Battery pack capable of dynamically adjusting pre-tightening force distribution

Abstract

The invention relates to the technical field of batteries, in particular to a battery pack capable of dynamically adjusting pretightening force distribution, the battery pack comprises a bottom shell and an internal battery cell module, a separation structure is arranged in the bottom shell to divide the space of the bottom shell into a control cavity and a battery cell cavity, and the interior of the battery cell cavity is divided into an upper battery cell mounting area and a lower emergency area; a module box is arranged in the cell mounting area, a hydraulic bag is mounted in a clamping groove in the side wall of the module box, and the hydraulic bag is filled with incompressible hydraulic oil and connected with a hydraulic control mechanism through a pipeline; the battery cells are arranged among the hydraulic bags, and the hydraulic bags apply adjustable pre-tightening force to the side walls of the battery cells; the hydraulic control mechanism comprises an oil box, a piezoelectric pump and a piezoelectric adjusting valve. The piezoelectric pump adjusts the pressure of the hydraulic bag based on sensor data. A sensing network is arranged in the battery pack and comprises a piezoresistive film sensor on the inner wall of the hydraulic bag, a distributed temperature sensor on the sealing cover and a piezoelectric film array sensor on the inner wall of the bottom shell; the battery pack can achieve the purpose of improving the safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery pack with dynamic adjustment of pre-tightening force distribution. BACKGROUND

[0002] With the rapid development of new energy vehicles, energy storage systems and other fields, lithium ion batteries have become the mainstream power source due to their high energy density, long cycle life and other advantages. As the core component of the battery system, the structural design of the battery pack directly affects the safety, reliability and service life of the battery. During the operation of the battery, the volume of the battery cell will expand during charging and discharging, especially under high rate or extreme temperature conditions, the expansion phenomenon is more pronounced. If there is no effective mechanical constraint, the expansion of the battery cell will cause the electrode material to break, the contact resistance to increase, and even cause internal short circuit, which seriously threatens the safety performance of the battery pack.

[0003] At present, the traditional battery pack usually uses rigid frame, fixed force spring or bolt pre-tightening to apply static pre-tightening force to the battery cell. However, such methods have the following defects: Pre-tightening force is not adjustable: static pre-tightening force cannot adapt to the expansion difference of the battery cell under different states of charge, temperature and aging stages, resulting in excessive pressure on the battery cell during low expansion, accelerating material aging, and insufficient constraint during high expansion, causing poor contact or local stress concentration.

[0004] Lack of dynamic response capability: the existing technology cannot monitor the state of the battery cell in real time and adjust the pre-tightening force, especially in the case of thermal runaway or mechanical impact, it cannot provide targeted protection quickly, increasing the risk of heat spread and structural failure.

[0005] Uniform force application limitation: traditional solutions usually apply uniform pre-tightening force to all battery cells in the battery pack, ignoring the uneven expansion of battery cells due to manufacturing tolerances or working condition differences, further exacerbating performance degradation and safety hazards. SUMMARY

[0006] The purpose of the present application is to provide a battery pack with dynamic adjustment of pre-tightening force distribution to improve the safety of the battery pack and solve the problems raised in the background.

[0007] To achieve the above purpose, the present application provides the following technical solution: a battery pack with dynamic adjustment of pre-tightening force distribution, comprising a bottom shell and an internal battery cell module, a partition structure is arranged in the bottom shell to divide the space of the bottom shell into a control cavity and a battery cell cavity, and the battery cell cavity is divided into an upper battery cell mounting area and a lower emergency area; A module box is arranged in the battery cell mounting area, a hydraulic capsule is mounted in the side wall clamping groove of the module box, the hydraulic capsule is filled with incompressible hydraulic oil and connected to a hydraulic control mechanism through a pipeline; battery cells are arranged between the hydraulic capsules, and the hydraulic capsules apply adjustable pre-tightening force to the side walls of the battery cells; The hydraulic control mechanism comprises an oil box, a piezoelectric pump and a piezoelectric regulating valve, the piezoelectric pump adjusts the hydraulic capsule pressure based on sensor data; the battery pack is provided with a sensing network, including a piezoresistive film sensor on the inner wall of the hydraulic capsule, a distributed temperature sensor on the closure cover and a piezoelectric film array sensor on the inner wall of the bottom shell; A liftable protection plate is arranged in the emergency area, the protection plate is communicated with the hydraulic capsule through a piston transmission mechanism, a connecting pipe with a diaphragm and a manifold; when the impact signal is triggered, the piezoelectric pump is pressurized to break the diaphragm in the connecting pipe, the hydraulic oil drives the piston transmission mechanism to lift the protection plate to the side of the battery cell.

[0008] The separation structure comprises a first partition plate arranged vertically, a second partition plate arranged horizontally and a third partition plate arranged in the middle of the battery cell cavity. A horizontal rib is arranged in the upper battery cell mounting area of the battery cell cavity, and the rib divides the upper cavity into independent slots for inserting the battery cell module.

[0009] The bottom of the module box is provided with a through slot corresponding to the limiting slot on the second partition plate, and the top of the module box is provided with a closure cover fixed on the module box. The limiting slot on the second partition plate is used for the protection plate to pass through and enter the inside of the module box.

[0010] The hydraulic capsule is embedded in the outer frame around the hydraulic capsule, and the outer frame is fixed in the clamping groove of the side wall of the module box. 2-4 battery cells are arranged between two adjacent hydraulic capsules, the hydraulic capsules in the same battery cell module are connected to the same shunt pipe, and the shunt pipe is installed on the top of the module box.

[0011] The end of the shunt pipe is connected to a connector pipe through a flange, the connector pipe is a flexible pipe, and the connector pipe is connected to the piezoelectric regulating valve through a threaded joint. The oil box of the hydraulic control mechanism is arranged in the mounting space formed by the third partition plate.

[0012] The piezoelectric regulating valve adopts a double-channel structure and is connected to the piezoelectric pump and the oil box respectively, and is used for controlling the mechanical pressure of the hydraulic capsule.

[0013] The piezoresistive film sensor is used for detecting the real-time contact pressure of the hydraulic capsule and the battery cell, the distributed temperature sensor is used for detecting the local temperature of the single battery cell module, and the piezoelectric film array sensor is used for sensing the impact received by the battery pack and positioning the impact position and intensity through signal analysis.

[0014] The bottom of the module box in the emergency area is embedded with a manifold, and the manifold is communicated with all the hydraulic capsules in the module box. The protection plate is in a U-shaped structure, the protection plate is fixed on the bottom plate, the bottom plate is connected to a winding rope wheel through a lifting rope, the winding rope wheel is engaged with a gear through a coaxial gear, and the gear is connected to the piston rod of the piston transmission mechanism.

[0015] Wherein, the piston pipe of the piston transmission mechanism communicates with the connecting pipe through the transition pipe, and the other end of the connecting pipe communicates with the manifold pipe; The winding rope wheel is installed on the rotating shaft, the rotating shaft is installed on the shaft support through the bearing, the shaft support is fixed on the bottom surface of the second partition plate, one end of the hoisting rope is connected with the winding rope wheel, and the other end is connected with the lifting seat on the bottom plate.

[0016] Wherein, the connecting pipe is provided with threaded joints at both ends, and the middle part of the diaphragm in the connecting pipe is provided with a notch.

[0017] Wherein, the bottom plate is provided with a stop block on the side surface, the second partition plate is provided with a positioning seat on the bottom surface, a spring pin is arranged in the positioning seat, a ferromagnetic end block is arranged at the tail end of the spring pin, and an electromagnetic seat matched with the ferromagnetic end block is arranged on the side surface of the positioning seat.

[0018] Compared with the prior art, the beneficial effects of the present application are: 1. The present application dynamically adjusts the pre-tightening force distribution through the hydraulic capsule in the battery cell, so that the battery pack can adapt to the volume change of the battery cell in the charging and discharging process in real time, effectively suppresses the swelling deformation, reduces the internal stress concentration and structural deformation, thereby significantly improves the safety and service life of the battery; it adopts a closed-loop control system of multi-sensor fusion, including pressure, temperature and impact sensing unit, carries out mechanical pressure control of the hydraulic capsule, ensures the accurate adjustment and rapid response of the pre-tightening force provided by the hydraulic capsule, optimizes the electrical contact between the battery cells, reduces the contact resistance and improves the energy efficiency.

[0019] 2. Through the cooperative arrangement of the hydraulic capsule and the emergency protection mechanism, the rigid protection mechanism can be started quickly when the impact is detected, the protection plate is lifted and locked through hydraulic drive, and instant protection is provided for the battery cell, which greatly enhances the impact resistance of the battery pack under extreme working conditions.

[0020] 3. The intelligent decision layer of the hydraulic control system of the present application is based on a multi-objective optimization algorithm, combines the SOC, temperature and swelling pressure of the battery cell, dynamically adjusts the pre-tightening force of each partition, realizes differentiated mechanical constraint, avoids damage to the battery cell caused by over-tightening, prevents poor contact caused by over-looseness, and the piezoelectric pump and regulating valve of the execution layer have high precision and rapid response characteristics, ensuring the real-time and stability of the pre-tightening force adjustment. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the first schematic diagram of the overall structure of the battery pack of the present application.

[0022] Figure 2 It is the second schematic diagram of the overall structure of the battery pack of the present application.

[0023] Figure 3 It is a schematic diagram of the bottom shell and the partition structure of the battery pack of the present application.

[0024] Figure 4 Figure 1 is a schematic diagram of the battery cell module structure of the present application.

[0025] Figure 5 Figure 2 is a first schematic diagram of the module box and protection plate structure of the present application.

[0026] Figure 6 Figure 3 is a second schematic diagram of the module box and protection plate structure of the present application.

[0027] Figure 7 Figure 4 is a position schematic diagram of the hydraulic bag structure of the present application.

[0028] Figure 8 Figure 5 is a position schematic diagram of the hydraulic bag and protection plate structure of the present application.

[0029] Figure 9 Figure 6 is a schematic diagram of the protection plate lifting structure of the present application.

[0030] Figure 10 Figure 7 is an internal schematic diagram of the connecting pipe structure of the present application.

[0031] Figure 11 Figure 8 is a schematic diagram of the internal structure of the positioning seat of the present application.

[0032] In the figure: 1, bottom shell; 101, first partition; 102, second partition; 103, third partition; 104, limiting groove; 105, rib; 2, module box; 3, closed cover; 4, clamping groove; 5, outer frame; 6, hydraulic bag; 7, battery cell; 8, shunt pipe; 9, joint pipe; 10, oil box; 11, piezoelectric pump; 12, piezoelectric regulating valve; 13, manifold pipe; 14, bottom plate; 15, protection plate; 16, lifting seat; 17, piston pipe; 18, piston rod; 19, rack; 20, shaft support; 21, gear; 22, rope winding wheel; 23, lifting rope; 24, lifting seat; 25, transition pipe; 26, connecting pipe; 27, diaphragm; 28, notch; 29, stop block; 30, positioning seat; 31, spring pin; 32, ferromagnetic end block; 33, electromagnetic seat. DETAILED DESCRIPTION

[0033] Hereinafter, the present application will be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that the following described embodiments or technical features can be combined in any manner to form new embodiments, provided that there is no conflict. It should be understood that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0034] Please refer to Figures 1 to 11The application provides a technical scheme: a battery pack capable of dynamically adjusting pre-tightening force distribution, which is mainly applied to a new energy driven vehicle such as a plug-in hybrid drive, pure electric drive and fuel cell drive, and can serve as a power source.

[0035] The battery pack comprises a battery armor shell formed by a bottom shell 1 and an upper shell, wherein the bottom shell 1 is provided with a separation structure for distributed assembly of the battery cell module and the control system.

[0036] The separation structure comprises a first partition plate 101, a second partition plate 102 and a third partition plate 103 installed by screws, wherein the first partition plate 101 is vertically installed in the bottom shell 1 to divide the mounting space of the bottom shell 1 into a control cavity and a battery cell cavity for isolated installation of the control system and the battery cell module, the second partition plate 102 is horizontally installed in the battery cell cavity to divide the battery cell cavity into an upper part and a lower part, the upper part is an installation position of the battery cell module, and the lower part is an installation position of an emergency protection structure, further, the third partition plate 103 is arranged in the middle of the battery cell cavity to divide the battery cell cavity into two symmetrical parts for symmetrical installation of two rows of battery cell modules, and the third partition plate 103 forms a mounting space in the middle of the battery cell cavity for installation of a hydraulic control mechanism.

[0037] The second partition plate 102 is provided with limiting grooves 104 arranged in rows, so that the emergency protection mechanism can enter the battery cell module through the limiting grooves 104 to play a protection role.

[0038] A horizontal rib 105 is assembled between the third partition plate 103 and the inner wall of the bottom shell 1 by screws, the upper cavity of the battery cell cavity is further divided into independent insertion slots by the rib 105, the battery cell module is inserted into the insertion slot, the outer shell of the battery cell module comprises a module box 2 and a sealing cover 3, the module box 2 is connected to the rib 105 by screws, and the sealing cover 3 is fixed to the module box 2 by welding to protect and install the internal components, and meanwhile, the bottom of the module box 2 is provided with through grooves corresponding to the limiting grooves 104, so that the emergency protection mechanism can enter the module box 2.

[0039] The side wall of the module box 2 is provided with a clamping groove 4 arranged equidistantly, through which the hydraulic bag 6 can be distributed and installed, the periphery of the hydraulic bag 6 is fitted in an outer frame 5, the outer frame 5 is fixedly installed in the clamping groove 4 through screws, the electric core 7 can be arranged between two adjacent hydraulic bags 6, usually three electric cores 7 are assembled between two hydraulic bags 6, the hydraulic bag 6 is filled with incompressible hydraulic oil and is connected to a hydraulic control mechanism through a pipeline, the internal pressure of the hydraulic bag 6 is controlled through the hydraulic control mechanism, thereby generating a pre-tightening force on the side wall of the electric core 7, the pre-tightening force refers to the mechanical pressure on the electric core 7 that keeps it in close contact and stable, which is used to maintain good electrical contact between the electric cores 7, reduce contact resistance, and inhibit the volume expansion of the electric core 7 during the charging and discharging process, reduce internal stress concentration and structural deformation, and during the entire life cycle of the battery pack, the pressure of the hydraulic bag 6 can be adjusted in real time according to different working conditions, and the size of the mechanical constraint force applied to the electric core 7 in different areas is actively adjusted to adapt to the changing physical state inside the battery.

[0040] The hydraulic bags 6 in the same electric core module are connected to the same shunt pipe 8, the shunt pipe 8 is installed on the top of the module box 2 through a pipe clamp, and the end of the shunt pipe 8 is connected to a joint pipe 9 through a flange, the joint pipe 9 is a hose and can be connected to a piezoelectric regulating valve 12 through a threaded joint.

[0041] As an embodiment of the present application, the installation space of the third partition plate 103 is clamped with an oil box 10, and the piezoelectric pump 11 is connected to the oil box 10, the piezoelectric pump 11 is connected to the piezoelectric regulating valve 12, and the oil box 10 is also provided with incompressible hydraulic oil, and the piezoelectric pump 11 is a micro hydraulic pump, which can deform the piezoelectric vibrator by using the inverse piezoelectric effect of the piezoelectric ceramic when the input voltage is applied, and then the volume change of the pump cavity is generated by the deformation to realize the output of the hydraulic oil, and the pressure of the hydraulic bag 6 is increased according to the electric signal.

[0042] The piezoelectric regulating valve 12 adopts a double-channel structure and is connected to the piezoelectric pump 11 and the oil box 10, respectively, which can control the opening and closing of the two channels according to the electric signal to realize the accurate control of the mechanical pressure of the hydraulic bag 6.

[0043] A sensing network is arranged in the whole battery pack to monitor the state of the whole battery pack and single cell module, which mainly comprises a piezoresistive film sensor, a distributed temperature sensor and a piezoelectric film array sensor, wherein the piezoresistive film sensor is arranged on the inner wall of the hydraulic capsule 6 to detect the real-time contact pressure between the hydraulic capsule 6 and the cell 7, the distributed temperature sensor is arranged in the middle of the closed cover 3 to detect the local temperature of the single cell module, and the piezoelectric film array sensor is integrally arranged on the inner surface of the four walls of the bottom shell 1 to sense whether the battery pack is impacted, when impacted, the piezoelectric material generates a transient charge signal due to deformation, and the impact position and strength are located by analyzing the signal amplitude, frequency and spatial distribution.

[0044] Normally, the pre-tightening force generated by the hydraulic capsule 6 is mainly controlled by the two parameters of real-time contact pressure and local temperature to generate dynamic mechanical pressure for all cells 7 in the single cell 7 module, and when impact occurs, the piezoelectric pump 11 and the piezoelectric regulating valve 12 are opened through the signal of the piezoelectric film array sensor, so that the pressure in the hydraulic capsule 6 rapidly increases, and then the emergency protection mechanism under the second partition plate 102 is lifted into the module box 2 to replace the hydraulic capsule 6 to perform emergency protection for the cell 7.

[0045] As an embodiment of the present application, the header pipe 13 is embedded and installed at the bottom of the module box 2, the header pipe 13 is in communication with all hydraulic capsules 6 in the module box 2 at the same time, and the hydraulic capsule 6 is connected to the control structure of the emergency protection mechanism through the header pipe 13.

[0046] The emergency protection mechanism comprises a bottom plate 14 arranged in the bottom shell 1, the protection plate 15 is fixed on the bottom plate 14 in a welding manner, the protection plate 15 is in a U-shaped structure, the protection plate 15 is inserted into the limiting groove 104 and can enter the inside of the module box 2 from the limiting groove 104, and is inserted between the cell 7 and the hydraulic capsule 6 to replace the hydraulic capsule 6 to protect the side of the cell 7.

[0047] The second partition plate 102 is provided with a lifting seat 16 on the bottom surface by screwing, the piston pipe 17 is clamped in the lifting seat 16, the piston rod 18 is arranged in the piston pipe 17, the piston pipe 17 can be driven by hydraulic pressure, the outer end of the piston rod 18 is welded with a rack 19, meanwhile, the second partition plate 102 is provided with a shaft support 20 on the bottom surface by screwing, the rotating shaft is arranged on the shaft support 20 by bearing, the gear 21 and the winding rope wheel 22 are welded and fixed on the rotating shaft, the gear 21 is connected with the rack 19, the end block is arranged on the winding rope wheel 22 by welding, the lifting rope 23 is tied on the end block, the other end of the lifting rope 23 is tied on the lifting seat 24 of the bottom plate 14, therefore, when the piston rod 18 is extended from the piston pipe 17 under the driving of the hydraulic pressure, the gear 21 and the winding rope wheel 22 can be driven to rotate by the rack 19, the bottom plate 14 is lifted by the lifting rope 23, the protection plate 15 on the bottom plate 14 can enter the module box 2 to protect the battery cell 7.

[0048] The lifting of the protection plate 15 occurs when the battery pack is impacted from outside, the transition pipe 25 is welded on the end of the piston pipe 17 away from the piston rod 18, the transition pipe 25 is connected with the bus pipe 13 through the connecting pipe 26, the two ends of the connecting pipe 26 are provided with threaded joints, the connecting pipe 26 can be quickly assembled and disassembled, the diaphragm 27 is arranged in the pipe cavity of the connecting pipe 26 by welding, the diaphragm 27 is used to seal the connecting pipe 26, under normal circumstances, the hydraulic oil of the hydraulic capsule 6 cannot enter the transition pipe 25 and the piston pipe 17, the mechanical pressure of the hydraulic capsule 6 is dynamically controlled by the piezoelectric pump 11, meanwhile, the middle part of the diaphragm 27 is provided with a notch 28, when the battery pack is impacted, the piezoelectric pump 11 can quickly increase the internal pressure of the hydraulic capsule 6 in a short time, after the diaphragm 27 can bear the pressure, the diaphragm 27 can be damaged, so that the oil enters the piston pipe 17, the power is generated to drive the lifting of the protection plate 15, the battery cell 7 is provided with rigid protection.

[0049] As an embodiment of the application, the stop block 29 is welded on the side of the bottom plate 14, the positioning seat 30 is arranged on the bottom surface of the second partition plate 102 by screwing, the spring pin 31 is movably arranged in the positioning seat 30, when the impact occurs and the protection plate 15 is lifted with the bottom plate 14, the stop block 29 of the bottom plate 14 passes through the spring pin 31, the bottom plate 14 can be limited by the spring pin 31, the protection plate 15 is kept on the side of the battery cell 7, the stable protection effect is provided, further, the ferromagnetic end block 32 is welded on the tail end of the spring pin 31, the electromagnetic seat 33 is assembled on the side of the positioning seat 30 by screwing, when the battery pack is repaired after the impact, the electromagnetic seat 33 can be electrified to generate the attraction force to the ferromagnetic end block 32, so that the spring pin 31 is retracted, the fixation of the bottom plate 14 is released, the protection plate 15 can be reset, so as to facilitate the repair work of the hydraulic capsule 6 and the battery cell 7.

[0050] At the same time, the connecting pipe 26 is installed in a threaded joint connection mode, can be disassembled and replaced after the diaphragm 27 is broken.

[0051] In use, the battery pack first dynamically adjusts the internal pressure of each subzone hydraulic capsule 6 through the hydraulic control mechanism, the piezoelectric pump 11 adjusts the hydraulic oil output according to the contact pressure and temperature data of the battery cell 7 fed back by the piezoresistive film sensor and the distributed temperature sensor, and differentiates the pre-tightening force of the hydraulic capsule 6 in different areas on the battery cell 7 in real time, so as to suppress the swelling deformation in the charging and discharging process and maintain stable electrical contact; when the piezoelectric film array sensor detects an impact signal, the control system instantaneously increases the pressure of the corresponding area hydraulic capsule 6 to a threshold value, triggers the diaphragm 27 in the connecting pipe 26 to break, the hydraulic oil pushes the piston rod 18 to drive the rack 19 gear 21 mechanism, so that the rope winding wheel 22 tightens the lifting rope 23 to lift the protection plate 15 on the bottom plate 14 to the side of the battery cell 7 to form a rigid protection, and the spring pin 31 locks the stop block 29 to keep the protection state. The dynamic distribution of the pre-tightening force is closed-loop controlled through multi-sensor fusion in the whole process, which not only optimizes the real-time adaptability of the mechanical constraint of the battery cell 7, but also provides active safety protection in extreme working conditions through hydraulic and mechanical control mechanisms.

[0052] The pre-tightening force control system is carried in the control cavity of the battery pack, and is composed of a sensing layer, a decision layer and an execution layer, and dynamically adjusts through closed-loop feedback, and specifically includes the following components and function logic: Sensing layer Pressure monitoring unit: piezoresistive film sensor is integrated in the inner wall of each hydraulic capsule 6, which measures the contact surface pressure of the battery cell 7 in real time, the measurement range is 0-500kPa, the accuracy is ±1kPa, and the output analog signal is transmitted to the main control chip after AD conversion.

[0053] Temperature monitoring unit: the distributed temperature sensor is embedded in the closed cover 3, which monitors the local temperature, the measurement range is-40℃~120℃, and the resolution is 0.1℃.

[0054] Impact sensing unit: the piezoelectric film array is attached to the inner wall of the battery pack, and the impact intensity and position coordinates are output through the charge amplifier, and the response time is <2ms.

[0055] Decision layer The main control chip runs a multi-objective optimization algorithm, including: Dynamic pressure mapping model: based on the three-dimensional lookup table method of the SOC, temperature and swelling pressure of the battery cell 7, the optimal pre-tightening force set value of each subzone is output.

[0056] Impact emergency strategy: through the frequency analysis of the piezoelectric signal, slight vibration (10-50Hz) and violent collision (>100Hz) are distinguished to determine whether the protection plate 15 is started.

[0057] Communication protocol: CAN bus transmits sensor data to BMS, synchronously receives charge and discharge current, voltage parameters for cross verification.

[0058] Execution layer Hydraulic drive subsystem: Piezoelectric pump 11 array regulates oil output according to PWM signal, each pump independently controls 1-4 hydraulic capsules 6.

[0059] Piezoelectric regulating valve 12 (response time 10 ms) adopts double cone valve core structure, adjusts opening degree through duty cycle, realizes pressure fine adjustment, precision is ±0.5kPa.

[0060] Mechanical emergency subsystem: Diaphragm 27 explosion control: when the pressure of hydraulic capsule 6 exceeds the set threshold value, usually 250-300kPa, the diaphragm 27 breaks, and the oil liquid drives the piston mechanism through the bus pipe 13.

[0061] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, the scope of the present application being defined by the appended claims and their equivalents.

Claims

1. A battery pack with dynamically adjustable preload distribution, comprising a bottom shell and internal cell modules, characterized in that: The bottom shell is provided with a partition structure to divide the bottom shell space into a control cavity and a cell cavity. The cell cavity is further divided into an upper cell installation area and a lower emergency area. A module box is set up in the cell installation area, and a hydraulic bladder is installed in the slot on its side wall. The hydraulic bladder is filled with incompressible hydraulic oil and connected to a hydraulic control mechanism through pipelines. Cells are arranged between the hydraulic bladders, and the hydraulic bladders apply an adjustable preload to the side wall of the cell. The hydraulic control mechanism includes an oil box, a piezoelectric pump, and a piezoelectric regulating valve. The piezoelectric pump adjusts the pressure of the hydraulic bladder based on sensor data. The battery pack is equipped with a sensing network, including a piezoresistive thin-film sensor on the inner wall of the hydraulic bladder, a distributed temperature sensor on the sealing cover, and a piezoelectric thin-film array sensor on the inner wall of the bottom shell. The emergency zone is equipped with a liftable protection plate, which is connected to the hydraulic bladder via a piston transmission mechanism, a connecting pipe with a diaphragm, and a manifold. When an impact signal is triggered, the piezoelectric pump pressurizes the diaphragm in the connecting pipe, causing the hydraulic oil to drive the piston transmission mechanism and lift the protection plate to the side of the battery cell.

2. A battery pack with dynamically adjustable preload distribution according to claim 1, characterized in that: The partition structure includes a vertically arranged first partition, a horizontally arranged second partition, and a third partition located in the middle of the cell cavity; The upper part of the cell cavity has horizontal ribs in the cell mounting area, which divide the upper cavity into independent slots for inserting cell modules.

3. A battery pack with dynamically adjustable preload distribution according to claim 1, characterized in that: The bottom of the module box is provided with a through groove that corresponds one-to-one with the upper limit groove of the second partition, and the top of the module box is provided with a sealing cover, which is fixed on the module box. The limiting groove on the second partition is used to allow the protection plate to pass through and enter the module box.

4. A battery pack with dynamically adjustable preload distribution according to claim 1, characterized in that: The hydraulic bladder is fitted around the outer frame, and the outer frame is fixed in the slot on the side wall of the module box. Two to four battery cells are arranged between two adjacent hydraulic bladders. All hydraulic bladders in the same battery cell module are connected to the same shunt pipe, which is installed on the top of the module box.

5. A battery pack with dynamically adjustable preload distribution according to claim 1, characterized in that: The end of the diverter pipe is connected to a connector pipe via a flange. The connector pipe is a flexible hose and is connected to a piezoelectric regulating valve via a threaded connector. The oil box of the hydraulic control mechanism is located in the installation space formed by the third partition.

6. A battery pack with dynamically adjustable preload distribution according to claim 1, characterized in that: The piezoelectric regulating valve adopts a dual-channel structure, which is connected to the piezoelectric pump and the oil box respectively, and is used to control the mechanical pressure of the hydraulic bladder.

7. A battery pack with dynamically adjustable preload distribution according to claim 1, characterized in that: The piezoresistive thin-film sensor is used to detect the real-time contact pressure between the hydraulic bladder and the battery cell, the distributed temperature sensor is used to detect the local temperature of a single battery cell module, and the piezoelectric thin-film array sensor is used to sense the impact on the battery pack and locate the impact location and intensity through signal analysis.

8. A battery pack with dynamically adjustable preload distribution according to claim 1, characterized in that: A manifold is fitted into the bottom of the module box in the emergency zone, and the manifold is connected to all the hydraulic bladders inside the module box; The protective plate has a U-shaped structure and is fixed to the base plate. The base plate is connected to the rope reel via a suspension rope. The rope reel meshes with a rack via a coaxially mounted gear. The rack is connected to the piston rod of the piston transmission mechanism.

9. A battery pack with dynamically adjustable preload distribution according to claim 8, characterized in that: The piston tube of the piston transmission mechanism is connected to the connecting pipe through a transition pipe, and the other end of the connecting pipe is connected to the manifold. The rope reel is mounted on the rotating shaft, which is mounted on the shaft bracket via bearings. The shaft bracket is fixed to the bottom surface of the second partition. One end of the hoisting rope is connected to the rope reel, and the other end is connected to the lifting seat on the base plate.

10. A battery pack with dynamically adjustable preload distribution according to claim 9, characterized in that: The connecting tube has threaded joints at both ends, and the diaphragm inside the connecting tube has a groove in the middle.

11. A battery pack with dynamically adjustable preload distribution according to claim 10, characterized in that: The bottom plate has a stop block on the side, the bottom of the second partition plate has a positioning seat, the positioning seat has a spring pin, the end of the spring pin has a ferromagnetic end block, and the side of the positioning seat has an electromagnetic seat that cooperates with the ferromagnetic end block.

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