Impact test method for cylindrical battery cells and impact test apparatus for cylindrical battery cells therefor

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 based on Korean Patent Application No. 10-2022-0144009, filed on November 1, 2022, and all the contents disclosed in the Korean patent application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a method for testing the impact of a cylindrical battery cell and an impact testing apparatus for the same. Specifically, the present invention relates to an impact testing method for applying an impact of a certain magnitude to the side surface of a cylindrical battery cell to inspect whether the battery can explode, and an impact testing apparatus for the same.

Background Art

[0003] Lithium secondary batteries are classified into cylindrical battery cells and prismatic battery cells in which an electrode assembly is built into a cylindrical or prismatic metal can according to the shape of the battery case, and pouch-type battery cells in which an electrode assembly is built into a pouch-shaped case of an aluminum laminate sheet. Among them, cylindrical battery cells have the advantages of relatively large capacity and structural safety.

[0004] Lithium secondary batteries may explode due to strong external impacts. In addition, the case may be physically damaged and opened by an external impact. Alternatively, the inside of the battery may be short-circuited by an impact, and heat and gas may be generated by the reaction due to the short circuit. Since lithium secondary batteries are devices in which energy is stored at a high density, various tests for preventing safety accidents are required. The impact test of dropping a heavy object is the most typical test among them.

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

[0006] An impact test is performed on five samples, and it is determined to be a non-defective product only when all of the five samples do not rupture. Therefore, it is highly likely that it will be determined to be a non-defective product only when the same magnitude of impact is applied to all of the five samples.

[0007] The "non-rupture case" 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 surface of the battery case must not rupture. The "rupture case" includes both the case being opened by a simple physical impact or the internal electrode assembly being damaged by a physical impact and the case of the battery cell being secondarily opened by the reaction caused thereby.

[0008] For the impact test, conventionally, an experiment was carried out by placing a metal bar on the side surface of a cylindrical battery cell and dropping a weight on the metal bar. Since the side surface of the battery cell is a curved surface, one end of the metal bar touches the bottom, the center part touches the side surface of the battery cell, and the other end tilts upward. Therefore, the position where the metal bar is arranged on the side surface of the cylindrical battery cell may change, and differences may occur in the degree of tilt of the metal bar, etc., so there is a problem that the same magnitude of impact cannot be applied to the battery cell.

[0009] When a weight falls on a tilted metal bar, the relatively higher part of the metal bar first comes into primary contact with the weight and the impact is transmitted thereto. The relatively lower part of the metal bar receives the repulsive force from the weight that bounces up due to the impact caused by the primary contact. In this case, the amount of impact by the weight may not be entirely transmitted to the cylindrical battery cell. Also, it may be difficult to uniformly maintain the 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 a battery cell impact test apparatus that is implemented by a method in which when the second drive unit is lowered toward the upper part of a cylindrical battery cell, an impact part provided at the lower part of the second drive unit presses one side of the battery cell.

[0012] Patent Document 1 uses a laser sensor to calculate the distance from the second drive unit to the bottom surface of the chamber in which the cylindrical battery cell is disposed, and adjusts the height of the second drive unit according to the result of the distance measurement of the laser sensor. Therefore, it is possible to repeatedly press one side of the cylindrical battery cell, and the precision and reliability of the experiment can be improved.

[0013] Patent Document 1 only discloses a method of applying a certain impact when performing an impact test on the cap assembly part of a cylindrical battery cell, and does not present a method of uniformly applying an impact to the side surface of the cylindrical battery cell.

[0014] Patent Document 2 is a method different from UL standards 1642 and / or 2054, and performs an impact test using two shafts and a round bar that can be driven to rise and fall along the shafts. The shafts may be provided with recessed rails. In the case of Patent Document 2, it is due to the fall of the round bar, which is different from the international standard method, and there is a problem that the impact amount decreases or changes due to the frictional force of the round bar moving along the shafts.

[0015] Thus, when performing an impact test to check for explosion by impacting the side surface of a cylindrical battery cell according to international standards, a method and apparatus are needed to prevent the metal bar from detaching due to the weight and to increase the reliability of the impact test by applying the same magnitude of impact even when the test is repeated multiple times.

Prior Art Documents

Patent Documents

[0016]

Patent Document 1

[0017] The present invention is for solving the above problems, and by maintaining the contact state between the metal rod and the cylindrical battery cell in an impact test that impacts the side surface of the cylindrical battery cell, it is possible to apply the impact of the weight directly to the cylindrical battery cell. An object of the present invention is to provide a method for testing the impact of a cylindrical battery cell and an apparatus for testing the impact of a cylindrical battery cell for this purpose. [Means for Solving the Problems]

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

[0019] Both ends of the metal rod can be disposed on the upper portion of the side surface of the cylindrical battery cell while being mounted on a first guide and a second guide.

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

[0021] The magnetic portion can be formed on a part of the outer surface at the central portion in the longitudinal direction of the metal rod.

[0022] The method may further include the step of adjusting the positions of both ends of the metal rod with the first guide and the second guide so that the distances from both ends of the metal rod to the base portion are constant.

[0023] In order for the metal rod to be able to move up and down while maintaining a horizontal state, each of the two ends of the metal rod is provided with a first guide moving part and a second guide moving part, and each of 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.

[0024] The state in which the magnetic part of the metal rod is in contact with the side surface of the cylindrical battery cell can be maintained throughout the entire process of the weight falling onto the metal rod.

[0025] In an impact test device for a cylindrical battery cell for the method of impact testing the cylindrical battery cell, it includes a base part on which the cylindrical battery cell is arranged on the upper surface, a metal rod arranged on the side surface of the cylindrical battery cell, and a weight falling towards the metal rod, and a magnetic part can be provided at the central part of the metal rod.

[0026] It can be provided with a first guide and a second guide that are attached to each of the two ends of the metal rod and adjust the height of the metal rod.

[0027] Scales for checking the height of the metal rod can be formed on the first guide and the second guide.

[0028] In order for the metal rod to be able to move up and down while maintaining a horizontal state, each of the two ends of the metal rod is provided with a first guide moving part and a second guide moving part, and each of 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.

[0029] The first guide and the second guide include an up and down adjustment part for adjusting the height of the metal rod, and the up and down adjustment part can be configured in the form of a long bolt arranged on the upper part of the metal rod.

[0030] The first guide and the second guide include an up-and-down adjustment part for adjusting the height of the metal rod. The up-and-down adjustment part has an elastic member arranged on the upper part of the metal rod, and an adjustment part for adjusting the length of the elastic member can be provided on the upper part of the elastic member.

[0031] A level can be positioned on the outer surface of the metal rod.

[0032] The metal rod can be in a cylindrical form or a polygonal prism form.

[0033] The magnetic part can be configured in a form in which a permanent magnet or an electromagnet is provided on the outer surface of the metal rod.

[0034] The base part can include a mounting part for the cylindrical battery cell.

[0035] In addition, the present invention can also be provided in a form in which various combinations of the solutions to the above problems are made.

Effects of the Invention

[0036] As described above, in the present invention, even if a weight falls on the metal rod, the contact state between the cylindrical battery cell and the metal rod is maintained, so that the magnitude of the impact transmitted from the weight to the metal rod can be transmitted to the cylindrical battery cell without loss.

[0037] In addition, since the metal rod is in a state parallel to the base part and the weight falls while being arranged on the upper part of the side surface 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 carried out.

Brief Description of the Drawings

[0038]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0039] Hereinafter, based on the attached drawings, embodiments that enable a person having ordinary knowledge in the technical field to which the present invention pertains to easily implement the present invention will be described in detail. However, when explaining in detail the operating principle of the preferred embodiment of the present invention, if it is determined that the specific explanation of related known functions or configurations may unnecessarily obscure the gist of the present invention, the detailed explanation thereof will be omitted.

[0040] Also, the same drawing reference numerals are used for parts having similar functions and actions throughout the drawings. Throughout the specification, when it is said that a part is connected to another part, this includes not only the case where they are directly connected but also the case where they are indirectly connected with other elements interposed therebetween. Also, including a certain component means, unless otherwise stated to the contrary, not excluding other components but further including other components.

[0041] Also, the description of limiting or adding components for concretization is applicable to all inventions without special limitations and is not limited to a specific invention.

[0042] Also, those expressed in the singular throughout the description and claims of the present invention include plural cases unless otherwise mentioned.

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

[0044] The present invention will be described in detail together with specific embodiments based on the drawings.

[0045] For all embodiments of the present invention, a metal rod, a weight, and the dropping height of the weight can be applied as a metal rod with a diameter of 15.8 mm according to international standards, a weight of 9.1 kg (about 20 pounds), and a height of 610 ± 25 mm from the battery cell.

[0046] In the case of a 18650 cylindrical battery, since the diameter is 18 mm, it can be in a cylindrical form having a diameter similar to that of the 15.8 mm metal rod. However, in FIGS. 1 to 9, the cylindrical battery cell, the metal rod, and the weight are not proportional to the actual form and are schematically drawn with some parts emphasized. In the case of the weight, generally, it should be about 100 mm in width, length, and height, so in reality, its volume is larger than that of the 18650 cylindrical battery.

[0047] Also, the part for fixing the weight schematically shown in FIGS. 1 to 9 can be in any form as long as it is a device that can drop the weight from a certain height. For example, after fixing it using a hanger, it can be in a form of dropping, after placing it on a fixed base and pushing it to drop, or after fixing it with an electromagnet and then dropping it, and various deformations are possible.

[0048] 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, FIG. 2 is an enlarged perspective view of the metal rod in FIG. 1, and FIG. 3 is a vertical cross-sectional view taken along line A-A in FIG. 2.

[0049] Referring to FIGS. 1 to 3, an impact test apparatus for a cylindrical battery cell according to the present invention includes a base portion 100 on which the cylindrical battery cell 10 is disposed on the upper surface, a metal rod 300 disposed on the upper part of the side surface of the cylindrical battery cell 10, first guide 210 and second guide 220 attached to each of both ends of the metal rod 300 to adjust the height of the metal rod 300, and a weight 400 that falls toward the metal rod 300.

[0050] Since the metal rod 300 is disposed on the side surface of the cylindrical battery cell 10 with both ends thereof attached to the first guide 210 and the second guide 220, respectively, the central axis of the metal rod 300 and the central axis of the cylindrical battery cell 10 are arranged to be orthogonal to each other.

[0051] More simply than the first embodiment of the present invention, a form in which the first guide 210 and the second guide 220 are omitted is also possible. In this case, since the side surface of the battery cell is a curved surface as in the conventional method, one end of the metal rod 300 contacts the base portion 100, the central portion contacts the side surface of the cylindrical battery cell 10, and the other end may be inclined upward. As will be described later, when the magnetic portion 310 of the metal rod 300 is strong, the metal rod 300 can maintain a horizontal state 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 the cylindrical battery cell 10 ruptures when the side surface of the cylindrical battery cell 10 is disposed on the base portion 100 and the weight 400 is dropped toward the contact portion between the cylindrical battery cell 10 and the metal rod 300 with the metal rod 300 disposed on the side surface or the upper part of the side surface of the cylindrical battery cell 10. When the cylindrical battery cell 10 ruptures, it is determined as a defective battery cell, and when the cylindrical battery cell 10 does not rupture, it is determined as a normal battery cell.

[0053] When the weight 400 collides with the metal rod 300, it is preferable to maintain the state in which the metal rod 300 is in contact with the side surface of the cylindrical battery cell 10 so that the metal rod 300 does not bounce up or the weight 400 in contact with the cylindrical battery cell 10 does not move, and the magnitude of the impact due to the gravity of the weight 400 is transmitted to the cylindrical battery cell 10 as it is.

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

[0055] For example, it can be in a form in which the magnetic part 310 is provided on the entire outer surface of the metal rod 300, or the magnetic part 310 can be formed on a part of the outer surface of the central part in the longitudinal direction of the metal rod 300.

[0056] When the magnetic part 310 is provided on the entire outer surface of the metal rod 300, when the metal rod 300 is arranged on the side surface of the cylindrical battery cell 10, it is not necessary to consider the position of the magnetic part 310 formed on the metal rod 300, and the metal rod 300 attached to the outer surface of the cylindrical battery cell 10 is attached in an inclined state, or even if the part of the metal rod 300 that contacts the cylindrical battery cell 10 is a part deviating from the center of the metal rod 300, the contact between the metal rod 300 and the cylindrical battery cell 10 can be maintained during the impact test.

[0057] When the magnetic part 310 is provided on a part of the outer surface of the central part in the longitudinal direction of the metal rod 300, with the side surface of the cylindrical battery cell 10 arranged on the base part 100, when a contact surface is formed between the maximum protruding part and the magnetic part 310 on the side surface of the cylindrical battery cell, the balance of the metal rod 300 can be maintained around the contact surface, and the distances from both ends of the metal rod 300 to the base part 100 can be made uniform. Also, when the magnetic part 310 is strong enough, the metal rod 300 can maintain a horizontal state even if the first guide 210 and the second guide 220 are omitted. Therefore, even when performing an impact test on a plurality of samples while replacing the cylindrical battery cell 10, the magnitude of the impact applied to the metal rod 300 can be maintained uniformly.

[0058] When a magnetic part 310 is provided on a part of the outer surface of the metal bar 300, no step or groove is generated at the boundary between the surface of the magnetic part 310 and the surface of the metal bar 300 surrounding the magnetic part 310, and the diameter of the metal bar 300 at the position where the magnetic part 310 is located in the cross section of the metal bar 300 as shown in FIG. 3 is formed to be the same as the diameter of the metal bar 300 at the position where there is no magnetic part 310.

[0059] For example, the magnetic part 310 can be configured in a form in which a permanent magnet or an electromagnet is provided on the outer surface of the metal bar.

[0060] In FIGS. 1 to 3, the form of the metal bar is shown as a cylindrical form, but the form of the metal bar described in the present invention is not limited to the cylindrical form, and the present invention includes metal bars configured in a polygonal prism form.

[0061] As shown by the dotted line in FIG. 1, the base part 100 is in a form in which the vertical central axis and the horizontal central axis are displayed, and the positions of the weight 400 and the cylindrical battery cell 10 can be adjusted so that the dropping point of the weight 400 and the part for applying an impact in the cylindrical battery cell 10 are placed at the intersection C of 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 surface of the cylindrical battery cell 10 arranged on the base part 100, and both ends of the metal bar 300 are pushed with a uniform force from top to bottom, 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 in order to make the distances from both ends of the metal bar 300 to the base part 100 constant.

[0063] On the side surface of the first guide 210, a first scale 215 is formed, and on the side surface of the second guide 220, a second scale 225 is formed so that the height of the metal bar 300 from the base part 100 can be visually confirmed.

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

[0065] The first vertical adjustment portion is configured such that a first long bolt 211 is disposed to pass through the upper end 214 of the first guide, and the lower end of the first long bolt 211 contacts the metal rod 300. The height of the first long bolt 211 can be adjusted with a driver or wrench that fits the groove or screw head at the upper end 213 of the first long bolt 211 to level the metal rod 300. The second vertical adjustment portion is configured such that a second long bolt 221 is disposed to pass through the upper end 224 of the second guide, and the lower end of the second long bolt 221 contacts the metal rod 300. The height of the second long bolt 221 can be adjusted with a driver or wrench that fits the groove or screw head at the upper end 223 of the second long bolt 221 to level the metal rod 300.

[0066] In this way, by the first long bolt 211 and the second long bolt 221, the metal rod 300 can be made parallel to the base portion 100. Here, when the weight 400 falls, it is possible to prevent the metal rod 300 from tilting or bouncing up, and the impact amount applied by the weight 400 to the metal rod 300 can be directly transmitted to the cylindrical battery cell 10 without being dissipated.

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

[0068] Referring to FIG. 4, a form in which a level 320 is disposed on the outer surface of the metal rod 300 is shown. In the impact test apparatus for a cylindrical battery cell according to the present invention, since a first scale and a second scale are respectively displayed on each of the first guide and the second guide, the heights of both ends of the metal rod can be set to be the same. However, as shown in FIG. 4, when a level 320 is further provided, the metal rod can be leveled with reference to the level 320.

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

[0070] Referring to FIG. 5, the base portion 100 can include a mounting portion 110 formed with a groove corresponding 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 with at least a part of the lower portion of the cylindrical battery cell 10 accommodated in the mounting portion 110, the phenomenon that the cylindrical battery cell 10 jumps up due to the impact of the weight can be prevented. However, since different results from the international standard may occur depending on whether the mounting portion 110 is mounted or not, the mounting portion 110 can be further provided as long as statistically consistent results are observed.

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

[0073] Referring to FIG. 6, in the impact test apparatus for a cylindrical battery cell according to the second embodiment, each of the first guide 410 and the second guide 420 includes a first vertical adjustment portion and a second vertical adjustment portion for adjusting the height of the metal rod 300.

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

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

[0076] The first elastic member 412 and the second elastic member 422 are, for example, springs. 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 is in close contact with the first gripper 413 and the second gripper 423, and the metal rod 300 and the cylindrical battery cell 10 can be in close contact and contact with each other.

[0077] In the second vertical adjustment part, the description of the second gripper 423 can be applied mutatis mutandis 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 X-X, and FIG. 9 is a vertical cross-sectional view of the metal rod of FIG. 7 taken along line Y-Y.

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

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

[0081] The metal bar 300 according to the third embodiment includes a first guide moving part 321 and a second guide moving part 322, and moves up and down in a direction perpendicular to the base part along the spaces formed in the first guide 510 and the second guide 520. Therefore, the metal bar 300 can move up and down while maintaining a horizontal state with respect to the base part.

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

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

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

[0085] Thus, when the present invention is used, the contact state between the metal bar and the cylindrical battery cell can be stably maintained. Therefore, in the entire process of the weight falling onto the metal bar, the magnetic part of the metal bar and the side surface of the cylindrical battery cell can be maintained in a contact state. Thus, it is possible to prevent the problem that the force of the weight is not completely transmitted to the cylindrical battery cell due to the metal bar bouncing up when the weight is pressed conventionally.

[0086] Also, since the weight is dropped with the metal bar arranged in a horizontal state, when the weight of the weight and the position of the weight are made constant, the magnitude of the impact applied to the cylindrical battery cell can be kept constant, so the reliability of the impact test can be improved. Thus, the impact test method for the cylindrical battery cell according to the present invention and the impact test apparatus for the cylindrical battery cell therefor provide consistent results as compared with the prior art.

[0087] Those having ordinary knowledge in the field to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above content.

Explanation of Reference Numerals

[0088] 10 Cylindrical battery cell 100 Base portion 110 Mounting portion 210, 410, 510 First guide 211 First long bolt 213 Upper end of the first long bolt 214 Upper end of the first guide 215 First scale 220, 420, 520 Second guide 221 Second long bolt 223 Upper end of the second long bolt 224 Upper end of the second guide 225 Second scale 300 Metal bar 301 Metal bar body 310 Magnetic portion 320 Level 321 First guide moving portion 322 Second guide moving portion 400 Weight 411 First adjusting portion 412 First elastic member 413 First gripper 414 Upper portion of the first elastic member 421 Second adjusting portion 422 Second elastic member 423 Second gripper 424 Upper portion of the second elastic member C intersection

Claims

1. A method for an impact test of a cylindrical battery cell, comprising: placing a side surface of the cylindrical battery cell on a base portion; placing a metal rod on an upper portion of the side surface of the cylindrical battery cell; dropping a weight toward the metal rod; and arranging a magnetic portion provided on an outer surface of the metal rod to contact the side surface of the cylindrical battery cell.

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

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

4. The method for an impact test of 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 rod.

5. The method for an impact test of a cylindrical battery cell according to claim 2, further comprising adjusting positions of both ends of the metal rod with the first guide and the second guide so that distances from both ends of the metal rod to the base portion are constant.

6. Each of both ends of the metal rod is provided with a first guide moving portion and a second guide moving portion so that the metal rod can move vertically while maintaining a horizontal state, and each of the first guide moving portion and the second guide moving portion moves vertically along an inside of the first guide and the second guide.

7. The method for an impact test of a cylindrical battery cell according to claim 1, wherein a state where the magnetic portion of the metal rod is in contact with the side surface of the cylindrical battery cell is maintained throughout a process of the weight dropping onto the metal rod.

8. An impact test device for a cylindrical battery cell for the method for an impact test of a cylindrical battery cell according to any one of claims 1 to 7, comprising: a base portion on which the cylindrical battery cell is arranged on an upper surface; a metal rod arranged on a side surface of the cylindrical battery cell; a weight dropping toward the metal rod; and a magnetic portion is provided at a central portion of the metal rod.

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

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

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

12. The first guide and the second guide include an up-and-down adjustment part for adjusting the height of the metal rod. The impact test device for a cylindrical battery cell according to claim 9, wherein the up-and-down adjustment part is configured in the form of a long bolt disposed above the metal rod.

13. The first guide and the second guide include an up-and-down adjustment part for adjusting the height of the metal rod. The impact test device for a cylindrical battery cell according to claim 9, wherein an elastic member is disposed above the metal rod in the up-and-down adjustment part, and an adjustment part for adjusting the length of the elastic member is provided above the elastic member.

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

15. The impact test device for a cylindrical battery cell according to claim 8, wherein the metal rod is in a cylindrical form or a polygonal prism form.

16. The impact test device for a cylindrical battery cell according to claim 8, wherein the magnetic part is configured in a form having a permanent magnet or an electromagnet on the outer surface of the metal rod.

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

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