Porous structure and method for producing porous structure

Abstract

The porous structure (1) is made of a flexible resin or rubber, wherein the porous structure has a skeleton part (2) throughout its entire range, the skeleton part comprising: a plurality of bone parts (2B); and a plurality of connecting parts (2J), which respectively connect the ends of the plurality of bone parts to each other, and the porous structure is constructed so that the plurality of parts of the skeleton part interfere with each other when compressed and deformed along a predetermined load input direction.

Description

Technical Field

[0001] The present invention relates to a porous structure and a method for producing the porous structure.

[0002] This application claims priority based on Japanese Patent Application No. 2020-117991 filed in Japan on July 8, 2020, the entire contents of which are incorporated herein by reference. Background Art

[0003] Conventionally, porous structures having cushioning properties (for example, polyurethane foam) have been produced through a foaming process utilizing a chemical reaction, for example, in mold forming.

[0004] On the other hand, in recent years, porous structures having cushioning properties that can be easily manufactured using a 3D printer have been proposed (for example, Patent Document 1 and Patent Document 2).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: WO2019 / 235544

[0008] Patent Document 2: WO2019 / 235547 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] However, in the techniques of Patent Documents 1 and 2 described above, there is room for improvement in the degree of freedom in adjusting the dynamic characteristics of the porous structure.

[0011] An object of the present invention is to provide a porous structure and a method for producing the porous structure, which can increase the degree of freedom in adjusting the dynamic characteristics of the porous structure.

[0012] Solutions for solving problems

[0013] The porous structure of the present invention is composed of a flexible resin or rubber, wherein:

[0014] The porous structure has a skeleton portion throughout its entire range.

[0015] The skeleton part comprises:

[0016] multiple bones; and

[0017] A plurality of joints, which respectively connect the ends of the plurality of bone parts to each other,

[0018] The porous structure is configured so that a plurality of parts of the skeleton part interfere with each other when compressively deformed in a predetermined load input direction.

[0019] The method for producing a porous structure of the present invention uses a 3D printer to produce the above-mentioned porous structure.

[0020] Effects of the Invention

[0021] According to the present invention, it is possible to provide a porous structure and a method for producing the porous structure, which can increase the degree of freedom in adjusting the dynamic characteristics of the porous structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a perspective view showing a part of the porous structure according to the first embodiment of the present invention in a natural state without compression deformation.

[0023] Figure 2 Yes means Figure 1 A three-dimensional view of a unit dividing portion of a porous structure without a discontinuous bone portion.

[0024] Figure 3 Yes means Figure 1 A three-dimensional view of a unit dividing portion of a porous structure having a discontinuous bone portion.

[0025] Figure 4 (a) is shown in the natural state without compression deformation Figure 1 A partial stereogram of a porous structure. Figure 4 (b) is used to illustrate Figure 4 FIG. 1 is a diagram of a discontinuous bone portion of a porous structure in state (a).

[0026] Figure 5 (a) shows the state of compression deformation along the predetermined load input direction. Figure 1 A partial stereogram of a porous structure. Figure 5 (b) is used to illustrate Figure 5 FIG. 1 is a diagram of a discontinuous bone portion of a porous structure in state (a).

[0027] Figure 6 (a) is a perspective view of a unit partitioning portion having a discontinuous bone portion, showing a porous structure of a second embodiment of the present invention, Figure 6 (b) is used to illustrate Figure 6 (a) Illustration of a discontinuous bone portion of a porous structure.

[0028] Figure 7 (a) is a diagram for explaining a first modified example of the discontinuous bone portion of the porous structure according to the second embodiment of the present invention, Figure 7(b) is a diagram for explaining a second modified example of the discontinuous bone portion of the porous structure according to the second embodiment of the present invention.

[0029] Figure 8 (a) is a perspective view of a unit partition having a discontinuous bone portion, showing a porous structure according to a third embodiment of the present invention. Figure 8 (b) is used to illustrate Figure 8 (a) Illustration of a discontinuous bone portion of a porous structure.

[0030] Fig. 9 (a) is a perspective view of a unit partition having a discontinuous bone portion, showing a porous structure according to a fourth embodiment of the present invention. Fig. 9 (b) is used to illustrate Fig. 9 (a) Illustration of a discontinuous bone portion of a porous structure.

[0031] Fig.10 It is a drawing for explaining a first modified example of the discontinuous bone portion of the porous structure according to the fourth embodiment of the present invention.

[0032] Fig.11 (a) is a perspective view of a unit partition having a discontinuous bone portion, showing a porous structure according to a fifth embodiment of the present invention. Fig.11 (b) is used to illustrate Fig.11 (a) Illustration of a discontinuous bone portion of a porous structure.

[0033] Fig.12 (a) is a perspective view of a unit partition having a discontinuous bone portion, showing a porous structure according to a sixth embodiment of the present invention. Fig.12 (b) is used to illustrate Fig.12 (a) Illustration of a discontinuous bone portion of a porous structure.

[0034] Fig.13 This is a perspective view showing a part of the porous structure according to the seventh embodiment of the present invention in a natural state without compression deformation.

[0035] Fig.14 For the sake of convenience, the bridges are shown in a state of being extended. Fig.13 A partial three-dimensional image of a porous structure.

[0036] Fig.15 It is shown in the state of compression deformation along the predetermined load input direction. Fig.13 A three-dimensional diagram of a porous structure.

[0037] Fig.16 It is a perspective view showing the unit partitioning portion of the porous structure according to the eighth embodiment of the present invention.

[0038] Fig.17 This is a perspective view schematically showing a vehicle seat that can include a porous structure according to any embodiment of the present invention.

[0039] Fig.18 It is a drawing for explaining a method for producing a porous structure according to one embodiment of the present invention, which can be used to produce a porous structure according to any embodiment of the present invention. DETAILED DESCRIPTION

[0040] The porous structure and the method for producing the porous structure of the present invention are suitable for use in cushioning materials, for example, any vehicle seat and any vehicle seat cushion (seat pad), and are particularly suitable for use in vehicle seats and vehicle seat cushions.

[0041] Hereinafter, embodiments of the porous structure and the method for producing the porous structure of the present invention will be described by way of example with reference to the drawings.

[0042] The same reference numerals are given to common components in the drawings.

[0043] [First embodiment of porous structure]

[0044] First, refer to Figure 1 to Figure 5 A porous structure 1 according to a first embodiment of the present invention will be described. Figure 1 to Figure 4 A part of the porous structure 1 of the present embodiment is shown in a natural state. Here, the "natural state" means a state in which no external force is applied and no compression deformation or the like is performed. Figure 5 A part of the porous structure 1 of the present embodiment is shown in a state of being compressively deformed in a predetermined load input direction ID.

[0045] The porous structure 1 is formed by a 3D printer. Fig.18 Detailed description. By using a 3D printer to manufacture the porous structure 1, the manufacturing becomes simpler than the case of a foaming process using a chemical reaction as in the past, and the structure as expected can be obtained. In addition, through the future technological progress of 3D printers, it can be expected that manufacturing using a 3D printer can be achieved in a shorter time and at a lower cost in the future. In addition, by using a 3D printer to manufacture the porous structure 1, the structure of the porous structure 1 corresponding to various required characteristics can be simply and as expected.

[0046] The porous structure 1 is made of a flexible resin or rubber.

[0047] Here, "resin with flexibility" refers to a resin that can be deformed when a load is applied, for example, preferably an elastomer resin, more preferably polyurethane. As rubber, natural rubber or synthetic rubber can be cited. The porous structure 1 is composed of a flexible resin or rubber, so it can be compressed and restored according to the application and release of the load from the user, and thus can have a cushioning property.

[0048] In addition, from the viewpoint of ease of production using a 3D printer, it is more preferable for the porous structure 1 to be made of a flexible resin than of a rubber.

[0049] In addition, from the viewpoint of ease of production using a 3D printer, the porous structure 1 is preferably composed of materials of the same composition as a whole. However, the porous structure 1 may be composed of materials of different compositions depending on the location.

[0050] In addition, when the porous structure 1 is manufactured using a 3D printer, a resin using photocurable polyurethane (particularly ultraviolet curable polyurethane) as a raw material can be used as a material constituting the porous structure 1. As the photocurable polyurethane (particularly ultraviolet curable polyurethane), a resin using polyurethane acrylate or polyurethane methacrylate as a raw material can be used. As such a resin, for example, the materials described in US4337130 can be cited.

[0051] The porous structure 1 includes a skeleton part 2 forming the skeleton of the porous structure 1. The skeleton part 2 divides a plurality of unit pores C. The skeleton part 2 exists throughout the entirety of the porous structure 1 and is composed of a flexible resin or rubber. In the present embodiment, the portion other than the skeleton part 2 in the porous structure 1 is a void, in other words, the porous structure 1 is composed only of the skeleton part 2.

[0052] like Figure 1 As shown, the skeleton part 2 of the porous structure 1 includes a plurality of bone parts 2B and a plurality of joint parts 2J in its entirety. Figure 2 to Figure 4 As shown, in this embodiment, a part (one or more) of the multiple bone parts 2B included in the skeleton part 2 is a continuous bone part 2BA that is continuous within its entire range, and the remaining (one or more) of the multiple bone parts 2B included in the skeleton part 2 is a non-continuous bone part 2BB that is divided into two parts (a first divided bone part 51 and a second divided bone part 52 described later). Each continuous bone part 2BA is configured in a columnar shape. Each bone part 2B extends from one end 2Be to the other end 2Be.

[0053] like Figure 3As shown, one end 51r of the first segmented bone portion 51 constitutes one end 2Be of the bone portion 2B, and is hereinafter referred to as the "root portion 51r" for convenience. The other end 51t of the first segmented bone portion 51 is not connected to other parts of the skeleton portion 2, and is hereinafter referred to as the "front end portion 51t" for convenience. One end 52r of the second segmented bone portion 52 constitutes the other end 2Be of the bone portion 2B, and is hereinafter referred to as the "root portion 52r" for convenience. The other end 52t of the second segmented bone portion 52 is not connected to other parts of the skeleton portion 2, and is hereinafter referred to as the "front end portion 52t" for convenience.

[0054] In the present specification, when describing the bone portion 2B, the discontinuous bone portion 2BB is considered to be a single portion, regardless of whether the first divided bone portion 51 and the second divided bone portion 52 are in contact with each other in a natural state.

[0055] Each connecting portion 2J connects the ends 2Be of a plurality of (for example, three) bone portions 2B extending in different directions to each other at a location where the ends 2Be in the extending direction are adjacent to each other.

[0056] The skeleton portion 2 includes a plurality of bone portions 2B and a plurality of joint portions 2J in its entirety, and thus has a mesh shape.

[0057] The frame portion 2 is preferably integrally formed as a whole (ie, formed of one member), but may be formed of a plurality of members that are independent of each other.

[0058] exist Figure 1 to Figure 4In the figure, the skeleton line O of the skeleton part 2 is represented by a single-point dashed line in a part of the porous structure 1. The skeleton line O of the skeleton part 2 includes the skeleton line O of each bone part 2B and the skeleton line O of each joint part 2J. The skeleton line O of the bone part 2B is the central axis of the bone part 2B. The central axis of the bone part 2B is a line formed by smoothly connecting the center points of the shape formed by the bone part 2B at each point in the extension direction of the bone part 2B in a cross section perpendicular to the extension direction of the bone part 2B. In addition, the central axis of the discontinuous bone part 2BB is a line formed by smoothly connecting the center points of the shape formed by the discontinuous bone part 2BB at each point in the extension direction of the discontinuous bone part 2BB in a cross section perpendicular to the extension direction of the discontinuous bone part 2BB when the first split bone part 51 and the second split bone part 52 are regarded as one part. The skeleton line O (central axis) of the discontinuous bone portion 2BB may be different from the central axes of the first segmented bone portion 51 and the second segmented bone portion 52. The central axis of the first segmented bone portion 51 is a line formed by smoothly connecting the centroids of the shape formed by the first segmented bone portion 51 at each point in the extension direction of the first segmented bone portion 51 in a cross section perpendicular to the extension direction of the first segmented bone portion 51. The central axis of the second segmented bone portion 52 is a line formed by smoothly connecting the centroids of the shape formed by the second segmented bone portion 52 at each point in the extension direction of the second segmented bone portion 52 in a cross section perpendicular to the extension direction of the second segmented bone portion 52. The extension direction of the bone portion 2B is the extension direction of the skeleton line O of the bone portion 2B (the portion of the skeleton line O corresponding to the bone portion 2B. The same applies hereinafter). The skeleton line O of the joint portion 2J is an extended line portion obtained by smoothly extending the central axes of the bone portions 2B connected to the joint portion 2J into the joint portion 2J and connecting them to each other.

[0059] Since the porous structure 1 includes the skeleton portion 2 over substantially the entire area thereof, it can be compressed and deformed in accordance with the application and release of a load while ensuring air permeability, thereby improving the characteristics as a cushioning material.

[0060] In this embodiment, each continuous bone portion 2BA is columnar and extends linearly ( Figure 1 to Figure 4 In addition, in the present embodiment, each of the first segmented bone portions 51 and each of the second segmented bone portions 52 is columnar and extends in a straight line ( Figure 1 to Figure 4 ). Accordingly, each discontinuous bone portion 2BB is substantially columnar and extends substantially linearly.

[0061] However, it is also possible that part or all of the continuous bone portions 2BA constituting the skeleton portion 2 are extended in a curved manner. In this case, by bending part or all of the continuous bone portions 2BA, it is possible to prevent the continuous bone portion 2BA and thus the porous structure 1 from changing shape suddenly when a load is input, thereby suppressing local buckling. From the same point of view, it is also possible that part or all of the first segmented bone portions 51 constituting the skeleton portion 2 are extended in a curved manner. In addition, it is also possible that part or all of the second segmented bone portions 52 constituting the skeleton portion 2 are extended in a curved manner. In addition, it is also possible that part or all of the non-continuous bone portions 2BB constituting the skeleton portion 2 are substantially extended in a curved manner.

[0062] In this example, each of the continuous bone portions 2BA constituting the skeleton portion 2 has substantially the same shape and length ( Figure 1 to Figure 4 ). However, not limited to this example, the shapes and / or lengths of the continuous bone portions 2BA constituting the skeleton portion 2 may be different from each other. For example, the shape and / or length of a part of the continuous bone portion 2BA may be different from that of the other continuous bone portions 2BA. In this case, by making the shape and / or length of the continuous bone portion 2BA of a specific part of the skeleton portion 2 different from that of the continuous bone portion 2BA of other parts, different mechanical properties can be intentionally obtained.

[0063] In this example, the width W0 of each continuous bone portion 2BA ( Figure 4 ) and the cross-sectional area are constant over the entire length of the continuous bone portion 2BA (i.e., uniform along the extension direction of the continuous bone portion 2BA) ( Figure 1 to Figure 4 ).

[0064] Here, the cross-sectional area of ​​the continuous bone portion 2BA refers to the cross-sectional area of ​​the cross section perpendicular to the skeleton line O (central axis) of the continuous bone portion 2BA. Figure 4 ) refers to the maximum width of the cross section when measured along a cross section perpendicular to the skeleton line O of the continuous bone portion 2BA.

[0065] However, in each example described in the present specification, a part or all of the continuous bone portions 2BA constituting the skeleton portion 2 may have a width W0 and / or a cross-sectional area of ​​the continuous bone portion 2BA that is uneven along the extension direction of the continuous bone portion 2BA. For example, a part or all of the continuous bone portions 2BA constituting the skeleton portion 2 may have a width W0 of the continuous bone portion 2BA in a portion including the end portions 2Be on both sides of the extension direction of the continuous bone portion 2BA that gradually increases or decreases toward the two ends of the extension direction of the continuous bone portion 2BA. In addition, a part or all of the continuous bone portions 2BA constituting the skeleton portion 2 may have a cross-sectional area of ​​the continuous bone portion 2BA in a portion including the end portions 2Be on both sides of the extension direction of the continuous bone portion 2BA that gradually increases or decreases toward the two ends of the extension direction of the continuous bone portion 2BA.

[0066] In this specification, "gradually changing (increasing or decreasing)" means that the value is not constant in the middle but changes smoothly (increasing or decreasing) all the time.

[0067] Similarly, in this example, the width W1 ( Figure 4 ) and the cross-sectional area are constant over the entire length of the first segmented bone portion 51 (ie, uniform along the extending direction of the first segmented bone portion 51) ( Figure 1 , Figure 3 , Figure 4 In addition, in this example, the width W2 of each second segmented bone portion 52 ( Figure 4 ) and the cross-sectional area are constant over the entire length of the second segmented bone portion 52 (ie, uniform along the extending direction of the second segmented bone portion 52) ( Figure 1 , Figure 3 , Figure 4 ).

[0068] Here, the cross-sectional area of ​​the first segmented bone portion 51 refers to the cross-sectional area of ​​the section perpendicular to the central axis of the first segmented bone portion 51. The cross-sectional area of ​​the second segmented bone portion 52 refers to the cross-sectional area of ​​the section perpendicular to the central axis of the second segmented bone portion 52. In addition, the width W1 ( Figure 4 ) refers to the maximum width of the cross section when measured along a cross section perpendicular to the central axis of the first segmented bone portion 51. The width W2 ( Figure 4 ) refers to the maximum width of the cross section when measured along a cross section perpendicular to the central axis of the width W2 of the second divided bone portion 52.

[0069] However, in each example described in this specification, a part or all of the first segmented bone parts 51 constituting the skeleton part 2 may have a non-uniform width W1 and / or cross-sectional area along the extension direction of the first segmented bone part 51. In addition, in each example described in this specification, a part or all of the second segmented bone parts 52 constituting the skeleton part 2 may have a non-uniform width W2 and / or cross-sectional area along the extension direction of the second segmented bone part 52.

[0070] In each example described in this specification, from the perspective of simplifying the structure of the skeleton portion 2 and facilitating the manufacture of the porous structure 1 using a 3D printer, the width W0 ( Figure 4 ) is preferably greater than 0.05 mm, more preferably greater than 0.10 mm. When the minimum value of the width W0 is greater than 0.05 mm, the resolution of a high-performance 3D printer can be used for shaping, and when the minimum value of the width W0 is greater than 0.10 mm, not only the resolution of a high-performance 3D printer but also the resolution of a general 3D printer can be used for shaping. Here, the "minimum value of the width W0 of the continuous bone portion 2BA" refers to the width W0 of the portion in the extension direction where the width W0 of the continuous bone portion 2BA is the smallest.

[0071] Similarly, in each example described in this specification, the width W1 ( Figure 4 ) is preferably greater than 0.05 mm, and more preferably greater than 0.10 mm. In addition, in each example described in this specification, the second segmented bone portion 52 ( Figure 4 ) is preferably greater than 0.05 mm, more preferably greater than 0.10 mm. Here, the "minimum value of the width W1 of the first segmented bone portion 51" refers to the width W1 of the portion in the extension direction where the width W1 of the first segmented bone portion 51 is the smallest. In addition, the "minimum value of the width W2 of the second segmented bone portion 52" refers to the width W2 of the portion in the extension direction where the width W2 of the second segmented bone portion 52 is the smallest.

[0072] On the other hand, in each example described in this specification, from the viewpoint of improving the accuracy of the outer edge (outer contour) shape of the skeleton part 2, reducing the gap (interval) between the unit holes C, and improving the characteristics as a buffer material, the maximum value of the width W0 of the continuous bone part 2BA is preferably 2.0 mm or less. Here, the "maximum value of the width W0 of the continuous bone part 2BA" refers to the width W0 of the extension direction portion of the continuous bone part 2BA where the width W0 is the largest.

[0073] Similarly, in each example described in this specification, the maximum value of the width W1 of the first segmented bone portion 51 is preferably less than 2.0 mm. In addition, in each example described in this specification, the maximum value of the width W2 of the second segmented bone portion 52 is preferably less than 2.0 mm. Here, the "maximum value of the width W1 of the first segmented bone portion 51" refers to the width W1 of the portion in the extension direction where the width W1 of the first segmented bone portion 51 is the largest. In addition, the "maximum value of the width W2 of the second segmented bone portion 52" refers to the width W2 of the portion in the extension direction where the width W2 of the second segmented bone portion 52 is the largest.

[0074] In addition, each continuous bone portion 2BA constituting the skeleton portion 2 preferably satisfies the structure, but only a part of the continuous bone portions 2BA constituting the skeleton portion 2 may satisfy the structure. In this case, although there may be a difference in degree, the same effect can be obtained. In addition, each first segmented bone portion 51 constituting the skeleton portion 2 preferably satisfies the structure, but only a part of the first segmented bone portions 51 constituting the skeleton portion 2 may satisfy the structure. In this case, although there may be a difference in degree, the same effect can be obtained. In addition, each second segmented bone portion 52 constituting the skeleton portion 2 preferably satisfies the structure, but only a part of the second segmented bone portions 52 constituting the skeleton portion 2 may satisfy the structure. In this case, although there may be a difference in degree, the same effect can be obtained.

[0075] In this example, each continuous bone portion 2BA constituting the skeleton portion 2 is columnar, and each cross-sectional shape is circular (perfect circle) ( Figure 1 to Figure 4 ). In addition, in this example, each of the first segmented bone portions 51 constituting the skeleton portion 2 is columnar, and each of the cross-sectional shapes is circular (perfect circle) ( Figure 1 , Figure 3 , Figure 4 ). In addition, in this example, each of the second segmented bone portions 52 constituting the skeleton portion 2 is columnar, and each of the cross-sectional shapes is circular (perfect circle) ( Figure 1 , Figure 3 , Figure 4 ).

[0076] Thus, the structure of the skeleton part 2 is simple and easy to shape using a 3D printer. In addition, it is easy to reproduce the mechanical properties of a common polyurethane foam manufactured through a foaming process using a chemical reaction. Therefore, the properties of the porous structure 1 as a cushioning material can be improved. In addition, by configuring the continuous bone part 2BA, the first split bone part 51, and the second split bone part 52 to be columnar, the durability of the skeleton part 2 can be improved compared to the case where the continuous bone part 2BA, the first split bone part 51, and the second split bone part 52 are replaced with thinner membrane-like parts.

[0077] In addition, the cross-sectional shape of each continuous bone part 2BA is the shape of the cross-section perpendicular to the central axis (skeleton line O) of the continuous bone part 2BA. In addition, the cross-sectional shape of each first segmented bone part 51 is the shape of the cross-sectional shape perpendicular to the central axis of the first segmented bone part 51. In addition, the cross-sectional shape of each second segmented bone part 52 is the shape of the cross-sectional shape perpendicular to the central axis of the second segmented bone part 52.

[0078] In addition, not limited to this example, only a part of the continuous bone parts 2BA constituting the skeleton part 2 may satisfy the structure. In this case, although there may be differences in degree, the same effect can be obtained. In addition, only a part of the first split bone parts 51 constituting the skeleton part 2 may satisfy the structure. In this case, although there may be differences in degree, the same effect can be obtained. In addition, only a part of the second split bone parts 52 constituting the skeleton part 2 may satisfy the structure. In this case, although there may be differences in degree, the same effect can be obtained.

[0079] For example, in each example described in this specification, the cross-sectional shape of all or part of each continuous bone part 2BA constituting the skeleton part 2 may be a polygon (equilateral triangle, triangle other than equilateral triangle, quadrilateral, etc.), or a circle other than a perfect circle (ellipse, etc.), in which case, the same effect as in this example can be obtained. In addition, in each example described in this specification, the cross-sectional shape of all or part of each first segmented bone part 51 constituting the skeleton part 2 may be a polygon (equilateral triangle, triangle other than equilateral triangle, quadrilateral, etc.), or a circle other than a perfect circle (ellipse, etc.), in which case, the same effect as in this example can be obtained. In addition, in each example described in this specification, the cross-sectional shape of all or part of each second segmented bone part 52 constituting the skeleton part 2 may be a polygon (equilateral triangle, triangle other than equilateral triangle, quadrilateral, etc.), or a circle other than a perfect circle (ellipse, etc.), in which case, the same effect as in this example can be obtained.

[0080] In each example described in this specification, the cross-sectional shape of each continuous bone portion 2BA may be uniform along its extension direction, or may be non-uniform along its extension direction. In addition, in each example described in this specification, the cross-sectional shape of each first segmented bone portion 51 may be uniform along its extension direction, or may be non-uniform along its extension direction. In addition, in each example described in this specification, the cross-sectional shape of each second segmented bone portion 52 may be uniform along its extension direction, or may be non-uniform along its extension direction.

[0081] In each example described in this specification, the cross-sectional shapes of each continuous bone portion 2BA may be different from each other. In addition, in each example described in this specification, the cross-sectional shapes of each first segmented bone portion 51 may be different from each other. In addition, in each example described in this specification, the cross-sectional shapes of each second segmented bone portion 52 may be different from each other.

[0082] In each example described in this specification, the ratio of the volume VB occupied by the skeleton 2 to the apparent volume VS of the skeleton 2 (VB×100 / VS[%]) is preferably 3% to 10%. With this structure, the reaction force generated by the skeleton 2 when a load is applied to the skeleton 2, and thus the hardness of the skeleton 2 (and thus the hardness of the porous structure 1) can be improved when used as a cushioning material, such as a seat cushion (particularly a seat cushion for a vehicle).

[0083] Here, the "apparent volume VS of the skeleton 2" refers to the entire internal space surrounded by the outer edge (outer contour) of the skeleton 2 (the volume occupied by the skeleton 2, the volume of the membrane 3 ( Fig.16 ) is the volume occupied by the membrane 3 and the volume occupied by the voids.

[0084] When the materials constituting the skeleton 2 are considered to be the same, the higher the ratio of the volume VB occupied by the skeleton 2 in the apparent volume VS of the skeleton 2, the harder the skeleton 2 (and thus the porous structure 1) is. In addition, the lower the ratio of the volume VB occupied by the skeleton 2 in the apparent volume VS of the skeleton 2, the softer the skeleton 2 (and thus the porous structure 1) is.

[0085] From the viewpoint that the reaction force generated by the skeleton portion 2 when a load is applied to the skeleton portion 2 and therefore the hardness of the skeleton portion 2 (and therefore the porous structure 1) is good when used as a cushioning material, such as a seat cushion (especially a seat cushion for vehicles), the ratio of the volume VB occupied by the skeleton portion 2 in the apparent volume VS of the skeleton portion 2 is more preferably 4% to 8%.

[0086] In addition, as a method for adjusting the ratio of the volume VB occupied by the skeleton portion 2 in the apparent volume VS of the skeleton portion 2, any method can be used, for example, a method of adjusting the thickness (cross-sectional area) of a part of the bone portion 2B or all of the bone portion 2B constituting the skeleton portion 2 and / or the size (cross-sectional area) of a part of the joint portion J or all of the joint portion J constituting the skeleton portion 2.

[0087] In each example described in this specification, the 25% hardness of the porous structure 1 is preferably 60N to 500N, and more preferably 100N to 450N. Here, the 25% hardness (N) of the porous structure 1 is a measured value obtained by measuring the load (N) required to compress the porous structure by 25% in an environment of 23°C and 50% relative humidity using an inward compression tester. As a result, the hardness of the porous structure 1 can be made good when used as a cushioning material, such as a seat cushion (especially a seat cushion for a vehicle).

[0088] like Figure 1 to Figure 4 As shown, in this example, the skeleton part 2 has a plurality of unit dividing parts 21 (the number of unit holes C) that divide the unit holes C inside. The skeleton part 2 has a structure in which many unit dividing parts 21 are connected to each other. Each unit dividing part 21 is composed of a plurality of bone parts 2B and a plurality of connecting parts 2J. Figure 1 In the example, the plurality of unit division parts 21 provided in the skeleton part 2 include one or more (in Figure 1 In the example of multiple) unit division part 21A and having one or more (in Figure 1 In the example of multiple) non-continuous bone parts 2BB one or more (in Figure 1 However, in this embodiment, each unit dividing part 21 provided by the skeleton part 2 may be a unit dividing part 21B having one or more discontinuous bone parts 2BB. Each unit dividing part 21B having one or more discontinuous bone parts 2BB is preferably a unit dividing part 21B having one or more discontinuous bone parts 2BB. Figure 3 As in the example of FIG. 1 , it also has one or more continuous bone parts 2BA.

[0089] Figure 2 express Figure 1 The porous structure 1 includes a plurality of unit partitioning parts 21, which is a unit partitioning part 21A that does not have a discontinuous bone part 2BB. Each bone part 2B of the unit partitioning part 21A is a continuous bone part 2BA. Figure 3 express Figure 1 Among the plurality of unit division parts 21 provided in the porous structure 1, one or more (in Figure 3 In the example, there are multiple) unit dividing parts 21B of non-continuous bone parts 2BB.

[0090] like Figure 3-4 As shown, each unit dividing part 21 has a plurality of (14 in this example) annular parts 211. Each annular part 211 is configured to be annular (including substantially annular), and a substantially flat imaginary surface V1 is divided by the inner peripheral edge 2111 of each annular (including substantially annular). The imaginary surface V1 is an imaginary plane (i.e., an imaginary closed plane) divided by the inner peripheral edge 2111 of the annular part 211. In each unit dividing part 21, the plurality of annular parts 211 constituting the unit dividing part 21 are connected to each other in such a manner that the imaginary surfaces V1 divided by the respective inner peripheral edge 2111 do not intersect with each other.

[0091] The unit hole C is formed by dividing the unit dividing portion 21 by a plurality of annular portions 211 and a plurality of imaginary surfaces V1 respectively divided by the plurality of annular portions 211. In general, the annular portion 211 is a portion that divides the sides of the three-dimensional shape formed by the unit hole C, and the imaginary surface V1 is a portion that divides the structural surface of the three-dimensional shape formed by the unit hole C.

[0092] Each annular portion 211 is composed of a plurality of bone portions 2B and a plurality of connecting portions 2J connecting end portions 2Be of the plurality of bone portions 2B to each other.

[0093] The connection portion of the pair of mutually connected annular portions 211 is composed of a bone portion 2B shared by the pair of annular portions 211 and a pair of connecting portions 2J on both sides thereof. That is, each bone portion 2B and each connecting portion 2J are shared by a plurality of adjacent annular portions 211 .

[0094] Each imaginary surface V1 divides a portion of a certain unit hole C using the surface on one side of the imaginary surface V1 (the surface of the imaginary surface V1), and divides a portion of another unit hole C using the surface on the other side of the imaginary surface V1 (the back side of the imaginary surface V1). In other words, each imaginary surface V1 divides a portion of a different unit hole C using the surfaces on both sides thereof. In other words, each imaginary surface V1 is shared by a pair of unit holes C adjacent to the imaginary surface V1 (i.e., a pair of unit holes C sandwiching the imaginary surface V1).

[0095] In addition, each annular portion 211 is shared by a pair of unit dividing portions 21 adjacent to the annular portion 211 (that is, a pair of unit dividing portions 21 sandwiching the annular portion 211) ( Figure 1 , Figure 4 ) In other words, each annular portion 211 constitutes a portion of each of a pair of unit partitioning portions 21 adjacent to each other.

[0096] exist Figure 1 to Figure 4 In the example of FIG. 1 , each imaginary surface V1 of the porous structure 1 is not covered by the membrane 3 ( Fig.16) is not covered but opened, i.e., it forms an opening. Therefore, the unit pores C are interconnected through the imaginary surface V1, and air permeability between the unit pores C can be achieved. As a result, the air permeability of the skeleton part 2 can be improved, and the compression and recovery deformation corresponding to the application and release of the load of the skeleton part 2 become easy.

[0097] like Figure 1 to Figure 4 As shown in FIG. 1 , in this example, the skeleton line O of each unit partitioning portion 21 is substantially polyhedral, and thus each unit hole C is substantially polyhedral. More specifically, Figure 1 to Figure 4 In the example, the skeleton line O of each unit dividing portion 21 is roughly in the shape of a Kelvin tetradecahedron (truncated octahedron), and thus each unit hole C is roughly in the shape of a Kelvin tetradecahedron (truncated octahedron). The Kelvin tetradecahedron (truncated octahedron) is a polyhedron composed of 6 regular quadrilateral structural faces and 8 regular hexagonal structural faces. In general, the unit holes C constituting the skeleton portion 2 are arranged regularly in a manner that fills the internal space surrounded by the outer edge (outer contour) of the skeleton portion 2 (that is, the unit holes C are filled without useless gaps between each other, in other words, the gaps (intervals) between the unit holes C are reduced).

[0098] like Figure 1 to Figure 4 As shown, in this example, the plurality of (14 in this example) annular portions 211 constituting the unit dividing portion 21 respectively include one or more (6 in this example) small annular portions 211S and one or more (8 in this example) large annular portions 211L. Each small annular portion 211S is divided into a roughly flat small imaginary surface V1S by using its annular (also including substantially annular) inner peripheral side edge 2111. Each large annular portion 211L is divided into a roughly flat large imaginary surface V1L having a larger area than the small imaginary surface V1S by using its annular (also including substantially annular) inner peripheral side edge 2111. The small imaginary surface V1S and the large imaginary surface V1L are respectively imaginary planes (i.e., imaginary closed planes).

[0099] according to Figure 2 and Figure 3 It can be seen that in this example, the skeleton line O of the large annular portion 211L is a substantially regular hexagon, and accordingly, the large imaginary surface V1L is also a substantially regular hexagon. In addition, in this example, the skeleton line O of the small annular portion 211S is a substantially regular quadrilateral, and accordingly, the small imaginary surface V1S is also a substantially regular quadrilateral. Thus, in this example, the small imaginary surface V1S and the large imaginary surface V1L are different not only in area, but also in shape (specifically, the number and shape of the constituent surfaces).

[0100] Each large annular portion 211L is composed of a plurality of (six in this example) bone portions 2B and a plurality of (six in this example) joint portions 2J that join the ends 2Be of the plurality of bone portions 2B. Each small annular portion 211S is composed of a plurality of (four in this example) bone portions 2B and a plurality of (four in this example) joint portions 2J that join the ends 2Be of the plurality of bone portions 2B.

[0101] Moreover, in Figure 1 to Figure 4 In the example, the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton part 2 are respectively approximately Kelvin tetrahedrons (truncated octahedrons). As described above, the Kelvin tetrahedron (truncated octahedron) is a polyhedron composed of 6 regular quadrilateral structural faces and 8 regular hexagonal structural faces. Accordingly, the unit holes C divided by each unit dividing part 21 are also approximately Kelvin tetrahedrons. The skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton part 2 are connected to each other in a space-filling manner, forming a mesh shape. That is, there are no gaps between the skeleton lines O of the multiple unit dividing parts 21.

[0102] Thus, in this example, the skeleton lines O of the plurality of unit dividing parts 21 constituting the skeleton part 2 are respectively roughly polyhedrons (roughly Kelvin tetrahedrons in this example), and accordingly, the unit pores C are roughly polyhedrons (roughly Kelvin tetrahedrons in this example), so that the gaps (intervals) between the unit pores C constituting the porous structure 1 can be further reduced, and more unit pores C can be formed inside the porous structure 1. In addition, as a result, the compression and recovery deformation behaviors of the porous structure 1 corresponding to the application and release of the load become better when used as a cushioning material, such as a seat cushion (especially a seat cushion for a vehicle). In addition, the gaps (intervals) between the unit pores C are equivalent to the wall portions (bone portions 2B, joint portions 2J) of the skeleton part 2 that divide the unit pores C.

[0103] In addition, in this example, since the skeleton lines O of the plurality of unit partitions 21 constituting the skeleton portion 2 are connected to each other in a space-filling manner, the gaps (intervals) between the unit pores C constituting the porous structure 1 can be further reduced. Therefore, the characteristics of the porous structure as a buffer material can be improved.

[0104] The roughly polyhedron formed by the skeleton lines O of the unit partitioning portion 21 (and further, the roughly polyhedron formed by the unit holes C) is not limited to the examples in the respective drawings, and may be in any form.

[0105] For example, the roughly polyhedron formed by the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton part 2 (and then the roughly polyhedron formed by the unit pores C) is preferably able to fill the space (can be configured without gaps). Thus, the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton part 2 can be connected to each other in a way that fills the space, so the properties of the porous structure as a buffer material can be improved. In this case, the roughly polyhedron formed by the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton part 2 (and then the roughly polyhedron formed by the unit pores C) can include only one roughly polyhedron as in this example, or it can also include multiple roughly polyhedrons. Here, with respect to a polyhedron, "type" refers to a shape (the number and shape of the constituent faces), specifically, it means that two polyhedrons with different shapes (the number and shape of the constituent faces) are treated as two types of polyhedrons, and two polyhedrons with the same shape and only different sizes are treated as polyhedrons of the same type. As for the roughly polyhedron formed by the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton part 2, as examples of the roughly polyhedron that can fill the space and only includes one kind of roughly polyhedron, in addition to the roughly Kelvin tetrahedron, there can be listed roughly regular triangular prisms, roughly regular hexagonal prisms, roughly cubes, roughly rectangular parallelepipeds, roughly rhombic dodecahedrons, etc. In addition, when the shape of the skeleton lines O of the unit dividing part 21 is set to a roughly Kelvin tetrahedron (truncated octahedron) as in the examples of each figure, it is easiest to reproduce the characteristics of the cushioning material equivalent to the ordinary polyurethane foam manufactured through the process of foaming using chemical reaction compared to other shapes. In addition, when the shape of the skeleton lines O of the unit dividing part 21 is set to a roughly Kelvin tetrahedron (truncated octahedron), equal mechanical properties can be obtained in all directions. As examples of the roughly polyhedron formed by the skeleton lines O of the plurality of unit dividing portions 21 constituting the skeleton portion 2, which can fill the space and include a plurality of types of roughly polyhedrons, there can be cited a combination of a roughly regular tetrahedron and a roughly regular octahedron, a combination of a roughly regular tetrahedron and a roughly truncated tetrahedron, a combination of a roughly regular octahedron and a roughly truncated hexahedron, etc. In addition, these are examples of combinations of two roughly polyhedrons, but combinations of three or more roughly polyhedrons may also be used.

[0106] In addition, the approximate polyhedron formed by the skeleton lines O of the multiple unit dividing portions 21 constituting the skeleton portion 2 (and thus the approximate polyhedron formed by the unit holes C) can be, for example, any approximate regular polyhedron (a approximate convex polyhedron in which all faces are identical approximate regular polygons and the number of faces touching at all vertices is equal), an approximate semi-regular polyhedron (a polyhedron other than an approximate regular polyhedron in which all faces are approximate regular polygons and all vertices have the same shape (the types and order of the approximate regular polygons gathered at the vertices are the same)), a approximate prism, a approximate pyramid, etc.

[0107] In addition, the skeleton lines O of a part or all of the multiple unit dividing parts 21 constituting the skeleton part 2 may also be in a roughly three-dimensional shape other than a roughly polyhedron (for example, a roughly sphere, a roughly ellipsoid, a roughly cylinder, etc.). Furthermore, a part or all of the multiple unit holes C constituting the skeleton part 2 may also be in a roughly three-dimensional shape other than a roughly polyhedron (for example, a roughly sphere, a roughly ellipsoid, a roughly cylinder, etc.).

[0108] By including the small annular portion 211S and the large annular portion 211L of different sizes in the plurality of annular portions 211 constituting the unit dividing portion 21, the gap (interval) between the unit holes C constituting the skeleton portion 2 can be further reduced. In addition, when the shapes (number of sides) of the small annular portion 211S and the large annular portion 211L are different as in this example, the gap (interval) between the unit holes C constituting the skeleton portion 2 can be further reduced.

[0109] However, the size and / or shape (number of sides) of the plurality of annular portions 211 constituting the unit partitioning portion 21 may be the same as each other. When the size and shape (number of sides) of each annular portion 211 constituting the unit partitioning portion 21 are the same, equal mechanical properties can be obtained in all directions.

[0110] By making the skeleton line O of part or all (in this example, all) of the annular parts 211 constituting the unit dividing part 21 (and then part or all (in this example, all) of the imaginary surfaces V1 constituting the unit dividing part 21) roughly polygonal as in this example, the intervals between the unit holes C constituting the skeleton part 2 can be further reduced. In addition, the compression and recovery deformation behaviors of the skeleton part 2 corresponding to the application and release of the load become better when used as a seat cushion, especially as a seat cushion for vehicles. In addition, since the shape of the annular part 211 (and then the shape of the imaginary surface V1) becomes simple, the manufacturability and the ease of adjusting the characteristics can be improved. In addition, when at least one of the annular parts 211 constituting the skeleton part 2 (and then at least one of the imaginary surfaces V1 constituting the skeleton part 2) satisfies this structure, although there may be differences in degree, the same effect can be obtained.

[0111] In addition, the skeleton line O of at least one of the annular portions 211 constituting the skeleton portion 2 (and furthermore, at least one of the imaginary surfaces V1 constituting the skeleton portion 2) may be any roughly polygonal shape other than a roughly regular hexagon or a roughly regular quadrilateral as in this example, or a roughly planar shape other than a roughly polygonal shape (for example, a roughly circular shape (a roughly perfect circle, a roughly ellipse, etc.)). When the shape of the skeleton line O of the annular portion 211 (and furthermore, the shape of the imaginary surface V1) is a roughly circular shape (a roughly perfect circle, a roughly ellipse, etc.), the shape of the annular portion 211 (and furthermore, the shape of the imaginary surface V1) becomes simple, thereby improving manufacturability and ease of adjustment of characteristics, and obtaining more uniform mechanical characteristics. For example, when the shape of the skeleton line O of the annular portion 211 (and thus the shape of the imaginary surface V1) is an ellipse (a horizontally long ellipse) that is longer in a direction approximately perpendicular to the predetermined load input direction ID, the annular portion 211, and thus the skeleton portion 2 (and thus the porous structure 1) is easily deformed (becomes softer) relative to the input of load compared to the case where the shape of the skeleton line O of the annular portion 211 (and thus the shape of the imaginary surface V1) is an ellipse (a vertically long ellipse) that is longer in a direction approximately parallel to the predetermined load input direction ID.

[0112] In this example, the skeleton part 2 preferably has at least one unit hole C with a diameter of 5 mm or more. Thus, it is easy to manufacture the porous structure 1 using a 3D printer. If the diameter of each unit hole C of the skeleton part 2 is less than 5 mm, the structure of the skeleton part 2 becomes too complicated, and as a result, it may be difficult to generate three-dimensional shape data (CAD data, etc.) representing the three-dimensional shape of the porous structure 1 on a computer, or 3D modeling data generated based on the three-dimensional shape data.

[0113] Furthermore, the porous structure constituting the conventional cushioning material is produced through a foaming process utilizing a chemical reaction, and therefore it is not easy to form unit cells C having a diameter of 5 mm or more.

[0114] Furthermore, since the skeleton portion 2 has the unit pores C having a diameter of 5 mm or more, the air permeability and the ease of deformation of the skeleton portion 2 can be easily improved.

[0115] From such a viewpoint, the diameters of all the unit pores C constituting the skeleton portion 2 are preferably 5 mm or more.

[0116] The larger the diameter of the unit hole C, the easier it is to manufacture the porous structure 1 using a 3D printer, and it is also easy to improve air permeability and ease of deformation. From this point of view, the diameter of at least one (preferably all) unit holes C of the skeleton part 2 is more preferably 8 mm or more, and further preferably 10 mm or more.

[0117] On the other hand, if the unit pores C of the skeleton part 2 are too large, it is difficult to neatly (smoothly) form the outer edge (outer contour) shape of the skeleton part 2 (and then the porous structure 1), and the shape accuracy of the cushioning material (such as a seat cushion, especially a seat cushion for a vehicle) may decrease, and the appearance may deteriorate. In addition, the properties of the cushioning material (such as a seat cushion, especially a seat cushion for a vehicle) may also become not good enough. Therefore, from the viewpoint of improving the appearance and the properties of the cushioning material (such as a seat cushion, especially a seat cushion for a vehicle), the diameter of each unit pore C of the skeleton part 2 is preferably less than 30 mm, more preferably less than 25 mm, and further preferably less than 20 mm.

[0118] In addition, the more unit pores C that satisfy the numerical range of the diameter of the porous structure 1, the easier it is to obtain the above-mentioned effects. From such a viewpoint, the diameter of each unit pore C constituting the porous structure 1 preferably satisfies at least any one of the numerical ranges mentioned above. Similarly, the average value of the diameter of each unit pore C constituting the porous structure 1 more preferably satisfies at least any one of the numerical ranges mentioned above.

[0119] In addition, when the unit hole C has a shape different from a strict spherical shape as in the present example, the diameter of the unit hole C means the diameter of the sphere circumscribing the unit hole C.

[0120] If the unit pores C of the skeleton part 2 are too small, the structure of the skeleton part 2 becomes too complicated, and as a result, it may be difficult to generate three-dimensional shape data (CAD data, etc.) representing the three-dimensional shape of the porous structure 1 on a computer or 3D shaping data generated based on the three-dimensional shape data, so it is difficult to manufacture the porous structure 1 using a 3D printer. From the perspective of making it easier to manufacture the porous structure 1 using a 3D printer, the diameter of the unit pores C with the smallest diameter among the unit pores C constituting the skeleton part 2 is preferably 0.05 mm or more, and more preferably 0.10 mm or more. When the diameter of the unit pore C with the smallest diameter is 0.05 mm or more, shaping can be performed using the resolution of a high-performance 3D printer, and when the diameter of the unit pore C with the smallest diameter is 0.10 mm or more, shaping can be performed using not only the resolution of a high-performance 3D printer but also the resolution of a general 3D printer.

[0121] like Figure 4-5 As shown, the porous structure 1 is configured so that multiple parts of the skeleton 2 interfere with each other when the porous structure 1 is compressed and deformed in the predetermined load input direction ID. Therefore, when the porous structure 1 is compressed and deformed in the predetermined load input direction ID, the multiple parts of the skeleton 2 generate friction with each other. Figure 4 The porous structure 1 is shown in a natural state without compression deformation. Figure 5The porous structure 1 is shown in a state when it is compressively deformed in a predetermined load input direction ID.

[0122] In this specification, the "predetermined load input direction ID" is a direction in which a main load from a user or the like is input to the porous structure 1. For example, in the case where the porous structure 1 is constituted as a cushioning material (for example Fig.17 In the case of a seat cushion such as the example of ), the predetermined load input direction ID is preferably the thickness direction TD of the cushioning material.

[0123] In the present specification, “during compression deformation” specifically means a period during which compression deformation is performed in a state in which any cell C in the porous structure 1 is not completely crushed.

[0124] In the present specification, "interference" between multiple parts specifically refers to, for example, multiple parts that were previously in a state of contact or non-contact with each other rubbing against each other (moving in contact), or multiple parts that were previously in a state of non-contact with each other colliding with each other (just after the collision, they may or may not move in contact immediately).

[0125] More specifically, the porous structure 1 of the present embodiment is configured such that the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB rub ​​against each other when compressively deformed along a predetermined load input direction ID ( Figure 4 (b) and Figure 5 (b)). Thus, when the porous structure 1 is compressed and deformed along the predetermined load input direction ID, friction is generated between the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB. When the porous structure 1 is in a natural state, the first segmented bone portion 51 and the second segmented bone portion 52 of each non-continuous bone portion 2BB can be in either a contact state or a non-contact state with each other. From the viewpoint of suppressing the mutual fixation of the first segmented bone portion 51 and the second segmented bone portion 52 of each non-continuous bone portion 2BB when forming using a 3D printer, the first segmented bone portion 51 and the second segmented bone portion 52 of each non-continuous bone portion 2BB are preferably in a non-contact state with each other when the porous structure 1 is in a natural state.

[0126] More specifically, in this embodiment, if Figure 3 As shown, in at least one (preferably all) discontinuous bone parts 2BB, the first segmented bone part 51 has a first side surface 51S, and the second segmented bone part 52 has a second side surface 52S. Furthermore, the porous structure 1 is configured such that the first side surface 51S of the first segmented bone part 51 and the second side surface 52S of the second segmented bone part 52 of at least one (preferably all) discontinuous bone part 2BB rub ​​against each other when compressively deformed along a predetermined load input direction ID ( Figure 4 (b) and Figure 5 (b)). Thus, when the porous structure 1 is compressed and deformed along the predetermined load input direction ID, friction is generated between the first side surface 51S of the first segmented bone portion 51 and the second side surface 52S of the second segmented bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB. In addition, the "first side surface 51S" of the first segmented bone portion 51 is a portion of the side surface of the first segmented bone portion 51 (the portion of the surface of the first segmented bone portion 51 other than the end surfaces on both sides of the extension direction) that is configured to rub against the second segmented bone portion 52 when the porous structure 1 is compressed and deformed along the predetermined load input direction ID. In addition, the "second side surface 52S" of the second segmented bone portion 52 is a portion of the side surface of the second segmented bone portion 52 (the portion of the surface of the second segmented bone portion 52 other than the end surfaces on both sides of the extension direction) that is configured to rub against the first segmented bone portion 51 when the porous structure 1 is compressed and deformed along the predetermined load input direction ID.

[0127] picture Figure 3 As in the example of FIG. 1 , the extending directions of the discontinuous bone portions 2BB are preferably substantially parallel to each other. Figure 3 In the example, the six bone portions 2B that are approximately parallel to each other in the unit dividing portion 21B are respectively discontinuous bone portions 2BB, and the porous structure 1 is configured so that the first side surface 51S of the first divided bone portion 51 and the second side surface 52S of the second divided bone portion 52 of each discontinuous bone portion 2BB rub ​​against each other when compressed and deformed along a predetermined load input direction ID. However, it is also possible that a part (one or more) of the six bone portions 2B that are approximately parallel to each other in the unit dividing portion 21B are respectively discontinuous bone portions 2BB, and the porous structure 1 is configured so that the first side surface 51S of the first divided bone portion 51 and the second side surface 52S of the second divided bone portion 52 of at least one (preferably all) of the discontinuous bone portions 2BB rub ​​against each other when compressed and deformed along a predetermined load input direction ID. In addition, Figure 3 As in the example of , the predetermined load input direction ID is preferably substantially parallel to the extending direction of each discontinuous bone portion 2BB.

[0128] According to the present embodiment, as described above, the porous structure 1 is configured so that the multiple parts of the skeleton part 2 interfere with each other when the porous structure 1 is compressed and deformed along the predetermined load input direction ID. Thus, the porous structure 1 generates friction between the multiple parts of the skeleton part 2 when the porous structure 1 is compressed and deformed along the predetermined load input direction ID. More specifically, the porous structure 1 of the present embodiment is configured so that the first segmented bone part 51 and the second segmented bone part 52 of at least one (preferably all) non-continuous bone part 2BB rub ​​against each other when the porous structure 1 is compressed and deformed along the predetermined load input direction ID. Thus, the porous structure 1 generates friction between the first segmented bone part 51 and the second segmented bone part 52 of the at least one (preferably all) non-continuous bone part 2BB when the porous structure 1 is compressed and deformed along the predetermined load input direction ID. More specifically, in the present embodiment, the porous structure 1 is configured so that the first side surface 51S of the first segmented bone part 51 of at least one (preferably all) non-continuous bone part 2BB and the second side surface 52S of the second segmented bone part 52 rub against each other when the porous structure 1 is compressed and deformed along the predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in the predetermined load input direction ID, friction occurs between the first side surface 51S of the first divided bone portion 51 and the second side surface 52S of the second divided bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB.

[0129] By generating this friction, the viscosity of the porous structure 1 can be increased, and thus the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the hysteresis attenuation characteristics)) of the porous structure of the present embodiment can be made different from the dynamic characteristics of the above-mentioned previous porous structures. In addition, by adjusting the number and area of ​​the mutually interfering parts in the skeleton portion 2, the amount of friction can be adjusted, and thus the viscosity and thus the dynamic characteristics of the porous structure 1 can be adjusted. Therefore, compared with the past, more various dynamic characteristics can be achieved according to requirements. In this way, by adopting the porous structure 1 of the present embodiment, the degree of freedom of adjustment of the dynamic characteristics of the porous structure 1 can be increased. This is particularly preferred in the case where the porous structure 1 is used for a vehicle seat cushion that has vibration input during use.

[0130] The porous structure 1 is not limited to Figure 1 to Figure 5 The structure of the first embodiment shown in FIG. 1 can be configured so that a plurality of parts of the frame portion 2 interfere with each other when compressively deforming in the predetermined load input direction ID by adopting various structures. Figure 1 to Figure 5 Other embodiments of the porous structure 1 are described with a focus on the differences from the first embodiment. Figure 1 to Figure 5 The same points of the implementation modes are basically omitted.

[0131] In the following description of the structure of the porous structural body 1 , unless otherwise specified, the structure of the porous structural body 1 in its natural state is referred to.

[0132] The porous structure 1 of each embodiment described below is configured such that a plurality of parts of the skeleton 2 interfere with each other when compressively deformed in the predetermined load input direction ID. Therefore, the same effects as those of the first embodiment described above can be obtained.

[0133] [Second embodiment of porous structure]

[0134] Figure 6-7 It is a figure for demonstrating the porous structure 1 of 2nd Embodiment of this invention. Figure 6 FIG. 1 is a diagram for explaining an example of a porous structure 1 according to a second embodiment of the present invention. Figure 7 (a)~ Figure 7 (b) are drawings for explaining first to second modifications of the porous structure 1 according to the second embodiment of the present invention.

[0135] In the second embodiment, similarly to the first embodiment, the porous structure 1 is configured such that the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB rub ​​against each other when the porous structure 1 is compressively deformed in the predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in the predetermined load input direction ID, friction occurs between the first segmented bone portion 51 and the second segmented bone portion 52 of the at least one (preferably all) discontinuous bone portion 2BB.

[0136] More specifically, in the second embodiment, similarly to the first embodiment, in at least one (preferably all) discontinuous bone parts 2BB, the first segmented bone part 51 has a first side surface 51S, and the second segmented bone part 52 has a second side surface 52S, and the porous structure 1 is configured such that the first side surface 51S of the first segmented bone part 51 and the second side surface 52S of the second segmented bone part 52 of at least one (preferably all) discontinuous bone part 2BB rub ​​against each other when compressively deformed in a predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in a predetermined load input direction ID, friction occurs between the first side surface 51S of the first segmented bone part 51 and the second side surface 52S of the second segmented bone part 52 of at least one (preferably all) discontinuous bone part 2BB.

[0137] In the first embodiment ( Figure 1 to Figure 5 ), as described above, the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (all in the example of the figure) discontinuous bone portion 2BB are respectively configured as columns. Figure 6-7 ), at least one of the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB is configured as a strip. More specifically, Figure 6-7In each example, the first divided bone portion 51 and the second divided bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB are respectively configured in a belt shape.

[0138] like Figure 6 As shown in an enlarged manner in (b), in the at least one discontinuous bone portion 2BB, the side surface of the first divided bone portion 51 includes a pair of wide side surfaces 511 located on opposite sides to each other and a pair of narrow side surfaces 512 located on opposite sides to each other and having widths narrower than the pair of wide side surfaces 511. The first side surface 51S of the first divided bone portion 51 is any one of the pair of wide side surfaces 511 of the first divided bone portion 51. Similarly, in the at least one discontinuous bone portion 2BB, the side surface of the second divided bone portion 52 includes a pair of wide side surfaces 521 located on opposite sides to each other and a pair of narrow side surfaces 522 located on opposite sides to each other and having widths narrower than the pair of wide side surfaces 521. The second side surface 52S of the second divided bone portion 52 is any one of the pair of wide side surfaces 521 of the second divided bone portion 52.

[0139] However, although not shown in the figure, in the second embodiment, only one of the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB may be configured in a strip shape. In this case, the other of the first segmented bone portion 51 and the second segmented bone portion 52 of the discontinuous bone portion 2BB may be configured in a column shape, for example.

[0140] According to the second embodiment, since at least one of the first split bone portion 51 and the second split bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB is configured as a strip and thus configured to be wider, compared to the first embodiment, the first side surface 51S and the second side surface 52S can also rub more reliably when misalignment occurs.

[0141] In addition, according to Figure 6-7 In each example, since the first split bone portion 51 and the second split bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB are respectively constructed in a strip shape, the contact area between the first side surface 51S and the second side surface 52S can be increased compared to the first embodiment, and the amount of friction generated between the first side surface 51S and the second side surface 52S can be increased.

[0142] In the second embodiment, it is preferred that the first side surface 51S and the second side surface 52S of at least one (preferably all) of the discontinuous bone portion 2BB are not curved but are substantially flat. In this case, the first side surface 51S and the second side surface 52S may be smooth surfaces (smooth surfaces) without concave and convex portions, or may be formed by forming a flat surface as described later. Figure 8 As in the embodiment of the present invention, there are a plurality of protrusions P and there are projections and depressions.

[0143] However, the first side surface 51S and the second side surface 52S of at least one (preferably all) of the discontinuous bone portion 2BB may be curved in the same direction. In this case, the first side surface 51S and the second side surface 52S may be smooth surfaces (smooth surfaces) without concave and convex surfaces, or may be curved in the same direction as described later. Figure 8 As in the embodiment of the present invention, there are a plurality of protrusions P and there are projections and depressions.

[0144] exist Figure 6 In the example, in at least one (preferably all) of the above-mentioned non-continuous bone portions 2BB, the width of the first side surface 51S of the first divided bone portion 51 gradually increases from the root 51r of the first divided bone portion 51 toward the front end portion 51t of the first divided bone portion 51, and in addition, the width of the second side surface 52S of the second divided bone portion 52 gradually increases from the root 52r of the second divided bone portion 52 toward the front end portion 52t of the second divided bone portion 52.

[0145] However, the shapes of the first side surface 51S and the second side surface 52S are arbitrary.

[0146] For example, you can also Figure 7 As in the first variation shown in (a), in at least one (preferably all) of the above-mentioned non-continuous bone portions 2BB, the width of the first side surface 51S of the first split bone portion 51 is constant from the root 51r of the first split bone portion 51 toward the front end portion 51t of the first split bone portion 51, and in addition, the width of the second side surface 52S of the second split bone portion 52 is constant from the root 52r of the second split bone portion 52 toward the front end portion 52t of the second split bone portion 52.

[0147] Or, you can also do Figure 7 As in the second modified example shown in (b), in at least one (preferably all) of the above-mentioned non-continuous bone portions 2BB, the width of the first side surface 51S of the first split bone portion 51 gradually increases from the root 51r of the first split bone portion 51 toward the front end portion 51t of the first split bone portion 51, and in addition, the width of the second side surface 52S of the second split bone portion 52 gradually decreases from the root 52r of the second split bone portion 52 toward the front end portion 52t of the second split bone portion 52.

[0148] [Third embodiment of porous structure]

[0149] Figure 8 It is a figure for demonstrating the porous structure 1 of 3rd Embodiment of this invention.

[0150] In the third embodiment, similarly to the first embodiment, the porous structure 1 is configured such that the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB rub ​​against each other when the porous structure 1 is compressively deformed in the predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in the predetermined load input direction ID, friction occurs between the first segmented bone portion 51 and the second segmented bone portion 52 of the at least one (preferably all) discontinuous bone portion 2BB.

[0151] More specifically, in the third embodiment, similarly to the first embodiment, in at least one (preferably all) discontinuous bone parts 2BB, the first segmented bone part 51 has a first side surface 51S, and the second segmented bone part 52 has a second side surface 52S, and the porous structure 1 is configured so that the first side surface 51S of the first segmented bone part 51 and the second side surface 52S of the second segmented bone part 52 of at least one (preferably all) discontinuous bone part 2BB rub ​​against each other when compressively deformed in the predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in the predetermined load input direction ID, friction occurs between the first side surface 51S of the first segmented bone part 51 and the second side surface 52S of the second segmented bone part 52 of at least one (preferably all) discontinuous bone part 2BB.

[0152] In the first embodiment ( Figure 1 to Figure 5 ), the first side surface 51S of the first segmented bone portion 51 and the second side surface 52S of the second segmented bone portion 52 of at least one (all in the example of the figure) non-continuous bone portion 2BB are smooth surfaces (smooth surfaces) without bumps. Figure 8 ), at least one of the first side surface 51S of the first divided bone portion 51 and the second side surface 52S of the second divided bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB has a plurality of protrusions P. Thus, the surface roughness of at least one of the first side surface 51S and the second side surface 52S is higher than the surface roughness of the portion of the surface of the first divided bone portion 51 other than the first side surface 51S and the portion of the surface of the second divided bone portion 52 other than the second side surface 52S.

[0153] According to the third embodiment, at least one of the first side surface 51S of the first divided bone portion 51 and the second side surface 52S of the second divided bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB has a plurality of protrusions P, whereby the surface roughness of at least one of the first side surface 51S and the second side surface 52S is higher than the surface roughness of the portion of the surface of the first divided bone portion 51 other than the first side surface 51S and the portion of the surface of the second divided bone portion 52 other than the second side surface 52S, thereby increasing the magnitude of the friction generated between the first side surface 51S and the second side surface 52S as compared with the first embodiment.

[0154] From the viewpoint that the first side surface 51S and the second side surface 52S are easy to rub against each other, the height of each protrusion P is preferably, for example, 2 mm or less, and more preferably 1 mm or less. In addition, from the viewpoint of increasing the magnitude of the friction generated between the first side surface 51S and the second side surface 52S, the height of each protrusion P is preferably, for example, 0.1 mm or more, and more preferably 0.3 mm or more. In addition, the "height of the protrusion P" refers to the height from the base of the protrusion P to the front end of the protrusion P.

[0155] [Fourth embodiment of porous structure]

[0156] Figure 9-10 It is a figure for demonstrating the porous structure 1 of 4th Embodiment of this invention. Fig. 9 FIG. 1 is a diagram for explaining an example of a porous structure 1 according to a fourth embodiment of the present invention. Fig.10 It is a drawing for explaining a first modification example of the porous structure 1 according to the fourth embodiment of the present invention.

[0157] In the fourth embodiment, similarly to the first embodiment, the porous structure 1 is configured such that the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB rub ​​against each other when compressively deformed in the predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in the predetermined load input direction ID, friction occurs between the first segmented bone portion 51 and the second segmented bone portion 52 of the at least one (preferably all) discontinuous bone portion 2BB.

[0158] More specifically, in the fourth embodiment, similarly to the first embodiment, in at least one (preferably all) discontinuous bone parts 2BB, the first split bone part 51 has a first side surface 51S, and the second split bone part 52 has a second side surface 52S, and the porous structure 1 is configured so that the first side surface 51S of the first split bone part 51 and the second side surface 52S of the second split bone part 52 of at least one (preferably all) discontinuous bone part 2BB rub ​​against each other when compressively deformed in the predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in the predetermined load input direction ID, friction occurs between the first side surface 51S of the first split bone part 51 and the second side surface 52S of the second split bone part 52 of at least one (preferably all) discontinuous bone part 2BB.

[0159] In the first embodiment ( Figure 1 to Figure 5 ), as described above, the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (all in the example of the figure) discontinuous bone portion 2BB are respectively configured as columns. Figure 9-10), in at least one (preferably all) non-continuous bone parts 2BB, the second side surface 52S of the second split bone part 52 is configured to surround the first side surface 51S of the first split bone part 51 along the circumferential direction of the first split bone part 51 at least when the porous structure 1 is compressed and deformed along the predetermined load input direction ID. Thus, when the porous structure 1 is compressed and deformed along the predetermined load input direction ID, the first side surface 51S slides on the second side surface 52S while being guided by the second side surface 52S. Here, "the circumferential direction of the first split bone part 51" refers to the first side surface 51S around the central axis of the first split bone part 51 (at Fig. 9 (b) and Fig.10 The direction of rotation is shown by the single dotted line.

[0160] exist Fig. 9 and Fig.10 In each example, the first segmented bone portion 51 is formed in a columnar shape, whereby the first side surface 51S forms a convex surface. Fig. 9 and Fig.10 In the example, the second side surface 52S of the second divided bone portion 52 is formed as a concave surface that is concave so as to surround the first divided bone portion 51 along the circumferential direction of the first divided bone portion 51 and extends along the extending direction of the second divided bone portion 52 .

[0161] In addition, the second side surface 52S of the second segmented bone portion 52 (and thus the second segmented bone portion 52) may be formed like Fig. 9 and Fig.10 As in the examples above, the first side surface 51S of the first split bone portion 51 may be non-annular in a manner that surrounds only a portion of the circumference of the first split bone portion 51, or the first side surface 51S of the first split bone portion 51 may be annular in a manner that surrounds the first side surface 51S of the first split bone portion 51 over the entire circumference of the first split bone portion 51.

[0162] In addition, when the porous structure 1 is in a natural state, the second side surface 52S of the second segmented bone portion 52 may be Fig. 9 The first side surface 51S of the first divided bone portion 51 may be surrounded as in the example of FIG. 5 , or the first side surface 51S of the first divided bone portion 51 may not be surrounded.

[0163] According to the fourth embodiment, in at least one (preferably all) non-continuous bone parts 2BB, the second side surface 52S of the second segmented bone part 52 is configured to surround the first side surface 51S of the first segmented bone part 51 along the circumferential direction of the first segmented bone part 51 at least when the porous structure 1 is compressed and deformed in the predetermined load input direction ID, so that the contact area between the first side surface 51S and the second side surface 52S can be increased compared to the first embodiment, and the amount of friction generated between the first side surface 51S and the second side surface 52S can be increased. In addition, when the porous structure 1 is compressed and deformed in the predetermined load input direction ID, the first side surface 51S slides on the second side surface 52S while being guided by the second side surface 52S, so that the first segmented bone part 51 and the second segmented bone part 52 can rub against each other more stably.

[0164] exist Fig. 9 In the example, in at least one (preferably all) of the above-mentioned non-continuous bone parts 2BB, the first split bone part 51 is cylindrical, whereby the first side surface 51S forms a convex surface along the cylindrical shape, and further, the second side surface 52S of the second split bone part 52 forms a concave surface along the cylindrical shape.

[0165] However, the shapes of the first side surface 51S and the second side surface 52S are arbitrary.

[0166] For example, you can also Fig.10 As shown in the first variant example, in at least one (preferably all) of the above-mentioned non-continuous bone parts 2BB, the first split bone part 51 is in the shape of a quadrangular prism, whereby the first side surface 51S forms a convex surface along the shape of a square tube, and further, the second side surface 52S of the second split bone part 52 forms a concave surface along the shape of a square tube.

[0167] [Fifth embodiment of porous structure]

[0168] Fig.11 It is a drawing for explaining a porous structure 1 according to a fifth embodiment of the present invention.

[0169] In the fifth embodiment, similarly to the first embodiment, the porous structure 1 is configured such that the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB rub ​​against each other when compressively deformed in the predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in the predetermined load input direction ID, friction occurs between the first segmented bone portion 51 and the second segmented bone portion 52 of the at least one (preferably all) discontinuous bone portion 2BB.

[0170] In the fifth embodiment, similarly to the first embodiment, each of the first divided bone portion 51 and the second divided bone portion 52 is preferably columnar.

[0171] In the first embodiment ( Figure 1 to Figure 5 ), as described above, the porous structure 1 is configured such that, when compressed and deformed along the predetermined load input direction ID, the first side surface 51S of the first segmented bone portion 51 and the second side surface 52S of the second segmented bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB rub ​​against each other. Fig.11 ), in at least one (all in the example of the figure) non-continuous bone portion 2BB, the first split bone portion 51 has a first end face 51E inclined relative to a direction perpendicular to the extending direction of the first split bone portion 51 at an end (front end portion) 51t in the extending direction of the first split bone portion 51, and the second split bone portion 52 has a second end face 52E inclined relative to a direction perpendicular to the extending direction of the second split bone portion 52 at an end (front end portion) 52t in the extending direction of the second split bone portion 52, the first end face 51E and the second end face 52E are substantially parallel to each other, and the porous structure 1 is constructed so that the first end face 51E of the first split bone portion 51 and the second end face 52E of the second split bone portion 52 of the at least one (all in the example of the figure) non-continuous bone portion 2BB rub ​​against each other during compression deformation along a predetermined load input direction ID. Thus, when the porous structure 1 is compressed and deformed along the predetermined load input direction ID, friction is generated between the first end face 51E of the first segmented bone portion 51 and the second end face 52E of the second segmented bone portion 52 of the at least one (preferably all) non-continuous bone portion 2BB. In addition, the "extension direction of the first segmented bone portion 51" is the direction of extension of the first segmented bone portion 51 with respect to the central axis (in the direction of extension of the first segmented bone portion 51). Fig.11 In addition, the "extension direction of the second segmented bone portion 52" is the direction parallel to the central axis of the second segmented bone portion 52 (indicated by the single dotted line in (b)). Fig.11 The direction is parallel to the direction shown by the single-dotted line in (b).

[0172] When the porous structure 1 is in a natural state, the first end face 51E and the second end face 52E are preferably as follows: Fig.11 When the porous structure 1 is in a natural state, the first end face 51E and the second end face 52E can be Fig.11 They may be in a non-contact state with each other as in the example above, or they may be in a contact state with each other.

[0173] According to the fifth embodiment, in at least one (all in the example of the figure) non-continuous bone portion 2BB, the first divided bone portion 51 has a first end face 51E inclined relative to a direction perpendicular to the extending direction of the first divided bone portion 51 at an end (front end portion) 51t in the extending direction of the first divided bone portion 51, and the second divided bone portion 52 has a second end face 52E inclined relative to a direction perpendicular to the extending direction of the second divided bone portion 52 at an end (front end portion) 52t in the extending direction of the second divided bone portion 52. The first end face 51E and the second end face 52E are substantially parallel to each other, so that the first end face 51E and the second end face 52E can be easily rubbed against each other. In addition, the contact area between the first end face 51E and the second end face 52E can be ensured to be large, and the amount of friction generated between the first side surface 51S and the second side surface 52S can be ensured to be large.

[0174] [Sixth embodiment of porous structure]

[0175] Fig.12 It is a drawing for explaining the porous structure 1 according to the sixth embodiment of the present invention.

[0176] In the sixth embodiment, similarly to the first embodiment, the porous structure 1 is configured such that the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB rub ​​against each other when compressively deformed in the predetermined load input direction ID. Thus, when the porous structure 1 is compressively deformed in the predetermined load input direction ID, friction occurs between the first segmented bone portion 51 and the second segmented bone portion 52 of the at least one (preferably all) discontinuous bone portion 2BB.

[0177] In the sixth embodiment, similarly to the first embodiment, each of the first divided bone portion 51 and the second divided bone portion 52 is preferably columnar.

[0178] In the first embodiment ( Figure 1 to Figure 5 ), the extension direction of the first segmented bone portion 51 and the extension direction of the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB are parallel to each other. Fig.12), the extension direction of the first divided bone portion 51 and the extension direction of the second divided bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB are not parallel to each other. Moreover, the porous structure 1 is configured so that when compressively deformed along a predetermined load input direction ID, the first side surface 51S of the first divided bone portion 51 and the edge portion 52D of the second divided bone portion 52 in at least one (preferably all) non-continuous bone portion 2BB rub ​​against each other (at this time, the edge portion 52D scrapes the first side surface 51S or the first side surface 51S scrapes the edge portion 52D). As a result, when the porous structure 1 is compressively deformed along a predetermined load input direction ID, friction is generated between the first side surface 51S and the edge portion 52D of the at least one (preferably all) non-continuous bone portion 2BB. In addition, the "extension direction of the first divided bone portion 51" is a direction parallel to the center axis of the first divided bone portion 51 (in Fig.12 In addition, the "extension direction of the second segmented bone portion 52" is the direction parallel to the central axis of the second segmented bone portion 52 (indicated by the single dotted line in (b)). Fig.12 In the present embodiment, the "first side surface 51S of the first segmented bone portion 51" refers to the portion of the side surface of the first segmented bone portion 51 that is configured to rub against the edge portion 52D of the second segmented bone portion 52. In addition, the "edge portion 52D" of the second segmented bone portion 52 refers to the edge portion between the side surface of the second segmented bone portion 52 and the end surface on the side of the front end portion 52t of the second segmented bone portion 52.

[0179] When the porous structure 1 is in a natural state, the first side surface 51S and the edge portion 52D can be Fig.12 They may be in contact with each other as in the example above, or they may be in non-contact with each other.

[0180] According to the sixth embodiment, the extension direction of the first divided bone portion 51 and the extension direction of the second divided bone portion 52 of at least one (preferably all) non-continuous bone portion 2BB are not parallel to each other, and the porous structure 1 is constructed so that when compressively deformed along a predetermined load input direction ID, the first side surface 51S of the first divided bone portion 51 and the edge portion 52D of the second divided bone portion 52 in at least one (preferably all) non-continuous bone portion 2BB rub ​​against each other (at this time, the edge portion 52D scrapes the first side surface 51S), thereby ensuring that the amount of friction generated between the first side surface 51S and the edge portion 52D is large.

[0181] [Seventh embodiment of porous structure]

[0182] Figure 13 to Figure 15 It is a drawing for explaining the porous structure 1 according to the seventh embodiment of the present invention. Fig.13 It is a perspective view showing a part of the porous structure 1 according to the seventh embodiment of the present invention in a natural state without compression deformation. Fig.14 For the sake of convenience, each bridge portion 23 described later is shown in an extended state. Fig.13 A partial three-dimensional view of the porous structure 1. Fig.15 It is shown in the state of compression deformation along the predetermined load input direction ID Fig.13 A three-dimensional view of the porous structure 1.

[0183] In the first embodiment ( Figure 1 to Figure 5 ), as described above, the porous structure 1 is configured such that the first segmented bone portion 51 and the second segmented bone portion 52 of at least one (preferably all) discontinuous bone portion 2BB rub ​​against each other when compressively deformed along the predetermined load input direction ID. Figure 13 to Figure 15 ), the porous structure 1 is constructed so that when the porous structure 1 is compressed and deformed along a predetermined load input direction ID, two or more unit dividing parts 21 (specifically, the unit dividing parts 21 adjacent to each other among the two or more unit dividing parts 21) of the skeleton part 2 interfere with each other. More specifically, when the porous structure 1 is compressed and deformed along a predetermined load input direction ID, multiple parts of the two or more unit dividing parts 21 that were previously in a non-contact state with each other collide with each other (just after the collision, the multiple parts may not move in contact with each other immediately, or may move in contact with each other immediately). As a result, when the porous structure 1 is compressed and deformed along the predetermined load input direction ID, friction is generated between the two or more unit dividing parts 21.

[0184] In the first embodiment ( Figure 1 to Figure 5 ), as described above, each annular portion 211 is shared by a pair of unit dividing portions 21 adjacent to the annular portion 211 (i.e., a pair of unit dividing portions 21 sandwiching the annular portion 211). In other words, a pair of unit dividing portions 21 adjacent to each other share one annular portion 211. Figure 13 to Figure 15 In the example, a pair of mutually interfering unit division parts 21 adjacent to each other do not share a ring-shaped part 211, but each of the adjacent parts has a separate ring-shaped part 211 ( Fig.14 ), the pair of annular portions 211 interfere (collide) with each other.

[0185] When the porous structure 1 is in a natural state, the plurality of parts (in Figure 13 to Figure 15 In the example, a pair of annular portions 211) are preferably opposed to each other in a non-contact state.

[0186] exist Figure 13 to Figure 15In the example, the multiple unit dividing parts 21 possessed by the skeleton part 2 are unit dividing parts 21A that do not have the discontinuous bone part 2BB, but it is also possible that some or all of the multiple unit dividing parts 21 possessed by the skeleton part 2 are unit dividing parts 21B that have one or more discontinuous bone parts 2BB of any embodiment described in this specification.

[0187] According to the seventh embodiment, the same effects as those of the first embodiment can be obtained.

[0188] In the seventh embodiment, the skeleton part 2 preferably further includes one or more bridge parts 23 that interconnect the two or more unit division parts 21 that are configured to interfere with each other. Thus, the two or more unit division parts can be integrated with each other by means of the bridge part 23. Furthermore, when the porous structure 1 is in a natural state, the bridge part 23 can be used to maintain the positional relationship between the two or more unit division parts 21 as expected. In addition, it is easy to shape the porous structure 1 using a 3D printer.

[0189] Each bridge portion 23 is preferably formed in a columnar shape. From the viewpoint of making it easy to deform the bridge portion 23 and thereby making it easy to make the above-mentioned two or more unit dividing portions 21 interfere with each other, the cross-sectional area of ​​each bridge portion 23 (the cross-sectional area in a direction perpendicular to the central axis of the bridge portion 23) is preferably smaller than the minimum cross-sectional area of ​​the bone portion 2B, but it can also be greater than the minimum cross-sectional area of ​​the bone portion 2B.

[0190] exist Figure 13 to Figure 15 In the example of FIG. 1 , each bridge portion 23 connects a pair of connecting portions 2J of a pair of adjacent unit dividing portions 21 to each other ( Fig.14 ). Thus, when the porous structure 1 is in a natural state, each bridge portion 23 can more stably maintain the positional relationship between the pair of unit dividing portions 21. However, each bridge portion 23 may also connect any portion of a pair of adjacent unit dividing portions 21.

[0191] Furthermore, the above-mentioned embodiments may be appropriately combined with each other.

[0192] For example, the porous structure 1 may adopt the structures of the discontinuous bone parts 2BB of different embodiments in each of the plurality of different discontinuous bone parts 2BB in the first to sixth embodiments.

[0193] Furthermore, the porous structure 1 may have both the structure of the discontinuous bone portion 2BB of one or more of the first to sixth embodiments and the structure of the seventh embodiment.

[0194] In addition, the porous structure 1 can also apply the multiple protrusions P of the third embodiment to the first side face 51S and / or the second side face 52S of the first embodiment, the second embodiment and the fourth embodiment in the same non-continuous bone portion 2BB, or can also be applied to the first end face 51E and / or the second end face 52E of the fifth embodiment, or can also be applied to the first side face 51S of the sixth embodiment.

[0195] [Eighth embodiment of porous structure]

[0196] Fig.16 This is a drawing for explaining a porous structure 1 according to an eighth embodiment of the present invention. The structure explained in the eighth embodiment can be preferably applied to the porous structure 1 according to the first to seventh embodiments described above.

[0197] In the present embodiment, the porous structure 1 includes one or more membranes 3 in addition to the skeleton 2 .

[0198] The film 3 extends on the imaginary surface V1 defined by the annular inner peripheral edge 2111 of the annular portion 211, thereby covering the imaginary surface V1 defined by the annular portion 211. Fig.16 In the porous structure 1 of the example, at least one of the imaginary surfaces V1 constituting the skeleton 2 is covered by the membrane 3. The membrane 3 is made of the same material as the skeleton 2 and is integrally formed with the skeleton 2. Fig.16 In the example shown in FIG. 1 , the film 3 is configured to be flat. However, the film 3 may be configured to be non-flat (eg, curved (curved)).

[0199] The membrane 3 preferably has a width W0 ( Figure 4 ) Small thickness.

[0200] Due to the membrane 3, the two unit pores C sandwiching the imaginary surface V1 are no longer interconnected through the imaginary surface V1, and can no longer be ventilated with the help of the imaginary surface V1, so the overall air permeability of the porous structure 1 is reduced. By adjusting the number of imaginary surfaces V1 in each imaginary surface V1 constituting the porous structure 1 and covered by the membrane 3, the overall air permeability of the porous structure 1 can be adjusted, and various air permeability levels can be achieved as required. It is not preferred that all the imaginary surfaces V1 constituting the porous structure 1 are covered by the membrane 3. In other words, it is preferred that at least one of the imaginary surfaces V1 constituting the porous structure 1 is not covered by the membrane 3 but is open.

[0201] In addition, as described above, the conventional porous structure is manufactured by a foaming process using a chemical reaction, so it is difficult to form a film with interconnected pores that interconnect the units according to the expected position and number. When the porous structure 1 is manufactured using a 3D printer as in this example, the information of the film 3 is also included in the 3D modeling data read into the 3D printer in advance, so that the film 3 can be reliably formed according to the expected position and number.

[0202] At least one of the small imaginary surfaces V1S constituting the skeleton portion 2 may be covered with the film 3 . And / or at least one of the large imaginary surfaces V1L constituting the skeleton portion 2 may be covered with the film 3 .

[0203] In the case where the skeleton portion 2 has a discontinuous bone portion 2BB, from the viewpoint of preventing the friction movement of the discontinuous bone portion 2BB from being hindered by the membrane 3, each membrane 3 preferably covers an imaginary surface V1 divided by an annular portion 211 that does not have a discontinuous bone portion 2BB (i.e., all bone portions 2B are annular portions 211 of continuous bone portions 2BA).

[0204] [Seat cushion with porous structure]

[0205] As described above, the porous structure 1 according to each embodiment of the present invention can be used for a seat pad (particularly, a vehicle seat pad).

[0206] Below, refer to Fig.17 An example of a seat pad 302 including the porous structure 1 according to any embodiment of the present invention will be described.

[0207] Fig.17 This is a perspective view schematically showing an example of a vehicle seat 300 including a seat pad 302 (vehicle seat pad) that can be formed of the porous structure 1 according to various embodiments of the present invention.

[0208] like Fig.17As shown by the middle dotted line, the vehicle seat 300 includes a cushion pad 310 for a seated person and a back pad 320 for supporting the back of the seated person. The cushion pad 310 and the back pad 320 are respectively composed of a seat cushion 302. Hereinafter, the cushion pad 310 or the back pad 320 is sometimes referred to as "seat cushion 302". The cushion pad 310 and the back pad 320 can be respectively composed of the porous structure 1 of any embodiment described in this specification. In addition to the seat cushion 302 that respectively constitutes the cushion pad 310 and the back pad 320, the vehicle seat 300 can also include, for example, a skin 330 covering the surface side (seat occupant side) of the seat cushion 302, a frame (not shown) supporting the cushion pad 310 from the bottom side, a frame (not shown) provided on the back side of the back pad 320, and a headrest 340 provided on the upper side of the back pad 320 and used to support the head of the seated person. The skin 330 is made of, for example, a material with good air permeability (cloth, etc.). Fig.17 In the example of FIG. 3 , the cushion pad 310 and the backrest pad 320 are formed independently of each other, but may be formed integrally with each other.

[0209] In addition, Fig.17 In the example shown in FIG. 1 , the headrest 340 is independently configured with respect to the backrest pad 320 . However, the headrest 340 may be integrally configured with the backrest pad 320 .

[0210] In this manual, if Fig.17 As shown in the figure, the directions of "up", "down", "left", "right", "front" and "rear" when viewed from the perspective of a seated person sitting on the vehicle seat 300 (and thus the seat cushion 302) are abbreviated as "up", "down", "left", "right", "front" and "rear", etc., respectively.

[0211] The cushion pad 310 includes a main cushion portion 311 configured to support the buttocks and thighs of the seated person from below, and a pair of side cushion portions 312 located on the left and right sides of the main cushion portion 311, bulging upward relative to the main cushion portion 311, and configured to support the seated person from the left and right sides. The main cushion portion 311 includes a lower leg portion 311t configured to support the thighs of the seated person from below, and a lower buttock portion 311h located at a position behind the lower leg portion 311t and configured to support the buttocks of the seated person from below.

[0212] The backrest cushion 320 has: a main cushion portion 321, which is configured to support the back of the seated person from the rear side; and a pair of side cushion portions 322, which are located on the left and right sides of the main cushion portion 321 and bulge forward compared to the main cushion portion 321, and are configured to support the seated person from the left and right sides.

[0213] In this specification, the "extension direction (LD) of the seat cushion (302)" refers to a direction perpendicular to the left-right direction and the thickness direction (TD) of the seat cushion 302, and in the case of the cushion 310, refers to the front-back direction ( Fig.17 ), in the case of the backrest pad 320, refers to the direction in which the main pad portion 321 extends from the lower surface to the upper surface of the main pad portion 321 of the backrest pad 320 ( Fig.17 ).

[0214] In addition, the "thickness direction (TD) of the seat cushion (302)" refers to the vertical direction (TD) in the case of the cushion pad 310. Fig.17 ), in the case of the backrest pad 320, refers to the direction in which the main pad portion 321 extends within the range from the seat occupant side surface (surface) FS of the main pad portion 321 of the backrest pad 320 to the back surface BS ( Fig.17 ).

[0215] In addition, the "surface (FS) on the seat occupant side" of the seat cushion (302) refers to the upper surface ( Fig.17 ), which refers to the front surface ( Fig.17 The "back side (BS)" of the seat cushion (302) is the side of the seat cushion (302) opposite to the seat occupant side surface (FS), and in the case of the cushion 310, it refers to the lower surface ( Fig.17 ), which refers to the rear surface ( Fig.17 The "side surface (SS)" of the seat cushion (302) is the surface between the seat occupant side surface (FS) and the back surface (BS) of the seat cushion (302), and in the case of the cushion 310, it refers to any one of the front surface, the rear surface, the left surface, and the right surface ( Fig.17 ), in the case of the backrest pad 320, refers to any one of the lower surface, upper surface, left surface and right surface ( Fig.17 ).

[0216] The porous structure 1 is preferably oriented so that the predetermined load input direction ID becomes the thickness direction TD of the seat pad 302 .

[0217] In addition, Fig.17 In the illustrated example, the porous structure 1 constitutes the entirety of the cushion pad 310 and the back pad 320 of the seat pad 302 .

[0218] However, the porous structure 1 may constitute only one of the cushion pad 310 , the back pad 320 , and the headrest 340 of the seat pad 302 .

[0219] In addition, the porous structure 1 may only constitute a portion of the cushion 310 of the seat cushion 302, a portion of the backrest 320, and / or a portion of the headrest 340. Thus, the size of the porous structure 1 can be reduced, and it can also be manufactured using a relatively small 3D printer. In this case, the cushion 310, the backrest 320, and the headrest 340 of the seat cushion 302, except for the portion constituted by the porous structure 1, can be manufactured, for example, by a foaming process using a chemical reaction in mold forming or sheet forming, and thus be composed of the above-mentioned conventional porous structure (foam). For example, although not shown in the figure, the cushion pad 310, the backrest pad 320 and / or the headrest 340 of the seat cushion 302 may include a plurality of cushioning parts independently formed from each other, and only a part (one or more) of the plurality of cushioning parts may be formed from the porous structure 1, and the other cushioning parts may be formed from a porous structure (foam) manufactured by a foaming process using a chemical reaction in mold forming or sheet forming. More specifically, for example, the cushion pad 310, the backrest pad 320 and / or the headrest 340 of the seat cushion 302 may include: one or more inserts formed from the porous structure 1; and a main body that is independently formed from the one or more inserts and has a recess for accommodating the one or more inserts, and may be formed from a porous structure (foam) manufactured by a foaming process using a chemical reaction in mold forming or sheet forming.

[0220] Alternatively, the cushion pad 310, the backrest pad 320 and / or the headrest 340 of the seat cushion 302 may be composed of a plurality of cushioning parts independently formed from each other, and each of the plurality of cushioning parts is composed of the porous structure 1. Thus, the size of the porous structure 1 can be reduced, and further, it can be manufactured using a relatively small 3D printer.

[0221] The porous structure 1 preferably constitutes at least a part of the main pad portion 311 , 321 of the cushion pad 310 or the back pad 320 .

[0222] [Method for producing porous structure]

[0223] Next, refer to Fig.18 The method for producing the porous structure 1 of the present invention is described by way of example. The method described below is a method for producing the porous structure 1 using a 3D printer, and can be preferably used to produce the porous structure 1 of any embodiment described in this specification. Fig.18 A state of manufacturing the porous structure 1 constituting a seat pad is shown.

[0224] First, three-dimensional shape data (for example, three-dimensional CAD data) representing the three-dimensional shape of the porous structure 1 is prepared in advance using a computer.

[0225] Next, the three-dimensional shape data is converted into 3D modeling data 500 using a computer. The 3D modeling data 500 is read into the control unit 410 of the 3D printer 400 when the modeling unit 420 of the 3D printer 400 is modeling, and the control unit 410 is configured to make the modeling unit 420 model the porous structure 1. The 3D modeling data 500 includes, for example, slice data representing the two-dimensional shape of each layer of the porous structure 1.

[0226] Next, the porous structure 1 is formed using a 3D printer 400. The 3D printer 400 can be formed using any forming method such as a photoforming method, a powder sintering lamination method, a hot melt lamination method (FDM method), an inkjet method, etc. From the perspective of productivity, the photoforming method is preferred. Fig.18 The following shows the case where the light shaping method is used for shaping.

[0227] The 3D printer 400 includes, for example, a control unit 410 composed of a CPU, a forming unit 420 that performs forming according to the control of the control unit 410, a support table 430 for placing a formed object (i.e., a porous structure 1), and a storage body 440 that stores liquid resin LR, the support table 430, and the object. When the light forming method is used as in this example, the forming unit 420 has a laser irradiator 421, which is configured to irradiate ultraviolet laser LL. The storage body 440 is filled with liquid resin LR. When the ultraviolet laser LL irradiated from the laser irradiator 421 irradiates the liquid resin LR, the liquid resin LR is cured and becomes a flexible resin.

[0228] In the 3D printer 400 thus constructed, the control unit 410 first reads the 3D shaping data 500, and based on the three-dimensional shape included in the read 3D shaping data 500, controls the shaping unit 420 to irradiate the ultraviolet laser LL, and shapes each layer in sequence.

[0229] After the formation by the 3D printer 400 is completed, the formed object is taken out from the storage body 440. Thus, the porous structure 1 is finally obtained as the formed object.

[0230] By manufacturing the porous structural body 1 using a 3D printer, the porous structural body 1 can be realized as intended simply and with high accuracy in one process.

[0231] In addition, when the porous structure 1 is made of resin, the porous structure 1 as a shaped object may be heated in a heating furnace after the shaping by the 3D printer 400 is completed. In this case, the bonding between the layers constituting the porous structure 1 can be strengthened, thereby reducing the anisotropy of the porous structure 1, and thus the cushioning property of the porous structure 1 can be further improved.

[0232] Furthermore, when the porous structural body 1 is made of rubber, the porous structural body 1 as a shaped object may be vulcanized after the shaping by the 3D printer 400 is completed.

[0233] Industrial Applicability

[0234] The porous structure and the method for producing the porous structure of the present invention are suitable for use in cushioning materials, for example, any vehicle seat and any vehicle seat cushion (seat pad), and are particularly suitable for use in vehicle seats and vehicle seat cushions.

[0235] Description of Reference Numerals

[0236] 1. porous structure; 2. skeleton; 2B. bone; 2Be. end of bone; 2BA. continuous bone; 2BB. discontinuous bone; 51. first segmented bone; 51t. front end; 51r. root; 51S. first side; 511. wide side; 512. narrow side; 51E. first end; 52. second segmented bone; 52t. front end; 52r. root; 52S. second side; 521. wide side; 522. narrow side; 52E. second end; 52D. edge; P. protrusion; 2J. joint; 21, 21A, 21B. unit division; 211. annular; 211L. large annular; 211S. small annular; 2111. inner peripheral edge of annular; 23. bridge; 3. membrane; C. unit hole; O, skeleton line; V1, imaginary surface; V1L, large imaginary surface; V1S, small imaginary surface; ID, predetermined load input direction; 300, vehicle seat; 302, seat cushion; 310, cushion pad; 311, main cushion part (sitting part); 311t, lower leg part; 311h, lower buttocks part; 312, side cushion part; 320, backrest pad; 321, main cushion part; 322, side cushion part; 330, epidermis; 340, headrest; FS, surface (surface) on the seated person's side; SS, side; BS, back; TD, thickness direction; LD, extension direction; 400, 3D printer; 410, control unit; 420, shaping unit; 421, laser irradiator; 430, support table; 440, storage body; LL, ultraviolet laser; LR, liquid resin; 500, data for 3D shaping.

Claims

1. A porous structure composed of a flexible resin or rubber, wherein: The porous structure has a skeleton portion throughout its entire range. The skeleton part comprises: multiple bones; and A plurality of joints, which respectively connect the ends of the plurality of bone parts to each other, The porous structure is configured such that the plurality of parts of the skeleton part interfere with each other when compressively deformed in a predetermined load input direction. At least one of the plurality of bone parts is a discontinuous bone part including a first divided bone part and a second divided bone part that are divided from each other. The porous structure is configured so that the first divided bone portion and the second divided bone portion of the discontinuous bone portion rub against each other when the porous structure is compressively deformed in the predetermined load input direction.

2. The porous structure according to claim 1, wherein In the non-continuous bone portion, The first split bone portion has a first side surface. The second split bone portion has a second side surface, The porous structure is configured so that the first side surface of the first divided bone portion and the second side surface of the second divided bone portion of the discontinuous bone portion rub against each other when the porous structure is compressively deformed in the predetermined load input direction.

3. The porous structure according to claim 2, wherein At least one of the first divided bone portion and the second divided bone portion of the discontinuous bone portion is in a band shape.

4. The porous structure according to claim 2, wherein At least one of the first side surface and the second side surface of the discontinuous bone portion has a plurality of protrusions.

5. The porous structure according to claim 2, wherein In the discontinuous bone portion, the second side surface is configured to surround the first side surface along a circumferential direction of the first divided bone portion when the porous structure is compressively deformed in the predetermined load input direction.

6. The porous structure according to claim 1, wherein In the non-continuous bone portion, The first segmented bone portion has a first end surface inclined with respect to a direction perpendicular to the extending direction of the first segmented bone portion at an end portion in the extending direction of the first segmented bone portion. The second segmented bone portion has a second end surface inclined with respect to a direction perpendicular to the extending direction of the second segmented bone portion at an end portion of the extending direction of the second segmented bone portion. The first end face and the second end face are substantially parallel to each other, The porous structure is configured so that the first end surface of the first divided bone portion and the second end surface of the second divided bone portion of the discontinuous bone portion rub against each other when the porous structure is compressively deformed in the predetermined load input direction.

7. The porous structure according to claim 1, wherein An extending direction of the first divided bone portion and an extending direction of the second divided bone portion of the discontinuous bone portion are not parallel to each other.

8. The porous structure according to any one of claims 1 to 7, wherein The skeleton part has a plurality of unit dividing parts which divide unit holes inside. Each of the unit division parts has a plurality of annular parts each configured in an annular shape. The plurality of annular portions constituting the unit dividing portion are connected to each other in such a manner that imaginary surfaces divided by the respective inner peripheral side edges do not intersect each other. Each of the annular parts is respectively composed of a plurality of the bone parts and a plurality of the connecting parts. Each of the imaginary surfaces is approximately flat. The unit holes are formed by dividing the plurality of annular portions and the plurality of imaginary surfaces respectively divided by the plurality of annular portions.

9. The porous structure according to claim 8, wherein The plurality of annular portions constituting the unit dividing portion include one or more small annular portions and one or more large annular portions, Each of the small annular portions is divided into a substantially flat small imaginary surface by its inner peripheral edge. Each of the large annular portions defines a large imaginary surface that is substantially flat and larger in area than the small imaginary surface by its inner peripheral edge.

10. The porous structure according to claim 9, wherein The shape of the small imaginary surface and the shape of the large imaginary surface are different from each other.

11. The porous structure according to claim 8, wherein Each of the unit holes is substantially in the shape of a Kelvin tetrahedron.

12. The porous structure according to any one of claims 1 to 7, wherein The porous structure is used for a buffer material.

13. The porous structure according to any one of claims 1 to 7, wherein The porous structure is formed by using a 3D printer.

14. A porous structure composed of a flexible resin or rubber, wherein: The porous structure has a skeleton portion throughout its entire range. The skeleton part comprises: multiple bones; and A plurality of joints, which respectively connect the ends of the plurality of bone parts to each other, The porous structure is configured such that the plurality of parts of the skeleton part interfere with each other when compressively deformed in a predetermined load input direction. The skeleton part has a plurality of unit dividing parts which divide unit holes inside. Each of the unit divisions is respectively composed of a plurality of the bone parts and a plurality of the connecting parts. The porous structure is configured such that two or more of the plurality of unit divisions interfere with each other when the unit divisions are compressed and deformed in the predetermined load input direction. The skeleton portion further includes one or more bridge portions connecting the two or more unit dividing portions to each other.

15. The porous structure according to claim 14, wherein The skeleton part has a plurality of unit dividing parts which divide unit holes inside. Each of the unit division parts has a plurality of annular parts each configured in an annular shape. The plurality of annular portions constituting the unit dividing portion are connected to each other in such a manner that imaginary surfaces divided by the respective inner peripheral side edges do not intersect each other. Each of the annular parts is respectively composed of a plurality of the bone parts and a plurality of the connecting parts. Each of the imaginary surfaces is approximately flat. The unit holes are formed by dividing the plurality of annular portions and the plurality of imaginary surfaces respectively divided by the plurality of annular portions.

16. The porous structure according to claim 15, wherein The plurality of annular portions constituting the unit dividing portion include one or more small annular portions and one or more large annular portions, Each of the small annular portions is divided into a substantially flat small imaginary surface by its inner peripheral edge. Each of the large annular portions defines a large imaginary surface that is substantially flat and larger in area than the small imaginary surface by its inner peripheral edge.

17. The porous structure according to claim 16, wherein The shape of the small imaginary surface and the shape of the large imaginary surface are different from each other.

18. The porous structure according to any one of claims 15 to 17, wherein Each of the unit holes is substantially in the shape of a Kelvin tetrahedron.

19. The porous structure according to any one of claims 14 to 17, wherein The porous structure is used for a buffer material.

20. The porous structure according to any one of claims 14 to 17, wherein The porous structure is formed by using a 3D printer.

21. A method for producing a porous structure, wherein: The porous structure according to any one of claims 1 to 12 and 14 to 19 is manufactured using a 3D printer.

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