross-sectional shape of the limit block 10, and the narrow mouth portion is provided with a deceleration hole 22 connected to the outside.

[0077] The impact head 9 has a large amount of kinetic energy when impacting the battery pack. Therefore, the impact head 9 will not be over-ejected when hammering on the battery pack during the test. However, if the impact head 9 is not loaded or the hammer force is adjusted due to errors, over-ejection may occur. This will cause the impact energy to directly act on the limit block 10, affecting its service life.

[0078] In this embodiment, by providing a buffer spring 21, the limit block 10 will enter the narrow mouth when it exceeds its range of movement. During this process, the movement of the limit block 10 will be restricted by the air pressure inside the narrow mouth, which can produce a damping effect. At the same time, the process contacts the buffer spring 21 to provide a reverse force, causing the limit block 10 to gradually slow down until it stops moving, and then rebound until it is reset.

[0079] like Figure 4 As shown, preferably, the diameter of the ejection groove 15 is larger than the impact head 9, and a guide ring 23 is fixedly connected to the outside of the impact head 9, and the bottom of the guide ring 23 is set to be rounded.

[0080] Since the ejection process of the impact head 9 requires the block 18 to leave the slot 20, the impact head 9 is freed from its restraint. That is, the impact head 9 will be ejected quickly as soon as the block 18 leaves the slot 20. During this process, the side wall of the impact head 9 continues to slide relative to the block 18, thereby generating friction. This process will lose some energy, making it difficult to control the energy of the impact head 9 when it hits the target.

[0081] In this embodiment, a guide ring 23 with a larger outer diameter is provided on the outside of the impact head 9. The guide ring 23 is flush with one side of the slot 20. When the block 18 leaves the slot 20, the slot 20 must be moved to the outside of the guide ring 23. During the ejection process of the impact head 9, only this part of the guide ring 23 and the block 18 generate contact friction. Therefore, the wear of the impact head during the ejection process can be reduced, and the accuracy of the test results is improved.

[0082] The working principle of the battery pack fire simulation test device is described in detail below.

[0083] like Figures 1-12As shown, the battery pack is fixed: the battery pack is placed on the bracket 57, and then the motor 36 is controlled to drive the lifting shaft 47 to rotate, thereby driving the two gears 59 to rotate and causing the two racks 58 to move upward, thereby lifting the battery pack upward until the top of the battery pack contacts the top of the inner side of the mounting frame 3 to fix the battery pack, thereby completing the lifting and fixing of the battery pack;

[0084] Loading the impact head 9: The two-axis moving module 4 controls the moving platform 5 to move to the position directly below the hydraulic cylinder 6. The hydraulic cylinder 6 is then controlled to work, pushing the pressure plate 7 downward, and pushing the impact head 9 downward, compressing the energy storage spring 11 until the block 18 is aligned with the slot 20 (the locking spring 19 is in a compressed state when the block 18 is not aligned with the slot 20). The locking spring 19 rebounds and resets, ejecting the block 18 into the slot 20. The piston rod of the hydraulic cylinder 6 is then controlled to retract, completing energy storage.

[0085] Impact test process: The dual-axis moving module 4 drives the mobile platform 5 to the position where the impact is required. By controlling the electromagnet 14 to be energized and generate magnetic force, the iron block 16 is attracted, causing the iron block 16 to move quickly in the direction close to the electromagnet 14, squeezing the locking spring 19, and driving the block 18 to move through the slide bar 17 until the block 18 leaves the slot 20. At this time, the impact head 9 is no longer restrained, and the potential energy of the energy storage spring 11 is released, pushing the impact head 9 out and impacting the bottom of the battery pack;

[0086] Repeat the above-mentioned impact head 9 loading and impact test process three times. After the impact operation is completed, observe for 2 hours at the test environment temperature to monitor the temperature change inside the battery pack and the fire situation.

[0087] The above generally describes the present invention in detail. However, it is obvious to those skilled in the art that modifications or improvements may be made based on the present invention. Therefore, modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A battery pack fire simulation test device, comprising a test bench (1); characterized in that: Also includes: A positioning component, installed inside the test bench (1), for fixing the battery pack to be tested; Mechanism simulation components, used to simulate external impact on the battery pack; A loading component for storing potential energy for the mechanism simulation component; A water tank (2) containing water for extinguishing a battery pack that has caught fire after the test is completed; A release component is provided on the top of the test bench (1) and is used to release the battery pack in the event of fire, causing the battery pack to fall into the water pool (2); A dual-axis moving module (4) is used to control the movement of the mechanism simulation component to the position on the bottom of the battery pack that needs to be impacted; Thermal feedback component, used to sense abnormal heating and drive the release component to operate; The mechanism simulation component includes a mobile platform (5) fixedly connected to the movable end of the biaxial mobile module (4), the top and bottom of the mobile platform (5) are respectively provided with an ejection groove (15) and a clearance groove (29), one side of the inner wall of the ejection groove (15) is slidably connected to a pressure rod (8), the top of the pressure rod (8) is fixedly connected to a collision head (9), the end of the pressure rod (8) away from the collision head (9) extends to the inside of the clearance groove (29) and is fixedly connected to a limit block (10), and the pressure rod (8) is located at the ejection groove (15) and is sleeved with an energy storage spring (11); The release component includes a side plate (60) fixedly connected to the top of the test bench (1), one side of the side plate (60) is rotatably connected to a first synchronous wheel (46), an inner side of the upper part of the test bench (1) is rotatably connected to a lifting shaft (47), a motor (36) for driving the lifting shaft (47) to rotate is fixedly installed on the top of the test bench (1), the outer side of the lifting shaft (47) is fixedly connected to a second synchronous wheel (48), a first spline groove (49) is provided on the central axis of the first synchronous wheel (46), a side of the side plate (60) close to the first synchronous wheel (46) is fixedly connected to a first piston cylinder (38), an inner wall of the first piston cylinder (38) is slidably connected to a first piston plate (39), a side of the first piston cylinder (38) is slidably connected to a linkage rod (51), one end of the linkage rod (51) extends to the interior of the first piston cylinder (38) and is fixedly connected to the first piston plate (39), and the linkage rod ( The end of the linkage rod (51) away from the first piston plate (39) is fixedly connected to the movable plate (43), the portion of the linkage rod (51) located in the first piston cylinder (38) is sleeved with a return spring (42), the upper portion of the movable plate (43) is rotatably connected to a transmission shaft (44), both ends of the transmission shaft (44) are fixedly connected to a spline shaft (45), the output end of the motor (36) is fixedly connected to a transmission sleeve (37), the end of the transmission sleeve (37) away from the motor (36) is fixedly connected to the transmission sleeve (37). A second spline groove (50) is provided, and the two spline shafts (45) correspond to the first spline groove (49) and the second spline groove (50) respectively and are plug-fitted; an air inlet pipe (40), an air outlet pipe (41) and a drive pipe (55) are provided on the first piston cylinder (38), and a one-way valve is provided inside the air inlet pipe (40), the air outlet pipe (41) and the drive pipe (55); the diameter of the air outlet pipe (41) is smaller than that of the air inlet pipe (40) and the drive pipe (55).

2. A battery pack fire simulation test device according to claim 1, characterized in that: The loading component includes a mounting groove (12) symmetrically opened inside the ejection groove (15), a clamping block (18) is slidably connected between the inner walls of the mounting groove (12), and a locking spring (19) is fixedly connected between the clamping block (18) and one side of the inner wall of the mounting groove (12), and the two sides of the mobile platform (5) are symmetrically fixedly connected to the mounting cylinder (13), and one side of the inner wall of the mounting groove (12) is slidably connected to a sliding rod (17), and one end of the sliding rod (17) is fixedly connected to the clamping block (18). , one end away from the clamping block (18) extends to the inside of the mounting cylinder (13) and is fixedly connected to an iron block (16), one side of the inner wall of the mounting cylinder (13) is fixedly connected to an electromagnet (14), the clamping block (18) is set as a wedge block, and a clamping groove (20) is opened on the side wall of the impact head (9), and the clamping groove (20) surrounds the periphery of the impact head (9); a hydraulic cylinder (6) is fixedly installed inside the test bench (1), and the end of the piston rod of the hydraulic cylinder (6) is fixedly connected to a pressure plate (7).

3. The battery pack fire simulation test device according to claim 2, characterized in that: The positioning component includes a mounting frame (3), the mounting frame (3) is fixedly connected to the inside of the test bench (1), the top of the inner side of the mounting frame (3) is slidably connected to four guide rods (56), the bottom of the guide rods (56) is fixedly connected to a bracket (57), the top of the guide rods (56) extends to the top of the mounting frame (3) and is fixedly connected to a limiting head, two racks (58) are symmetrically fixedly connected on both sides of the top of the bracket (57), and two gears (59) are symmetrically fixedly connected to the outside of the lifting shaft (47), and the gears (59) are meshed with the racks (58).

4. A battery pack fire simulation test device according to claim 3, characterized in that: The thermal feedback component includes a plurality of feedback cylinders (25), the inner walls of the feedback cylinders (25) are slidably connected to a second piston plate (27), the mouth of the feedback cylinder (25) is connected to a stud (26) by a screw, the stud (26) is made of copper and one end of the stud (26) is located in the feedback cylinder (25) and is a hollow structure, and a thermal expansion block (34) is fixedly connected inside the hollow structure, the volume of the thermal expansion block (34) increases when the temperature rises, one end of the thermal expansion block (34) is fixedly connected to a pressure block (35), a tension spring (28) is fixedly connected between the second piston plate (27) and the top wall of the feedback cylinder (25), and a lock ring (30) is fixedly connected to the side away from the tension spring (28), a lock seat (31) is fixedly connected to one side of the inner wall of the feedback cylinder (25), and the inner walls of the lock seat (31) are slidably connected. A locking block (32) is provided, wherein a locking spring (33) is fixedly connected between the locking block (32) and the inner wall of the lock seat (31), and the two corners of the locking block (32) away from the locking spring (33) are both beveled, and the side length of the locking block (32) close to the second piston plate (27) is smaller than the side length away from the second piston plate (27); a plurality of through holes (24) corresponding to the feedback cylinder (25) are equidistantly provided on the top of the mounting frame (3), and the inner wall of the through hole (24) is provided with a thread, and the feedback cylinder (25) is connected to the inside of the through hole (24) through a stud (26) and the inner thread of the through hole (24), and an input pipe (53) and an output pipe (52) are provided on the feedback cylinder (25), and a one-way valve is provided inside the input pipe (53) and the output pipe (52), and the air inlet pipe (40) is connected to the output pipe (52).

5. The battery pack fire simulation test device according to claim 4, characterized in that: An air pump (54) is fixedly installed on the top of the test bench (1), and the output end of the air pump (54) is connected to the input pipe (53), and the diameter of the input pipe (53) is larger than that of the output pipe (52).

6. The battery pack fire simulation test device according to claim 5, characterized in that: The portion of the pressure rod (8) located in the clearance groove (29) is sleeved with a buffer spring (21), the top of the buffer spring (21) is fixedly connected to the top of the clearance groove (29), the clearance groove (29) includes a narrow mouth portion arranged at the upper part and a wide mouth portion arranged at the lower part, and a transition portion is provided between the narrow mouth portion and the wide mouth portion, the cross-sectional shape of the narrow mouth portion matches the cross-sectional shape of the limit block (10), and the narrow mouth portion is provided with a deceleration hole (22) connected to the outside.

7. The battery pack fire simulation test device according to claim 6, characterized in that: The diameter of the ejection groove (15) is larger than that of the impact head (9), and a guide ring (23) is fixedly connected to the outside of the impact head (9), and the bottom of the guide ring (23) is configured as a rounded corner.

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