Clamp for evaluating a cushion and method for evaluating a cushion using the clamp

Abstract

The present invention relates to a jig for evaluating a cushion. The jig for evaluating a cushion includes a first plate located on one surface of the cushion to press the cushion, a second plate located on the other surface of the cushion to press the cushion from the other surface, and a magnet member located between the first plate and the second plate, wherein a recess is formed at an edge of at least one of the first plate or the second plate, the recess being recessed to allow the magnet member to be disposed therein.

Description

TECHNICAL FIELD

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2020-0119694, filed on September 17, 2020, and the entire contents of which are incorporated herein by reference.

[0002] The present application relates to a jig for evaluating a cushion and a method of evaluating a cushion using the same, and more particularly, to a jig for evaluating a cushion to be used for a battery module and a method of evaluating a cushion to be used for a battery module. BACKGROUND

[0003] Recently, a secondary battery capable of charging and discharging has been widely used as an energy source of a wireless mobile device. In addition, an electric vehicle, a hybrid electric vehicle, etc. are proposed as a solution to air pollution of existing gasoline vehicles and diesel vehicles using fossil fuels, and a secondary battery has been attracting attention as an energy source of these electric vehicles, hybrid electric vehicles, etc. Therefore, due to the advantages of the secondary battery, the application type using the secondary battery is currently very diverse, and it is expected that the secondary battery will be applied to many fields and products in the future.

[0004] Such a secondary battery can be classified into a lithium ion battery, a lithium ion polymer battery, a lithium polymer battery, etc., and according to the shape of a battery case, can also be classified into a cylindrical battery or a prismatic battery in which an electrode assembly is embedded in a cylindrical or prismatic metal can, and a pouch-type battery in which an electrode assembly is embedded in a pouch-type case of an aluminum laminate sheet. The electrode assembly embedded in the battery case is a rechargeable power generation element realized by including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode, and can be classified into a jelly-roll type electrode assembly which is wound by having a separator disposed between a long sheet type positive electrode and a negative electrode which have been coated with an active material, and a stacked type electrode assembly which is obtained by sequentially stacking a plurality of positive electrodes and negative electrodes in a state in which a separator has been disposed between the positive electrodes and the negative electrodes having a predetermined size.

[0005] In addition, in order to increase the output and capacity of a battery cell, a plurality of battery cells are electrically connected to each other to form a packaged battery module. In particular, since the pouch-type secondary battery has an advantage of being easily stacked, it is widely used in medium to large-sized devices.

[0006] Such a battery module has a structure in which a plurality of battery modules are accommodated in a module case, and in order to protect the battery cells in the battery module against an impact or a vibration from the outside of the module case, a cushion is disposed between the module case and the battery cells or between the battery cells accommodated in the module case.

[0007] Furthermore, for dynamic structural analysis for a battery module, such as vibration analysis and impact analysis, information on dynamic stiffness of such a cushion is necessary. In particular, because the stiffness of the cushion differs depending on the compression rate, a technique for measuring the dynamic stiffness while changing the compression rate is required.

[0008] Therefore, there is a need for a jig for charging and discharging a battery cell that solves the above problems. SUMMARY

[0009] TECHNICAL PROBLEM

[0010] The present application is believed to solve at least some of the above problems. For example, an aspect of the present application provides a jig for evaluating a cushion and a method of evaluating a cushion using the jig, which is capable of evaluating performance depending on a compression rate of a cushion inserted into a battery module.

[0011] TECHNICAL SOLUTION

[0012] The present application relates to a jig for evaluating a cushion, and the jig includes a first plate located on one surface of the cushion and pressing the cushion, a second plate located on the other surface of the cushion and pressing the cushion from the other surface, and a magnet member located between the first plate and the second plate, wherein a recess is formed at an edge of at least one of the first plate and the second plate, the recess being recessed to allow the magnet member to be placed.

[0013] In a specific example, the first plate and the second plate are made of a metal material that responds to a magnet, and the first plate and the second plate are the same in area and size.

[0014] In a specific example, a portion of the magnet member that contacts the recess corresponds in shape to the shape of the recess to allow the magnet member to be closely attached to the recess.

[0015] In one example, the recess is formed at a partial area of the edge of the first plate or the second plate and is symmetrically formed based on the central portion of the plate.

[0016] At this time, the length and width of the portion of the first plate or the second plate that has the recess formed correspond to the length and width of the magnet member.

[0017] In one example, a recess can be formed at the first plate and the second plate, respectively.

[0018] At this time, the thickness of the magnet member is greater than the sum of the depth of the recess formed in the first plate and the depth of the recess formed in the second plate.

[0019] In another example, the recess can be formed in one of the first plate and the second plate.

[0020] At this time, the thickness of the magnet member is greater than the depth of the recess.

[0021] In another example, the recess can be formed in the entire area of the edge of the first plate or the second plate.

[0022] At this time, the width of the portion of the first plate or the second plate in which the recess has been formed corresponds to the width of the magnet member.

[0023] Further, the thickness of the internal space enclosed by the first plate, the second plate, and the magnet member can be equal to or less than the thickness of the target cushion.

[0024] Here, the area of the horizontal cross section of the internal space enclosed by the first plate, the second plate, and the magnet member can be equal to or greater than the area of the target cushion.

[0025] Further, the present application provides a method of evaluating a cushion, and the method includes: preparing the jig for evaluating a cushion described above; fastening the first plate to the second plate by having the cushion be placed between the first plate and the second plate and having the magnet member be placed in the recess; and measuring the dynamic stiffness of the cushion.

[0026] In a specific example, measuring the dynamic stiffness includes measuring the dynamic stiffness according to the compression rate of the cushion by changing the compression rate of the cushion.

[0027] At this time, the compression rate of the cushion can be adjusted by the thickness of the magnet member.

[0028] Advantageous Effects

[0029] In the present application, the compression rate of the cushion inserted into the battery module can be easily adjusted by using the magnet member, whereby the dynamic stiffness corresponding to the compression rate can be evaluated. Further, because the jig for evaluating a cushion according to the present application has a simple structure, the influence of the jig can be minimized when the cushion is evaluated. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a photograph showing the shape of a cushion.

[0031] Figure 2is an exploded perspective view showing the structure of a jig for evaluating a cushion according to an embodiment of the present application.

[0032] Figure 3 is a perspective view showing a jig for evaluating a cushion in an assembled state according to an embodiment of the present application.

[0033] Figure 4 is a schematic view showing a shape in which a cushion has been fastened to a jig for evaluating a cushion according to an embodiment of the present application.

[0034] Figure 5 is an exploded perspective view showing the structure of a jig for evaluating a cushion according to another embodiment of the present application.

[0035] Figure 6 is a schematic view showing a shape in which a cushion has been fastened to a jig for evaluating a cushion according to another embodiment of the present application.

[0036] Figure 7 is an exploded perspective view showing the structure of a jig for evaluating a cushion according to another embodiment of the present application.

[0037] Figure 8 is a flowchart showing a flow of a method for evaluating a cushion according to the present application.

[0038] Figure 9 is a schematic view showing a process of adjusting a compression rate of a cushion in a method for evaluating a cushion according to the present application. DETAILED DESCRIPTION

[0039] Hereinafter, the present application will be described in detail with reference to the accompanying drawings. The terms and words used in the present specification and claims should not be interpreted as being limited to the commonly- used or dictionary definitions and the meanings of the terms and words should be construed as consistent with the technical idea of the present application. Accordingly, the terms and words should be interpreted based on the meanings and concepts of the present application presented herein.

[0040] In this application, it is to be understood that terms such as "including" or "having," are intended to be open-ended and also to permit for the presence of additional features or components in the described implementations. Furthermore, when referring to a part as being "on" another part, this is intended to mean that the part is either directly on the other part or is indirectly on the other part with additional intervening parts present. In another aspect, when referring to a part as being "under" another part, this is intended to mean that the part is either directly under the other part or is indirectly under the other part with additional intervening parts present. Also, "disposed on" in this application can include both bottom and top placement.

[0041] Hereinafter, the present application will be described in detail with reference to the accompanying drawings.

[0042] The present application relates to a jig for evaluating a cushion, and the jig includes a first plate located on one surface of the cushion and pressing the cushion, a second plate located on the other surface of the cushion and pressing the cushion from the other surface, and a magnet member located between the first and second plates, wherein a recess is formed at an edge of at least one of the first and second plates, the recess being recessed to allow the magnet member to be disposed.

[0043] As described above, in a battery module, a cushion is disposed between a module case and a battery cell or between battery cells accommodated in the module case, thereby protecting the battery cells in the module case from an impact or vibration from the outside of the module case. At this time, for dynamic structural analysis (such as vibration analysis and impact analysis) of the battery module, information on dynamic stiffness of such a cushion is necessary.

[0044] In the present application, the compression rate of a cushion inserted into a battery module can be easily adjusted by using a magnet member, thereby enabling dynamic stiffness corresponding to the compression rate to be evaluated. Furthermore, because the jig for evaluating a cushion according to the present application has a simple structure, the jig can be minimized in its influence when evaluating a cushion.

[0045] Hereinafter, the jig for evaluating a cushion according to the present application will be described in detail.

[0046] Figure 1 is a photograph showing the shape of a cushion.

[0047] In the present application, a cushion pad that becomes an evaluation object can be inserted into a battery module.

[0048] Specifically, a plurality of battery cells are accommodated in the battery module. Particularly, the battery cells can be pouch-type battery cells, and the pouch-type battery cells can include an electrode assembly, an electrolyte solution, and a pouch case. Here, the electrode assembly is an assembly of an electrode and a separator, and can be configured in a form in which one or more positive electrode plates and one or more negative electrode plates are disposed such that the separator is interposed between the positive electrode plates and the negative electrode plates. In addition, each of the electrode plates of the electrode assembly is provided with an electrode tab, and one or more electrode tabs can be connected to an electrode lead. In addition, the electrode lead is interposed between the pouch cases and one end thereof is exposed to the outside, and the exposed portion can be used as an electrode terminal of a secondary battery. The pouch case can accommodate the electrolyte solution together with the electrode assembly in an internal space. In addition, the pouch case can be configured in a form in which edge portions are sealed by a method such as heat fusion. The pouch case can be composed of an upper pouch and a lower pouch, and each of the pouches includes an outer insulating layer, a metal layer, and an inner adhesive layer such that the inner adhesive layers can be fused to each other.

[0049] The configuration of such a battery cell will be apparent to those skilled in the art to which the present application pertains, and thus a more detailed description thereof will be omitted. In addition, in the battery pack according to the present application, various battery cells known at the time of filing the present application can be employed.

[0050] A plurality of battery cells are mounted in a module case. The module case can be formed of a metal material having high mechanical strength and excellent heat conductivity.

[0051] Furthermore, in use, the battery module can be affected by various vibrations and impacts from the outside. In order to prevent the battery cells accommodated in the module case from being damaged by such vibrations and impacts, a cushion pad is interposed between the battery cells and the module case or between the battery cells.

[0052] Reference Figure 1 Such a cushion pad can contain a material including a soft elastic material such as silicon, polyurethane, or ethylene propylene diene rubber (EPDM). Particularly, a foam pad such as a polyurethane foam can be used as the cushion pad. Since such a material has excellent vibration absorption and compression resistance, the battery cells can be effectively protected against external impacts and vibrations. In addition, such a cushion pad can serve as a heat dissipation member when heat is generated from the battery cells.

[0053] Meanwhile, the jig for evaluating a cushion pad according to the present application includes a pair of pressing plates between which a cushion pad can be interposed.

[0054] In detail, the jig for evaluating a cushion according to the present application includes a first plate located on one surface of a cushion and pressing the cushion, and a second plate located on the other surface of the cushion and pressing the cushion from the other surface.

[0055] The first and second plates can be made of a metal material that responds to a magnet. In detail, the first and second plates can be made of one material selected from iron, nickel, and cobalt, and more particularly, the first and second plates can be made of iron.

[0056] Further, the area and thickness of the first and second plates can be appropriately designed according to the area and thickness of a target cushion. However, considering compression of the cushion, the area of the portion of the first and second plates that contacts the cushion is preferably greater than the area of the cushion. Further, the area and size of the first and second plates can be the same to simplify the structure of the jig and minimize the influence of the jig on evaluation. Here, the area and size of the plate mean the area and size of the outer periphery of the plate. For example, when the plate has a square shape, the width of the plate can be the same as the length of the plate.

[0057] Further, the first and second plates are fastened by a magnet member. That is, because in the jig for evaluating a cushion according to the present application, the plates are fastened using a magnet instead of a fastening member such as a bracket or a bolt, the structure is simple, and the influence of the jig on evaluation of the characteristics of the cushion can be minimized. Further, as will be described later, because the separation distance between the plates can be adjusted by adjusting the thickness of the magnet member, the compression rate of the cushion can be easily adjusted.

[0058] In the present application, the magnet member is located between the first and second plates, and a recess is formed at the edge of the first and second plates, the recess being recessed to allow the magnet member to be placed. More particularly, the recess is formed at the edge of the surface of the first and second plates that contacts the cushion. That is, the recess has a shape that is recessed from the end portion of the first and second plates toward the central portion to have a predetermined width. Similarly, by forming a recess at the portion where the magnet member is located, the magnet can be easily placed at an appropriate position.

[0059] The shape of the portion of the magnet member contacting the recess corresponds to the shape of the recess to allow the magnet member to be closely attached to the recess. Here, the fact that the shape of the portion contacting the recess corresponds to the shape of the recess means that the cross-sectional shape of the recess is the same as the cross-sectional shape of the magnet member. For example, when the magnet member has a cubic shape, the cross-sectional shape of the recess also has a cubic shape, and if the magnet member has a cylindrical shape, the recess can also be recessed in a curved surface shape to have the same curvature radius as the curvature radius of the cylinder.

[0060] In one example, the recess is formed at a partial region of the edge of the first or second plate. Here, the partial region of the edge means a portion of the edge region formed along the periphery of the first or second plate. At this time, for stable fastening, the recess can be symmetrically formed based on the central portion of the plate. For example, when the first or second plate has a quadrangular shape, the recess can be formed on two sides facing each other.

[0061] At this time, the length and width of the portion of the first or second plate in which the recess has been formed correspond to the length and width of the magnet member. That is, the recess can be formed only on the portion of the plate contacting the magnet member, and the magnet member can be set to be closely attached to the inner wall of the recess. However, the present application is not limited to this example, and the area of the magnet member can be smaller than the area of the recess.

[0062] In one example, the recess can be formed at the first and second plates, respectively. That is, the first and second plates can have the same shape, and the clamp has a vertically symmetrical structure. The magnet member is interposed between the recess formed at the first plate and the recess formed at the second plate. Similarly, because only one type of plate can be manufactured by using the same shape for the first and second plates, the manufacturing process of the plate and the fastening structure of the plate can be simplified.

[0063] Similarly, when the recess is formed at the first and second plates, respectively, the thickness of the magnet member is preferably greater than the sum of the depth of the recess formed at the first plate and the depth of the recess formed at the second plate. This is to prepare a space in which a cushion pad can be interposed between the first and second plates. As will be described later, by adjusting the thickness of the magnet member, the compression rate of the cushion pad can be adjusted by adjusting the thickness of the space formed between the first and second plates.

[0064] Further, the present application is not limited thereto, and in another example, the recess can be formed at either of the first and second plates. In this case, the plate in which the recess is not formed can have a flat shape on the surface on which no convex-concave portion is formed.

[0065] Similarly, when the recess is formed on either of the first and second plates, the thickness of the magnet member is preferably greater than the depth of the recess formed on either of the first and second plates. This is to make a space in which the cushion pad can be interposed between the first and second plates. As will be described later, by adjusting the thickness of the magnet member, the compression rate of the cushion pad can be adjusted by adjusting the thickness of the space formed between the first and second plates.

[0066] In another example, the recess is formed in the entire area of the edge of the first or second plate. That is, the recess can be formed on the entire edge area formed along the periphery of the first or second plate. Similarly, by forming a recess at the entire area of the edge of the plate and interposing the magnet member, the fastening force between the first and second plates can be improved, and the plate can be prevented from being separated from the magnet member during the evaluation process. For example, when the first and second plates have a quadrangular shape, the recess can be formed on all four sides of the first or second plate.

[0067] At this time, the width of the portion of the first or second plate in which the recess has been formed can correspond to the width of the magnet member. The recess can be formed only on the portion of the plate that contacts the magnet member, and the magnet member can be set to be closely attached to the inner wall of the recess. However, the present application is not limited to this example, and the area of the magnet member can be smaller than the area of the recess.

[0068] Further, as described above, a space in which the cushion pad can be interposed is formed between the first plate, the second plate, and the magnet member. At this time, the thickness of the internal space enclosed by the first plate, the second plate, and the magnet member can be equal to or less than the thickness of the target cushion pad. This is to allow the cushion pad to be compressed in the space. When the thickness of the internal space is the same as the thickness of the cushion pad, the cushion pad can be evaluated in a state in which the cushion pad is not compressed, and when the thickness of the internal space is less than the thickness of the cushion pad, the cushion pad can be evaluated in a state in which the cushion pad has been compressed.

[0069] Further, an area of a horizontal cross section of an internal space surrounded by the first plate, the second plate, and the magnet member can be equal to or greater than an area of the target cushion. Here, the area of the horizontal cross section means an area of a cross section in a direction perpendicular to a stacking direction of the first plate and the second plate. Similarly, by setting the area of the horizontal cross section of the internal space surrounded by the first plate, the second plate, and the magnet member to correspond to or be greater than the area of the cushion, it is possible to accommodate a portion whose area has increased when the area increases. For example, when the cushion, the first plate, and the second plate have a quadrangular shape, a width and a length of the space formed by the first plate, the second plate, and the magnet member can be the same as or greater than a width and a length of the cushion.

[0070] Further, the present application provides a method of evaluating a cushion, and the method includes: preparing the jig for evaluating a cushion described above; placing a cushion between the first plate and the second plate and placing a magnet member in the recess, thereby fastening the first plate to the second plate; and measuring a dynamic stiffness of the cushion.

[0071] First, a jig for evaluating a cushion as described above is prepared. The jig includes: a first plate that is located on one surface of the cushion and presses the cushion; a second plate that is located on the other surface of the cushion and presses the cushion from the other surface; and a magnet member that is located between the first plate and the second plate, wherein a recess is formed at an edge of at least one of the first plate and the second plate, the recess being recessed to allow the magnet member to be placed therein.

[0072] When the jig for evaluating a cushion is prepared, a cushion is placed between the first plate and the second plate, and a magnet member is placed in the recess, thereby fastening the first plate to the second plate.

[0073] Thereafter, a dynamic stiffness of the cushion is measured. The dynamic stiffness means a degree of resistance to displacement of a simple harmonic motion at an arbitrary point of a dynamic system. Here, the simple harmonic motion includes a general vibration motion and the like.

[0074] In order to measure the dynamic stiffness of the cushion, a predetermined impact or vibration is applied to the cushion, and a degree of displacement and a degree of resistance to displacement at each point of the cushion are measured. At this time, in order to prevent interference of the ground with the cushion, it is preferable to perform a test in a state in which the cushion is suspended.

[0075] Further, the dynamic stiffness of the cushion varies depending on a compression rate of the cushion. Therefore, in the present application, the step of measuring the dynamic stiffness includes a process of measuring the dynamic stiffness according to the compression rate of the cushion by changing the compression rate of the cushion.

[0076] Specifically, the compression rate of the cushion is adjusted by the thickness of the magnet member. For example, the thickness of the internal space formed between the first plate, the second plate, and the magnet member can be reduced by reducing the thickness of the magnet member, thereby increasing the compression rate of the cushion. Also, the thickness of the internal space formed between the first plate, the second plate, and the magnet member can be increased by increasing the thickness of the magnet member, thereby reducing the compression rate of the cushion. That is, the dynamic stiffness can be measured in a state in which the cushion has been compressed.

[0077] Similarly, in the present invention, the compression rate of the cushion inserted into the battery module can be easily adjusted by using the magnet member, whereby the dynamic stiffness according to the compression rate can be evaluated. Also, because the jig for evaluating the cushion according to the present invention has a simple structure, the influence of the jig can be minimized when the cushion is evaluated.

[0078] Because the inventive concept allows for various changes and multiple embodiments, a specific embodiment will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the disclosed specific form, and this should be understood as including all changes, equivalents, and alternatives included in the spirit and scope of the present invention.

[0079] (First Embodiment)

[0080] Figure 2 is an exploded perspective view showing the structure of a jig for evaluating a cushion according to an embodiment of the present invention, and Figure 3 is a perspective view showing a jig for evaluating a cushion in an assembled state according to one embodiment of the present invention. Figure 4 is a schematic view showing the shape of a jig for evaluating a cushion according to an embodiment of the present invention to which a cushion has been fastened.

[0081] Referring to Figures 2 to 4 , a jig 10 for evaluating a cushion according to the present invention includes a first plate 11 located on one surface of a cushion 15 and pressing the cushion 15, a second plate 12 located on the other surface of the cushion 15 and pressing the cushion 15 from the other surface, and a magnet member 13 located between the first plate 11 and the second plate 12. The first plate 11 and the second plate 12 can be made of a metal material that responds to a magnet.

[0082] A magnet member 13 for fastening the first plate 11 to the second plate 12 is located between the first plate 11 and the second plate 12. Further, a recess 14 is formed at an edge of at least one of the first plate 11 and the second plate 12, the recess 14 being recessed to allow the magnet member to be placed.

[0083] A portion of the magnet member 13 contacting the recess 14 has a shape corresponding to that of the recess 14 to be completely attached to the recess 14. Referring to Figures 2 to 4 , a cross section of the magnet member 13 has a quadrangular shape, and accordingly a cross section of the recess 14 is also shown to have a quadrangular shape.

[0084] The recess 14 is formed at a partial area of an edge of the first plate 11 or the second plate 12. Further, the recess 14 is formed at the first plate 11 and the second plate 12, respectively. In Figure 2 and Figure 3 , among four sides of the first plate 11 and the second plate 12 having a quadrangular shape, the recess 14 is formed on two sides facing each other. At this time, a length (l1) and a width (w1) of the first plate 11 and the second plate 12, on which the recess 14 has been formed, correspond to a length (l2) and a width (w2) of the magnet member 13. Further, in order to make a space capable of placing the cushion 15 between the first plate 11 and the second plate 12, a thickness (t) of the magnet member 13 is greater than a sum of a depth (h1) of the recess formed on the first plate 11 and a depth (h2) of the recess 14 formed on the second plate 12.

[0085] Further, referring to Figure 4 , the cushion 15 is placed in an inner space between the first plate 11, the second plate 12, and the magnet member 13. At this time, a thickness of the inner space can be equal to or less than a thickness of the target cushion 15, and an area of a horizontal cross section of the inner space can correspond to or be greater than an area of the cushion 15.

[0086] (Second Embodiment)

[0087] Figure 5 is an exploded perspective view showing a structure of a jig for evaluating a cushion according to another embodiment of the present application, and Figure 6 is a schematic view showing a shape in which a cushion has been fastened to the jig for evaluating a cushion according to another embodiment of the present application.

[0088] Referring to Figure 5 and Figure 6, The jig 20 for evaluating a cushion according to the present application includes a first plate 21 located on one surface of a cushion 25 and pressing the cushion 25, a second plate 22 located on the other surface of the cushion 25 and pressing the cushion 25 from the other surface, and a magnet member 23 located between the first and second plates 21 and 22. Further, a recess 24 recessed to allow the magnet member 23 to be placed is formed at an edge of at least one of the first and second plates 21 and 22.

[0089] Referring to Figure 5 and Figure 6 , the recess 24 is formed at a partial area of the first or second plate 21 and 22. For example, the recess 24 is formed on both sides facing each other in the side edges of the first and second plates 21 and 22. Further, the recess 24 is formed at one of the first and second plates 21 and 22. Referring to Figure 5 and Figure 6 , the recess 24 is formed only on the first plate 21. In order to prepare a space in which the cushion 25 can be placed between the first and second plates 21 and 22, the thickness (t) of the magnet member 23 can be greater than the depth (h) of the recess 24 formed on the first plate 21.

[0090] Further, referring to Figure 6 , the cushion is placed in an inner space between the first plate 21, the second plate 22, and the magnet member 23. At this time, the thickness of the inner space can be equal to or less than the thickness of the target cushion 25, and the area of the horizontal cross section of the inner space can correspond to or be greater than the area of the cushion 25.

[0091] (third embodiment)

[0092] Figure 7 is an exploded perspective view showing the structure of a jig for evaluating a cushion according to another embodiment of the present application.

[0093] Referring to Figure 7 , the jig 30 for evaluating a cushion according to the present application includes a first plate 31 located on one surface of a cushion (not shown) and pressing the cushion, a second plate 32 located on the other surface of the cushion and pressing the cushion from the other surface, and a magnet member 33 located between the first and second plates 31 and 32. Further, a recess 34 recessed to allow the magnet member 33 to be placed is formed at an edge of at least one of the first and second plates 31 and 32.

[0094] Referring to Figure 7 , the recess 34 is formed at the entire area of the edge of the first plate 31 or the second plate 32. For example, the recess 34 is formed on all four sides of the first plate 31 and the second plate 32. Further, Figure 7 The recess 34 formed in the first plate 31 and the second plate 32 is shown.

[0095] Referring to Figure 7 , the magnet member 33 is configured to be placed in the entire recessed area, or can be integrally formed, and can also be placed in the area as a plurality of magnet members as shown in Figure 7 At this time, the width of the portion of the first plate 31 and the second plate 32 in which the recess 34 has been formed corresponds to the width of the magnet member 33.

[0096] (Fourth Embodiment)

[0097] Figure 8 is a flowchart showing the flow of a method for evaluating a cushion according to the present application.

[0098] Referring to Figure 8 , the method of evaluating a cushion includes preparing the jig for evaluating a cushion described above (S10), placing the cushion between the first plate and the second plate and placing a magnet member in the recess, thereby fastening the first plate to the second plate (S20), and measuring the dynamic stiffness for the cushion (S30).

[0099] Figure 9 is a schematic diagram showing the process of adjusting the compression rate of a cushion in the method of evaluating a cushion according to the present application.

[0100] Referring to Figure 9 , the cushion 15 is placed in the space between the first plate 11 and the second plate 12 constituting the jig 10 for evaluating a cushion. Thereafter, if the magnet member 13 is placed on the recess 14, the cushion 15 is compressed by applying a force to the first plate 11 and the second plate 12. In this state, the jig 10 for evaluating a cushion is suspended, and the dynamic stiffness of the cushion 15 is measured.

[0101] At this time, the measurement of the dynamic stiffness includes measuring the dynamic stiffness according to the compression rate of the cushion 15 by changing the compression rate of the cushion 15.

[0102] In particular, referring to Figure 9 , the compression rate is adjusted by the thickness of the magnet member 13. Figure 9 (a) shows a case where the compression rate of the cushion 15 is increased by reducing the thickness (t1) of the magnet member 13,Figure 9 (b) shows a case where the compressibility of the cushion 15 is reduced by increasing the thickness (t2) of the magnet member 13.

[0103] The above description merely illustrates the technical idea of the present application, and those skilled in the art to which the present application pertains can make various modifications and changes without departing from the essential characteristics of the present application. Accordingly, the drawings disclosed in the present application are not intended to limit the technical idea of the present application, but to describe the present application, and the scope of the technical idea of the present application is not limited by these drawings. The scope of protection of the present application should be interpreted by the appended claims, and all technical ideas within the scope equivalent thereto should be understood to be included in the scope of the present application.

[0104] In another aspect, in this specification, terms indicating directions such as up, down, left, right, front, and back are used, but it is obvious that these terms are only for convenience of description, and can be changed according to the position of the object or the position of the observer.

Claims

1. A fixture for evaluating the performance of a cushioning pad based on its compression ratio, the fixture comprising: A first plate is positioned on one surface of the cushioning pad and compresses the cushioning pad. A second plate is located on another surface of the cushioning pad and presses the cushioning pad from that other surface; and A magnet component, located between the first plate and the second plate. Recesses are formed at the edges of the first plate and the second plate, respectively, and these recesses are recessed to allow the placement of the magnet component. The thickness of the space formed between the first and second plates is adjusted by adjusting the thickness of the magnet component, thereby adjusting the compression ratio of the buffer pad. The thickness of the magnet component is greater than the sum of the depth of the recess formed in the first plate and the depth of the recess formed in the second plate.

2. The clamp according to claim 1, wherein, The first plate and the second plate are made of a metallic material responsive to a magnet, and the first plate and the second plate have the same area and size.

3. The clamp according to claim 1, wherein, The shape of the portion of the magnet component that contacts the recess corresponds to the shape of the recess, so as to allow the magnet component to be tightly attached to the recess.

4. The clamp according to claim 1, wherein, The recess is formed in a local area at the edge of the first plate or the second plate, and is formed symmetrically based on the central portion of the plate.

5. The clamp according to claim 4, wherein, The length and width of the portion of the first or second plate where the recess has been formed correspond to the length and width of the magnet component.

6. A fixture for evaluating the performance of a cushioning pad based on its compression ratio, the fixture comprising: A first plate is positioned on one surface of the cushioning pad and compresses the cushioning pad. A second plate is located on another surface of the cushioning pad and presses the cushioning pad from that other surface; and A magnet component, located between the first plate and the second plate. Wherein, a recess is formed at the edge of one of the first plate and the second plate, the recess being recessed to allow placement of the magnet component, and the thickness of the magnet component being greater than the depth of the recess; The compression ratio of the buffer pad is adjusted by adjusting the thickness of the magnet component to adjust the thickness of the space formed between the first plate and the second plate.

7. The clamp according to claim 1, wherein, The recess is formed over the entire area of ​​the edge of the first plate or the second plate.

8. The clamp according to claim 7, wherein, The width of the portion of the first or second plate where the recess has been formed corresponds to the width of the magnet component.

9. The clamp according to claim 1, wherein, The thickness of the internal space surrounded by the first plate, the second plate, and the magnet component is equal to or less than the thickness of the target buffer pad.

10. The clamp according to claim 1, wherein, The area of ​​the horizontal cross-section of the internal space surrounded by the first plate, the second plate, and the magnet component is equal to or greater than the area of ​​the target buffer pad.

11. A method for evaluating a cushioning pad, the method comprising: Prepare a fixture according to any one of claims 1-10 for evaluating the performance based on the compression rate of the cushioning pad; A buffer pad is placed between the first plate and the second plate, and a magnet component is placed in the recess, thereby securing the first plate to the second plate. and Measure the dynamic stiffness of the buffer pad.

12. The method according to claim 11, wherein, Measuring the dynamic stiffness includes changing the compression ratio of the cushioning pad and measuring the dynamic stiffness based on the compression ratio of the cushioning pad.

13. The method according to claim 12, wherein, The compression ratio of the buffer pad is adjusted by the thickness of the magnet component.

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