Compression elastic body

Abstract

To reduce the change in reaction force relative to the amount of compression. [Solution] The pressurized elastic body 1 is made of 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. Each protrusion 3 has a cylindrical side wall portion 10 extending along an axis x and an end wall portion 20 covering the tip of the side wall portion 10. The side wall portion 10 has a portion that generates a force toward the inner circumference and a portion that generates a force toward the outer circumference in response to a force applied to the protrusion 3 in the axial direction x.

Description

Technical Field

[0001] The present invention relates to a pressurized elastomer, and particularly to a pressurized elastomer used for pressurizing cells of a battery.

Background Art

[0002] For example, batteries are used in electric vehicles (EVs) and hybrid electric vehicles (HEVs). The performance of a battery deteriorates due to long-term use. For example, the performance of a battery deteriorates due to the deposition of dendrites. Conventionally, in order to suppress such performance deterioration, a configuration for pressurizing cells of a battery has been proposed. For example, it is conceivable to use an elastomer that has conventionally been used as a cushioning material between adjacent cells (see, for example, Patent Document 1) as a pressurized elastomer to pressurize the cells and suppress deterioration of the battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems 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 so that the protruding portions contact the cells. When the conventional cushioning material is used as a pressurized elastomer, the protruding portions contact the cells as pressurizing portions. The cells of a battery expand and contract during charging and discharging. Therefore, when charging and discharging are repeated, the cells repeat expansion and contraction. The plurality of protruding portions of the pressurized elastomer are compressed by the cells that repeat expansion and contraction, and the reaction force generated in the protruding portions varies between the maximum reaction force and the 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 material be small. If the protrusion is solid, as in conventional cushioning materials, the change in the reaction force of the protrusion in response to the amount of compression of the protrusion is large. In contrast, it is conceivable to form a recess on the back of the protrusion and make the protrusion hollow, but in this case, abrupt deformation may occur with the compression of the protrusion, causing the reaction force to drop sharply and potentially increasing the difference between the maximum and minimum reaction forces. Furthermore, in recent years, in order to increase the output of batteries, the amount of cell expansion and contraction has increased, and the volume change of the cell between expansion and contraction has also increased. As a result, the displacement of the cell has also increased, and therefore the amount of compression of the protrusion has also increased.

[0006] Thus, compared to conventional pressurized elastic bodies, there is a need for a configuration that can reduce the change in reaction force with respect to the amount of compression of the protrusions.

[0007] The present invention has been made in view of the above-mentioned problems, and its objective is to provide a pressurized elastic body that can reduce the amount of change in reaction force with respect to the amount of compression. [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 protruding portions which protrude from the base portion, wherein the protruding portions have a side wall portion which is a cylindrical portion which extends along an axis, and an end wall portion which covers the tip of the side wall portion, and the side wall portion has a portion which generates a force toward the inner circumference and a portion which generates a force toward the outer circumference with respect to the axial force applied to the protruding portion.

[0009] In a pressurized elastic body according to one aspect of the present invention, the side wall portion is formed into a bellows.

[0010] In a pressurized elastic body according to one aspect of the present invention, the side wall portion has at least one bellows portion, and the bellows portion has an enlarged diameter portion which is a portion that expands in diameter toward one direction in the axial direction, and a reduced diameter portion which is a portion that shrinks in diameter toward one direction in the axial direction.

[0011] In a pressurized elastic body according to one aspect of the present invention, the reduced diameter portion is connected to the enlarged diameter portion on one side in the axial direction.

[0012] In a pressurized elastic body according to one aspect of the present invention, the enlarged diameter portion and the reduced diameter portion are conical in shape.

[0013] In a pressurized elastic body according to one aspect of the present invention, the cross-sections of the enlarged diameter portion and the reduced diameter portion, formed by a plane along the axis, protrude outward.

[0014] 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 protrudes from one of the pair of surfaces and defines a recess that is recessed from the other of the pair of surfaces.

[0015] A pressurized elastic body according to one aspect of the present invention is used in a battery to pressurize the cells. [Effects of the Invention]

[0016] According to the present invention, the amount of change in reaction force with respect to the amount of compression can be made smaller. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic perspective view showing a compressible elastic body according to an embodiment of the present invention. [Figure 2] This is a front view of a pressurized elastic body. [Figure 3] This is a rear view of a pressurized elastic body. [Figure 4] This is a cross-sectional view showing the section along line AA in Figure 2. [Figure 5]It is a partial enlarged cross-sectional view showing a part of FIG. 4 enlarged. [Figure 6] It is a diagram schematically showing a pressure elastic body in a state where the pressure elastic body is attached to a battery. [Figure 7] It is a partial enlarged cross-sectional view of a protrusion for explaining the protrusion in a compressed state. [Figure 8] It is a partial enlarged cross-sectional view of a comparative example of a protrusion for explaining the compressed state of the comparative example of the protrusion. [Figure 9] It is a diagram showing a graph for exemplifying the relationship between the compression ratio and the reaction force of the protrusion and the comparative example of the protrusion. [Figure 10] It is a diagram showing the state of deformation of a comparative example of a protrusion when the reaction force suddenly decreases. [Figure 11] It is a diagram showing the state of deformation of the protrusion of the pressure elastic body according to an embodiment of the present invention at a high compression amount. [Figure 12] It is a partial enlarged cross-sectional view showing a modified example of the protrusion of the pressure elastic body. [Figure 13] It is a partial enlarged cross-sectional view showing another modified example of the protrusion of the pressure elastic body.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, not all of the plurality of components are labeled, and some of the labels of the plurality of components may be omitted.

[0019] FIG. 1 is a perspective view schematically showing a pressure elastic body 1 according to an embodiment of the present invention, FIG. 2 is a front view of the pressure elastic body 1, and FIG. 3 is a rear view of the pressure elastic body 1. Further, FIG. 4 is a cross-sectional view showing a cross-section along line A-A of FIG. 2. Further, FIG. 5 is a partial enlarged cross-sectional view showing a part of FIG. 4 enlarged. As will be described later, the pressure elastic body 1 is used, for example, to pressurize a cell of a battery. Note that the application target for which the pressure elastic body according to the present invention is used is not limited to a battery. The application target of the pressure elastic body according to the present invention includes other application targets.

[0020] The pressurized elastic body 1 is formed from an elastic material and, as shown in Figures 1 to 5, comprises a base portion 2 that extends along a plane and a plurality of protruding portions 3 that protrude from the base portion 2. Each protruding portion 3 has a side wall portion 10 that is a cylindrical portion extending along the axis x and an end wall portion 20 that covers the tip of the side wall portion 10. The side wall portion 10 has a portion that generates a force toward the inner circumference and a portion that generates a force toward the outer circumference in response to a force applied to the protruding portion 3 in the axial direction x. The configuration of the pressurized elastic body 1 will be described in detail below.

[0021] The front side is the side in the direction of projection 3 in the axis x direction, and the back side is the side in the direction opposite to the front side in the axis x direction. The direction perpendicular to axis x is the radial direction, and the side away from axis x in the radial direction is the outer circumference side, and the side approaching axis x in the radial direction is the inner circumference side.

[0022] As shown in Figures 1-4, the base 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 2 and 3, for example, the base 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 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 axis x. The back surface 32 is specifically, for example, a surface extending on a plane perpendicular to axis x or a substantially plane perpendicular to axis x. Also, the surface 31 specifically extends parallel to or substantially parallel to the back surface 32.

[0023] Furthermore, as shown in Figure 3, for example, the base 2 has a plurality of grooves 33 on its back surface 32. The grooves 33 are recessed on the front side. As shown in Figure 3, each groove 33 is connected to a projection 3. For example, each groove 33 is connected to a recess 3a formed by the projection 3, which will be described later. Specifically, for example, a portion of the plurality of grooves 33 extends between two recesses 3a, and another portion of the plurality of grooves 33 extends between one recess 3a and the end 2a of the base 2. The end 2a of the base 2 is the circumferential surface of the base 2, and is the surface facing the outer periphery that extends between the end of the surface 31 and the end of the back surface 32. Also, as shown in Figure 3, the plurality of grooves 33 are arranged to form a plurality of rows extending between the ends 2a, and each of the plurality of rows formed by the plurality of grooves 33 has a recess 3a of the plurality of projections 3. Furthermore, both ends of each of the plurality of rows formed by the plurality of grooves 33 are located at the ends 2a.

[0024] As described above, the pressurized elastic body 1 has a plurality of protrusions 3, and as shown in Figures 1 to 3, the plurality of protrusions 3 are arranged in a line, for example, to form a plurality of rows. For example, as shown in Figures 2 and 3, 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.

[0025] As shown in Figures 1-4, the projection 3 protrudes from the surface 31, which is one of a pair of surfaces of the base 2, and defines a recess 3a that is recessed from the back surface 32, which is the other of the pair of surfaces of the base 2. The recess 3a is a space that is recessed from the back surface 32 toward the front surface, and on the back surface, it is in contact with the side wall 10 and the end wall 20. Thus, the projection 3 is hollow.

[0026] As described above, the multiple grooves 33 formed on the back surface 32 of the base 2 are connected to the recesses 3a, and the space of the recesses 3a is in communication with the space of the grooves 33. Also, as described above, for example, the multiple rows formed by the multiple protrusions 3 each extend in parallel with each other, and the multiple rows formed by the multiple grooves 33 each extend in parallel with each other, as shown in Figure 3. The multiple rows formed by the multiple grooves 33 each cross the recesses 3a of the multiple protrusions 3 located on this row, and the space of each recess 3a is in communication with the space outside the end 2a of the base 2 via the grooves 33.

[0027] As described above, in each projection 3, the tip of the side wall portion 10 is covered by the end wall portion 20. As shown in Figures 4 and 5, the tip of the side wall portion 10 is the front end of the side wall portion 10 in the axial x direction. The opening at the tip of the side wall portion 10 is closed by the end wall portion 20. On the other hand, the opening at the rear end of the side wall portion 10 is open to the rear side. In other words, the recess 3a of the projection 3 is open to the rear side from the rear surface 32 of the base portion 2.

[0028] As shown in Figures 4 and 5, the side wall portion 10 forms, for example, a bellows. Specifically, for example, as shown in Figure 5, the side wall portion 10 has at least one bellows section 11. The bellows section 11 has an expanding portion 12, which is a portion that expands in diameter toward one direction in the axial x direction, and a contracting portion 13, which is a portion that contracts in diameter toward one direction in the axial x direction. As an example, as shown in Figure 5, the expanding portion 12 expands toward the rear side in the axial x direction, and the contracting portion 13 contracts toward the rear side in the axial x direction. The contracting portion 13 is also connected to the expanding portion 12 on the rear side in the axial x direction. Specifically, the rear end 12a, which is the maximum diameter of the expanded portion 12, and the front end 13a, which is the maximum diameter of the reduced portion 13, are connected to each other, and the diameter at the rear end 12a of the expanded portion 12 and the diameter at the front end 13a of the reduced portion 13 are the same or approximately the same. The rear end 12a of the expanded portion 12 is the rear end in the axial x direction of the expanded portion 12, and the front end 13a of the reduced portion 13 is the front end in the axial x direction of the reduced portion 13. As shown in Figure 5, the bellows portion 11 protrudes outward.

[0029] Furthermore, as shown in Figure 5, the diameter of the front end 12b of the enlarged diameter portion 12 and the diameter of the rear end 13b of the reduced diameter portion 13 are the same or approximately the same. However, the diameter of the front end 12b of the enlarged diameter portion 12 and the diameter of the rear end 13b of the reduced diameter portion 13 may be different. The front end 12b of the enlarged diameter portion 12 is the front end in the axial x direction of the enlarged diameter portion 12, and the rear end 13b of the reduced diameter portion 13 is the rear end in the axial x direction of the reduced diameter portion 13.

[0030] As shown in Figure 5, as an example, the side wall portion 10 has one bellows portion 11. The side wall portion 10 may have two or more bellows portions 11. In this case, the multiple bellows portions 11 are formed aligned along the axis x. As shown in Figure 5, the front end of the bellows portion 11 is connected to the end wall portion 20. Specifically, the front end 12b of the enlarged diameter portion 12 of the bellows portion 11 is connected to the end wall portion 20. Also, as shown in Figure 5, the outer circumferential surface of the bellows portion 11 is flush or nearly flush with the circumferential end surface 23 of the end wall portion 20. Specifically, the outer circumferential surface 12c of the enlarged diameter portion 12 of the bellows portion 11 is flush or nearly flush with the circumferential end surface 23 of the end wall portion 20. The outer circumferential surface 12c of the enlarged diameter portion 12 is the surface facing the outer circumferential side of the enlarged diameter portion 12. Furthermore, the circumferential end surface 23 of the end wall portion 20 is the outer edge of the end wall portion 20.

[0031] Furthermore, as shown in Figure 5, the side wall portion 10 has a connecting portion 14, which is a cylindrical portion connected to the bellows piece portion 11. For example, the side wall portion 10 has a connecting portion 14 on the back side of the bellows piece portion 11, and the connecting portion 14 is connected to the base portion 2. The connecting portion 14 has a shape similar to that of the enlarged diameter portion 12, and its diameter is enlarged toward the back side in the axial x direction. Note that the shape of the connecting portion 14 is not limited to that of the enlarged diameter portion 12, but can be various shapes. For example, the shape of the connecting portion 14 may be cylindrical or substantially cylindrical extending along the axis x, may be similar to that of the reduced diameter portion 13, or may be any other shape. Also, the connecting portion 14 may be formed on the front side of the bellows piece portion 11, and the connecting portion 14 may be connected to the end wall portion 20. Furthermore, if a plurality of bellows piece portions 11 are provided on the side wall portion 10, the connecting portion 14 may be provided between adjacent bellows piece portions 11. Furthermore, the side wall portion 10 does not necessarily have a connecting portion 14. In this case, the side wall portion 10 is composed only of bellows portion 11, and the bellows portion 11 is connected to the base portion 2.

[0032] As shown in Figure 5, the enlarged diameter portion 12 and the reduced diameter portion 13 are conical or substantially conical in shape. Specifically, as shown in Figure 5, in a cross-section drawn with a plane containing axis x, the outer circumferential surface 12c of the enlarged diameter portion 12 traces a straight line or substantially straight line inclined toward the outer circumference with respect to axis x toward the back side, and the outer circumferential surface 12c of the enlarged diameter portion 12 is a conical or substantially conical surface. The inner circumferential surface 12d of the enlarged diameter portion 12 extends parallel or substantially parallel to the outer circumferential surface 12c. The inner circumferential surface 12d of the enlarged diameter portion 12 is the surface facing the inner circumference of the enlarged diameter portion 12. Furthermore, specifically, as shown in Figure 5, in a cross-section drawn with a plane containing axis x, the outer circumferential surface 13c of the reduced-diameter portion 13 traces a straight line or substantially straight line inclined toward the inner circumference with respect to axis x toward the back side, and the outer circumferential surface 13c of the reduced diameter portion 13 is a conical or substantially conical surface. The inner circumferential surface 13d of the reduced diameter portion 13 extends parallel or substantially parallel to the outer circumferential surface 13c. The outer circumferential surface 13c and the inner circumferential surface 13d of the reduced diameter portion 13 are the surfaces facing the outer and inner sides of the reduced diameter portion 13, respectively.

[0033] As shown in Figure 5, the end wall portion 20 has a plate-like shape and, for example, a pair of surfaces facing away from each other, namely a surface 21 and a back surface 22. The surface 21 and back surface 22 extend, for example, along a plane perpendicular to axis x. Specifically, the surface 21 is, for example, a circular or substantially circular surface extending on a plane perpendicular to axis x or a substantially circular plane perpendicular to axis x. The back surface 22 is, for example, a circular or substantially circular surface extending parallel to or substantially parallel to the surface 21. The shapes of the surface 21 and back surface 22 correspond to the shapes of the side wall portion 10.

[0034] Furthermore, for example, the height H and width W of the protruding portion 3 are set such that the ratio of the height H to the width W of the protruding portion 3 is a predetermined value. The ratio of the height H to the width W of the protruding portion 3 (W / H) is, for example, 2 or more. As shown in Figure 5, the height H of the protruding portion 3 is the dimension in the axial x direction of the protruding portion 3, for example, the distance in the axial x direction between the back surface 32 of the base portion 2 and the surface 21 of the end wall portion 2 of the protruding portion 3. Also, as shown in Figure 5, the width W of the protruding portion 3 is the dimension in the radial direction of the protruding portion 3, for example, the diameter of the side wall portion 3. Specifically, for example, the width W of the protruding portion 3 is the diameter of the outer circumferential surface at the root end of the side wall portion 3, and the diameter of the outer circumferential surface 14b at the back side end 14a of the connecting portion 14. The back side end 14a of the connecting portion 14 is the back side end of the connecting portion 14 in the axial x direction, and is the part where the side wall portion 3 is connected to the base portion 2. Furthermore, the outer circumferential surface 14b of the connecting portion 14 is the surface facing the outer circumferential side of the connecting portion 14. Note that the height H and width W of the protruding portion 3 are not limited to the distance and diameter described above, but may be the distance and diameter at other positions.

[0035] 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 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. Also, the material of the base 2 does not have to be an elastic material.

[0036] 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 6 is a schematic diagram showing the pressurized elastic body 1 in a usage state when it is applied to the battery 100. Note that in Figure 6, a part of the battery 100 is shown disassembled.

[0037] 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 6. 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.

[0038] 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.

[0039] In the operating state of the pressurized elastic body 1, the back surface 32 of the base 2 is in contact with the ends 124 and 125, and the surface 21 of the end wall portion 20 of each protrusion 3 is in contact with the cell 110 and is pressed toward the back side. As a result, the side wall portion 10 of each protrusion 3 is compressed. In this way, in the operating state of the pressurized elastic body 1, each protrusion 3 is compressed in the axial x direction and pressed toward the back side by the cell 110, generating a reaction force toward the cell 110 and pressurizing the cell 110.

[0040] When the battery 100 is charged or discharged, if the cell 110 expands, the protrusion 3 is pushed further back and compressed, generating a greater reaction force and pressurizing the cell 110 with greater force. On the other hand, when the battery 100 is charged or discharged, if the cell 110 contracts, the force pressing the protrusion 3 backward by the cell 110 decreases, the compression of the protrusion 3 is relieved, the reaction force generated on the protrusion 3 decreases, and the force pressing on the cell 110 decreases. In this way, the magnitude of the reaction force that the protrusion 3 pressurizes the cell 110 during the charging and discharging of the battery 100 changes between the maximum and minimum reaction forces.

[0041] Figure 7 is an enlarged cross-sectional view of the protruding portion 3 to illustrate the protruding portion 3 in a compressed state. As shown in Figure 7, when the protruding portion 3, specifically the end wall portion 20, is pressed by the cell 110 with a pressing force F0 toward the rear side, the protruding portion 3 is compressed and the side wall portion 10 is compressed. At this time, the enlarged diameter portion 12 is compressed between the rear side end 12a and the front side end 12b, and as shown in Figure 7, a compressive force F1 is applied from the front side end 12b toward the rear side end 12a. Similarly, the reduced diameter portion 13 is compressed between the front side end 13a and the rear side end 13b, and as shown in Figure 7, a compressive force F2 is applied from the front side end 13a toward the rear side end 13b. As shown in Figure 7, the compressive force F1 applied to the enlarged diameter portion 12 has a force component F1a toward the outer circumference and a force component F1b toward the rear side. On the other hand, as shown in Figure 7, the compressive force F2 applied to the reduced diameter portion 13 has a force component F2a directed toward the inner circumference and a force component F2b directed toward the back surface.

[0042] As described above, when the side wall portion 10 is compressed, the bellows portion 11 of the side wall portion 10 is subjected to forces (force components F1a and F2a) that are directed in opposite directions in the radial direction. Therefore, the forces (force components F1a and F2a) directed in opposite directions in the radial direction applied to the bellows portion 11 are canceled out or absorbed by one side and reduced, and the radial deformation of the expanded diameter portion 12 and the contracted diameter portion 13 of the bellows portion 11 is suppressed when compressed by the cell 110. As a result, when the amount of compression of the protruding portion 3 exceeds a predetermined size, deformation such as the side wall portion 10 suddenly deforming greatly toward the recess 3a side can be suppressed.

[0043] On the other hand, as shown in Figure 8, if the projection 3 is a projection 4, and the side wall portion 4a of the projection 4 does not have a bellows piece portion 11, and is, for example, a conical or substantially conical shape extending along the axis x, then when the projection 4 is pressed by the cell 110 with a pressing force F0 toward the rear side, the side wall portion 4a is compressed, and at this time, as shown in Figure 8, a compressive force F3 is applied to the side wall portion 4a from the front end toward the rear end. As shown in Figure 8, the compressive force F3 applied to the side wall portion 4a has a force component F3a toward the outer circumference and a force component F3b toward the rear side. Thus, no force is generated in the side wall portion 4a of the projection 4 that cancels out or absorbs the force (force component F3a) toward the radial direction, and the deformation of the side wall portion 4a toward the radial direction is not suppressed when compressed by the cell 110. Therefore, when the amount of compression of the protruding portion 4 exceeds a predetermined size, deformation may occur in which the side wall portion 4a suddenly deforms significantly toward the recessed portion 3a.

[0044] Thus, unlike the protrusion 4, the protrusion 3 of the pressurized elastic body 1 can suppress deformation such that the side wall 10 suddenly deforms greatly toward the recess 3a when the amount of compression of the protrusion 3 exceeds a predetermined amount. For this reason, as shown in Figure 9, the reaction force generated in the protrusion 3 increases gradually with increasing compression of the protrusion 3, preventing or suppressing a sudden and large decrease in the reaction force. On the other hand, in the case of the protrusion 4, as shown in Figure 9, the reaction force generated in the protrusion 4 increases with increasing compression of the protrusion 4, and when it exceeds a predetermined amount of compression, the reaction force suddenly and greatly decreases. Figure 9 is a graph illustrating the relationship between the compressibility of the protrusions 3 and 4 and the reaction forces generated in the protrusions 3 and 4.

[0045] As shown in Figure 10, when the compression amount of the protrusion 4 exceeds a predetermined compression amount, the protrusion 4 deforms such that the side wall portion 4a tilts inward, and the reaction force drops sharply. On the other hand, as shown in Figure 11, even when the compression amount of the protrusion 3 exceeds a predetermined compression amount, the protrusion 3 does not deform such that the side wall portion 10 tilts inward.

[0046] As described above, in the protruding portion 3 of the pressurized elastic body 1, the reaction force generated in the protruding portion 3 increases with increasing compression, preventing or suppressing a sudden and large decrease in the reaction force. Therefore, the minimum value of the reaction force generated in the protruding portion 3 is prevented or suppressed from deviating significantly from the maximum value of the reaction force generated in the protruding portion 3. In this way, the difference between the maximum and minimum reaction forces of the protruding portion 3 can be reduced, and the amount of change in the reaction force with respect to the compression amount of the protruding portion 3 can be reduced.

[0047] Furthermore, the protruding portion 3 defines a recess 3a and is hollow. Therefore, compared to a solid protruding portion, the change in reaction force with respect to the amount of compression of the protruding portion 3 can be reduced. In addition, the multiple grooves 33 formed on the back surface 32 of the base portion 2 connect the recess 3a of each protruding portion 3 to the space outside the end 2a of the base portion 2. Therefore, even if the protruding portion 3 is compressed, the air inside the recess 3a is not compressed or is not significantly compressed. This also reduces the change in reaction force with respect to the amount of compression of the protruding portion 3.

[0048] As described above, according to the compression elastic body 1 of the present invention, the amount of change in reaction force with respect to the amount of compression can be made smaller.

[0049] Next, a modified example of the protruding portion 3 of the pressurized elastic body 1 will be described. Figure 12 is a partially enlarged cross-sectional view showing a modified example of the protruding portion 3 of the pressurized elastic body 1. As shown in Figure 12, the cross-section of the bellows portion 11, formed by a plane along the axis x of the enlarged diameter portion 12 and the reduced diameter portion 13, may protrude outward.

[0050] Specifically, as shown in Figure 12, in a cross-section drawn with a plane containing axis x, the outer circumferential surface 12c of the enlarged diameter portion 12 forms a curved line that is convex outward, for example, a circular arc or a roughly circular arc. The inner circumferential surface 12d of the enlarged diameter portion 12 extends parallel to or approximately parallel to the outer circumferential surface 12c. Also specifically, as shown in Figure 12, in a cross-section drawn with a plane containing axis x, the outer circumferential surface 13c of the reduced diameter portion 13 forms a curved line that is convex outward, for example, a circular arc or a roughly circular arc. The inner circumferential surface 13d of the reduced diameter portion 13 extends parallel to or approximately parallel to the outer circumferential surface 13c.

[0051] Next, other modifications of the protruding portion 3 of the pressurized elastic body 1 will be described. Figure 13 is a partially enlarged cross-sectional view showing another modification of the protruding portion 3 of the pressurized elastic body 1. As shown in Figure 13, in the bellows portion 11, the reduced diameter portion 13 may be provided on the front side of the expanded diameter portion 12, and the rear side end 13b of the reduced diameter portion 13 may be connected to the front side end 12b of the expanded diameter portion 12.

[0052] 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.

[0053] 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.

[0054] 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. [Explanation of symbols]

[0055] 1 Pressurized elastic body, 2 Base, 2a End, 3 Protrusion, 3a Recess, 4 Protrusion, 4a Side wall, 10 Side wall, 11 Bellows piece, 12 Enlarged diameter, 12a Rear side end, 12b Front side end, 12c Outer surface, 12d Inner surface, 13 Reduced diameter, 13a Front side end, 13b Rear side end, 13c Outer surface, 13d Inner surface, 14 Connection part, 20 End wall, 21 Surface, 22 Back, 23 Peripheral end surface, 31 Surface, 32 Back, 33 Groove, 100 Battery, 101 Housing space, 110 Cell, 120 Housing, 120a, 120b End, 121 Bottom, 122, 123 Side, 124, 125 End, F0 Pressing force, F1, F2, F3; Compression force, F2a, F2b, F3a, F3b; Force component, G1, G2; Gap, H; Width, T; Height, x-axis.

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 aforementioned protruding portion has a side wall portion which is a cylindrical part extending along the axis, and an end wall portion which is a part that covers the tip of the side wall portion. The side wall portion has a portion that generates a force toward the inner circumference and a portion that generates a force toward the outer circumference in response to the axial force applied to the protrusion. Compression-elastic body.

2. The aforementioned side wall portion forms a bellows. The pressurized elastic body according to claim 1.

3. The aforementioned side wall portion has at least one bellows-like section, The bellows portion has an enlarged diameter portion which is a part that expands in diameter toward one direction in the axial direction, and a reduced diameter portion which is a part that contracts in diameter toward one direction in the axial direction. The pressurized elastic body according to claim 2.

4. The reduced diameter portion is connected to the enlarged diameter portion on one side in the axial direction. The pressurized elastic body according to claim 3.

5. The enlarged diameter portion and the reduced diameter portion are conical in shape. The pressurized elastic body according to claim 3.

6. The cross-section of the enlarged diameter portion and the reduced diameter portion, formed by a plane along the axis, protrudes outward. The pressurized elastic body according to claim 3.

7. The base has a pair of surfaces facing away from each other, The aforementioned protrusion extends from one of the pair of surfaces and defines a recess that is recessed from the other of the pair of surfaces. The pressurized elastic body according to claim 1.

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

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