Compression elastic body

Abstract

This suppresses variations in the maximum and minimum reaction forces generated at protrusions in manufactured pressurized elastic bodies. [Solution] The pressurized elastic body 1 is formed from an elastic material and comprises a base portion 2 extending along a plane and a plurality of protrusions 3 projecting from the base portion 2. The number of design factors for the reaction force generated by the protrusions 3 in the shape of the base portion 2 and the protrusions 3 is less than 6.

Description

Technical Field

[0001] The present invention relates to a pressurizing elastic body, and particularly to a pressurizing elastic body used for pressurizing battery cells. Background Art

[0002] For example, batteries are used in electric vehicles (EV) and hybrid electric vehicles (HEV). Battery performance degrades after long-term use. For example, the precipitation of dendrites degrades battery performance. Conventionally, in order to suppress this performance degradation, configurations for pressurizing battery cells have been proposed. For example, it has been considered that by using an elastic body conventionally used as a cushioning material between adjacent cells (see, for example, Patent Document 1) as a pressurizing elastic body, the cells are pressurized and battery degradation is suppressed. Prior Art Literature Patent Literature

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 2022-119556 Summary of the Invention Problem to be Solved by the Invention

[0004] A conventional cushioning material has a plate-shaped base portion and a plurality of protruding portions protruding from the plate-shaped base portion, and is attached to a battery such that the protruding portions contact the cells. When a conventional cushioning material is used as a pressurizing elastic body, the protruding portions serve as pressurizing portions that contact the cells. Battery cells expand and contract during charge and discharge. Therefore, when charge and discharge are repeated, the cells repeatedly expand and contract. The plurality of protruding portions of the pressurizing elastic body are compressed by the cells that repeatedly expand and contract, the reaction force generated in the protruding portions fluctuates between a maximum reaction force and a minimum reaction force, and the protruding portions pressurize the cells between the maximum reaction force and the minimum reaction force.

[0005] If the reaction force of the protrusion is too large, it may damage the cell or battery casing. On the other hand, if the reaction force of the protrusion is too small, the function of preventing cell degradation may be reduced. For this reason, it is desirable that the difference between the maximum and minimum reaction forces of the protrusion of the compressed elastic body be small. Also, if there is variation in the dimensions of the protrusion that affect the reaction force of the protrusion, such as its height, the reaction force of the protrusion will vary accordingly. For this reason, if there is a large variation in the dimensions that affect the reaction force of the protrusion, the maximum and minimum reaction forces of the protrusion will vary, and the difference between the maximum and minimum reaction forces of the protrusion will be large.

[0006] Thus, for conventional pressurized elastic bodies, there is a need for a configuration that can prevent variations in the maximum and minimum reaction forces generated at the protrusions in the manufactured pressurized elastic body.

[0007] The present invention has been made in view of the above-mentioned problems, and its object is to provide a pressurized elastic body that can suppress variations in the maximum and minimum reaction forces generated at protruding parts in a manufactured pressurized elastic body. [Means for solving the problem]

[0008] To achieve the above objective, the pressurized elastic body according to the present invention is a pressurized elastic body formed from an elastic material, comprising a base portion which extends along a plane, and a plurality of protrusions which are portions which protrude from the base portion, wherein the number of design factors for the reaction force generated by the protrusions in the shape of the base portion and the protrusions is less than 6.

[0009] In a pressurized elastic body according to one aspect of the present invention, the variation in reaction force generated by the protrusion is within 14%.

[0010] In a pressurized elastic body according to one aspect of the present invention, the number of design factors is 3.

[0011] In a pressurized elastic body according to one aspect of the present invention, the design factor is a design factor in the shape of the cross-section of the base and the protrusion, based on a plane along the direction in which the protrusion protrudes.

[0012] In a pressurized elastic body according to one aspect of the present invention, the protrusion is annular, and the design factors are the height of the protrusion, the thickness of the base, and the diameter of the portion of the base that the protrusion surrounds on the inner circumference.

[0013] In a pressurized elastic body according to one aspect of the present invention, the contour of the protruding portion in the cross-section follows a circle.

[0014] In a pressurized elastic body according to one aspect of the present invention, the contour of the protruding portion in the cross-section is a semicircle.

[0015] In a pressurized elastic body according to one aspect of the present invention, the protrusion extends along a circle, and the outer peripheral end of the portion of the base surrounded by the protrusion on the inner circumference is also along a circle.

[0016] In a pressurized elastic body according to one aspect of the present invention, the thickness of the base is constant.

[0017] In a pressurized elastic body according to one aspect of the present invention, the base portion has a pair of surfaces facing away from each other, and the protruding portion has a first portion which is a part that protrudes from one of the pair of surfaces and a second portion which is a part that protrudes from the other of the pair of surfaces, and the first portion and the second portion are symmetrical with respect to each other.

[0018] In one aspect of the present invention, a pressurized elastic body is used in a battery to pressurize cells. [Effects of the Invention]

[0019] According to the present invention, the pressure-sensitive elastic body can suppress variations in the maximum and minimum reaction forces generated at the protruding portion of the manufactured pressure-sensitive elastic body. [Brief explanation of the drawing]

[0020] [Figure 1] This is a schematic perspective view showing a compressible elastic body according to an embodiment of the present invention. [Figure 2] It is a perspective view schematically showing the pressure elastic body according to an embodiment of the present invention. [Figure 3] It is a front view of the pressure elastic body. [Figure 4] It is a rear view of the pressure elastic body. [Figure 5] It is a cross-sectional view showing a cross-section taken along line A-A of FIG. 3. [Figure 6] It is a partially enlarged cross-sectional view showing a partial enlargement of FIG. 5. [Figure 7] It is a diagram schematically showing the pressure elastic body in a use state where the pressure elastic body is attached to a battery. [Figure 8] It is a partially enlarged cross-sectional view of the protrusion for explaining the protrusion in a compressed state. [Figure 9] It is a partially enlarged cross-sectional view of a pressure elastic body as a comparative example. MODE FOR CARRYING OUT THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that in the drawings, reference numerals are not attached to all of the plurality of constituent elements, and reference numerals for some of the plurality of constituent elements may be omitted.

[0022] FIGS. 1 and 2 are perspective views schematically showing a pressure elastic body 1 according to an embodiment of the present invention, FIG. 3 is a front view of the pressure elastic body 1, and FIG. 4 is a rear view of the pressure elastic body 1. Further, FIG. 5 is a cross-sectional view showing a cross-section taken along line A-A of FIG. 3. Further, FIG. 6 is a partially enlarged cross-sectional view showing a partial enlargement of FIG. 5. Note that FIGS. 1 and 2 respectively show the pressure elastic body 1 viewed from the front side and the rear side. As will be described later, the pressure elastic body 1 is used, as an example, for pressurizing battery cells. Note that the application target to which the pressure elastic body according to the present invention is applied is not limited to batteries. The application target of the pressure elastic body according to the present invention includes other application targets.

[0023] The pressurized elastic body 1 is formed from an elastic material and, as shown in Figures 1 to 6, comprises a base portion 2 that extends along a plane and a plurality of protrusions 3 that protrude from the base portion 2. The number of design factors for the reaction force generated by the protrusions 3 in the shape of the base portion 2 and the protrusions 3 is less than 6. The configuration of the pressurized elastic body 1 will be described in detail below.

[0024] Specifically, the design factors are the dimensions of the base 2 and the protruding portion 3 that affect the magnitude of the reaction force generated in the compressed protruding portion 3 when the pressurized elastic body 1 is in use, as described later. The design factors are, for example, the dimensions of the cross-sectional shape of the base 2 and the protruding portion 3. The design factors are, for example, the design factors of the cross-sectional shape of the base 2 and the protruding portion 3 as defined by the plane along the direction in which the protruding portion 3 protrudes.

[0025] As shown in Figures 1-6, the base portion 2 specifically has a surface 31 and a back surface 32, which are a pair of surfaces facing away from each other, and is plate-shaped. Also, as shown in Figures 3 and 4, for example, the base portion 2 is rectangular or substantially rectangular, and the surface 31 and back surface 32 are also rectangular or substantially rectangular. Note that the shape of the base portion 2 is not limited to a rectangle and can be various shapes depending on the form of the application. The surface 31 and back surface 32 extend, for example, along a plane perpendicular to the axis x, which will be described later. Specifically, the surface 31 and back surface 32 are surfaces that extend on a plane perpendicular to the axis x or a substantially plane perpendicular to the axis x. The base portion 2 also has an end 2a. The end 2a is the circumferential end of the base portion 2 and is a surface facing the outer periphery that extends between the end of the surface 31 and the end of the back surface 32.

[0026] As described above, the pressurized elastic body 1 has a plurality of protrusions 3, and as shown in Figures 1 to 4, the plurality of protrusions 3 are arranged in a line, for example, to form a plurality of rows. For example, as shown in Figures 3 and 4, the plurality of protrusions 3 are arranged at equal or approximately equal intervals from one another, and the plurality of rows formed by the plurality of protrusions 3 each extend in parallel from one another and also extend along the end 2a of the base 2. Note that the plurality of protrusions 3 do not have to be aligned as described above, and may be arranged irregularly.

[0027] The number of design factors for the pressurized elastic body 1 is, for example, 3. Furthermore, the design factors for the pressurized elastic body 1 are, for example, design factors for the cross-sectional shape of the base 2 and the protruding portion 3, based on a plane along the direction in which the protruding portion 3 protrudes. Specifically, for example, the protruding portion 3 is annular, and the design factors for the pressurized elastic body 1 are the height of the protruding portion 3, the thickness of the base 2, and the diameter of the inner membrane portion 33. The inner membrane portion 33 is the part of the base 2 that the protruding portion 3 surrounds on the inner circumference, as shown in Figures 1-6.

[0028] As shown in Figures 1-6, each projection 3 is, for example, annular around axis x. Axis x is the axis of each projection 3 and is an imaginary straight line. The projection 3 extends along a circle, and therefore, as shown in Figures 3-6, the outer peripheral ends 34 and 35 of the inner membrane portion 33 each extend along a circle. The outer peripheral ends 34 and 35 of the inner membrane portion 33 are the outer peripheral ends of the inner membrane portion 33, respectively. Outer peripheral end 34 is the outer peripheral end of the inner membrane portion 33 on the surface 31, while outer peripheral end 35 is the outer peripheral end of the inner membrane portion 33 on the back surface 32. Specifically, the projection 3 extends along a circle centered on axis x. As an example, the projection 3 extends on a circle centered on axis x.

[0029] Each projection 3 also has a first portion 10 and a second portion 20. The projection 3 protrudes from the surface 31 of the base 2 toward one direction in the axial x direction, and also protrudes from the back surface 32 of the base 2 toward the other direction in the axial x direction. In the projection 3, the portion that protrudes toward the front side from the surface 31 of the base 2 is the first portion 10, while the portion that protrudes toward the back side from the back surface 32 of the base 2 is the second portion 20. In the axial x direction, the side that the surface 31 of the base 2 faces is the front side, and the side that the back surface 32 of the base 2 faces is the back side. The first portion 10 and the second portion 20 are symmetrical or substantially symmetrical with respect to each other in the axial x direction. Specifically, the first portion 10 and the second portion 20 are symmetrical or substantially symmetrical with respect to each other with respect to the surface 31 or the back surface 32.

[0030] As shown in Figures 3, 5, and 6, in each projection 3, the first portion 10 forms the front side of the projection 3 and is annular around axis x. As shown in Figures 3, 5, and 6, the first portion 10 has a convex surface 11 facing the front side. The convex surface 11 is the surface of the first portion 10 and is an annular surface that projects outward from the surface 31 of the base 2. As shown in Figures 3, 5, and 6, the convex surface 11 extends, for example, along a circle. Specifically, the convex surface 11 extends along a circle centered on axis x. As an example, the convex surface 11 extends on a circle centered on axis x.

[0031] As shown in Figure 6, the contour of the projection 3 in cross-section follows a circle. Specifically, as shown in Figure 6, in the cross-section of the projection 3 by the plane containing axis x, the convex surface 11 follows a circle. For example, in the cross-section of the projection 3 by the plane containing axis x, the convex surface 11 extends along a circle or approximately a circle. As an example, in the cross-section of the projection 3 by the plane containing axis x, the convex surface 11 forms a semicircle or approximately a semicircle.

[0032] Furthermore, as shown in Figure 6, the first part 10 has an inner circumference end 12, which is the inner circumference end, and an outer circumference end 13, which is the outer circumference end. The inner circumference end 12 and the outer circumference end 13 are the inner circumference end and the outer circumference end of the convex surface 11, respectively, and are the parts in which the convex surface 11 connects to the surface 31 of the base 2. The inner circumference side is inward in the radial direction, which is perpendicular to the axis x direction, and the outer circumference side is outward in the radial direction. As an example, the shape of the inner circumference end 12 and the outer circumference end 13 are circles or approximately circles centered on the axis x. Also, the height h1 of the first part 10 is set to a predetermined value. The height h1 is the height of the first part 10 in the axial x direction, as shown in Figure 6, and is the distance in the axial x direction between the vertex 11a of the convex surface 11 and the surface 31 of the base 2. The vertex 11a of the convex surface 11 is the part of the convex surface 11 that is located on the front side in the axial x direction.

[0033] For example, as shown in Figure 6, the inner circumferential end 12 is connected to the surface 31 of the base 2 via a transition surface 14. Similarly, for example, the outer circumferential end 13 is connected to the surface 31 via a transition surface 15. The transition surfaces 14 and 15 are annular surfaces that smoothly connect the convex surface 11 and the surface 31, respectively. Note that the first part 10 does not necessarily have transition surfaces 14 and 15. In this case, the convex surface 11 is connected to the surface 31 at both the inner circumferential end 12 and the outer circumferential end 13.

[0034] As shown in Figure 6, the first part 10 surrounds the inner membrane surface 36, which is the portion of the surface 31 of the inner membrane portion 33, on its inner circumference side. The outer peripheral end 36a of the inner membrane surface 36 is connected to the inner peripheral end 12 of the convex surface 11 via a transition surface 14. The outer peripheral end 36a is the outer peripheral end 34 of the inner membrane portion 33 described above. If the first part 10 does not have a transition surface 14, the outer peripheral end 36a of the inner membrane surface 36 is connected to the inner peripheral end 12 of the convex surface 11. The outer peripheral end 36a of the inner membrane surface 36 has a shape corresponding to the inner peripheral end 12 of the convex surface 11, and for example, extends parallel or approximately parallel to the inner peripheral end 12 of the convex surface 11. As an example, the shape of the outer peripheral end 36a of the inner membrane surface 36 is a circle or approximately a circle centered on axis x. Also, the diameter R1, which is the diameter of the outer peripheral end 36a of the inner membrane surface 36, is a predetermined value. Note that diameter R1 is the width of the outer edge 36a in the radial direction.

[0035] As described above, in the protruding portion 3, the first portion 10 and the second portion 20 are mutually symmetrical or substantially symmetrical, and the second portion 20 has corresponding configurations that are mutually symmetrical or substantially symmetrical to each configuration of the first portion 10. In other words, the second portion 20 has a convex surface 21, a vertex 21a, an inner circumferential end 22, an outer circumferential end 23, and transition surfaces 24, 25, which correspond to the convex surface 11, vertex 11a, inner circumferential end 12, outer circumferential end 13, and transition surfaces 14, 15 of the first portion 10, respectively. The second portion 20 is the same as or substantially the same as the first portion 10, but with a different orientation in which it protrudes from the base portion 2.

[0036] The height h2 of the second part 20 is set to a predetermined value, similar to the height h1 of the first part 10. Note that height h2 is the height of the second part 20 in the axial x direction, as shown in Figure 6, and is the distance in the axial x direction between the vertex 21a of the convex surface 21 and the back surface 32 of the base 2. The vertex 21a of the convex surface 21 corresponds to the vertex 11a of the convex surface 11, as described above, and is the part of the convex surface 21 located on the back side in the axial x direction. The height h2 of the second part 20 is the same as or approximately the same as the height h1 of the first part 10.

[0037] Furthermore, as shown in Figure 6, the second portion 20 surrounds the inner membrane surface 37, which is the back surface 32 portion of the inner membrane portion 33, on its inner circumferential side. The outer peripheral end 37a of the inner membrane surface 37 is connected to the inner circumferential end 22 of the convex surface 21 via a transition surface 24. The outer peripheral end 37a is the outer peripheral end 35 of the inner membrane portion 33 described above. If the second portion 20 does not have a transition surface 24, the outer peripheral end 37a of the inner membrane surface 37 is connected to the inner circumferential end 22 of the convex surface 21. The outer peripheral end 37a of the inner membrane surface 37 has a shape corresponding to the inner circumferential end 22 of the convex surface 21, and for example, extends parallel or approximately parallel to the inner circumferential end 22 of the convex surface 21. As an example, the shape of the outer peripheral end 37a of the inner membrane surface 37 is a circle or approximately a circle centered on axis x. The diameter R2, which is the diameter of the outer peripheral end 37a of the inner membrane surface 37, is a predetermined value. Note that diameter R2 is the width of the outer peripheral edge 37a in the radial direction. The inner membrane surfaces 37 and 36 are also mutually symmetrical or substantially symmetrical in the axial x direction, similar to the first part 10 and the second part 20, and the diameter R2 of the inner membrane surface 37 is the same as or substantially the same as the diameter R1 of the inner membrane surface 36. For this reason, in the following description, diameter R1 will include the diameter R2 of the inner membrane surface 37.

[0038] As shown in Figure 6, the thickness T1 of the inner membrane portion 33 is constant or approximately constant throughout the entire inner membrane portion 33. Note that the thickness T1 is the distance between the inner membrane surfaces 36 and 37 in the axial x-direction. The inner membrane portion 33 is formed by a part of the base portion 2, and the thickness of the base portion 2 is the same as the thickness T1 of the inner membrane portion 33. Furthermore, the thickness T1 of the base portion 2 is, for example, uniform or approximately uniform throughout.

[0039] As shown in Figure 6, the height H1 of the protrusion 3 is a predetermined value. The height H1 is the height of the protrusion 3 in the axial x direction, as shown in Figure 6, and is the distance in the axial x direction between the vertex 11a of the convex surface 11 of the first part 10 and the vertex 21a of the convex surface 21 of the second part 20. In other words, the height H1 of the protrusion 3 is the sum of the height h1 of the first part 10, the height h2 of the second part 20, and the thickness T1 of the connecting part 38 (H1 = h1 + h2 + T1). The connecting part 38 is the part of the base 2 located between the first part 10 and the second part 20 in the axial x direction.

[0040] As shown in Figure 6, the first part 10 defines a hollow space 16 on its inner circumference, and similarly, the second part 20 defines a hollow space 26 on its inner circumference. Specifically, the hollow space 16 is the space defined by the first part 10 and the inner membrane 33, and specifically, the hollow space 26 is the space defined by the second part 20 and the inner membrane 33. Like the first part 10 and the second part 20, the hollow spaces 16 and 26 are symmetrical or nearly symmetrical in the axial x direction, are the same or nearly the same as each other, and have different opening directions.

[0041] The pressurized elastic body 1 has the above-described structure. As described above, the pressurized elastic body 1 is formed from an elastic material. The elastic material used to make the pressurized elastic body 1 is, for example, an elastomer, such as rubber or resin. Specifically, the elastic material used to make the pressurized elastic body 1 is, for example, ethylene propylene rubber (EPDM) or silicone rubber. Furthermore, the pressurized elastic body 1 is formed integrally from the same elastic material. That is, the base 2 and the multiple protrusions 3 are part of the integrally formed pressurized elastic body 1, and the multiple protrusions 3 and the base 2 are integrated. However, the pressurized elastic body 1 does not have to be formed integrally from the same elastic material. For example, the base 2 may be formed from a different material than the material of the protrusions 3. The base 2 may be formed separately from the protrusions 3, and the first part 10 and the second part 20 of the protrusions 3 may be connected to the base 2 by fixing means such as adhesive. Alternatively, the base 2 may be created first, and then the multiple protrusions 3 may be integrally molded to form the pressurized elastic body 1. Furthermore, the material of the base 2 does not have to be an elastic material.

[0042] Next, the operation of the pressurized elastic body 1 having the above-described configuration will be explained in detail. As described above, the pressurized elastic body 1 is applied to the housing that supports the battery cells in order to pressurize the battery cells, as an example. Figure 7 is a schematic diagram showing the pressurized elastic body 1 in a state of use when applied to the battery 100. Note that in Figure 7, a part of the battery 100 is shown disassembled.

[0043] A battery 100, an example of an application target for the pressurized elastic body 1, is a battery used in EVs, HEVs, etc., and has multiple cells 110 stacked on top of each other. The multiple cells 110 are supported by a housing 120. A support plate (not shown) is provided between two adjacent cells 110. The support plate is, for example, a plate-shaped member made of resin or rubber. The housing 120 forms a housing space 101, which is a space for housing the multiple stacked cells 110, and has a bottom 121 and a pair of side parts 122, 123. The bottom 121 and the side parts 122, 123 extend in the stacking direction of the cells 110. The bottom 121 and the side parts 122, 123 are open at both ends 120a, 120b in the stacking direction of the cells 110. The housing 120 also has a pair of ends 124, 125 that face each other in the stacking direction of the cells 110, as shown in Figure 7. Ends 124 and 125 are members that close the open portions 120a and 120b at both ends of the bottom 121 and side portions 122 and 123. Ends 124 and 125 are the same or substantially the same member. The cell 110 on the end 120a side of the stacked cells 110 and end 124 face each other with a gap G1 between them, and similarly, the cell 110 on the end 120b side of the stacked cells 110 and end 125 face each other with a gap G2 between them.

[0044] A pressurized elastic body 1 is placed between the end 124 and the cell 110 facing the end 124, filling the gap G1. Similarly, a pressurized elastic body 1 is placed between the end 125 and the cell 110 facing the end 125, filling the gap G2. The pressurized elastic body 1 is compressed in the stacking direction of the cells 110 between the end 124 and the cell 110, and between the end 125 and the cell 110, thereby pressurizing the cells 110 of the battery 100 in the stacking direction. Note that the support plate provided between two adjacent cells 110 may also be a pressurized elastic body 1.

[0045] In the operating state of the pressurized elastic body 1, one of the first portion 10 and the second portion 20 of each protrusion 3 is in contact with the ends 124 and 125 and is pressed against the other side of the first portion 10 and the second portion 20, and the other side of the first portion 10 and the second portion 20 of each protrusion 3 is in contact with the cell 110 and is pressed against the one side of the first portion 10 and the second portion 20. As a result, the first portion 10 and the second portion 20 of each protrusion 3, as well as the connecting portion 38 which is the base portion 2 between the first portion 10 and the second portion 20, are compressed. In this way, in the operating state of the pressurized elastic body 1, each protrusion 3 and the connecting portion 38 are compressed in the axial x direction, and each protrusion 3 generates a reaction force against the cell 110, pressurizing the cell 110.

[0046] During charging and discharging of the battery 100, when the cell 110 expands, the protrusion 3 is pressed more by the cell 110, the protrusion 3 and the connection part 38 are compressed more, the protrusion 3 generates a greater reaction force, and pressurizes the cell 110 with greater force. On the other hand, when the cell 110 contracts during charging and discharging of the battery 100, the force pressing the protrusion 3 by the cell 110 decreases, the compression of the protrusion 3 and the connection part 38 is relieved, the reaction force generated in the protrusion 3 decreases, and the force pressing on the cell 110 decreases. Thus, during charging and discharging of the battery 100, the magnitude of the reaction force that the protrusion 3 pressurizes on the cell 110 changes between the maximum reaction force and the minimum reaction force.

[0047] Figure 8 is an enlarged cross-sectional view of the protruding portion 3 in a compressed state. In Figure 8, the portion of the compressed and deformed pressurized elastic body 1 is shown by a dashed line. As shown in Figure 8, when the protruding portion 3 is pressed by the cell 110, the protruding portion 3 and the connecting portion 38 are compressed, the first portion 10, the second portion 20, and the connecting portion 38 are deformed, and the height H1 of the protruding portion decreases to the height H2. Also, due to the deformation of the first portion 10, the second portion 20, and the connecting portion 38, the inner membrane portion 33 is pressed toward the inner circumference, thereby deforming the inner membrane portion 33. Also, due to the deformation of the first portion 10, the second portion 20, and the connecting portion 38, the outer peripheral portion of the connecting portion 38 of the base portion 2 (hereinafter also referred to as the outer peripheral portion 39) is pressed toward the outer circumference, thereby deforming the outer peripheral portion 39.

[0048] The reaction force that presses against the cell 110 when the protruding portion 3 is compressed in use is the force generated by these deformations. In other words, the reaction force generated in the protruding portion 3 is the force generated by the deformation of the first portion 10, the second portion 20, the connecting portion 38, the inner membrane portion 33, and the outer peripheral portion 39. Therefore, the magnitude of the reaction force generated from the protruding portion 3 differs depending on the manner in which the first portion 10, the second portion 20, the connecting portion 38, the inner membrane portion 33, and the outer peripheral portion 39 are deformed. However, the deformation that occurs in the outer peripheral portion 39 when the protruding portion 3 is compressed in use is small, and the influence of the deformation of the outer peripheral portion 39 on the reaction force generated in the protruding portion 3 can be ignored. In other words, the magnitude of the reaction force generated from the protruding portion 3 differs substantially depending on the manner in which the first portion 10, the second portion 20, the connecting portion 38, and the inner membrane portion 33 are deformed.

[0049] In cross-section, the convex surface 11 of the first part 10 is a semicircle or approximately a semicircle; therefore, in cross-section, the shape and size of the first part 10 are determined by the value of the radius r1 of the convex surface 11, that is, by the value of the height h1 of the first part 10. Similarly, in cross-section, the convex surface 21 of the second part 20 is a semicircle or approximately a semicircle; therefore, in cross-section, the shape and size of the second part 20 are determined by the value of the radius r2 of the convex surface 21, that is, by the value of the height h2 of the second part 20. The manner of deformation of the first part 10 under compression in the axial x direction is mainly based on the shape and size of the first part 10 in cross-section; therefore, the manner of deformation of the first part 10 under compression in the axial x direction is mainly based on the height h1 of the first part 10. Similarly, the manner of deformation of the second part 20 under compression in the axial x direction is mainly based on the height h2 of the second part 20.

[0050] Furthermore, the manner in which the connecting portion 38 deforms under compression in the axial x-direction is mainly based on the thickness of the connecting portion 38, that is, the thickness T1 of the base portion 2. Also, the manner in which the inner membrane portion 33 deforms is mainly based on the thickness T1 and size of the inner membrane portion 33, that is, the thickness T1 and diameter R1 of the inner membrane portion 33.

[0051] Thus, the deformation of the first part 10 under compression in the axial x direction is mainly based on the height h1 of the first part 10, the deformation of the second part 20 under compression in the axial x direction is mainly based on the height h2 of the second part 20, the deformation of the connecting part 38 under compression in the axial x direction is mainly based on the thickness T1 of the base part 2, and the deformation of the inner membrane part 33 is based on the thickness T1 (thickness T1 of the base part 2) and diameter R1 of the inner membrane part 33. In other words, the deformation of the first part 10, the second part 20, and the connecting part 38 under compression in the axial x direction is mainly based on the height H1 of the protruding part 3, and the deformation of the inner membrane part 33 is based on the thickness T1 and diameter R1 of the inner membrane part 33.

[0052] Therefore, the magnitude of the reaction force generated from the protrusion 3 due to compression in the axial x direction when the pressurized elastic body 1 is in use is mainly based on the height H1 of the protrusion 3, the thickness T1 of the inner membrane 33, and the diameter R1 of the inner membrane 33. Thus, when the pressurized elastic body 1 is in use, the magnitude of the reaction force generated from the protrusion 3 due to compression in the axial x direction varies depending on the values ​​of the height H1 of the protrusion 3, the thickness T1 of the inner membrane 33, and the diameter R1 of the inner membrane 33. In other words, the height H1 of the protrusion 3, the thickness T1 of the inner membrane 33, and the diameter R1 of the inner membrane 33 are design factors for the magnitude of the reaction force generated from the protrusion 3 due to compression in the axial x direction.

[0053] In this way, in the compressed elastic body 1 under use, the number of design factors for the magnitude of the reaction force generated by compression in the axial x direction is 3.

[0054] The number of design factors for the pressurized elastic body 1 is 3, and the number of design factors that affect the magnitude of the reaction force of the protrusion 3 to compression in the axial x direction is small. Therefore, the pressurized elastic body 1 can reduce the sensitivity of the reaction force of the protrusion 3 to the magnitude of compression in the axial x direction. This makes it possible to reduce the difference between the maximum and minimum reaction forces of the reaction force that the protrusion 3 applies to the cell 110 during charging and discharging of the battery 100.

[0055] Product dimensions, which are the dimensions of manufactured products, are not constant but vary. When the product dimensions, which are design factors for the magnitude of the reaction force generated from the protrusion 3 due to compression in the x-axis direction, vary, the magnitude of the reaction force generated at the protrusion 3 due to compression in the x-axis direction will vary. If the product dimensions, which are design factors, vary greatly, the magnitude of the reaction force generated at the protrusion 3 due to compression in the x-axis direction will also vary greatly. Furthermore, if there are many product dimensions that are design factors, the variation in the magnitude of the reaction force generated at the protrusion 3 due to compression in the x-axis direction will also be large among the multiple pressurized elastic bodies 1 that have been manufactured. For this reason, the fewer the number of design factors for the magnitude of the reaction force generated at the protrusion 3 due to compression in the x-axis direction, the more the variation in the magnitude of the reaction force generated at the protrusion 3 due to compression in the x-axis direction can be reduced among the multiple pressurized elastic bodies 1 that have been manufactured.

[0056] In the pressurized elastic body 1, the number of design factors for the magnitude of the reaction force generated at the protrusion 3 by compression in the axial x direction is 3. Since the number of design factors is small, the pressurized elastic body 1 can reduce the variation in the magnitude of the reaction force generated at the protrusion 3 by compression in the axial x direction among multiple manufactured pressurized elastic bodies 1. As a result, the difference between the maximum and minimum reaction forces from the protrusion 3 of the pressurized elastic body 1 can be reduced among multiple manufactured pressurized elastic bodies 1. Therefore, it is possible to prevent or suppress damage to the cell 110 or the housing 120 of the battery 100 due to an excessively large reaction force from the protrusion 3, while on the other hand, it is possible to prevent or suppress a decrease in the function of preventing deterioration of the cell 110 due to an excessively small reaction force from the protrusion 3.

[0057] As described above, according to the embodiment of the present invention, it is possible to suppress variations in the maximum and minimum reaction forces generated at the protrusion 3 in the manufactured pressure elastic body 1.

[0058] For example, the variation in the reaction force generated at the protrusion 3 is within 14% when the compressibility ratio is between 14% and 43%. The compressibility ratio is the compressibility ratio of the compressed elastic body 1 in the axial x-direction. Specifically, in a compressed elastic body 1 having predetermined nominal dimensions and predetermined tolerances set for each nominal dimension, the variation in the reaction force generated at the protrusion 3 in the compressed elastic body 1 compressed in the axial x-direction at a compressibility ratio of 14% to 43% is within 14%. The variation is the rate of change in the magnitude of the reaction force generated at the protrusion 3 in the compressed elastic body 1 with the maximum tolerance, and the rate of change in the magnitude of the reaction force generated at the protrusion 3 in the compressed elastic body 1 with the minimum tolerance, relative to the magnitude of the reaction force generated at the protrusion 3 in the compressed elastic body 1 with nominal dimensions. The magnitude of the reaction force generated at the protrusion 3 in the compressed elastic body 1 compressed in the axial x-direction at a predetermined compressibility ratio can be determined, for example, by FEM analysis. Furthermore, the magnitude of the reaction force generated at the protrusion 3 in the pressurized elastic body 1, which is compressed in the axial x-direction at a predetermined compression ratio, can be determined, for example, by actually compressing the manufactured pressurized elastic body 1 and measuring the reaction force generated at the compressed protrusion 3.

[0059] Next, a comparative example, the pressurized elastic body 50, will be described. Figure 9 is a partially enlarged cross-sectional view of the pressurized elastic body 50 as a comparative example. The cross-section of the pressurized elastic body 50 shown in Figure 9 corresponds to the cross-section of the pressurized elastic body 1 shown in Figure 6. The pressurized elastic body 50 is an example of a pressurized elastic body with many design factors. As shown in Figure 9, the pressurized elastic body 50, like the pressurized elastic body 1, has a base portion 51 and a plurality of protrusions 52. The protrusions 52 also have a first portion 53 that protrudes to the front side and a second portion 54 that protrudes to the back side. The first portion 53 and the second portion 54 are annular and extend on a circle centered on axis x1. The pressurized elastic body 50 also has an inner membrane portion 55. The inner membrane portion 55 is the portion of the base portion 51 that is surrounded on the inner circumference side by each protrusion 52.

[0060] As shown in Figure 9, the inner circumferential surface 53a of the first part 53 is a tapered surface that widens outward toward the front, and the outer circumferential surface 54a of the first part 53 is a tapered surface that narrows inward toward the front. The second part 54 is symmetrical with respect to the first part 53 in the axial x direction, and the second part 54 is the same as the first part 53, except that it faces the back side instead of the front side.

[0061] As shown in Figure 9, in the pressurized elastic body 50, the number of design factors for the magnitude of the reaction force generated in the protrusion 52 by compression in the axial x direction is 6. Specifically, the design factors for the pressurized elastic body 50 are the height H3 of the protrusion 52, the inclination angle α1 of the inner circumferential surface 53a of the first part 53 or the inclination angle β1 of the inner circumferential surface 54a of the second part 54, the inclination angle α2 of the outer circumferential surface 53b of the first part 53 or the inclination angle β2 of the outer circumferential surface 54b of the second part 54, the width W3 of the protrusion 52, the thickness T3 of the inner membrane 55, and the diameter R3 of the inner membrane 55. As mentioned above, the first part 53 and the second part 54 are the same, the inclination angles α1 and β1 are the same, and the inclination angles α2 and β2 are the same.

[0062] Thus, in the pressurized elastic body 50, the number of design factors for the magnitude of the reaction force generated at the protrusion 52 by compression in the axial x1 direction is 6. This is a large number of design factors, and among the multiple pressurized elastic bodies 50 manufactured, there is a large variation in the magnitude of the reaction force generated at the protrusion 52 by compression in the axial x1 direction. As a result, among the multiple pressurized elastic bodies 50 manufactured, the difference between the maximum and minimum reaction forces from the protrusion 52 of the pressurized elastic body 50 becomes large.

[0063] Although the present invention has been described above through the embodiments described above, the technical scope of the present invention is not limited to the scope described in the embodiments above. It will be obvious to those skilled in the art that various modifications or improvements can be made to the embodiments described above. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0064] The embodiments described above are for the purpose of facilitating understanding of the present invention and are not intended to limit its interpretation. Furthermore, the embodiments described above do not limit the scope of application of the present invention, and the present invention may encompass anything as its target application. The components of the above embodiments, as well as their arrangement, materials, conditions, shapes, and sizes, are not limited to those exemplified and can be modified as appropriate. For example, the present invention includes differences that arise in the implementation of manufacturing tolerances, etc. Furthermore, components shown in different embodiments can be partially substituted or combined to the extent that they do not contradict each other in a technical sense. In addition, each configuration can be selectively combined as appropriate to achieve at least some of the problems and effects described above.

[0065] For example, the pressurized elastic body according to the present invention can also be used as a component for providing a cushioning function. Therefore, the applications of the pressurized elastic body according to the present invention include, for example, those where shock absorption is required.

[0066] Furthermore, the protrusion 3 is not limited to extending along a circle; for example, it may extend along a rectangle such as a square or rectangle, or it may extend along an ellipse. Also, the protrusion 3 may extend in an annular shape along other shapes.

[0067] Furthermore, in the above-described pressurized elastic body 1, the convex surfaces 11 and 21 in the cross-section of the projection 3 in a plane containing the axis x may form a circular arc or a nearly circular arc. Specifically, the circular arc is either a subarc or a superior arc. In this case, the size of the radius r1 (r2) of the convex surface 11 (convex surface 21) is added to the design factors of the pressurized elastic body 1, and the number of design factors for the pressurized elastic body 1 becomes 4.

[0068] Furthermore, in the above-described pressurized elastic body 1, the thickness of the inner membrane portion 33 at the base portion 3 may differ from the thickness of other parts. In this case, the thickness of the inner membrane portion 33 is added to the design factors of the pressurized elastic body 1, and the number of design factors for the pressurized elastic body 1 becomes 4. [Explanation of Symbols]

[0069] 1 Compressed elastic body, 2 Base, 2a End, 3 Protrusion, 10 First part, 11 Convex surface, 11a Top, 12 Inner circumferential end, 13 Outer circumferential end, 14,15 Transition surface, 16 Hollow space, 20 Second part, 21 Convex surface, 21a Top, 22 Inner circumferential end, 23 Outer circumferential end, 24,25 Transition surface, 26 Hollow space, 31 Surface, 32 Back surface, 33 Inner membrane part, 34,35 Outer circumferential end, 36,37 Inner membrane surface, 36a,37a Outer circumferential end, 38 Connecting part, 39 Outer circumferential part, 50 Compressed elastic body, 51 Base, 52 Protrusion, 53 First part, 53a Inner circumferential surface, 53b Outer circumferential surface, 54 Second part, 54a Inner circumferential surface, 54b Outer circumferential surface, 55 Inner membrane, 100 Battery, 101 Housing space, 110 Cell, 120 Housing, 120a,120b End, 121 Bottom, 122,123 Side, 124,125 End, H1,H2,H3, h1,h2 Height, R1,R2,R3 Diameter, r1,r2 Radius, T1,T3 Thickness, W3 Width, x,x1 Axis, Inclination angle α1,α2,β1,β2

Claims

1. A pressurized elastic body formed from an elastic material, The base is the part that extends along the plane, It comprises a plurality of protruding parts that extend from the base, The number of design factors for the reaction force generated by the protrusion in the shape of the base and the protrusion is less than 6. Compression-elastic body.

2. The variation in the reaction force generated by the aforementioned protrusion is within 14%. The pressurized elastic body according to claim 1.

3. The number of design factors is 3. The pressurized elastic body according to claim 1.

4. The design factor is a design factor for the shape of the cross-section of the base and the protrusion, based on a plane along the direction in which the protrusion protrudes. The pressurized elastic body according to claim 1.

5. The aforementioned protrusion is annular, The design factors are the height of the protrusion, the thickness of the base, and the diameter of the portion of the base that the protrusion surrounds on the inner circumference. The pressurized elastic body according to claim 3.

6. The contour of the aforementioned protrusion in the cross-section follows a circle. The pressurized elastic body according to claim 3.

7. The contour of the protruding portion in the cross-section is a semicircle. The pressurized elastic body according to claim 6.

8. The aforementioned protrusion extends along the circle, The outer circumferential end of the base portion surrounded by the protrusion on the inner circumference is aligned with a circle. The pressurized elastic body according to claim 3.

9. The thickness of the base is constant. The pressurized elastic body according to claim 3.

10. The base has a pair of faces that face away from each other. The protruding portion has a first portion which is a part that protrudes from one of the pair of surfaces, and a second portion which is a part that protrudes from the other of the pair of surfaces. The first part and the second part are symmetrical with respect to each other. The pressurized elastic body according to claim 5.

11. In batteries, used to pressurize the cells, The pressurized elastic body according to claim 1.

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