Battery load curve test fixture, apparatus, and method

Abstract

A battery load curve test tool, equipment and method are provided. The battery load curve test tool comprises: a vertical lifting and restraining mechanism, including a top plate and a bottom plate, the top plate having a vertical lifting degree of freedom relative to the bottom plate; a horizontal limiting and restraining mechanism, including a limiting slot, the limiting slot having an upward opening, the limiting slot being capable of accommodating a battery, the depth direction of the limiting slot being perpendicular to the thickness direction of the accommodated battery; a pressure head, the pressure head being located on the side of the top plate facing the bottom plate, the pressure head being capable of contacting one side of the battery and impacting and / or extruding the battery; wherein the contact surface of the pressure head and the battery is a convex curved surface, the corresponding revolution generatrix of the convex curved surface being a line segment, the line segment being parallel to the thickness direction of the battery. In this way, the side of the battery is impacted or extruded by the pressure head, which facilitates accurate simulation of the blunt impact that the battery may encounter when installed in a new energy vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery testing, and in particular to a battery load curve testing tool, device and method. BACKGROUND

[0002] In recent years, new energy vehicles have developed rapidly. Among the batteries used by new energy, lithium-ion batteries have the advantages of high energy density, long cycle life, high charging efficiency, etc., and are widely used in power battery systems of pure electric vehicles or hybrid electric vehicles. Since lithium-ion power batteries are generally installed at the bottom of the vehicle, when a traffic accident occurs, the lithium-ion battery is easily subjected to extrusion or impact. If the lithium-ion battery is under abusive conditions, there is a high risk of fire and explosion. Therefore, a mature lithium-ion battery usually undergoes testing under multiple mechanical abuse conditions before being applied to new energy vehicles.

[0003] Common lithium-ion batteries include cylindrical batteries, soft-pack batteries, prismatic batteries, and blade batteries, among others. The constraints on the cells vary with different battery types. Meanwhile, different host manufacturers also have significant differences in the arrangement of the batteries, such as using modular battery modules or directly using battery monomers. These different arrangements result in the diversity and complexity of the constraints.

[0004] In traffic accidents, the lithium-ion batteries of new energy vehicles often face dynamic impact conditions. Due to the structural characteristics of the battery pack, the battery mainly bears blunt impacts. This impact condition poses a severe challenge to the safety and stability of the battery. Different types of batteries have different arrangements and fixing methods in the battery pack, resulting in differences in the constraints. These differences significantly affect the response characteristics of the battery under mechanical impact. Therefore, it is necessary to conduct dynamic blunt impact tests on lithium-ion batteries under different constraints to evaluate their safety performance and stability under various actual conditions, thereby providing important support for battery pack design optimization and reducing the risk of personnel and property damage in traffic accidents.

[0005] Chinese patent application with publication number "CN115265993A" discloses "a battery pack flying carpet side column impact test method and test system". The test system installation includes a column impact device with a collision column installed on a fixed barrier, a mobile trolley with wheels for installing the battery pack, and a mobile flying carpet for carrying the mobile trolley set on the traction track. The mobile flying carpet can run on the traction track and make the battery pack collide with the collision column. This test system can simulate the pure new energy vehicle battery pack flying carpet side column impact condition to the greatest extent, and can better investigate the protective performance of the battery pack against external intrusion. However, this collision test system is based on the environment imitating the size of a real vehicle, and it is a collision test for the entire battery pack.

[0006] Chinese utility model patent with publication number "CN203772999U" discloses "a lithium battery short circuit test tool". The test tool includes a tool body, which is an open-sided rectangular frame. A battery positioning mechanism is arranged on the bottom plate of the tool body, and a short circuit mechanism is arranged on the top plate. The battery positioning mechanism includes oppositely arranged left and right positioning seats. The short circuit mechanism is composed of a short circuit metal module, a gas cylinder and heat insulation ceramic. The short circuit metal module and the heat insulation ceramic can move up and down under the control of the gas cylinder. Although the test tool is small in size, it mainly relies on the movable short circuit metal module to perform the short circuit test of the positive and negative electrodes of the battery, and is not a test of the battery extrusion under load.

[0007] Some existing clamping tools cannot change the constraint form of the battery or cannot perform dynamic blunt impact test on the battery. In actual battery accident conditions, lithium ion batteries usually face dynamic impact working conditions in the in-plane direction, and the constraint conditions are affected by the battery type and the internal structure of the battery pack. In addition, due to the influence of the structure around the battery, the battery is mostly subjected to blunt impact in the in-plane direction. The performance of the lithium ion battery is affected by the loading speed, the constraint condition and the impact surface. The existing battery test fixture cannot perform dynamic blunt impact test on the battery under different constraint conditions, so it is difficult to accurately simulate and test the mechanical response of the battery under real collision accidents. This limitation makes the current test method insufficient to comprehensively evaluate the mechanical safety of the battery in actual use. SUMMARY

[0008] The present application is made in view of the above state of the art. The present application aims to solve or alleviate at least one of the above problems.

[0009] In a first aspect, the application provides a battery load curve testing tool, comprising: a vertical lifting and restraining mechanism, the vertical lifting and restraining mechanism comprising a top plate and a bottom plate, the top plate having a vertical lifting freedom relative to the bottom plate; a horizontal limiting and restraining mechanism, the horizontal limiting and restraining mechanism comprising a limiting groove, the limiting groove having an upward opening, the limiting groove being capable of accommodating a battery, the depth direction of the limiting groove being perpendicular to the thickness direction of the battery accommodated; a pressure head, the pressure head being located on the side of the top plate facing the bottom plate, the pressure head being capable of contacting one side of the battery and impacting and / or extruding the battery; wherein the contact surface of the pressure head and the battery is a convex surface, the corresponding generatrix of the convex surface being a line segment, the line segment being parallel to the thickness direction of the battery. As a further improvement of the application, the two ends of the pressure head are end planes, the end planes perpendicularly intersecting the convex surface, the shape of the end planes being arcuate, the distance between the two end planes being not less than the thickness of the battery, the opening width of the limiting groove being not less than the distance between the two end planes; the opening width of the limiting groove being capable of changing and realizing horizontal clamping and restraining of the battery.

[0010] As a still further improvement of the application, the shape of the end planes is inferior arc or semicircular, the top of the pressure head has a top plane, the top plane being in surface contact with the top plate, the top plate having a through mounting hole, the mounting hole being detachably assembled with the top plane of the pressure head through a fastener.

[0011] As a still further improvement of the application, the top plate and the bottom plate are movably assembled through a plurality of guide columns, the guide columns passing through the top plate.

[0012] As a still further improvement of the application, the bottom plate is assembled with a pair of mirror-symmetric clamping pieces, a plurality of bolts connecting the pair of clamping pieces, the pair of clamping pieces being capable of accommodating or clamping and restraining the battery.

[0013] As a still further improvement of the application, the clamping pieces comprise a horizontal plate and a vertical plate perpendicularly intersecting each other, the horizontal plate being in surface contact with the bottom plate, the bolts passing through the vertical plate, a plurality of the bolts being symmetrically distributed on both sides of the testing tool; the limiting groove being a space relatively surrounded by the vertical plate and the bolts.

[0014] As a still further improvement of the application, the bolts comprise a screw rod segment, the screw rod segment being assembled with a nut; a sleeve is further sleeved on the screw rod segment, the two ends of the sleeve being in surface contact with the opposite faces of the respective vertical plates of the pair of clamping pieces.

[0015] As a further improvement of the present application, the horizontal plate and the vertical plate in the same clamping plate are fixed vertically with a rib plate.

[0016] In a second aspect, a test device for battery load curve is provided, comprising: a temperature sensor arranged on the battery, and a voltage sensor electrically connected with the battery.

[0017] In a third aspect, a test method for battery load curve is provided, comprising: step S1: lifting the top plate by using a lifting device; step S2: placing the battery in the limiting groove, selecting a sleeve with a proper shaft length according to the thickness of the battery, the sleeve passing through the bolt, and the bolt connecting a pair of clamping plates; step S3: releasing the top plate at an acceleration less than free fall, and relying on the weight of the top plate to fall on the side of the battery; step S4: applying static load until the battery voltage drops suddenly and short circuit occurs, or applying dynamic impact to impact the battery, the drop starting height of the dynamic impact being adjustable, and the weight of the dynamic impact being adjustable.

[0018] The test device for battery load curve has the following advantages: a simple and reliable device is provided, which can test single batteries. The pressure head is used to impact or extrude one side of the battery, so that the tester can study the deformation of the battery under load. First, the top plate drives the pressure head to rise and fall, so that the pressure head can apply force to the battery. The top plate is in direct contact with the power source, and then the force is transmitted to the pressure head, and the pressure head directly applies force to the battery. Second, the limiting groove limits and wraps the battery, avoiding deviation of the battery under load, and providing a reaction force. Finally, the side of the pressure head in contact with the battery is a curved surface, which is a convex curved surface. This makes the pressure head and the battery contact in a line when they first contact, and the contact between the pressure head and the battery changes to a surface contact as the impact or extrusion continues. This facilitates accurate simulation of the blunt impact that the battery may encounter when installed in a new energy vehicle. The form of force received by the battery at different positions of the battery is also close, which facilitates the control of irrelevant variables and facilitates subsequent evaluation after testing. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 is a perspective view of an embodiment of the test device for battery load curve of the present application;

[0021] Figure 2is a front view of one embodiment of the battery load curve test fixture of the present application;

[0022] Figure 3 is a right view of one embodiment of the battery load curve test fixture of the present application;

[0023] Figure 4 is Figure 3 A-A sectional view of the battery load curve test fixture of the present application;

[0024] Figure 5 is a perspective view of one embodiment of the battery load curve test fixture of the present application with the top plate and the indenter hidden;

[0025] Figure 6 is an assembly view of one embodiment of the top plate and the indenter of the present application;

[0026] Figure 7 is a perspective view of one embodiment of the battery of the present application;

[0027] Figure 8 of (a) is a schematic view of one contact state of the indenter and the battery of the present application;

[0028] Figure 8 of (b) is a schematic view of another contact state of the indenter and the battery of the present application;

[0029] Figure 9 is an assembly view of the bolt and the sleeve of the present application;

[0030] Figure 10 is a graph of the constraint load of the bolt and the sleeve of the present application versus the expansion displacement of the battery.

[0031] BRIEF DESCRIPTION OF DRAWINGS

[0032] 1 - base plate; 2 - guide post; 3 - top plate; 31 - mounting hole; 4 - clamping plate member; 41 - horizontal plate; 42 - vertical plate; 5 - rib plate; 6 - indenter; 61 - convex curved surface; 62 - end flat surface; 7 - bolt; 71 - enlarged head; 72 - threaded shank; 8 - nut; 9 - sleeve; 10 - battery; 101 - terminal; 11 - limiting groove. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood that the specific description is merely for the purpose of teaching one skilled in the art how to practice the present application, and is not intended to limit the scope of the present application in any way.

[0034] The battery load curve testing device, the battery load curve testing method and the battery load curve testing tool of the present application will be further described in detail below in combination with specific embodiments.

[0035] Referring to Figure 1 and Figure 5 , the embodiment of the present application provides a battery load curve testing tool. The testing tool can include a vertical lifting and restraining mechanism, a horizontal limiting and restraining mechanism, and a pressure head 6. The vertical lifting and restraining mechanism includes a top plate 3 and a bottom plate 1, and the top plate 3 has a vertical lifting freedom relative to the bottom plate 1. As shown in Figure 5 , the horizontal limiting and restraining mechanism has a limiting groove 11, and the limiting groove 11 has an upward opening. The limiting groove 11 can accommodate the battery 10, and the depth direction of the limiting groove 11 is perpendicular to the thickness direction of the battery 10 accommodated in the limiting groove 11. The pressure head 6 is located on the side of the top plate 3 facing the bottom plate 1, and the pressure head 6 can contact and impact or extrude one side of the battery 10. As shown in Figure 6 , the contact surface of the pressure head 6 and the battery 10 is a convex curved surface 61, which is a surface of revolution. The generatrix of the convex curved surface 61 is a line segment, and the line segment is parallel to the thickness direction of the battery 10.

[0036] Thus, the battery load curve testing tool of the present application has both vertical restraining capability and horizontal linear restraining capability. The vertical restraining mainly allows the battery 10 to achieve impact or extrusion deformation, and the horizontal linear restraining mainly adapts to different specifications of the battery 10 and is also convenient for correlating the horizontal expansion deformation of the battery 10 caused by the extrusion deformation due to the vertical restraining.

[0037] The battery can be a lithium ion battery. The battery 10 is generally subjected to load in two directions, i.e., the battery cover plate direction and the battery side direction. As shown in Figure 8 (a) and Figure 8 (b), the pressure head 6 contacts the battery 10, and the generatrix of the convex curved surface 61 is parallel to the thickness direction of the battery 10. To be specific, Figure 8 in (a), the pressure head 6 contacts the cover plate of the battery 10, Figure 8 in (b), the pressure head 6 contacts the side of the battery 10, Figure 8 the battery 10 in (a) is rotated by 90° compared with Figure 8 the battery 10 in (b).

[0038] Considering the single battery 10 is placed inside the battery pack, the two sides of the battery 10 are constrained by other structures (such as mica sheet, back-type frame and other batteries 10). In a real collision accident, the loading curve of the battery 10 in the plane direction contains the influence of the constraint condition. Therefore, when testing the in-plane loading curve of the lithium ion battery 10, the two sides of the battery 10 need to be individually constrained to obtain the mechanical response of the battery 10 under different constraint conditions.

[0039] In the placement direction of the mainstream battery pack, when the vehicle is subjected to side impact, the loading direction is the in-plane direction of the single battery 10. Regardless of the load when the external collision, it is transmitted to the single battery 10 through the beam on the vehicle body, which is equivalent to a blunt impact, so the contact surface of the pressure head 6 and the battery 10 is simulated by a convex surface 61. And, as shown in Figure 8 (b), the convex surface 61 is in contact with the side of the battery 10 in the initial state.

[0040] In an embodiment, as shown in Figure 6 , the two ends of the pressure head 6 are end planes 62, the end planes 62 are perpendicular to the convex surface 61, and the shape of the end planes 62 is arc-shaped or semicircular. The distance between the two end planes 62 (that is, the thickness of the pressure head 6) is not less than the thickness of the battery 10, and the opening width of the limiting groove 11 is not less than the distance between the two end planes 62. With further extrusion of the battery 10, the pressure head 6 can be deep into the limiting groove 11. The opening width of the limiting groove 11 can be greater than or equal to the thickness of the pressure head 6.

[0041] For a single battery 10 in a group of batteries 10, it is constrained by two side batteries 10, and the loading of the pressure head 6 on the battery also only needs a single battery 10 thickness range.

[0042] In an embodiment, the shape of the end plane 62 is arc-shaped or semicircular, and the top of the pressure head 6 has a top plane, which realizes surface contact with the top plate 3. As shown in Figure 4 , the top plate 3 has a through mounting hole 31, which is detachably assembled with the top plane of the pressure head 6 through a fastener. The mounting hole 31 can be stepped, and the top of the fastener in the mounting hole 31 is not higher than the opening of the mounting hole 31, so that the top plate 3 provides a complete plane to bear the impact or extrusion. When the impact, the pressure head 6 can perform blunt impact on the battery 10.

[0043] The shape of the pressure head 6 is also convenient for processing, and is calculated by finite element, so the arc shape, that is, part of the disc shape, is adopted.

[0044] The radius corresponding to the convex surface 61 of the pressure head 6 can be 90mm.

[0045] In an embodiment, the top plate 3 is movably assembled with the bottom plate 1 by means of several guide columns 2, which pass through the top plate 3. Optionally, the top plate 3 can be provided with guide sleeves for the guide columns 2 to pass through.

[0046] The number of guide columns 2 can be four. The guide sleeves can comprise or be linear motion bearings, and the movable assembly of the guide sleeves with the guide columns 2 is such that the frictional resistance between the guide sleeves and the guide columns 2 is small, thereby ensuring smooth lifting of the top plate 3, and the guide columns 2 and the guide sleeves also serve the function of precise guidance, ensuring lifting of the top plate 3 in the vertical direction.

[0047] In an embodiment, the upper surface of the top plate 3 is in contact with a hydraulic machine or a drop hammer.

[0048] The hydraulic machine can realize static loading, and the drop hammer can realize dynamic impact. The maximum equivalent weight of the hydraulic machine is about tens of tons.

[0049] A guide rail can also be provided in the falling path of the drop hammer, which can ensure that the drop hammer impacts the center position of the top plate and does not deviate.

[0050] In an embodiment, the bottom plate 1 is assembled with a pair of mirror-symmetric clamping plate members 4, and the pair of clamping plate members 4 are connected by means of several bolts 7, and the pair of clamping plate members 4 can accommodate the battery 10 therebetween. The clamping plate member 4 is a structure similar to an angle steel.

[0051] The clamping plate member 4 can be made of high-strength steel material, so as not to be easily deformed by the expanded battery 10.

[0052] In an embodiment, as shown in Figure 1 , the clamping plate member 4 comprises a horizontal plate 41 and a vertical plate 42, the horizontal plate 41 forms a surface contact with the bottom plate 1, and the bolts 7 pass through the vertical plate 42, and the several bolts 7 are symmetrically distributed on both sides of the battery 10. The limiting groove 11 is a space relatively surrounded by the vertical plate 4 and the bolts 7. The connecting lines of the several bolts 7 on the same side of the battery 10 are located on the same vertical line, and are arranged at equal intervals with each other. As shown in Figure 2 or Figure 4 , the number of bolts 7 can be six.

[0053] The inner wall of the limiting groove 11 is not provided with a buffer layer, so that most of the impact or extrusion energy of the pressure head 6 can be absorbed by the battery 10, and adding a buffer layer will destroy the simple boundary conditions of the limiting groove 11, which is not conducive to model verification work.

[0054] The inner wall of the limiting groove 11 is mainly composed of the opposite surfaces of the vertical plate 42, and the horizontal plate 41 is used for fixed support with the bottom plate 1.

[0055] In one embodiment, the horizontal plate 41 can be provided with a waist-shaped hole (not shown in the figure) in which a fastener is threaded and which assembles the horizontal plate 41 with the base plate 1. The length direction of the waist-shaped hole is parallel to the length direction of the bolt 7. This makes it possible to fine-tune the position of the clamping plate 4 on the base plate 1 when necessary, thereby changing the actual opening width of the limiting groove 11.

[0056] In one embodiment, as shown in Figure 9 , the bolt 7 comprises an integral enlarged head 71, a screw rod segment 72, the screw rod segment 72 being threaded through the vertical plates 42 of the respective clamping plate 4, the screw rod segment 72 being assembled with the nut 8, the nut 8, the enlarged head 71 and the opposite faces of the vertical plates 42 of the respective clamping plate 4 being in contact, the screw rod segment 72 being further sleeved with the sleeve 9, the two ends of the sleeve 9 being in contact with the opposite faces of the vertical plates 42 of the respective clamping plate 4. As shown in Figure 9 , in order to facilitate the representation of the internal structure, Figure 9 , the sleeve 9 in

[0057] The nut 8 plays a role in controlling the constraint condition, as shown in Figure 9 , the initial distance between the two vertical plates 42 is controlled by the customized sleeve 9, and only the nut 8 needs to be tightened during the experiment. As shown in Figure 10 Figure 10 is a schematic diagram of the relationship between the constraint load of the bolt and the sleeve and the swelling displacement of the battery. When the battery 10 is not pressed by the pressure head 6, the sleeve 9 is generally subjected to axial compression force. That is, after the nut 8 is rotated, the two vertical plates 42 press the sleeve 9 towards each other, thereby constraining the battery 10 in the horizontal direction, and the constraint ability of the battery 10 in the horizontal direction is determined by the actual rotation degree of the nut 8, that is, the actual constraint ability of the battery 10 in the horizontal direction is multiple and adjustable. When the battery 10 is pressed by the pressure head 6 and swells laterally, when the initial swelling amount is small, as shown in the left half of the relationship line in Figure 10 , the sleeve 9 is still subjected to inward pressing force. When the battery 10 continues to swell after contacting the vertical plate 42, as shown in the right half of the relationship line in Figure 10 , the pressing of the two vertical plates 42 on the sleeve 9 is relaxed, and the inward constraint of the battery 10 from the outside depends on the size and material of the bolt 7. The constraint stiffness of the battery 10 can be controlled by customizing different bolts 7. The combination of the two can control the constraint condition. The nut 8 determines the widest limit position of the horizontal limiting and constraint mechanism, and the sleeve 9 determines the narrowest limit position of the horizontal limiting and constraint mechanism.

[0058] During the battery 10 pressure head 6 extrusion test phase, the bolt 7 is only subjected to tension and not compression. The axial length of the sleeve 9 is determined according to the thickness of the battery 10 and other specific needs, and the axial length of the sleeve 9 can be selected to be equal to or slightly greater than the thickness of the battery 10, and can be selected to be 2 mm more than the thickness of the battery 10. ​

[0059] When the test is performed on the battery 10 of different thickness specifications, the sleeve 9 of different shaft length is replaced according to the thickness of the battery 10. In addition, because the pressure head 6 and the top plate 3 are also detachable, a new pressure head 6 can also be replaced, and the distance between the end planes 62 at both ends of the new pressure head 6 is different to adapt to the new battery 10.

[0060] In an embodiment, a rope such as a steel cable can also be connected between the vertical plates 42 of each clamping plate 4, and the tension of the rope can limit the maximum distance between the two vertical plates 42.

[0061] In an embodiment, as shown in Figure 1 The horizontal plate 41 and the vertical plate 42 in the same clamping plate 4 are vertically fixed together with the rib plate 5. The rib plate 5, the horizontal plate 41 and the vertical plate 42 are vertically spaced from each other, and the rib plate 5 can be fixed to the horizontal plate 41 or the vertical plate 42 by welding. Each horizontal plate 41 or vertical plate 42 can be fixed to multiple rib plates 5. The rib plates 5 in the same clamping plate 4 are arranged at equal intervals.

[0062] The battery load curve test tool of the present application is simple and ingenious, which improves the repeatability and reliability of the in-plane compression experiment of the battery 10, and is beneficial to model verification. It can solve the actual problem of inconsistent test standards of the in-plane load curve of the battery 10, and can simulate the rationality of real load as much as possible, and can provide simple boundary conditions for the battery 10.

[0063] The present application also provides a battery load curve test device. It adds a temperature sensor and a voltage sensor to the battery load curve test tool. As shown in Figure 7 The battery 10 has a terminal 101 that can be electrically connected. The temperature sensor is used to sense whether the temperature of the battery 10 under deformation exceeds the normal value. The voltage sensor is used to sense whether the voltage of the battery 10 under deformation exceeds the normal value.

[0064] The application also provides a battery load curve testing method. The method comprises the following steps: S1, lifting the top plate 3 and the pressure head 6 together by using a testing machine (i.e. the lifting mechanism of the drop hammer impact or the quasi-static hydraulic testing machine). When the top plate 3 and the pressure head 6 need to be lifted together, the top plate 3 can be bound to the moving end of the testing machine by means of a binding belt, so that the moving end of the testing machine can also lift the top plate 3 and the pressure head 6 when it is rising. S2, placing the single battery 10 between the two clamping plate members 4, selecting the sleeve 9, and fixing the two clamping plate members 4 by using the bolts 7, and placing the entire limiting groove 11 directly below the pressure head 6. S3, slowly releasing the top plate 3 and the pressure head 6, so that the top plate 3 and the pressure head 6 fall on the side of the battery 10 by their own gravity. S4, applying quasi-static loading to the top plate 3 until the voltage of the battery 10 drops suddenly and a short circuit occurs, and then the experiment is ended. Alternatively, dynamic impact is applied to the top plate 3 to impact the battery 10. The falling height of the drop hammer and the weight of the drop hammer can be adjusted. The battery 10 is placed first, and then the sleeve 9, the bolts 7 and the clamping plate members 4 are installed. If the sleeve 9, the bolts 7 and the clamping plate members 4 are installed first, and then the battery 10 is placed, the battery 10 must be placed from the top opening of the limiting groove 11, which requires the pressure head 6 to be lifted to a higher position. This will result in the length of the corresponding guide column 2 needing to be lengthened, and the stability between the bottom plate 3, the guide column 2 and the top plate 3 may be deteriorated.

[0065] The method is to test the single battery 10, not the entire battery pack. During the test phase, the top plate 3 can be in contact with the battery 10 at all times, and the impact object impacts the top plate 3, and the impact force is transmitted to the battery 10 through the top plate 3 and the pressure head 6 in sequence.

[0066] After the impact test of the battery 10 is completed, all the bolts 7 can be removed because the battery 10 is deformed. In this way, the limiting groove 11 not only has an opening at the top, but also has openings on the left and right sides of the limiting groove 11, which facilitates the test personnel to take out the battery 10. One of the purposes of the battery load curve testing tool and the battery load curve testing device of the application is to facilitate the long-term and repeated implementation of the battery load curve testing method.

[0067] The above embodiments are only used to illustrate the technical concept and characteristics of the application, and the purpose is to enable those skilled in the art to understand the content of the application and implement it, and cannot limit the protection scope of the application. Any equivalent changes or modifications made according to the spirit and essence of the application should be covered within the protection scope of the application.

Claims

1. A test fixture for measuring the load curve of a battery, characterized in that, include: A vertical lifting and restraint mechanism, comprising a top plate (3) and a bottom plate (1), wherein the top plate (3) has a vertical lifting degree of freedom relative to the bottom plate (1); A horizontal limiting and restraining mechanism, the horizontal limiting and restraining mechanism including a limiting groove (11), the limiting groove (11) having an upward opening, the limiting groove (11) being able to accommodate a battery (10), the depth direction of the limiting groove (11) being perpendicular to the thickness direction of the battery (10) accommodated therein; A pressure head (6) is located on the side of the top plate (3) facing the bottom plate (1). The pressure head (6) is capable of contacting one side of the battery (10) and impacting and / or squeezing the battery (10). The contact surface between the pressure head (6) and the battery (10) is a convex curved surface (61), and the generatrix of rotation corresponding to the convex curved surface (61) is a line segment, which is parallel to the thickness direction of the battery (10). The two ends of the pressure head (6) are end planes (62), the end planes (62) intersect perpendicularly with the convex curved surface (61), the shape of the end planes (62) is arc-shaped, the distance between the two end planes (62) is not less than the thickness of the battery (10), and the opening width of the limiting groove (11) is not less than the distance between the two end planes (62). The opening width of the limiting groove (11) can be varied and it can clamp the battery (10) in the horizontal direction. The base plate (1) is equipped with a pair of mirror-symmetrical clamping plates (4), which are connected by several bolts (7). The pair of clamping plates (4) can accommodate or clamp and constrain the battery (10). The clamping plate (4) includes a horizontal plate (41) and a vertical plate (42) that intersect each other perpendicularly. The horizontal plate (41) forms a surface contact with the base plate (1). The bolts (7) pass through the vertical plate (42). Several bolts (7) are symmetrically distributed on both sides of the test fixture. The limiting groove (11) is the space surrounded by the vertical plate (42) and the bolt (7); The end plane (62) is shaped as a minor arc or a semi-circle. The top of the pressure head (6) has a top plane. The top plane is in surface contact with the top plate (3). The top plate (3) has a through mounting hole (31). The mounting hole (31) is detachably assembled with the top plane of the pressure head (6) by fasteners. The pressure head (6) is capable of blunt-surface impacting the battery (10); The bolt (7) includes a threaded section (72) and the threaded section (72) is fitted with a nut (8); A sleeve (9) is also fitted on the screw section (72), and the two ends of the sleeve (9) are in contact with the opposing surfaces of the vertical plates (42) of each of the pair of clamping plates (4); The inner wall of the limiting groove (11) is not provided with a buffer layer; The bolt (7) is only under tension and not under compression; The axial length of the sleeve (9) is equal to or slightly greater than the thickness of the battery (10).

2. The test fixture for battery load curves according to claim 1, characterized in that: The top plate (3) and the bottom plate (1) are movably assembled through a number of guide posts (2), and the guide posts (2) pass through the top plate (3).

3. The test fixture for battery load curves according to claim 1, characterized in that: The horizontal plate (41) and the vertical plate (42) in the same clamping member (4) are vertically fixed with ribs (5).

4. A test device for battery load curves, characterized in that, The test fixture for the battery load curve according to any one of claims 1 to 3 further includes a temperature sensor and a voltage sensor, wherein the temperature sensor is arranged on the battery (10) and the voltage sensor is electrically connected to the battery (10).

5. A method for testing the load curve of a battery, characterized in that, It uses the test fixture for the battery load curve as described in claim 1, and the test method for the battery load curve includes: Step S1: Use a lifting device to lift the top plate (3); Step S2: Place the battery (10) in the limiting groove (11), select a sleeve (9) with an appropriate shaft length according to the thickness of the battery (10), the sleeve (9) passes through the bolt (7), and the bolt (7) connects a pair of clamping plates (4); Step S3: Release the top plate (3) with an acceleration less than that of free fall, and let the top plate (3) fall onto the side of the battery (10) by its own weight; Step S4: Apply static load until the voltage of the battery (10) drops sharply, causing a short circuit; Alternatively, a dynamic impact may be applied to the battery (10), wherein the starting height of the dynamic impact is adjustable and the load of the dynamic impact is adjustable.

Images