Fatigue acceleration tester for battery module or pack

Abstract

The present invention relates to a fatigue acceleration tester for evaluating durability against fatigue failure of a battery module by repeated expansion and contraction of the battery module and, more specifically, to a fatigue acceleration tester and method capable of realizing reliable fatigue acceleration by simulating actual repeated expansion and contraction. According to one embodiment of the present invention, an actual swelling phenomenon may be simulated by pressing a side wall in the width direction of a case from the inside to the outside using a plurality of actuators provided along the longitudinal direction of the case. In particular, the number and height of the actuators can be changed, and the pressing length of each actuator can be independently set, so that versatility can be enhanced.

Description

Accelerated fatigue testing machine for battery modules or packs

[0001] The present invention relates to a fatigue acceleration tester for evaluating the durability of a battery module against fatigue destruction through repeated expansion and contraction of the battery module, and more specifically, to a fatigue acceleration tester and method capable of implementing reliable fatigue acceleration by simulating actual repeated expansion and contraction.

[0002] Rechargeable secondary batteries are widely used as the energy source for wireless mobile devices. Furthermore, secondary batteries are attracting attention as a solution to air pollution caused by conventional gasoline and diesel vehicles that use fossil fuels, such as electric vehicles and hybrid electric vehicles, as well as small vehicles like electric bicycles and kick scooters. Consequently, the applications that utilize secondary batteries are diversifying significantly due to their advantages, and their application is expected to expand even further in the future.

[0003] Electric vehicles and other vehicles use high-power electrical energy, requiring multiple battery modules per vehicle. These battery modules contain multiple battery cells housed within a module case. Multiple battery modules can be configured to form a single battery pack. Recently, technologies are being developed to directly construct battery packs from multiple battery cells, bypassing battery modules.

[0004] Battery cells housed within the module case of a battery module or the pack case of a battery pack can experience repeated swelling as a result of repeated charging and discharging. This repeated swelling repeatedly applies stress to the case, which can lead to accumulated fatigue in the case's welds, potentially leading to weld failure. Therefore, simulation tests are needed to assess the fatigue of the case's welds.

[0005] Figure 1 illustrates a battery pack or battery module.

[0006] A battery pack or battery module (1) comprises a case (10) that accommodates a plurality of battery cells therein. The case (10) may be formed in a hexahedral shape and includes an upper cover (11) and a lower cover (12), which form the upper and lower surfaces of the case (1), respectively. In addition, the case (10) includes side walls (13, 14, 15, 15) that form the side surfaces of the case (1), and in the case of a rectangular parallelepiped shape, long side walls (13, 14) and short side walls (15, 16) may be formed.

[0007] Terminal connections can be made through the above-described short side walls (15, 16), and the battery cells can be arranged inside the case so that swelling occurs between the opposing long side walls (13, 14).

[0008] After the four side walls (13, 14, 15, 16) and the lower cover (12) are joined, the battery cells are accommodated inside the case (1), and then the upper cover (11) is joined so that the pack or module (1) can be assembled.

[0009] The side walls (13, 14) where swelling occurs, for example, the long side walls, may be connected at both ends to another side wall (15, 16), for example, the short side walls, through a weld (17). That is, the side walls (13, 14) may be considered plates with both ends fixed, and swelling may cause fatigue failure of the weld (17). Ultimately, a fatigue failure test is required to secure the reliability of the weld (17) from fatigue failure. That is, it is necessary to perform an accelerated fatigue test by applying artificial pressure to the case.

[0010] Figure 2 illustrates an example of a conventional fatigue acceleration tester.

[0011] A sample used for a fatigue acceleration test, i.e., a case (1), is positioned between test jigs (20, 30) facing each other, and the jigs (20, 30) may be provided with a connecting portion (22, 32) for connection to a tensile tester. In addition, the test jigs (20, 30) are provided with a plurality of pressurizing portions (21, 31), and the plurality of pressurizing portions (21) provided in the upper jig (20) may be coupled with one side wall (13) where swelling occurs, and the plurality of pressurizing portions (31) provided in the lower jig (30) may be coupled with the other side wall (14) where swelling occurs.

[0012] In order to simulate swelling, for example, the upper jig (20) can be repeatedly moved up and down by a tensile tester, and at this time, the pressurizing portions (21, 32) repeatedly pressurize and return the side walls (13, 14). That is, the pressurizing portions perform external pressurization on the side walls. In addition, since the pressurization is generated through one tensile tester or both tensile testers, the displacements of the multiple pressurizing portions become the same. In addition, the contact surface between the pressurizing portions (21, 32) and the side walls (13, 14) becomes a plane.

[0013] However, in an actual case, swelling occurs in the form of pressure from the inside of the case to the outside, and the displacement due to swelling appears to be smallest at both ends of the side wall and largest at the center of the side wall.

[0014] For conventional fatigue acceleration tests, multiple pressurized passage holes (18) must be formed separately in the side walls (13, 15). Therefore, the side walls of the sample are bound to have different physical properties from the side walls of the actual case.

[0015] For this reason, it is difficult to simulate actual swelling using conventional accelerated fatigue testing equipment. Consequently, the reliability of accelerated fatigue test results is inevitably reduced.

[0016] The present invention aims to solve the problems of conventional fatigue acceleration testing machines.

[0017] Through one embodiment of the present invention, it is intended to provide a fatigue acceleration tester capable of precisely simulating actual swelling by applying pressure from the inside to the outside, expanding the pressure area, and performing three-dimensional pressure.

[0018] Through one embodiment of the present invention, it is intended to provide a fatigue acceleration tester capable of precisely simulating actual swelling by independently setting and controlling the pressurizing displacement by implementing a plurality of pressurizing actuators.

[0019] Through one embodiment of the present invention, it is intended to provide a fatigue acceleration tester that can flexibly respond to changes in the size of a case to be tested.

[0020] Through one embodiment of the present invention, it is intended to provide a fatigue acceleration tester capable of effectively controlling the variation of the pressurized displacement by utilizing the proportional relationship between the rotational speed of a motor and the pressurized displacement of an actuator.

[0021] Through one embodiment of the present invention, it is intended to provide a fatigue acceleration tester capable of easily setting and changing the pressurization height of an actuator.

[0022] In order to achieve the above-described object, according to one embodiment of the present invention, a fatigue acceleration tester can be provided, comprising: a base plate; a plurality of motors provided on a lower portion of the base plate; a plurality of actuators provided to be positioned inside a case that accommodates a battery cell on an upper portion of the base plate, and corresponding to each of the plurality of motors, a plurality of actuators provided along a longitudinal direction of the case; and a drive transmission member that vertically penetrates the base plate and transmits a rotational displacement of the motor to the actuator, wherein the actuator is characterized in that it converts the rotational displacement transmitted through the drive transmission member into a linear pressure displacement to pressurize a widthwise side wall of the case from the inside to the outside.

[0023] The above motor is preferably a servo motor capable of precisely controlling the rotation speed and / or rotation angle. The rotation speed and / or rotation angle and the pressurized displacement have a proportional relationship, so that the pressurized displacement can be precisely controlled.

[0024] It is preferable that the lower cover of the case is fixedly secured to the upper surface of the base plate, and the actuator is fixedly secured to the lower cover. That is, since the case and the actuator can apply pressure to the side wall of the case while being fixed in a horizontal state, precise and stable pressure displacement can be provided to the case.

[0025] It is preferable that the base plate be supported by a frame spaced apart from the ground, and that the plurality of motors are fixed to the frame. In particular, since the motors are provided on the inside of the frame, interference with the operation of the motors by external factors can be minimized.

[0026] The above drive transmission member is provided in multiple numbers corresponding to each of the above motors, and it is preferable that a through hole is formed in the base plate for the multiple drive transmission members to vertically penetrate therethrough. The drive transmission member may be provided in a chain shape, and since the entire portion of the drive transmission member except for the upper portion thereof is provided inside the frame, interference with the operation of the drive transmission member due to external factors can be minimized. In addition, since the upper portion of the drive transmission member is shielded by an actuator cover described below, safety can be guaranteed.

[0027] The above actuator may include an adjustment plate for adjusting the pressurization height of the actuator by varying the fixed height of the actuator with respect to the lower cover of the case.

[0028] The actuator may include a pressurizing plate that pressurizes the side wall and a screw nut that converts rotational displacement into linear pressurizing displacement and transmits it to the pressurizing plate.

[0029] The above-mentioned pressure plate preferably has a pressure surface facing the side wall formed into a curved surface in the height direction of the side wall. The side wall can actually be formed into a continuous curved surface due to swelling. Therefore, by forming the pressure surface into a curved surface, actual swelling can be effectively simulated. In addition, it is preferable that an elastic dummy pad is interposed between the pressure surface and the side wall. Since the pressure is generated through the elastic pad, the pressure force can be applied to a wide area.

[0030] The actuator may be provided with the pressure plate and screw nut on both sides, so that the actuator can simultaneously pressurize both width-wise side walls of the case. Since the pressure is applied to both sides while the actuator and the case are fixed to the base plate, the same pressure displacement can be provided to both sides.

[0031] In particular, in order to apply the same pressure displacement to both width-wise side walls of the case for the rotational displacement transmitted through the driving transmission member, it is preferable that the pressure plate and screw nut provided on one side of the actuator be provided symmetrically with the pressure plate and screw nut provided on the other side.

[0032] For repeated movement between the original position and the pressurized position of the actuator, a controller may be included that controls the motor to repeat forward and reverse rotation.

[0033] For example, the motor rotates forward from the pre-pressurization position (home position) of the pressurization plate to the pressurization position, and the pressurization plate returns from the pressurization position to the home position due to the motor's reverse rotation. The pressurization plate can be maintained in the pressurization position for a set period of time.

[0034] The above controller can precisely control the rotation direction, rotation speed, rotation angle, rotation point, and stop point of the motor through the motor drive. Through this, the pressurization cycle, pressurization displacement, pressurization time, and pressurization maintenance time can be precisely controlled.

[0035] In particular, the controller can individually control multiple motors. Furthermore, the controller can independently control each of the multiple motors. Therefore, actual swelling can be precisely simulated.

[0036] In order to vary the magnitude of the pressure displacement of the actuator, it is preferable that the controller variably controls the rotation angle of the motor. The rotation angle may be 360 ​​degrees or more. Accordingly, the controller can variably control the rotation speed of the motor. By precisely setting the rotation speed of the motor to one decimal place or more, the variable displacement can also be precisely set and controlled.

[0037] A user interface may be included for inputting the magnitude of the pressurized displacement by each of the plurality of actuators. The magnitude of the pressurized displacement of each actuator may be individually input through the user interface.

[0038] The above controller and user interface can be implemented through a control panel. When a user sets a variable displacement for each actuator through the user interface, the controller can calculate the motor rotation speed corresponding to the set variable displacement by reflecting the proportional relationship between the variable displacement and the motor rotation speed. The rotation of the motor can be controlled based on the calculated motor rotation speed.

[0039] The case may include a displacement measuring sensor positioned on the outside of the side wall and detecting displacement of the side wall due to operation of the actuator. A plurality of displacement measuring sensors may be provided.

[0040] The controller preferably compares the displacement detected by the displacement measuring sensor with the size of a preset pressure displacement to control the rotation angle or rotation speed of the motor. For example, when a specific pressure displacement is set through a specific actuator, an error in the measured pressure displacement can be detected by the displacement measuring sensor. The rotation speed of the motor can be increased or decreased to compensate for the error in the pressure displacement.

[0041] A fatigue acceleration tester is a device that accelerates and tests the swelling that occurs over the life of a battery. Therefore, the number of swelling cycles (swelling cycles) that occur over the life of a battery is accelerated and tested in a short period of time.

[0042] During the initial swelling cycle, a process of correcting for errors in the applied displacement using a displacement measurement sensor can be performed using a fatigue acceleration tester. After the error in the applied displacement has been corrected, the swelling cycle can be performed continuously and repeatedly without the need for an error correction process.

[0043] Of course, the error correction process can be performed every time a swelling cycle is performed, or it can be performed periodically. In this case, displacement measurement using a displacement sensor and utilizing the measured displacement can only be performed during the error correction process.

[0044] The above controller preferably controls the plurality of actuators to repeat pressurization and relaxation according to a preset pressure displacement according to a set cycle. The swelling cycle time, i.e., the swelling cycle, the number of swelling repetitions, and the total operating time can be input by the user through the user interface.

[0045] The displacement measuring sensor is preferably provided in multiple numbers in the longitudinal direction of the case, and includes a sensor support member movably fixed to the base plate so that the multiple displacement measuring sensors are mounted and the distance between them and the side wall is adjusted.

[0046] The above sensor support member can be moved as a whole, and thus a plurality of sensors can be provided so as to be moved as a whole.

[0047] It may include a support plate provided at the lower portion of the base plate to support the plurality of motors.

[0048] A height adjustment member may be included to adjust the fixing position of the motor relative to the base plate. Since the support plate is fixed to the frame, the fixing position of the motor relative to the support plate can be adjusted up and down by adjusting the fixing position of the motor relative to the base plate.

[0049] The support plate includes an upper stopper and a lower stopper fixedly provided, and the height adjustment member may be provided to adjust and fix the height of the servo motor between the upper stopper and the lower stopper.

[0050] The main body of the above motor can be fixed to the rear of the support plate. In addition, the upper stopper and the lower stopper can be fixed by protruding from the rear of the support plate. The height adjustment member can be provided so that the insertion length is variable with respect to the upper stopper and the lower stopper. Accordingly, the height adjustment member is positioned rearwardly from the rear of the support plate and supports the main body of the motor from the upper and lower surfaces. Through this, the motor can be supported more firmly. In particular, the rear of the motor can be prevented from sagging downward.

[0051] The above motor may be provided with two integrally driven sprockets, and the drive transmission member may include a double chain formed integrally and simultaneously coupled with the two sprockets. One sprocket may be formed in duplicate, resulting in one motor having two integrally driven double sprockets. In this case, the drive transmission member may be a single quadruple chain with the double chains overlapped.

[0052] Through one embodiment of the present invention, a fatigue acceleration tester capable of precisely simulating actual swelling can be provided by applying pressure from the inside to the outside, expanding the pressure area, and performing three-dimensional pressure.

[0053] Through one embodiment of the present invention, a fatigue acceleration tester capable of precisely simulating actual swelling can be provided by independently setting and controlling the pressurizing displacement by implementing a plurality of pressurizing actuators.

[0054] Through one embodiment of the present invention, a fatigue acceleration tester capable of flexibly responding to changes in the size of a case to be tested can be provided.

[0055] Through one embodiment of the present invention, a fatigue acceleration tester capable of effectively controlling the variation of the pressurized displacement can be provided by utilizing the proportional relationship between the rotational speed of the motor and the pressurized displacement of the actuator.

[0056] Through one embodiment of the present invention, a fatigue acceleration tester capable of easily setting and changing the pressurization height of an actuator can be provided.

[0057] Figure 1 illustrates an example of the external appearance of a battery pack or battery module,

[0058] Figure 2 illustrates an example of a fatigue acceleration test using a conventional fatigue acceleration tester.

[0059] Figure 3 illustrates the appearance of a fatigue acceleration tester according to one embodiment of the present invention.

[0060] Figure 4 illustrates the combination of a sample and an actuator.

[0061] Figure 5 illustrates the combination of the actuator, motor, and driving transmission member.

[0062] Figure 6 shows the combination of the lower cover of the case and the actuator.

[0063] Figure 7 shows the fixed connection between the motor and the support plate,

[0064] Figure 8 illustrates adjusting and fixing the fixed height of the motor on the support plate.

[0065] Figure 9 shows a cross-sectional view of the case side wall and the pressurized plate before pressurization (swelling).

[0066] Figure 10 shows a cross-sectional view of the case side wall and the pressurized plate after pressurization (swelling).

[0067] Hereinafter, with reference to the attached drawings, a fatigue acceleration tester according to an embodiment of the present invention will be described in detail.

[0068] Figure 3 illustrates an example of a fatigue acceleration tester.

[0069] As shown, the fatigue acceleration tester (100) is provided in the form of a table and may include a base plate (40) and a frame (70) that supports the base plate (40) with respect to the ground.

[0070] A sample, i.e., a case (10) for performing a fatigue acceleration test, may be fixed to the upper surface of the base plate (40). In addition, an actuator (50) for pressurizing the side surface of the case (10) from the inside to the outside may be fixed to the upper surface of the base plate (40).

[0071] First, the case (10) is fixed to the base plate (40) using a fixing member such as a screw, and the actuator (50) can be fixed to the base plate (40) inside the case (10) using a fixing member such as a screw. Of course, the fixing member can fix the actuator and the case (10) to the base plate (40) simultaneously.

[0072] The above base plate (40) may be equipped with a plurality of displacement measuring sensors (60). The displacement measuring sensors (60) may be equipped to contact the outer surface of the side surface of the case (10) and may be equipped to sense the pressure displacement generated on the side surface. That is, the sensors may be equipped to sense the linear displacement that the actuator (50) pushes outward through the inner surface of the side surface of the case.

[0073] Meanwhile, a single accelerated fatigue tester needs to be equipped to perform accelerated fatigue tests on cases of various sizes. For example, simulating swelling may require pressurization of virtually the entire side of the case. Therefore, depending on the case size, the number of actuators (50) and displacement measurement sensors (60) may increase.

[0074] The displacement measuring sensor (60) may be fixed to the upper portion of the base plate (40) by a sensor fixing member (61). In particular, a plurality of displacement measuring sensors (60) may be arranged in a row and fixed to one sensor fixing member (61). The distance between the displacement measuring sensor (60) and the outer surface of the side surface of the case, i.e., the outer surface, may vary depending on the size of the case. Accordingly, the distance between the plurality of displacement measuring sensors (60) and the case may be adjusted by adjusting the position of the sensor fixing member (61).

[0075] A slot (41) may be formed in the base plate (40). The slots (41) may be formed at the front and rear of the base plate (40), and the sensor fixing member (61) may be linearly moved through the slots. That is, a slot may be formed long from left to right, and the sensor fixing member (61) may be moved along the slots. In addition, the sensor fixing member (61) may be fixed to the base plate (40) by a fixing knob (62).

[0076] It is preferable that the sensor fixing member (61) be provided on each of the left and right sides of the actuator (50). In addition, the plurality of displacement measuring sensors (60) provided on the left and right sensor fixing members (61) may be provided to face each other. In addition, it is preferable that the linear displacements to be measured are provided to be symmetrical on both sides so as to form a coaxial axis.

[0077] Meanwhile, a long through hole (42) may be formed in the center of the base plate (40) in the front and rear directions. The case (10) and the actuator (60) may be fixed to the upper portion of the base plate (40) so as to be symmetrical left and right about the through hole (42). As described below, the through hole (42) may be formed so that the driving transmission member may vertically penetrate the base plate (40).

[0078] The actuator (50) may be provided to externally pressurize and release two case sides facing each other. Therefore, it is preferable to provide a plurality of actuators depending on the size of the case (10). In addition, it is preferable that the pressurized displacement generated by one actuator (50) be the same on both sides. To this end, it is preferable that the actuator (50) and the case (10) are firmly fixed to the base plate (40).

[0079] It is preferable that a servo motor (90) be provided at the lower portion of the base plate (40). The servo motor (90) is configured to generate a driving force transmitted to an actuator (50), and the servo motor and the actuator may be provided to correspond one-to-one. The servo motor (90) generates a rotational displacement, and the actuator may be provided to convert the transmitted rotational displacement into a linear displacement to pressurize the side wall of the case (10).

[0080] The above fatigue acceleration tester (100) can basically simulate swelling by controlling the operation of the servo motor (90). Therefore, it is preferable to have a control panel (85) for controlling the operation of the fatigue acceleration tester (100). The control panel (85) may be provided for a user interface and may perform a function of performing various commands or inputs by the user. The control panel (85) may include a display through which various status information may be displayed. In addition, the display may be a touch display through which various inputs may be performed.

[0081] The above control panel (85) may be fixedly installed on one upper side of the base plate (40) for ease of use, and an electric unit (80) may be installed on the lower part of the control panel (85). The electric unit (80) may be installed in the form of an electric unit box. A power supply, PLC, wiring, etc. may be installed on the control panel (85) or the electric unit (80).

[0082] A logger (87) may be provided at the lower part of the base plate (40), i.e., inside the frame (70). Through the logger, various records such as data for the fatigue acceleration test, such as the pressurization cycle, test time, and pressurization displacement, can be stored.

[0083] Hereinafter, the actuator (50), the driving transmission member (59), and the motor (90) will be described in detail with reference to FIGS. 4 to 6.

[0084] As shown, the side surfaces (13, 14) of the case pressurized for the fatigue acceleration test are identical to those of the actual case. That is, it is preferable that there be no structure processed or added for pressurization.

[0085] On the other hand, it is preferable that a plurality of through holes (12a) be formed in the lower surface (12) of the case. The through holes (12a) are formed corresponding to the actuators (50), and the number of through holes (12a) may be the same as the number of actuators (50). In addition, the through holes (12a) may be configured to allow the driving transmission member (59) to pass through the upper portion of the case from the lower portion of the case.

[0086] In addition, a fastening hole (12b) is formed on the lower surface (12a) of the case, and the lower surface (12a) of the case can be fixedly joined to the base plate (40) through the fastening hole (12b). In particular, the case (10) and the actuator (50) can be fixed simultaneously through the fastening hole (12b).

[0087] Here, the lower surface (12a) of the case is not substantially stressed by the pressurization of the actuator. Therefore, additional processing of the lower surface of the case is expected to have only a very minor effect on the swelling simulation for the actual swelling phenomenon. On the other hand, since the swelling is simulated while the actuator and the case are firmly fixed, it is possible to simulate the swelling that corresponds to reality.

[0088] The actuator (50) may include a pressure plate (54). The pressure plate (54) may be formed so that the width from left to right is longer than the width from top to bottom, and may be formed in an approximately rectangular shape. Since the pressure plates (54) are arranged sequentially, they can substantially apply pressure to the entire side surfaces (13, 14) of the case.

[0089] When swelling, the greatest pressure is generated at the center of the length direction and the center of the height direction of the side, and a pressure displacement may occur. In addition, when swelling, the pressure may be continuously generated to the side. In order to effectively simulate such swelling, a dummy pad (19) may be provided. The dummy pad (19) is a pad made of an elastic material and may be interposed between the pressure plate (54) and the inner surface of the case. That is, the pressure plate (54) can pressurize the side surface of the case by pressing the dummy pad (19). Through this, continuous pressure applied to the side surface can be effectively simulated.

[0090] In addition, it is preferable that the pressure surface of the pressure plate (53), i.e., the surface facing the side surfaces (13, 14) of the case, be formed as a curved surface. In particular, it is preferable that it have a curved surface that is curved in the vertical direction. This allows for more effective simulation of actual swelling.

[0091] Meanwhile, it is preferable that the pressure plate (53) be positioned so as to apply pressure symmetrically up and down based on the upper and lower centers of the sides (13, 14). For example, when the size of the case (10) changes, it is preferable that the upper and lower positions of the pressure plate (53) be adjusted. To this end, an adjustment plate (57) interposed between the actuator (50) and the lower surface of the case (12) may be provided. By varying the number or thickness of the adjustment plates (57), the height of the actuator, i.e., the height of the pressure plate, can be adjusted.

[0092] It is preferable that the actuator (50) be formed symmetrically. That is, it is preferable that the portion facing one side wall (13) of the case and the portion facing the other side wall (14) of the case be symmetrical. That is, the pressure plates (53) may be provided on each side of the actuator (50) so as to simultaneously pressurize and release both side walls with the same pressure displacement.

[0093] The actuator (50) may include a support frame (55) and a driving bracket (51). The support frame (55) is configured to support the components of the actuator (50) while fixing the actuator (50) to the base plate (40), and the driving bracket (51) may be configured to support components such as a screw (52) that converts rotational displacement transmitted through a driving transmission member (59) into linear displacement.

[0094] The screw (52) is formed to protrude left and right from the center of the actuator (50), and may be provided so that the protrusion length can be varied while rotating according to the rotational displacement transmitted through the driving transmission member (59). For example, the screw (52) on the right side may be formed with a right-hand screw, and the screw on the left side may be formed with a left-hand screw. Accordingly, the screws (52) on both sides can be pressed with the same displacement. In other words, the same pressurized displacement can be generated on both sides for one rotational displacement.

[0095] Specifically, a screw nut (53) may be interposed between the screw (52) and the pressure plate (54). If a right-hand thread is formed in the screw (52), a right-hand thread may also be formed inside the screw nut. The screw nut (53) converts rotational displacement into linear displacement, and the transformed linear displacement can be directly transmitted to the pressure plate (54). In addition, the screw nut (53) is supported by a linear guide (55a), and the linear guide (55a) can guide the screw nut (53) to move linearly back and forth. The linear guide (55a) may be supported on a support frame (55) so as to be linearly movable.

[0096] The actuator (50) may include an actuator cover (56) that covers the entire actuator from the top, except for the pressure plate (54). The actuator cover (56) can prevent dust and the like from entering the interior of the actuator, thereby enabling smooth power transmission and displacement conversion.

[0097] At the center of the actuator (50), a drive transmission member (59) is connected to screws (52) on both the left and right sides. The drive transmission member (59) is provided in a chain shape to effectively transmit rotational displacement. A double chain is connected to one screw (52), and thus the drive transmission member (59) may be a single quadruple chain in which a double chain and a double chain are combined.

[0098] The above driving transmission member (59) is provided to transmit rotational displacement between a motor (90) provided on the lower part of the base plate (40) and an actuator (50) provided on the upper part of the base plate (40).

[0099] The motor (90) is preferably a servo motor capable of controlling precise rotational displacement, i.e., rotational angle. The motor (90) may include a main body (91) and a motor drive (94) for precisely controlling the rotational angle of the motor (90). The motor drive (94) is provided at the rear of the main body (91), and the motor shaft (92) is provided at the front of the main body (91). A sprocket (93) is provided on the motor shaft (92). The sprocket (93) may be formed in a double or quadruple configuration. That is, a plurality of sprockets (93) rotate in the same direction at the same angle. In other words, they rotate as one unit.

[0100] Therefore, by the forward and reverse rotation in which the motor (90) rotates in one direction by a set angle and then returns to the original position, the actuator (50) can be simultaneously pressurized in both directions and then returned to the original position. When the forward and reverse rotation of the motor (90) is performed according to a set cycle, the actuator (50) repeats pressurization and relaxation according to the same set cycle. Here, it can be seen that variable control of the pressurization displacement of the actuator (50) can be performed through variable control of the rotation angle of the motor (90).

[0101] The swelling mechanism through the motor (90), the driving transmission member (59) and the actuator (50) is described in detail.

[0102] When swelling is implemented for the case (10), the rotational drive of the motor (90) is transmitted to the actuator (50) through the drive transmission member (59). Here, the motor, the drive transmission member, and the actuator are in a one-to-one correspondence, and a plurality of each may be provided. When the rotational drive is transmitted to the actuator, the actuator moves linearly in the direction in which the two pressure plates (54) spread apart, and can inflate by pressurizing both sides of the frame from the inside to the outside.

[0103] When the case (10) is restored to its original state, the reverse rotation drive of the motor (90) is transmitted to the actuator (50) through the drive transmission member (59). At this time, the pressure plate (54) moves in the backward direction, releasing the pressure applied to both sides of the frame and returning the deformation to its original state.

[0104] The number of motors, actuators, and drive transmission members can be determined depending on the size of the case (10) to be tested. For example, five sets of motors, actuators, and drive transmission members can be used in a medium-sized case, and seven sets of motors, actuators, and drive transmission members can be used in a large case.

[0105] Since multiple motors (90) are provided for one case (10), the rotational amount, for example, the rotational speed, of each motor (90) can be set differently. The pressurized displacement of the actuator can vary in proportion to the rotational angle or rotational speed of the motor. For example, the rotational speed of the motor driving the actuators located at both ends of the case can be set to the smallest, and the rotational speed of the motor driving the actuator located at the center of the case can be set to the largest. Of course, the rotational speed of the motor can be considered the rotational speed in one cycle of pressurization. Therefore, by inducing the central part of the case side wall to expand more than both ends and swell into a jar shape, the swelling of the battery can be simulated. Through this, a fatigue failure test on the welded part of the frame (10) can be performed very quickly and precisely. For example, it can be verified very quickly and precisely whether fatigue failure occurs within the expected life of the battery.

[0106] Meanwhile, in addition to changing the number of motors and actuators according to a change in the size of the case (10), a change in the pressurization position may also be required. This is because the height of the side surfaces (13, 14) of the case (10) may also change according to the case size. Due to the characteristics of the motors and actuators that are installed in fixed positions, changing the pressurization position may not be easy.

[0107] As described above, the fixed position of the actuator can be varied via the adjustment plate (57). In this case, if the position of the motor is fixed, the length of the drive transmission member must be varied. However, it is not easy to change the length of the drive transmission member or to change to a different drive transmission member every time the pressurization height changes. In addition, it is very cumbersome and laborious to disengage and re-engage the drive transmission member and the actuator.

[0108] Therefore, it is necessary to devise a method that can very easily control the pressure position, i.e. the pressure height.

[0109] Hereinafter, with reference to FIGS. 7 and 8, the fixed structure and height variable structure of the motor (90) will be described in detail.

[0110] A plurality of motors (90) and a support plate (95) supporting the motors may be provided at the lower portion of the base plate (40). The support plate (95) may be fixed to the frame (70).

[0111] The above support plate (95) may be formed with a through hole (96) through which the shaft of the motor passes. The main body (91) of the motor may be positioned on one side of the through hole (96), and the sprocket (93) of the motor may be positioned on the other side. As the mounting position of the motor changes, the height of the shaft (92) changes. Therefore, it is preferable that the through hole (96) be formed in the shape of a long hole extending vertically so that the height of the motor can be changed.

[0112] A sprocket (93) is positioned on the front of the support plate (95), and the motor body (91) is fixed to the rear using a fixing member such as a screw. A slot (97) through which the fixing member passes may be formed in the vertical direction in the support plate (95). In addition, an auxiliary plate (95a) may be provided on the front of the support plate (95).

[0113] The above motor body (91) can be fixed to the rear of the support plate (95) using screws or bolts at four locations on the top, bottom, left, and right. The screws or bolts can penetrate the body (91), slots (97), and auxiliary plate (95a) to fix the motor (91). For example, when the bolts are loosened, the motor body (91), bolts, and auxiliary plate (95a) can move up and down to set the height, and then the motor can be fixed by varying the fixing height by tightening the bolts.

[0114] Additionally, an upper stopper (98a) and a lower stopper (98b) may be provided on the rear of the support plate (95) to further strengthen the fixation of the motor (90) and limit the variable height.

[0115] A height adjustment member (99a) may be provided between the upper stopper (98a) and the upper surface of the motor body (91), and a height adjustment member (99b) may also be provided between the lower stopper (98b) and the lower surface of the motor body (91).

[0116] The upper height adjustment member (99a) may be provided so that the insertion length with respect to the upper stopper (98a) is adjusted, and the lower height adjustment member (99b) may be provided so that the insertion length with respect to the lower stopper (98b) is adjusted. The insertion length may be adjusted by rotating the height adjustment member. Accordingly, the position at which the height adjustment member supports the main body (91) from the upper and lower portions may be varied by adjusting the insertion length of the height adjustment member (99a, 99b). In particular, the lower height adjustment member (99b) may perform the function of supporting the motor main body (91) with respect to the frame (70).

[0117] Due to the aforementioned motor fixing structure, the height can be easily adjusted without completely separating the motor from the support plate (95). In addition, the front of the motor body can be fixed to the rear of the support plate, and the rear upper and lower surfaces of the motor body can be fixed at positions spaced apart from the support plate (95), respectively. Therefore, the motor can be supported firmly.

[0118] Figure 9 shows a cross-sectional view of the case side before swelling, and Figure 10 shows a cross-sectional view of the case side after swelling.

[0119] As shown, since the pressure plate (4) has a rectangular shape that is long from left to right, a plurality of pressure plates (4) can substantially pressurize the entire side wall (13, 14) by interfacing with the dummy pad (19).

[0120] During swelling, the pressure displacement of the centrally located pressure plate can be set to be the largest, and the pressure displacement of the pressure plates can be set to decrease toward either side. In other words, by setting the pressure displacement differently for each pressure plate, the deformation pattern into a curved surface can be simulated with greater accuracy.

[0121] In addition, the non-contact area between the pressure plate and the side wall can be prevented from occurring through the dummy pad (19), thereby alleviating the discontinuity of the swelling surface.

[0122] Additionally, the vertical curvature radius of the frame side during swelling can be effectively simulated through the upper and lower curved surfaces of the pressure plate. These curvature radii for the upper and lower curved surfaces of the frame can be optimized through structural analysis and field measurements.

[0123] Meanwhile, swelling may occur in the form of left and right curves with respect to the sides (13, 14). In this case, the pressure displacement at the left and right ends may differ based on pressure plates located on both sides, not at the exact center, for example, one pressure plate. That is, the pressure displacement occurs at the center of the pressure plate, but if the pressure plate does not rotate about the center, a very wide discontinuous pressure area may occur.

[0124] Therefore, it is preferable that the pressure plate be rotatable about its center. That is, it is preferable that the pressure plate be rotatable left and right about a vertical axis by a certain angle. To this end, it is preferable that a rotation axis (54a) be provided at the rear center of the pressure plate. In practice, it is preferable that the setting or measuring reference for the pressure displacement be a position corresponding to the rotation axes of the pressure plates.

[0125] As described in the detailed description of the invention.

Claims

1. Base plate; A plurality of servo motors provided on the lower portion of the base plate; An actuator provided to be positioned inside a case that accommodates a battery cell on the upper portion of the base plate, and a plurality of actuators provided along the length direction of the case corresponding to each of the plurality of servo motors; and It is composed of a driving transmission member that vertically penetrates the base plate and transmits the rotational displacement of the servo motor to the actuator, A fatigue acceleration tester characterized in that the actuator is provided to convert the rotational displacement transmitted through the driving connecting member into a linear pressure displacement to pressurize the widthwise side wall of the case from the inside to the outside.

2. In paragraph 1, A fatigue acceleration tester characterized in that the lower cover of the case is fixedly secured to the upper surface of the base plate, and the actuator is fixedly secured to the lower cover.

3. In paragraph 2, A fatigue acceleration tester characterized in that it includes a frame that supports the base plate so as to be spaced apart from the ground, and the plurality of motors are fixed to the frame.

4. In paragraph 2, A fatigue acceleration tester characterized in that a plurality of the above drive transmission members are provided corresponding to each of the above motors, and a through hole is formed in the base plate for the plurality of drive transmission members to pass through vertically.

5. In paragraph 2, A fatigue acceleration tester characterized in that the actuator includes an adjustment plate for adjusting the pressurization height of the actuator by varying the fixed height of the actuator with respect to the lower cover.

6. In paragraph 1, A fatigue acceleration tester characterized in that the actuator includes a pressure plate that pressurizes the side wall and a screw nut that converts rotational displacement into linear pressure displacement and transmits it to the pressure plate.

7. In paragraph 6, A fatigue acceleration tester characterized in that the pressure plate has a pressure surface facing the side wall formed as a curved surface in the height direction of the side wall, and an elastic dummy pad is interposed between the pressure surface and the side wall.

8. In paragraph 6, A fatigue acceleration tester characterized in that the actuator is provided with the pressure plate and screw nut on both sides thereof, so that the actuator is provided to simultaneously pressurize both width-direction side walls of the case.

9. In paragraph 8, A fatigue acceleration tester characterized in that the pressure plate and screw nut provided on one side of the actuator are provided symmetrically with the pressure plate and screw nut provided on the other side so as to apply the same pressure displacement to both width-wise side walls of the case with respect to the rotational displacement transmitted through the driving transmission member.

10. In paragraph 1, A fatigue acceleration tester characterized by including a controller that controls the motor to repeat forward and reverse rotation for repeated movement between the original position and the pressurized position of the actuator.

11. In paragraph 10, A fatigue acceleration tester characterized in that the controller variably controls the rotation angle of the motor so that the size of the pressure displacement of the actuator is variably changed.

12. In paragraph 11, A fatigue acceleration tester characterized by including a user interface for individually inputting the magnitude of the pressurized displacement by each of the plurality of actuators.

13. In paragraph 11, A fatigue acceleration tester characterized by including a displacement measuring sensor located on the outside of the side wall of the case and detecting displacement of the side wall due to operation of the actuator.

14. In paragraph 13, A fatigue acceleration tester characterized in that the controller compares the displacement detected by the displacement measuring sensor with the size of a preset pressure displacement and controls the rotation angle of the motor.

15. In paragraph 13, A fatigue acceleration tester characterized in that the controller controls the plurality of actuators to repeat pressurization and relaxation according to a preset pressurization displacement according to a set cycle.

16. In paragraph 13, A fatigue acceleration tester characterized in that the displacement measuring sensor is provided in a plurality in the longitudinal direction of the case, and includes a sensor support member movably fixed to the base plate so that the plurality of displacement measuring sensors are mounted and the separation distance from the side wall is adjusted.

17. In paragraph 1, A fatigue acceleration tester characterized by including a support plate provided at the lower portion of the base plate and supporting the plurality of motors.

18. In paragraph 17, A fatigue acceleration tester characterized by including a height adjustment member for adjusting the fixed position of the motor with respect to the base plate.

19. In paragraph 18, A fatigue acceleration tester comprising an upper stopper and a lower stopper fixedly provided on the base plate, and characterized in that the height adjustment member is provided to adjust and fix the height of the motor between the upper stopper and the lower stopper.

20. In paragraph 16, A fatigue acceleration tester characterized in that the motor is provided with two sprockets that are driven integrally, and the drive transmission member includes a double chain that is formed integrally and is simultaneously coupled with the two sprockets.

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