A battery module expansion force measurement device and an expansion force distribution test method

Abstract

The present invention belongs to the technical field of battery module expansion force testing, and discloses a battery module expansion force measuring device. Its adjustment mechanism relies on a structural combination similar to a crank-slider-crank structure, and cooperates with the chute structure of its frame structure to realize the synchronous forward or reverse movement of the two side plates to adjust the space size, ensuring the same width as the battery module to be measured; in addition, its force measuring mechanism can not only apply an accurate pre-tightening force to the battery module through a motor, but also measure the magnitude of the average expansion force of the battery module during the charging and discharging process of the battery. In addition, the present invention also discloses a method for testing the expansion force distribution of a battery module. By utilizing the particularity of fluorescent materials, a fluorescent solution is evenly coated on the surface of the battery cells in the battery module. When the battery cells in the battery module expand, the formed fluorescent material will emit light under the action of a specific light source excitation. By using a CCD camera system to obtain and record the fluorescent photos, the distribution of the expansion force on the surface of the module can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery module expansion force testing, and specifically relates to a battery module expansion force measuring device and a test method for expansion force distribution. Background Art

[0002] As an indispensable energy storage device in modern society, the battery plays a crucial role in people's daily lives. With the continuous growth of the demand for portable devices and electric vehicles, the pursuit of battery energy density has become increasingly urgent. However, in the process of pursuing high specific energy density, a series of new challenges and problems have emerged. One of them is that high specific energy batteries will generate huge volume expansion during charge and discharge. When the battery volume expands to a certain extent, it will cause the shell to rupture and the electrolyte to flow out, which may lead to major safety problems such as combustion and explosion, seriously affecting the electrochemical performance and safety of the battery. Therefore, it is extremely important to measure the expansion force of the battery module.

[0003] At the same time, due to the difference in the battery capacity requirements according to the application scenarios, batteries of different specifications and sizes are designed. Considering the diversity of battery specifications, the device must be able to accommodate batteries of various sizes to ensure accurate measurement of the expansion force of batteries of different specifications and sizes. To adapt to these changes, the battery expansion force test device needs to have the ability to freely adjust its size, which is crucial for the versatility of the device.

[0004] In addition, due to the uneven internal chemical reactions during the charge and discharge process of the battery module, there will be a problem that the forces on different battery cells and different parts of the same battery cell are inconsistent, resulting in differences in the expansion force distribution on the surface of the battery module. Because high specific energy batteries are more sensitive to potential safety hazards and the harm after danger is greater, it is even more important to be able to characterize the differences in the expansion forces on the surfaces of each battery cell in the battery module, so as to more comprehensively understand the battery working state, timely adjust the design and manufacturing processes, and improve the service life and safety of the battery. Summary of the Invention

[0005] The present invention aims to solve the relevant technical problems in the battery expansion force test and develop a battery module expansion force measuring device. Its adjustment mechanism relies on a structural combination similar to a crank-connecting rod slider, and cooperates with the slide groove structure of its frame structure to achieve synchronous unidirectional or reverse movement of the side plates on both sides to adjust the space size, ensuring that it is equal to the width of the battery module to be measured; in addition, its force measuring mechanism not only applies accurate preload force to the battery module through the motor, but also can measure the size of the average expansion force of the battery module during the battery charging and discharging process. At the same time, the present invention proposes a battery module expansion force distribution test method, which utilizes the particularity of fluorescent materials to evenly coat the surface of the battery cell in the battery module with a fluorescent solution. When the battery cell in the battery module expands, the film-forming material will be acted upon by force and emit light under the excitation of a specific light source. The fluorescent photos on the battery surface are obtained and recorded by the CCD camera system, so the distribution of the expansion force on the module surface can be obtained.

[0006] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0007] According to one aspect of the present invention, there is provided a battery module expansion force measuring device, comprising a frame structure, an adjustment mechanism and a force measuring mechanism;

[0008] The frame structure includes a bottom support plate of a rectangular structure, wherein two rows of the first slide grooves are opened on the upper surface of the bottom support plate, and the two rows of the first slide grooves are symmetrically arranged side by side in the width direction of the bottom support plate, and the plurality of the first slide grooves in each row are spaced apart along the length direction of the bottom support plate; the first slide groove is used to connect the side plates of the adjustment mechanism and to adjust the spacing between the two side plates; a through hole groove is provided at one end of the bottom support plate, and the through hole groove is used to connect the fixing plate and to adjust the position of the fixing plate in the length direction of the bottom support plate, and the fixing plate is perpendicular to the bottom support plate and the side plate at the same time; an isolation plate is fixed to the other end of the bottom support plate, and the isolation plate is parallel to and opposite to the fixing plate; a fixing hole is opened in the middle of the isolation plate, and the fixing hole passes through the isolation plate along the length direction of the bottom support plate;

[0009] The adjusting mechanism includes two side plates mounted on the bottom support plate. The battery module is placed on the bottom support plate during the test and is located between the two side plates with the fixed plate as a reference. Each side plate includes a side plate main board. A plurality of first sliders are provided at the bottom of the side plate main board, and the first sliders are respectively mounted in the first chutes and can slide along the first chutes to adjust the position of the side plate main board in the width direction of the bottom support plate. At the top of the side plate main board, there is a first T-shaped rod and a plurality of second T-shaped rods. The height of the second T-shaped rods is lower than that of the first T-shaped rod. The first T-shaped rod and the second T-shaped rods are evenly spaced along the length direction of the side plate main board. The first T-shaped rod is located at the middle position at the top of the side plate main board, and the same number of the second T-shaped rods are distributed on both sides of the first T-shaped rod. A cover plate is provided on the two side plate main boards. The cover plate is provided with two rows of second chutes, which are respectively located above the two side plates. Each row of the second chutes is respectively matched with the first T-shaped rod and the second T-shaped rods and can enable the first T-shaped rod and the second T-shaped rods to slide in the second chutes. The cover plate is provided with two slide rails between the two rows of second chutes. The two slide rails are both arranged along the symmetric center line of the two rows of second chutes, and the two slide rails are symmetrically arranged relative to the two second chutes corresponding to the first T-shaped rod. Each slide rail is mounted with a second slider, and the second slider can slide within the slide rail. A groove is provided on the upper surface of the cover plate, and the groove is located between the two second chutes corresponding to the first T-shaped rod and the two slide rails. A pedestal bearing is mounted in the groove. A connecting shaft is mounted on the pedestal bearing, and the connecting shaft is connected to the turntable through a key. The turntable includes a circular flat plate structure, and a fixed rod is fixedly connected to the upper surface of the circular flat plate structure. The fixed rod is connected to one of the first T-shaped rods through a first connecting rod. The two ends of the first connecting rod are respectively hinged to the fixed rod and the first T-shaped rod. Each first T-shaped rod is respectively connected to the two second sliders through two second connecting rods. The two ends of the second connecting rod are respectively hinged to the first T-shaped rod and the second slider it is connected to. The four second connecting rods are equal in length and are connected into a rhombus. By pushing the turntable to rotate through the fixed rod, the first connecting rod drives the first T-shaped rod to perform a reciprocating linear motion in the second chute. At the same time, through the change of the rhombus formed by the four second connecting rods, with the synchronous reverse movement of the two second sliders, the synchronous reverse movement of the two side plates is realized, so as to realize the adjustment of the size of the space for accommodating the battery module.

[0010] The force measuring mechanism includes a forward and reverse motor, which is arranged on the side of the partition plate facing away from the fixing plate; the output shaft of the forward and reverse motor passes through the fixing hole in the middle of the partition plate and is connected to one end of a coupling, and the other end of the coupling is threadedly connected to one side of a sensor fixing plate through a transmission shaft. The other side of the sensor fixing plate is connected to one side of a pressing plate through a force sensor, and the other side of the pressing plate is connected to one side of an insulating plate through a telescopic rod; a telescopic spring is sleeved outside the telescopic rod, and the two ends of the telescopic spring respectively abut against the pressing plate and the insulating plate; the other side of the insulating plate is used to directly apply pressure to the battery module.

[0011] Further, all the first chutes have the same structure, and their dimension along the width direction of the bottom support plate is larger than that along the length direction; all the second chutes have the same structure, and their dimension along the width direction of the cover plate is larger than that along the length direction.

[0012] Further, two through-hole grooves are symmetrically arranged side by side in the width direction of the bottom support plate; the two through-hole grooves have the same structure, and their dimension along the length direction of the bottom support plate is larger than that along the width direction; the fixing plate includes a vertical limiting plate and a base horizontally connected to the bottom of the limiting plate, and through holes are respectively arranged on both sides of the base for connecting to the two through-hole grooves through bolts and nuts.

[0013] Further, the middle part of the cover plate is thickened relative to both ends.

[0014] Further, the forward and reverse motor is fixed on the bottom support plate through a motor mounting seat.

[0015] Further, the surface of the insulating plate is flat and free of burrs, and it is a flat plate with a length and width equal to the contact surface size of the battery module.

[0016] According to another aspect of the present invention, there is provided a method for testing the expansion force distribution of a battery module, which is carried out based on the above-mentioned battery module expansion force measuring device, and includes: uniformly coating a fluorescent solution on the surface of each battery in the battery module, and forming a film of the fluorescent solution on the surface of each battery; then measuring the expansion force of the battery module. After the battery module expands under force, under the excitation of ultraviolet light, the fluorescent material on the surface of each battery in the battery module is excited to emit fluorescence due to the action of force, and a CCD camera system is used to obtain and record a fluorescent photo, so that the distribution of the expansion force on the surface of each battery in the battery module can be obtained; the brighter the fluorescence, the greater the deformation and the greater the expansion force generated.

[0017] Further, the fluorescent material is tetranitro-tetraphenylethylene, and the wavelength of the ultraviolet light is 365 nm.

[0018] Further, the concentration of the fluorescent material is 0.01 - 1 g / mL.

[0019] The beneficial effects of the present invention are as follows:

[0020] The present invention provides a device for measuring the expansion force of a battery module. Its adjustment mechanism relies on a structural combination similar to a crank - connecting rod slider, and cooperates with the chute structure of its frame structure to achieve the synchronous forward or reverse movement of the two side plates. This design improves the flexibility and adaptability of the device, ensures that the measuring device can adapt to modules of different sizes, and improves the universality of the measuring device. At the same time, the addition of the force - measuring mechanism can not only simulate the initial working conditions of the battery module during actual use, but also measure the average expansion force of the module during the charge - discharge process in real time, which helps to more realistically simulate and measure the expansion force of the battery module during the charge - discharge process and is of great significance for battery safety management and performance evaluation.

[0021] The present invention provides a test method for the expansion force distribution of a battery module, which proposes to use a fluorescent material in combination with a CCD camera system to obtain the distribution of the expansion force on the surface of the battery module. This method innovatively applies visual detection technology to the test of the expansion force distribution of the battery module, simply and intuitively observes the distribution of the expansion force, facilitates the analysis of weak links in the battery module structure, and provides a scientific basis for improving the reliability of the battery module. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an assembly schematic diagram of the device for measuring the expansion force of a battery module provided by an embodiment of the present invention.

[0023] Figure 2 It is a schematic structural diagram of the frame structure in the device for measuring the expansion force of a battery module provided by an embodiment of the present invention.

[0024] Figure 3 It is a schematic structural diagram of the adjustment mechanism in the device for measuring the expansion force of a battery module provided by an embodiment of the present invention.

[0025] Figure 4 It is a schematic structural diagram of the side plate in the device for measuring the expansion force of a battery module provided by an embodiment of the present invention.

[0026] Figure 5 It is a schematic structural diagram of the cover plate in the device for measuring the expansion force of a battery module provided by an embodiment of the present invention.

[0027] Figure 6 It is a schematic diagram of the input transmission structure of the adjustment mechanism in the device for measuring the expansion force of a battery module provided by an embodiment of the present invention.

[0028] Figure 7Schematic structural diagram of the force measuring mechanism in the battery module expansion force measuring device provided by the embodiment of the present invention.

[0029] Figure 8 Variation diagram of the fluorescence intensity of the fluorescent material on the surface of the square battery case under different forces in the battery module expansion force distribution test method provided by the embodiment of the present invention.

[0030] In the above figures:

[0031] 1: Frame structure; 11: Bottom support plate, 111: First chute, 112: Through hole groove, 12: Fixed plate, 13: Partition plate, 131: Fixed hole; 14: Motor mounting seat; 2: Battery module; 3: Adjusting mechanism; 31: Side plate, 311: First slider, 312: Side plate main board, 313: First T-shaped rod, 314: Second T-shaped rod, 32: Cover plate, 321: Second chute; 322: Slide rail; 323: Groove; 33: Bearing with housing, 34: Connecting shaft, 35: Key, 36: Turntable, 361: Circular flat plate structure, 362: Fixed rod; 37: First connecting rod; 38: Second connecting rod; 39: Second slider; 4: Force measuring mechanism; 41: Reversible motor; 42: Coupling; 43: Sensor fixing plate; 44: Force sensor, 45: Extrusion plate, 46: Telescopic rod, 47: Insulating plate, 48: Telescopic spring. Detailed implementation manners

[0032] To further understand the content, features and effects of the present invention, the following embodiments are exemplified and described in detail with reference to the accompanying drawings:

[0033] See Figure 1 As shown, the embodiment of the present invention provides a battery module expansion force measuring device, and the whole device is composed of a frame structure 1, an adjusting mechanism 3 and a force measuring mechanism 4.

[0034] See Figure 2 As shown, the frame structure 1 includes a bottom support plate 11, a fixed plate 12, a partition plate 13, and a motor mounting seat 14.

[0035] The bottom support plate 11 generally adopts a rectangular structure, and two rows of first chutes 111 are opened on its upper surface. The two rows of first chutes 111 are symmetrically arranged side by side in the width direction of the bottom support plate 11, and multiple first chutes 111 in each row are spaced apart along the length direction of the bottom support plate 11. Moreover, the structures of all the first chutes 111 are the same, and the dimension along the width direction of the bottom support plate 11 is larger than the dimension along the length direction.

[0036] One end of the bottom support plate 11 is provided with two through-hole grooves 112, and the two through-hole grooves 112 are symmetrically arranged side by side in the width direction of the bottom support plate 11. The two through-hole grooves 112 have the same structure, and their dimension along the length direction of the bottom support plate 11 is larger than that in the width direction. The through-hole grooves 112 are used to connect the bottom support plate 11 and the fixing plate 12 through bolts and nuts, and can appropriately move the position of the fixing plate 12 in the length direction of the bottom support plate 11 to achieve the purpose of finely adjusting the space for accommodating the battery module 2.

[0037] As an implementation manner of the present invention, the fixing plate 12 includes a vertically arranged limiting plate and a base horizontally connected to the bottom of the limiting plate. The fixing plate 12 is perpendicular to both the bottom support plate 11 and the side plate 31 at the same time. Through holes are respectively provided on both sides of the base for connecting with the two through-hole grooves 112 of the bottom support plate 11 through bolts and nuts, so that the limiting plate is used as the installation reference for the battery module 2.

[0038] The other end of the frame structure 1 is provided with a partition plate 13. The partition plate 13 is parallel and opposite to the limiting plate of the fixing plate 12, and the bottom can be fixed to the bottom support plate 11 by welding. A fixing hole 131 is provided in the middle of the partition plate 13, and the fixing hole 131 penetrates through the partition plate 13 along the length direction of the bottom support plate 11. A motor mounting seat 14 can also be provided on the side of the partition plate 13 facing away from the fixing plate 12. The bottom of the motor mounting seat 14 can be fixed to the bottom support plate 11 by welding, and the motor mounting seat 14 is used to support the forward and reverse motor 41.

[0039] See Figure 3 As shown, the adjusting mechanism 3 includes side plates 31, a cover plate 32, a pedestal bearing 33, a connecting shaft 34, a key 35, a turntable 36, a first connecting rod 37, a second connecting rod 38, and a second slider 39.

[0040] The two side plates 31 are installed on the upper part of the bottom support plate 11 and are respectively located on both sides of the bottom support plate 11. See Figure 4 As shown, each side plate 31 includes a side plate main board 312, and the side plate main board 312 plays a major role in restricting the position of the battery module 2. A plurality of circular first sliders 311 are provided at the bottom of the side plate main board 312. The first sliders 311 are evenly spaced along the length direction of the side plate main board 312 for being respectively installed in the first sliding grooves 111 and capable of sliding in the first sliding grooves 111. A first T-shaped rod 313 and a plurality of second T-shaped rods 314 are provided at the top of the side plate main board 312, and the height of the second T-shaped rods 314 is lower than that of the first T-shaped rod 313. The first T-shaped rod 313 and the second T-shaped rods 314 are evenly spaced along the length direction of the side plate main board 312 together, and the first T-shaped rod 313 is located at the middle position of the top of the side plate main board 312, and the same number of second T-shaped rods 314 are distributed on both sides of the first T-shaped rod 313.

[0041] The cover plate 32 is arranged on the two side plate main boards 312 and supported by the first T-shaped rod 313 and the second T-shaped rod 314. The middle part of the cover plate 32 is thickened relative to both ends, so that on the premise of realizing the installation of the pillow block bearing 33, it can not only ensure that the cover plate 32 has sufficient strength, but also can reduce the weight as much as possible.

[0042] See Figure 5 As shown, the cover plate 32 is provided with two rows of second sliding grooves 321, and the two rows of second sliding grooves 321 are respectively located above the two side plates 31. Each row of second sliding grooves 321 cooperates with the first T-shaped rod 313 and the second T-shaped rod 314 one by one, and can realize that the first T-shaped rod 313 and the second T-shaped rod 314 pass through the second sliding groove 321 and slide in the second sliding groove 321. The structures of all the second sliding grooves 321 are the same, and the dimension in the width direction of the cover plate 32 is larger than the dimension in the length direction.

[0043] The cover plate 32 is provided with two slide rails 322 between the two rows of second sliding grooves 321. The two slide rails 322 are both arranged along the symmetry center line of the two rows of second sliding grooves 321, and the two slide rails 322 are symmetrically arranged with respect to the center line of the two second sliding grooves 321 corresponding to the first T-shaped rod 313. Each slide rail 322 is installed with a second slider 39, and the second slider 39 can slide in the slide rail 322.

[0044] See Figure 6 As shown, the upper surface of the cover plate 32 is provided with a groove 323, and the groove 323 is located between the two second sliding grooves 321 corresponding to the first T-shaped rod 313 and the two slide rails 322, and is used for installing the pillow block bearing 33. Preferably, the cross section of the groove 323 is a square with rounded corners.

[0045] The connecting shaft 34 is installed in the pillow block bearing 33 and connected to the turntable 36 through a key 35. The turntable 36 is generally located above the groove 323.

[0046] The turntable 36 includes a circular flat plate structure 361, and a fixing rod 362 is fixedly connected to the upper surface of the circular flat plate structure 361. The fixing rod 362 is connected to one of the first T-shaped rods 313 through a first connecting rod 37, and both ends of the first connecting rod 37 are hinged to the fixing rod 362 and the first T-shaped rod 313 respectively.

[0047] Each first T-shaped rod 313 is respectively connected to the two second sliders 39 through two second connecting rods 38. Both ends of the second connecting rod 38 are hinged to the first T-shaped rod 313 and the second slider 39 to which it is connected respectively. The four second connecting rods 38 with equal lengths form a rhombus.

[0048] The turntable 36 is pushed by the fixed rod 362, and the first connecting rod 37 drives one of the first T-shaped rods 313 to perform reciprocating linear motion in the second sliding groove 321. At the same time, by means of the rhombus formed by four equal-length second connecting rods 38, with the synchronous reverse movement of the two second sliders 39, the synchronous reverse movement of the two side plates 31 is realized, so as to facilitate the adjustment of the size of the space for accommodating the battery module 2.

[0049] See Figure 7 As shown, the force measuring mechanism 4 includes a forward and reverse motor 41, which is placed on the motor mounting seat 14 and fixed to the motor mounting seat 14 by screws. The output shaft of the forward and reverse motor 41 passes through the fixing hole 131 in the middle of the partition plate 13 and is connected to one end of the coupling 42. The other end of the coupling 42 is threadedly connected to one side of the sensor fixing plate 43 through a transmission shaft. The other side of the sensor fixing plate 43 is connected to one side of the pressing plate 45 through a force sensor 44. The force sensor 44 is threadedly connected to both the sensor fixing plate 43 and the pressing plate 45. The other side of the pressing plate 45 is connected to one side of the insulating plate 47 through a telescopic rod 46. A telescopic spring 48 is sleeved outside the telescopic rod 46, and both ends of the telescopic spring 48 abut against the pressing plate 45 and the insulating plate 47 respectively. While connecting the pressing plate 45 and the insulating plate 47, the telescopic rod 46 also ensures a certain deformation, and at the same time, the telescopic spring 48 provides a buffering effect for the pressure received by the insulating plate 47.

[0050] The other side of the insulating plate 47 is used to directly apply pressure to the battery module 2. The insulating plate 47 is a flat plate with a flat surface without burrs, and its length and width are equal to the contact surface size of the battery module 2, avoiding damage to the battery caused by direct contact between the force measuring mechanism 4 and the battery module 2.

[0051] Based on the above battery module expansion force measuring device, the present invention provides a test method for measuring the expansion force distribution of the battery module. Through the special properties of the fluorescent material, the mechanical information that is difficult to identify by the naked eye can be converted into visible fluorescent signals to characterize the distribution of the expansion forces of different batteries in the battery module during charge and discharge.

[0052] The force-induced fluorescent material tetranitro-tetraphenylethylene (TPE-4N) has a rapid luminescence response, is sensitive to external stress stimuli, has a high luminescence efficiency, and the fluorescence can be detected non-contact visually. It does not require the use of a large number of devices and can be coated over a large area. In this embodiment, the tetranitro-tetraphenylethylene fluorescent material is used. The tetranitro-tetraphenylethylene is dissolved in a solvent to form a fluorescent solution. The solvent should be an organic solvent with good solubility and suspension, such as chloroform. Preferably, the concentration of the fluorescent solution is 0.01 - 1 g / mL.

[0053] Use a brush, spray gun, etc. to evenly apply the pre-prepared fluorescent solution onto the surface of each battery in the battery module 2. Place the coated batteries in a well-ventilated place to form a film, avoiding the occurrence of bubbles or unevenness. Refer to Figure 8 As shown, when the film of the tetranitro-tetraphenylethylene fluorescent material is formed, it will emit green fluorescence under 365 nm ultraviolet light without force and under different forces of 1 KN, 10 KN, and 20 KN. The fluorescent photos can be obtained and recorded by a CCD camera system, and then the distribution of the swelling force on the surface of the battery module can be obtained.

[0054] According to the size of the battery module 2 to be measured, place the fixing plate 12 on the upper surface of the bottom support plate 11, move it along the through-hole groove 112 to a suitable position, and fix it with bolts and nuts. Place the battery module 2 coated with the fluorescent material on the bottom support plate 11, and at the same time make one side of the battery module 2 abut against the fixing plate 12, so that the central axis of the battery module 2 coincides with the central axis of the bottom support plate 11. Rotate the fixing rod 362, and drive the first T-shaped rod 313 on one side plate 31 to make a reciprocating linear motion in the second chute 321 on the cover plate 32 through the first connecting rod 37. At the same time, use the rhombus structure formed by the four second connecting rods 38, with the first T-shaped rod 313 and the second slider 39 as vertices, to realize the simultaneous reverse movement of the two side plates 31, so as to adjust the distance between the two side plates 31 to fix the battery module 2.

[0055] After the battery module 2 is fixed, start the forward and reverse motor 41. The output shaft of the forward and reverse motor 41 drives the sensor fixing plate 43 and the pressing plate 45 to move through the coupling 42. The pressing plate 45 is connected to the insulating plate 47 through the telescopic rod 46 and the telescopic spring 48 to realize the linear motion of the insulating plate 47, so as to press the battery module 2.

[0056] After the battery module 2 is fixed, conduct charge and discharge tests on the battery module 2. The magnitude of the swelling force during the charge and discharge process of the battery module 2 can be recorded in real time through the force sensor 44. After the test is completed, take out the battery module 2. Under the excitation of the ultraviolet light source, the difference in the green fluorescence brightness on the surface of the battery module 2 can be seen. The brighter the fluorescence, the greater the deformation and the greater the swelling force generated. At the same time, the fluorescent photos can be obtained and recorded by using a CCD camera system.

[0057] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can make many specific transformations in form without departing from the spirit of the invention and the scope protected by the claims. All of these are within the protection scope of the present invention.

Claims

1. A battery module expansion force measuring device, characterized in that: It includes a frame structure, an adjustment mechanism and a force measuring mechanism; The frame structure includes a bottom support plate of a rectangular structure, wherein two rows of first slide grooves are opened on the upper surface of the bottom support plate, and the two rows of first slide grooves are symmetrically arranged side by side in the width direction of the bottom support plate, and the plurality of first slide grooves in each row are spaced apart along the length direction of the bottom support plate; the first slide groove is used to connect the side plates of the adjustment mechanism and to adjust the spacing between the two side plates; a through hole groove is provided at one end of the bottom support plate, and the through hole groove is used to connect the fixing plate and to adjust the position of the fixing plate in the length direction of the bottom support plate, and the fixing plate is perpendicular to the bottom support plate and the side plate at the same time; an isolation plate is fixed to the other end of the bottom support plate, and the isolation plate is parallel to and opposite to the fixing plate; a fixing hole is opened in the middle of the isolation plate, and the fixing hole passes through the isolation plate along the length direction of the bottom support plate; The adjustment mechanism includes two side plates installed on the bottom support plate, the battery module is placed on the bottom support plate during the test, and is located between the two side plates with the fixed plate as the reference; each of the side plates includes a side plate main board, a plurality of first sliders are arranged at the bottom of the side plate main board, the first sliders are installed in the first slide grooves one by one and can slide along the first slide grooves to achieve position adjustment of the side plate main board in the width direction of the bottom support plate; a first T-bar and a plurality of second T-bars are arranged on the top of the side plate main board, the height of the second T-bar is lower than the first T-bar; the first T-bar and the second T-bar are arranged along the The side panel mainboards are evenly spaced in the length direction, and the first T-shaped rod is located in the middle of the top of the side panel mainboard, and the same number of the second T-shaped rods are distributed on both sides of the first T-shaped rod; a cover plate is arranged on the two side panel mainboards, and the cover plate is provided with two rows of second slide grooves, and the two rows of the second slide grooves are respectively located above the two side panels, and the second slide grooves in each row are matched with the first T-shaped rod and the second T-shaped rod in a one-to-one correspondence, and the first T-shaped rod and the second T-shaped rod can slide in the second slide groove; the cover plate is provided with two slide rails between the two rows of the second slide grooves, and the two slide rails are arranged along the symmetrical center lines of the two rows of the second slide grooves. , and the two slide rails are symmetrically arranged relative to the two second slide grooves corresponding to the first T-shaped rod; each of the slide rails is equipped with a second slider, and the second slider can slide in the slide rail; a groove is arranged on the upper surface of the cover plate, and the groove is located between the two second slide grooves corresponding to the first T-shaped rod and the two slide rails, and a seat bearing is installed in the groove; the seat bearing is equipped with a connecting shaft, and the connecting shaft is connected to the turntable through a key; the turntable includes a circular flat plate structure, and a fixing rod is fixedly connected to the upper surface of the circular flat plate structure, and the fixing rod is connected to one of the first T-shaped rods through a first connecting rod, and the two ends of the first connecting rod are respectively connected to the The fixing rod and the first T-shaped rod are hinged; each of the first T-shaped rods is respectively connected to two of the second sliders through two second connecting rods, and the two ends of the second connecting rod are respectively hinged to the first T-shaped rod and the second slider connected thereto; the four second connecting rods are of equal length and are thus connected in a rhombus shape; the rotating disk is driven to rotate by the fixing rod, and the first connecting rod drives the first T-shaped rod to perform reciprocating linear motion in the second slide groove, and at the same time, through the change of the rhombus formed by the four second connecting rods, the synchronous reverse motion of the two second sliders is realized, thereby realizing the synchronous reverse motion of the two side plates, thereby realizing the adjustment of the size of the space for the battery module accommodated; The force measuring mechanism includes a forward and reverse motor, which is arranged on the side of the isolation plate facing away from the fixed plate; the output shaft of the forward and reverse motor passes through the fixed hole in the middle of the isolation plate and is connected to one end of the coupling, the other end of the coupling is threadedly connected to one side of the sensor fixing plate through a transmission shaft, the other side of the sensor fixing plate is connected to one side of the extrusion plate through a force sensor, and the other side of the extrusion plate is connected to one side of the insulating plate through a telescopic rod; a telescopic spring is sleeved on the outside of the telescopic rod, and the two ends of the telescopic spring are respectively pressed against the extrusion plate and the insulating plate; the other side of the insulating plate is used to directly apply pressure to the battery module.

2. A battery module expansion force measuring device according to claim 1, characterized in that: All of the first slide grooves have the same structure, and their dimensions along the width direction of the bottom support plate are larger than their dimensions along the length direction; all of the second slide grooves have the same structure, and their dimensions along the width direction of the cover plate are larger than their dimensions along the length direction.

3. A battery module expansion force measuring device according to claim 1, characterized in that: The two through hole grooves are symmetrically arranged side by side in the width direction of the bottom support plate; the two through hole grooves have the same structure, and their dimensions along the length direction of the bottom support plate are larger than their dimensions in the width direction; the fixed plate includes a vertically arranged limit plate and a base horizontally connected to the bottom of the limit plate, and through holes are respectively arranged on both sides of the base for connecting with the two through hole grooves through bolts and nuts.

4. A battery module expansion force measuring device according to claim 1, characterized in that: The middle portion of the cover plate is thicker than the two ends.

5. A battery module expansion force measuring device according to claim 1, characterized in that: The forward and reverse motor is fixed on the bottom support plate through a motor mounting seat.

6. A battery module expansion force measuring device according to claim 1, characterized in that: The surface of the insulating plate is flat and free of burrs, and the length and width are equal to the contact surface of the battery module.

7. A battery module expansion force distribution test method, characterized in that: The method is based on the battery module expansion force measuring device as described in any one of claims 1 to 6, comprising: uniformly coating the surface of each battery in the battery module with a fluorescent solution, and forming a film of the fluorescent solution on the surface of each battery; then measuring the expansion force of the battery module, after the battery module is expanded by force, under the excitation of ultraviolet light, the fluorescent material on the surface of each battery in the battery module is excited to fluoresce due to the action of the force, and a CCD camera system is used to obtain and record fluorescent photos, so that the distribution of the expansion force on the surface of each battery in the battery module can be obtained; the brighter the fluorescence, the greater the deformation and the greater the expansion force generated.

8. A battery module expansion force distribution testing method according to claim 7, characterized in that: The fluorescent material is tetranitro-tetraphenylethylene, and the wavelength of the ultraviolet light is 365nm.

9. A battery module expansion force distribution testing method according to claim 7, characterized in that: The concentration of the fluorescent material is 0.01-1 g / mL.

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