Impact test method for cylindrical battery cells and impact test device for cylindrical battery cells

Abstract

The present invention relates to a cylindrical battery cell impact test method and cylindrical battery cell impact test device therefor, the method including the steps of placing a side surface of a cylindrical battery cell on a base portion, placing a metal rod on an upper portion of the side surface of the cylindrical battery cell, and dropping a weight onto the metal rod, in which a magnetic portion on the outer surface of the metal rod is placed so as to come into contact with the side surface of the cylindrical battery cell.

Description

[Technical field]

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2022-0144009 filed on November 1, 2022, and all contents disclosed in the Korean Patent Application are incorporated herein by reference.

[0002] The present invention relates to an impact test method and an impact test device for cylindrical battery cells, and more particularly to an impact test method and an impact test device for testing whether a battery can explodes by applying a certain amount of impact to a side surface of a cylindrical battery cell. [Background technology]

[0003] Lithium secondary batteries are classified according to the shape of the battery case into cylindrical battery cells and prismatic battery cells in which an electrode assembly is housed in a cylindrical or prismatic metal case, and pouch battery cells in which an electrode assembly is housed in a pouch case made of an aluminum laminate sheet. Among these, cylindrical battery cells have the advantages of being relatively large in capacity and structurally safe.

[0004] Lithium secondary batteries may explode due to strong external impact. In addition, the case may be physically damaged and opened due to the external impact. Alternatively, the impact may cause a short circuit inside the battery, and the reaction caused by the short circuit may cause overheating and gas generation. Since lithium secondary batteries are devices that store energy at high density, various tests are required to prevent safety accidents. The most typical test among these is the impact test in which a heavy object is dropped.

[0005] The impact test is a test based on UL Standard 1642 and / or 2054. The impact test is performed by placing a metal rod with a diameter of 15.8 mm on the side of a cylindrical battery cell so that the rod is perpendicular to the central axis of the cylindrical battery cell, and dropping a weight of 9.1 kg (about 20 pounds) from a height of 610±25 mm from the battery cell onto the top surface of the metal rod, and then observing the condition of the cylindrical battery cell.

[0006] An impact test is performed on five samples, and only if none of the five samples explode is the sample considered to be good. Therefore, only if all five samples receive the same magnitude of impact is the sample considered to be good.

[0007] The "case where it does not burst" means that the case of the cylindrical battery cell must not be opened. For example, the cap assembly must not be separated from the battery cell, and the side of the battery case must not be broken. "In the case where it bursts" includes both the case where the case is opened by a simple physical impact, and the case where the internal electrode assembly is damaged by a physical impact, and the battery cell case is opened secondary to the reaction of the electrode assembly.

[0008] Conventionally, the impact test was carried out by placing a metal rod on the side of a cylindrical battery cell and dropping a weight onto the metal rod. Since the side of the battery cell is curved, one end of the metal rod touches the bottom, the center touches the side of the battery cell, and the other end is tilted upward. Therefore, the position where the metal rod is placed on the side of the cylindrical battery cell may change, and there may be differences in the degree to which the metal rod is tilted, which causes a problem that the battery cells cannot be subjected to the same magnitude of impact.

[0009] When a weight falls on a tilted metal rod, the relatively higher part of the metal rod comes into primary contact with the weight first, transmitting an impact to it. The relatively lower part of the metal rod receives a repulsive force from the weight that bounces up due to the impact from the primary contact. In this case, the impact from the weight may not be transmitted entirely to the cylindrical battery cell. Also, it may be difficult to maintain a uniform magnitude of the impact applied to the cylindrical battery cell.

[0010] Therefore, there is a need for an impact test method and an impact test device that can improve the accuracy and reliability of the impact test.

[0011] Patent document 1 discloses an impact test device for a battery cell in which when a second driving unit is lowered toward the top of a cylindrical battery cell, an impact unit provided at the bottom of the second driving unit presses one side of the battery cell.

[0012] Patent Document 1 uses a method of calculating the distance from the second actuator to the bottom of the chamber in which the cylindrical battery cell is placed using a laser sensor, and adjusts the height of the second actuator according to the distance measurement result of the laser sensor. This makes it possible to repeatedly press one side of the cylindrical battery cell, improving the precision and reliability of the experiment.

[0013] Patent Document 1 only discloses a method for applying a constant impact when performing an impact test on the cap assembly portion of a cylindrical battery cell, but does not provide a method for applying a uniform impact to the side surface of the cylindrical battery cell.

[0014] Patent Document 2 uses a different method from UL Standards 1642 and / or 2054, and performs impact tests using two shafts and a round bar that can be driven up and down along the shafts. The shafts may be equipped with recessed rails. Patent Document 2 uses a round bar that is dropped, which is different from the international standard method and has the problem that the amount of impact is reduced or changed depending on the frictional force of the round bar moving along the shaft.

[0015] Thus, when conducting an impact test according to international standards to check for explosion by impacting the side of a cylindrical battery cell, a method and apparatus are needed that can prevent the metal rod from coming off due to the weight and can apply the same magnitude of impact even when the test is repeated multiple times, thereby improving the reliability of the impact test. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] Korean Patent Publication No. 10-2014-0000398 [Patent Document 2] Korean Patent No. 10-2132980 Summary of the Invention [Problem to be solved by the invention]

[0017] The present invention has been made to solve the above problems, and has an object to provide an impact test method and impact test device for cylindrical battery cells which can apply the impact of a weight directly to the cylindrical battery cell by maintaining contact between a metal rod and the cylindrical battery cell during an impact test in which the side of the cylindrical battery cell is impacted. [Means for solving the problem]

[0018] In order to achieve the above-mentioned object, a method for impact testing a cylindrical battery cell according to the present invention includes the steps of placing a side of a cylindrical battery cell on a base portion, placing a metal rod on an upper portion of a side of the cylindrical battery cell, and dropping a weight onto the metal rod, and a magnetic portion provided on an outer surface of the metal rod may be positioned so as to contact the side of the cylindrical battery cell.

[0019] Both ends of the metal bar may be disposed on an upper side of the cylindrical battery cell while being attached to a first guide and a second guide, respectively.

[0020] The central axis of the metal bar and the central axis of the cylindrical battery cell may be disposed perpendicular to each other.

[0021] The magnetic portion may be formed on the outer surface of a portion of the central portion in the longitudinal direction of the metal bar.

[0022] The method may further include adjusting positions of both ends of the metal bar by the first guide and the second guide so that a distance from each of the both ends of the metal bar to the base portion is constant.

[0023] In order to allow the metal bar to move up and down while maintaining a horizontal state, a first guide moving part and a second guide moving part are provided on each end of the metal bar, and the first guide moving part and the second guide moving part can move up and down along the inside of the first guide and the second guide, respectively.

[0024] The state in which the magnetic portion of the metal bar and the side surface of the cylindrical battery cell are in contact with each other can be maintained throughout the entire process of the weight dropping onto the metal bar.

[0025] The cylindrical battery cell impact test device for the cylindrical battery cell impact test method may include a base portion on which a cylindrical battery cell is placed, a metal bar placed on a side of the cylindrical battery cell, and a weight that drops toward the metal bar, and a magnetic portion may be provided in the center of the metal bar.

[0026] The metal bar may include a first guide and a second guide attached to both ends thereof to adjust the height of the metal bar.

[0027] The first guide and the second guide may be formed with a scale for checking the height of the metal bar.

[0028] In order to allow the metal bar to move up and down while maintaining a horizontal state, a first guide moving part and a second guide moving part are provided at each end of the metal bar, and the first guide moving part and the second guide moving part can move up and down along the insides of the first guide and the second guide, respectively.

[0029] The first guide and the second guide may include a vertical adjustment portion for adjusting a height of the metal bar, and the vertical adjustment portion may be configured in the form of a long bolt disposed on an upper portion of the metal bar.

[0030] The first guide and the second guide may include an up-down adjustment portion for adjusting the height of the metal bar, and the up-down adjustment portion may include an elastic member disposed on an upper portion of the metal bar, and an adjustment portion for adjusting the length of the elastic member disposed on an upper portion of the elastic member.

[0031] A spirit level may be located on the outer surface of the metal bar.

[0032] The metal rod may be in the form of a cylinder or a polygonal prism.

[0033] The magnetic portion may be configured in the form of a permanent magnet or an electromagnet provided on the outer surface of a metal bar.

[0034] The base portion may include a mounting portion for the cylindrical battery cell.

[0035] Furthermore, the present invention can also be provided in the form of a combination of various means for solving the above problems. Effect of the Invention

[0036] As described above, in the present invention, even if a weight falls on a metal rod, the cylindrical battery cells maintain contact with the metal rod, so that the amount of impact transmitted from the weight to the metal rod can be transmitted to the cylindrical battery cells without any loss.

[0037] In addition, since the weight falls while the metal rod is parallel to the base and positioned at the top of the side of the cylindrical battery cell, the magnitude of the impact applied to the cylindrical battery cell can be made uniform even when repeated experiments are performed. [Brief description of the drawings]

[0038] [Figure 1] FIG. 1 is a perspective view of an impact test device for a cylindrical battery cell according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged perspective view of the metal rod of FIG. [Diagram 3] FIG. 3 is a vertical cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 3 is a perspective view of the metal rod of FIG. 2 with a spirit level attached. [Diagram 5] 13 is a perspective view of a base portion on which a cylindrical battery cell mounting portion is formed. FIG. [Figure 6] FIG. 11 is a perspective view of an impact test device for a cylindrical battery cell according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a perspective view of a metal bar according to a third embodiment of the present invention. [Figure 8] 8 is a vertical cross-sectional view of the metal rod of FIG. 7 taken along line XX. [Figure 9] 8 is a vertical cross-sectional view of the metal rod of FIG. 7 taken along line YY. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, in which a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, when describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0040] In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, when a part includes a certain component, it does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0041] Furthermore, descriptions that specify or limit components are applicable to all inventions and are not limited to a particular invention unless otherwise specified.

[0042] Furthermore, throughout the description of the present invention and the claims, the singular includes the plural unless otherwise stated.

[0043] In addition, throughout the description of the present invention and the claims, unless otherwise stated, "or" includes "and." Therefore, "including A or B" means three cases: including A, including B, or including both A and B.

[0044] The invention will now be explained with reference to the drawings and in conjunction with detailed embodiments.

[0045] The drop height of the metal rod, weight, and weight used in all embodiments of the present invention can be set to an international standard of 15.8 mm diameter metal rod, 9.1 kg (approximately 20 pounds) weight, and 610±25 mm from the battery cell.

[0046] In the case of a 18650 cylindrical battery, the diameter is 18 mm, so it can be a cylinder with a diameter similar to that of the 15.8 mm metal rod, but in Figures 1 to 9, the cylindrical battery cell, metal rod, and weight are not in proportion to their actual shapes and are merely exaggerated. The weight also generally has to be about 100 mm in width, length, and height, so it actually has a larger volume than the 18650 cylindrical battery.

[0047] 1 to 9 are merely examples of the parts for fixing the weight, and any form is acceptable as long as the part is a device that can drop the weight from a certain height. For example, various modifications are possible, such as a form in which the weight is fixed using a hanger and then dropped, a form in which the weight is placed on a fixed stand and then pushed down, or a form in which the weight is fixed by an electromagnet and then dropped.

[0048] FIG. 1 is a perspective view of an impact test device for cylindrical battery cells according to a first embodiment of the present invention, FIG. 2 is an enlarged perspective view of a metal bar in FIG. 1, and FIG. 3 is a vertical sectional view taken along line AA in FIG.

[0049] 1 to 3, the impact test device for cylindrical battery cells according to the present invention includes a base part 100 on which a cylindrical battery cell 10 is placed on an upper surface, a metal bar 300 placed on an upper side of the cylindrical battery cell 10, a first guide 210 and a second guide 220 attached to both ends of the metal bar 300 to adjust the height of the metal bar 300, and a weight 400 that drops toward the metal bar 300.

[0050] The metal rod 300 is placed on the side of the cylindrical battery cell 10 with both ends attached to the first guide 210 and the second guide 220, so that the central axis of the metal rod 300 and the central axis of the cylindrical battery cell 10 are positioned perpendicular to each other.

[0051] A simpler embodiment than the first embodiment of the present invention may be possible in which the first guide 210 and the second guide 220 are omitted. In this case, as in the conventional method, since the side surface of the battery cell is curved, one end of the metal bar 300 may contact the base part 100, the center part may contact the side surface of the cylindrical battery cell 10, and the other end may be inclined upward. As will be described later, if the magnetic part 310 of the metal bar 300 is strong, the metal bar 300 can maintain a horizontal position even if the first guide 210 and the second guide 220 are omitted.

[0052] The present invention relates to an impact test method for checking whether a cylindrical battery cell 10 will explode when the side of the cylindrical battery cell 10 is placed on a base portion 100, a metal rod 300 is placed on the side or upper part of the side of the cylindrical battery cell 10, and a weight 400 is dropped toward the contact point between the cylindrical battery cell 10 and the metal rod 300. If the cylindrical battery cell 10 explodes, it is determined to be a defective battery cell, and if the cylindrical battery cell 10 does not explode, it is determined to be a normal battery cell.

[0053] When the weight 400 and the metal rod 300 collide, it is preferable to maintain the metal rod 300 in contact with the side of the cylindrical battery cell 10 so as to prevent the metal rod 300 from jumping up or the weight 400 in contact with the cylindrical battery cell 10 from moving, and to transmit the magnitude of the impact caused by the gravity of the weight 400 directly to the cylindrical battery cell 10.

[0054] Therefore, in the present invention, by providing the magnetic portion 310 on at least a portion of the outer surface of the metal bar 300, the contact state between the metal bar 300 and the cylindrical battery cell 10 can be maintained by magnetic force.

[0055] For example, the magnetic portion 310 may be provided on the entire outer surface of the metal bar 300, or the magnetic portion 310 may be formed on the outer surface of a portion of the central portion in the longitudinal direction of the metal bar 300.

[0056] When the magnetic portion 310 is provided on the entire outer surface of the metal bar 300, the position of the magnetic portion 310 formed on the metal bar 300 does not need to be considered when placing the metal bar 300 on the side of the cylindrical battery cell 10, and even if the metal bar 300 attached to the outer surface of the cylindrical battery cell 10 is attached in an inclined state or the part of the metal bar 300 that contacts the cylindrical battery cell 10 is a part that is off-center of the metal bar 300, contact between the metal bar 300 and the cylindrical battery cell 10 can be maintained during an impact test.

[0057] In the case where the magnetic part 310 is provided on the outer surface of a part of the center of the metal bar 300 in the longitudinal direction, when a contact surface is formed between the maximum protruding part of the side surface of the cylindrical battery cell 10 and the magnetic part 310 while the side surface of the cylindrical battery cell 10 is placed on the base part 100, the balance of the metal bar 300 can be maintained around the contact surface, and the distance from each end of the metal bar 300 to the base part 100 can be made uniform. In addition, if the magnetic part 310 is sufficiently strong, the metal bar 300 can be kept horizontal even if the first guide 210 and the second guide 220 are omitted. Therefore, even if impact tests are performed on multiple samples while replacing the cylindrical battery cell 10, the magnitude of the impact applied to the metal bar 300 can be maintained uniform.

[0058] When a magnetic portion 310 is provided on a portion of the outer surface of the metal rod 300, no step or groove is generated at the boundary between the surface of the magnetic portion 310 and the surface of the metal rod 300 surrounding the magnetic portion 310, and the diameter of the metal rod 300 at the position where the magnetic portion 310 is located in the cross section of the metal rod 300 as shown in Figure 3 is formed to be the same as the diameter of the metal rod 300 at the position where the magnetic portion 310 is not located.

[0059] For example, the magnetic portion 310 may be configured in the form of a permanent magnet or an electromagnet attached to the outer surface of a metal bar.

[0060] Although Figures 1 to 3 show the metal rod having a cylindrical shape, the shape of the metal rod described in the present invention is not limited to a cylindrical shape, and the present invention also includes metal rods having a polygonal prism shape.

[0061] The base unit 100 has a vertical central axis and a horizontal central axis, as shown by dotted lines in FIG. 1, and the positions of the weight 400 and the cylindrical battery cell 10 can be adjusted so that the drop point of the weight 400 and the part of the cylindrical battery cell 10 to which the impact is applied are located at the intersection C between the vertical central axis and the horizontal central axis.

[0062] Both ends of the metal bar 300 can be attached to the first guide 210 and the second guide 220. When the metal bar 300 is arranged so that the center of the metal bar 300 is placed on the side of the cylindrical battery cell 10 arranged on the base part 100, and both ends of the metal bar 300 are pressed from top to bottom with a uniform force, the metal bar 300 and the base part 100 can be in a parallel state. In this way, the first guide 210 and the second guide 220 can adjust the positions of both ends of the metal bar 300 to make the distance from each of the ends of the metal bar 300 to the base part 100 constant.

[0063] The first guide 210 and the second guide 220 have a first scale 215 formed on a side surface of the first guide 210 and a second scale 225 formed on a side surface of the second guide 220 so that the height of the metal rod 300 from the base portion 100 can be visually confirmed.

[0064] In the first embodiment, the first guide 210 and the second guide 220 include a first vertical adjustment portion and a second vertical adjustment portion for adjusting the height of the metal bar 300, respectively.

[0065] The first vertical adjustment unit is configured to arrange the first long bolt 211 to pass through the first guide upper end 214, and the lower end of the first long bolt 211 to contact the metal bar 300. The height of the first long bolt 211 can be adjusted with a screwdriver or wrench that fits the groove or screw head at the upper end 213 of the first long bolt 211 to adjust the horizontality of the metal bar 300. The second vertical adjustment unit is configured to arrange the second long bolt 221 to pass through the second guide upper end 224, and the lower end of the second long bolt 221 to contact the metal bar 300. The height of the second long bolt 221 can be adjusted with a screwdriver or wrench that fits the groove or screw head at the upper end 223 of the second long bolt 221 to adjust the horizontality of the metal bar 300.

[0066] In this way, the first long bolt 211 and the second long bolt 221 allow the metal bar 300 to be parallel to the base part 100. Here, the metal bar 300 can be prevented from tilting or jumping up when the weight 400 is dropped, and the impact of the weight 400 on the metal bar 300 can be transmitted directly to the cylindrical battery cell 10 without being lost.

[0067] FIG. 4 is a perspective view of the metal rod 300 of FIG. 2 with a spirit level attached thereto.

[0068] 4 shows a form in which a spirit level 320 is disposed on the outer surface of a metal rod 300. In the impact test device for cylindrical battery cells according to the present invention, the first and second scales are displayed on the first and second guides, respectively, so that the heights of both ends of the metal rod can be set to be the same, and if a spirit level 320 is further provided as shown in FIG.

[0069] FIG. 5 is a perspective view of the base portion on which the cylindrical battery cell mounting portion is formed.

[0070] Referring to FIG. 5 , the base unit 100 may include a mounting unit 110 having a groove formed therein that corresponds to the outer surface of the cylindrical battery cell 10 so as to accommodate the lower portion of the cylindrical battery cell 10 .

[0071] When an impact test is performed by dropping a weight while at least a portion of the bottom of the cylindrical battery cell 10 is housed in the mounting part 110, the cylindrical battery cell 10 can be prevented from jumping up due to the impact of the weight. However, since results that differ from the international standard may be obtained depending on whether or not the mounting part 110 is installed, the mounting part 110 may be further provided as long as statistically consistent results are observed.

[0072] FIG. 6 is a perspective view of an impact test device for cylindrical battery cells according to a second embodiment of the present invention.

[0073] 6, in the impact test device for cylindrical battery cells according to the second embodiment, a first guide 410 and a second guide 420 each include a first vertical adjustment portion and a second vertical adjustment portion for adjusting the height of the metal bar 300.

[0074] The first vertical adjustment part includes a first elastic member 412 disposed on the upper part of the metal bar 300, and a first adjustment part 411 coupled to an upper part 414 of the first elastic member 412 to adjust the length of the first elastic member 412. A first gripper 413 having a semi-cylindrical shape is coupled to a lower part of the first elastic member 412 to surround a part of the outer surface of the metal bar 300 having a cylindrical structure. When the metal bar 300 has a polygonal prism shape, the first gripper 413 may be configured to have a shape corresponding to the polygonal prism shape so as to closely surround a part of the outer surface of the polygonal prism shape. By providing the first gripper 413 configured in this shape, the metal bar 300 can be effectively pressed regardless of the shape of the metal bar 300.

[0075] The second vertical adjustment part includes a second elastic member 422 disposed on the upper part of the metal bar 300, and a second adjustment part 421 coupled to an upper part 424 of the second elastic member to adjust the length of the second elastic member 422. In addition, a second gripper 423 having a semi-cylindrical shape is coupled to a lower part of the second elastic member 422 to surround a part of the outer surface of the metal bar 300 having a cylindrical structure.

[0076] The first elastic member 412 and the second elastic member 422 are, for example, springs, and the first adjustment part 411 and the second adjustment part 421 press the first elastic member 412 and the second elastic member 422 so that the metal rod 300 comes into close contact with the first gripper 413 and the second gripper 423, and so that the metal rod 300 and the cylindrical battery cell 10 come into close contact with each other.

[0077] In the second up-down adjustment portion, the description of the second gripper 423 can be similarly applied to the description of the first gripper 413.

[0078] FIG. 7 is a perspective view of a metal rod according to a third embodiment of the present invention, FIG. 8 is a vertical cross-sectional view of the metal rod of FIG. 7 taken along line XX, and FIG. 9 is a vertical cross-sectional view of the metal rod of FIG. 7 taken along line YY.

[0079] 7 to 9, a metal rod 300 according to the third embodiment includes a metal rod body 301, and a first guide moving part 321 and a second guide moving part 322 coupled to both ends of the metal rod body 301, respectively.

[0080] The first guide moving part 321 is disposed in a space formed inside the first guide 510 and can move in an up and down direction within the space, and the second guide moving part 322 is disposed in a space formed inside the second guide 520 and can move in an up and down direction within the space.

[0081] The metal rod 300 according to the third embodiment includes a first guide moving portion 321 and a second guide moving portion 322, and moves up and down in a direction perpendicular to the base portion along the space formed within the first guide 510 and the second guide 520, so that the metal rod 300 can move up and down while maintaining a horizontal state relative to the base portion.

[0082] Further, although not shown in FIG. 7, it goes without saying that the vertical movement section shown in FIG. 1 and FIG. 6 can be applied as a means for moving the first guide movement section 321 and the second guide movement section 322 in the vertical direction.

[0083] Also, although not shown in FIG. 7, the magnetic portion may be formed on the entire outer surface of the metal rod body 301, or may be provided only on the lower surface of the central portion of the metal rod body 301.

[0084] Since the first guide moving part 321 and the second guide moving part 322 include a flat upper surface, when a long bolt is used as the elastic member, the contact surface that comes into contact with the lower surface of the long bolt can be formed as a plane parallel to the base part. Therefore, the metal bar can be pressed with a uniform force over the entire contact surface, so that the metal bar can be pressed stably and effectively.

[0085] In this way, when using the present invention, the contact state between the metal rod and the cylindrical battery cell can be maintained stably, and the magnetic part of the metal rod and the side of the cylindrical battery cell can be maintained in contact throughout the entire process of the weight falling onto the metal rod. This prevents the conventional problem of the force of the weight not being fully transmitted to the cylindrical battery cell due to the metal rod bouncing up when the weight is pressed.

[0086] In addition, since the weight is dropped while the metal rod is arranged horizontally, if the weight and position of the weight are kept constant, the magnitude of the impact applied to the cylindrical battery cell can be kept constant, thereby improving the reliability of the impact test. Thus, the cylindrical battery cell impact test method and cylindrical battery cell impact test device according to the present invention provide more consistent results than the prior art.

[0087] Those skilled in the art will appreciate that various applications and modifications within the scope of the present invention will be possible based on the above content. [Explanation of symbols]

[0088] 10 Cylindrical battery cells 100 Base 110 Mounting part 210, 410, 510 First Guide 211 First long bolt 213 First long bolt top end 214 First guide top 215 1st scale 220, 420, 520 2nd Guide 221 Second long bolt 223 Second long bolt top end 224 Second guide top 225 2nd scale 300 metal rod 301 Metal rod body 310 Magnetic part 320 horizontal scope 321 First guide moving part 322 Second guide moving part 400 weight 411 1st adjustment section 412 First elastic member 413 First Gripper 414 Upper part of first elastic member 421 2nd adjustment section 422 Second elastic member 423 Second Gripper 424 Upper part of second elastic member C Intersection point

Claims

1. A method for impact testing a cylindrical battery cell, comprising the steps of: placing a side surface of the cylindrical battery cell on a base; placing a metal rod on an upper side of the cylindrical battery cell; dropping a weight onto the metal bar; Including, A method for impact testing a cylindrical battery cell, comprising: arranging the magnetic portion on the outer surface of the metal bar so as to come into contact with the side surface of the cylindrical battery cell.

2. The impact test method for a cylindrical battery cell according to claim 1 , wherein both ends of the metal bar are disposed on an upper portion of a side surface of the cylindrical battery cell while being attached to a first guide and a second guide, respectively.

3. The impact test method for a cylindrical battery cell according to claim 1 , wherein the central axis of the metal bar and the central axis of the cylindrical battery cell are arranged perpendicular to each other.

4. The impact test method for a cylindrical battery cell according to claim 1 , wherein the magnetic portion is formed on an outer surface of a part of a central portion in a longitudinal direction of the metal bar.

5. 3. The method of claim 2, further comprising adjusting positions of both ends of the metal bar by the first guide and the second guide so that a distance from each of the both ends of the metal bar to the base portion is constant.

6. A first guide moving part and a second guide moving part are provided at both ends of the metal bar so that the metal bar can move up and down while maintaining a horizontal state, The impact test method for a cylindrical battery cell according to claim 2 , wherein the first guide moving part and the second guide moving part move up and down along the insides of the first guide and the second guide, respectively.

7. 2. The impact test method for a cylindrical battery cell according to claim 1, wherein the magnetic portion of the metal bar and the side surface of the cylindrical battery cell are kept in contact with each other throughout the entire process of dropping the weight onto the metal bar.

8. An impact test device for a cylindrical battery cell for the impact test method for a cylindrical battery cell according to any one of claims 1 to 7, comprising: a base portion on which the cylindrical battery cell is disposed; A metal rod disposed on a side surface of the cylindrical battery cell; A weight that falls towards the metal bar; Including, An impact test device for cylindrical battery cells, comprising a magnetic portion at the center of the metal rod.

9. 9. The impact test device for cylindrical battery cells according to claim 8, further comprising a first guide and a second guide attached to both ends of the metal bar, respectively, for adjusting the height of the metal bar.

10. The cylindrical battery cell impact test device according to claim 9 , wherein the first guide and the second guide are formed with a scale for checking the height of the metal bar.

11. A first guide moving part and a second guide moving part are provided at both ends of the metal bar so that the metal bar can move up and down while maintaining a horizontal state, The impact test device for cylindrical battery cells according to claim 9 , wherein the first guide moving portion and the second guide moving portion move up and down along the insides of the first guide and the second guide, respectively.

12. The first guide and the second guide include a vertical adjustment portion for adjusting the height of the metal bar, 10. The impact test device for cylindrical battery cells according to claim 9, wherein the vertical adjustment part is configured as a long bolt disposed on an upper portion of the metal bar.

13. The first guide and the second guide include a vertical adjustment portion for adjusting the height of the metal bar, 10. The impact test device for cylindrical battery cells according to claim 9, wherein the vertical adjustment part has an elastic member disposed on an upper part of the metal bar, and an adjustment part for adjusting a length of the elastic member disposed on an upper part of the elastic member.

14. The cylindrical battery cell impact test device according to claim 8, wherein a spirit level is located on the outer surface of the metal bar.

15. The impact test device for cylindrical battery cells according to claim 8 , wherein the metal bar has a cylindrical or polygonal prism shape.

16. The impact test device for cylindrical battery cells according to claim 8 , wherein the magnetic portion is configured in a form in which a permanent magnet or an electromagnet is provided on the outer surface of the metal bar.

17. The cylindrical battery cell impact test device according to claim 8 , wherein the base portion includes a mounting portion for the cylindrical battery cell.

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