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 includes a plurality of bone parts (2B) and a plurality of connecting parts (2J) that respectively connect the ends of the plurality of bone parts to each other, the skeleton part has a plurality of annular parts (211) each formed into an annular shape by a plurality of bone parts and a plurality of connecting parts, each annular part is divided into an imaginary surface (V1) by its inner peripheral side edge (2111), at least a portion of each of the one or more imaginary surfaces is covered by one or more local connecting membranes (31), and the one or more local connecting membranes are respectively only connected to a part of the circumference of the annular part.

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. 2020-160201 filed in Japan on September 24, 2020, the entire contents of which are incorporated herein by reference. Background Art

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

[0004] On the other hand, porous structures having cushioning properties that can be easily manufactured using a 3D printer have been proposed in recent years (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] Problems to be solved by the invention

[0010] However, in the technologies 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 portion includes a plurality of bone portions and a plurality of coupling portions for coupling ends of the plurality of bone portions to each other.

[0016] The skeleton portion includes a plurality of annular portions each formed into an annular shape by a plurality of the bone portions and a plurality of the connecting portions.

[0017] Each of the annular portions is divided into imaginary surfaces by its inner peripheral edge.

[0018] At least a portion of each of one or more of the imaginary surfaces is covered by one or more local bonding films,

[0019] The one or more partial bonding films are respectively bonded to only a portion of the circumference of the annular portion.

[0020] The method for producing a porous structure of the present invention uses a 3D printer to produce the porous structure.

[0021] Effects of the Invention

[0022] 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

[0023] Figure 1 It is a perspective view showing a part of the porous structure according to the first embodiment of the present invention.

[0024] Figure 2 It means from Figure 1 Observe in the direction of arrow A Figure 1 A-direction view of the situation when the porous structure is formed.

[0025] Figure 3 The diagram is shown with the partial connecting film omitted. Figure 1 A three-dimensional diagram of the unit division part of the porous structure.

[0026] Figure 4 is with Figure 3 The corresponding figure shows the state of the partial connection film. Figure 1 A three-dimensional diagram of the unit division part of the porous structure.

[0027] Figure 5 Yes Figure 4 Top view of the annular portion and the local connecting membrane.

[0028] Figure 6 It is used along Figure 5 The cross section of line BB shows Figure 5 BB cross-sectional view of the annular portion and the local connecting membrane.

[0029] Figure 7 The state of the porous structure when it is compressed or deformed is shown Figure 6 Cross-sectional view of the annular portion and the local connecting membrane.

[0030] Figure 8 is with Figure 5 The corresponding drawings are plan views showing the annular portion and the partially connected membrane of the porous structure according to the second embodiment of the present invention.

[0031] Figure 9 is with Figure 5 The corresponding drawings are plan views showing the annular portion and the partially connected membrane of the porous structure according to the third embodiment of the present invention.

[0032] Figure 10 is with Figure 5 The corresponding drawings are plan views showing the annular portion and the partially connected membrane of the porous structure according to the fourth embodiment of the present invention.

[0033] Figure 11 is with Figure 5 The corresponding drawings are plan views showing the annular portion and the partially connected membrane of the porous structure according to the fifth embodiment of the present invention.

[0034] Figure 12 is with Figure 5 The corresponding drawings are plan views showing the annular portion and the partially connected membrane of the porous structure according to the sixth embodiment of the present invention.

[0035] Figure 13 is with Figure 5 The corresponding drawings are plan views showing the annular portion and the partially connected membrane of the porous structure according to the seventh embodiment of the present invention.

[0036] Figure 14 is with Figure 4 The corresponding drawing is a perspective view showing a unit partition portion of a porous structure according to an eighth embodiment of the present invention.

[0037] Figure 15 This is a perspective view schematically showing a vehicle seat that can include the porous structure according to any embodiment of the present invention.

[0038] Figure 16 These are drawings 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

[0039] 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, and are particularly suitable for use in vehicle seats and vehicle seat cushions.

[0040] Hereinafter, embodiments of the porous structure and the method for producing the porous structure of the present invention will be described with reference to the drawings.

[0041] The same reference numerals are given to the common components in the drawings.

[0042] 〔Porous structure〕

[0043] First, refer to Figures 1 to 7 A porous structure 1 according to a first embodiment of the present invention will be described.

[0044] In addition, Figures 1 to 4 In FIG. 1 , in order to facilitate understanding of the directions of the porous structure 1 , directions of an XYZ orthogonal coordinate system fixed to the porous structure 1 are shown.

[0045] exist Figures 1 and 2 In FIG. 1 , a portion of the porous structure 1 having a substantially rectangular parallelepiped outer shape is observed from different angles. Figure 1 It is a perspective view showing this part of the porous structure 1 . Figure 2 It indicates viewing from the direction of arrow A (Y direction) Figure 1 A view of the portion of the porous structure 1 as viewed from the arrow A.

[0046] The porous structure 1 is formed by using a 3D printer. Figure 16 Detailed description. By using a 3D printer to manufacture the porous structure 1, manufacturing becomes simpler than in the conventional process of foaming by chemical reaction, and the desired structure can be obtained. In addition, with future technological advances in 3D printers, it is expected that manufacturing using 3D printers will be possible in the future in a shorter time and at a lower cost. Furthermore, by using a 3D printer to manufacture the porous structure 1, the structure of the porous structure 1 corresponding to a variety of required properties can be simply and as expected.

[0047] The porous structure 1 is made of flexible resin or rubber.

[0048] Here, "flexible resin" refers to a resin that can deform when an external force is applied. For example, an elastomeric resin is preferred, and polyurethane is more preferred. Examples of rubber include natural rubber and synthetic rubber. The porous structure 1 is composed of a flexible resin or rubber and can therefore compress and recover in response to the application and release of external force from the user, thereby providing cushioning properties.

[0049] Furthermore, from the viewpoint of ease of production using a 3D printer, it is more advantageous for the porous structure 1 to be made of a flexible resin than of rubber.

[0050] Furthermore, from the perspective of ease of production using a 3D printer, the porous structure 1 is preferably composed of a material of the same composition throughout. However, the porous structure 1 may be composed of materials of different compositions depending on the location.

[0051] In addition, when the porous structure 1 is manufactured using a 3D printer, a resin made of a light-curable polyurethane (particularly a UV-curable polyurethane) can be used as the material constituting the porous structure 1. As the light-curable polyurethane (particularly a UV-curable polyurethane), a resin made of a polyurethane acrylate or polyurethane methacrylate can be used. Examples of such resins include the materials described in US Pat. No. 4,337,130.

[0052] As described above, the porous structure 1 is formed by a 3D printer. The entire porous structure 1 is integrally formed.

[0053] The porous structure 1 is made of a flexible resin or rubber. More specifically, the porous structure 1 includes a skeleton portion 2 that forms the skeleton of the porous structure 1. The skeleton portion 2 divides a plurality of unit pores C. The skeleton portion 2 exists throughout the substantially entire porous structure 1 and is made of a flexible resin or rubber. As described later, in the present embodiment, the porous structure 1 includes one or more local connecting membranes 31 in addition to the skeleton portion 2. In the present embodiment, the portion of the porous structure 1 other than the skeleton portion 2 and the local connecting membrane 31 is a void. In other words, the porous structure 1 is composed only of the skeleton portion 2 and the local connecting membrane 31.

[0054] like Figures 1 to 4 As shown, the skeleton portion 2 of the porous structure 1 includes a plurality of bone portions 2B and a plurality of connecting portions 2J, and the skeleton portion 2 is integrally formed. In this example, each bone portion 2B is formed in a columnar shape and extends in a straight line. Each connecting portion 2J connects the ends 2Be of a plurality of (e.g., four) bone portions 2B extending in different directions at locations where these ends 2Be are adjacent to each other.

[0055] exist Figures 1 to 4 In the figure, the skeleton line O of the skeleton part 2 is represented by a single-dot chain 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 connecting part 2J. The skeleton line O of the bone part 2B is the central axis of the bone part 2B. The skeleton line O of the connecting part 2J is an extension line portion formed by smoothly extending the central axes of each bone part 2B connected to the connecting part 2J into the connecting part 2J and connecting them to each other. The central axis of the bone part 2B is a line formed by 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 and in a cross section perpendicular to the extension direction of the bone part 2B.

[0056] The extending direction of the bone portion 2B is the extending 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).

[0057] The porous structure 1 has a skeleton portion 2 throughout its substantially entirety, thereby being able to compress and recover in response to the application and removal of external forces while ensuring breathability, thereby improving its properties as a cushioning material. Furthermore, the porous structure 1 is simple in structure and easily molded using a 3D printer.

[0058] Alternatively, some or all of the bone portions 2B constituting the skeleton portion 2 may be curved and extended. In this case, by curving some or all of the bone portions 2B, a sudden change in shape of the bone portions 2B and, consequently, the porous structure 1, can be prevented when a load is applied, thereby suppressing local buckling.

[0059] In this example, the bone portions 2B that make up the skeleton 2 have substantially the same shape and length. However, this example is not limiting, and the shapes and / or lengths of the bone portions 2B that make up the skeleton 2 may also differ. For example, the shape and / or length of one portion of the bone portions 2B may differ from that of the other portions of the bone portions 2B. In this case, by making the shape and / or length of the bone portions 2B of a specific portion of the skeleton 2 differ from that of the other portions of the bone portions 2B, different mechanical properties can be intentionally achieved.

[0060] In this example, the width W0 of each bone portion 2B ( Figure 1 ) and the cross-sectional area are constant over the entire length of the bone portion 2B (ie, uniform along the extension direction of the bone portion 2B).

[0061] Here, the cross-sectional area of the bone portion 2B refers to the cross-sectional area of the cross section perpendicular to the skeleton line O of the bone portion 2B. Figure 1 ) refers to the maximum width of the cross section when measured along a cross section perpendicular to the skeleton line O of the bone portion 2B.

[0062] However, in each example described in this specification, the width W0 and / or cross-sectional area of the bone portion 2B of a part or all of the bone portions 2B constituting the skeleton portion 2 may be uneven along the extension direction of the bone portion 2B. For example, the width W0 of the bone portion 2B in the portion including the end portions 2Be on both sides of the extension direction of the bone portion 2B may gradually increase or decrease as it moves toward the two ends of the extension direction of the bone portion 2B. In addition, the cross-sectional area of the bone portion 2B in the portion including the end portions 2Be on both sides of the extension direction of the bone portion 2B may gradually increase or decrease as it moves toward the two ends of the extension direction of the bone portion 2B. In addition, in this specification, "gradually changing (increasing or decreasing)" means not being constant in the middle but changing smoothly (increasing or decreasing) all the time.

[0063] 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 of the bone portion 2B ( Figure 1 ) is preferably 0.05 mm or greater, more preferably 0.10 mm or greater. When the width W0 is 0.05 mm or greater, shaping can be performed using the resolution of a high-performance 3D printer. When the width W0 is 0.10 mm or greater, shaping can be performed using the resolution of both high-performance 3D printers and general-purpose 3D printers.

[0064] On the other hand, from the perspective 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 width W0 of the bone part 2B is preferably less than 2.0 mm.

[0065] In addition, each bone 2B constituting the skeleton 2 preferably satisfies this structure, but only a part of the bones 2B constituting the skeleton 2 may satisfy this structure. In this case, although there may be a difference in degree, the same effect can be obtained.

[0066] In this example, each bone portion 2B constituting the skeleton portion 2 is columnar, and each cross-sectional shape is circular (perfect circle).

[0067] Thus, the structure of the skeleton portion 2 is simple and easy to shape using a 3D printer. In addition, it is easy to reproduce the mechanical properties of conventional 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 bone portion 2B as a columnar shape, the durability of the skeleton portion 2 can be improved compared to the case where the bone portion 2B is replaced with a thinner membrane-like portion.

[0068] In addition, the cross-sectional shape of each bone portion 2B is the shape of a cross section perpendicular to the central axis (skeleton line O) of the bone portion 2B.

[0069] Furthermore, the present invention is not limited to this example, and only a part of the bones 2B constituting the skeleton 2 may satisfy this configuration. In this case, although there may be a difference in degree, the same effect can be obtained.

[0070] For example, in each example described in this specification, the cross-sectional shape of all or part of the bone portions 2B constituting the skeleton portion 2 may be a polygon (an equilateral triangle, a triangle other than an equilateral triangle, a quadrilateral, etc.), or a circle other than a true circle (an ellipse, etc.). In this case, the same effect as in this example can be obtained. In addition, the cross-sectional shape of each bone portion 2B may be uniform along its extending direction, or may be uneven along its extending direction. In addition, the cross-sectional shapes of each bone portion 2B may also be different from each other.

[0071] 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%. This structure can improve the reaction force generated by the skeleton 2 when an external force is applied to the skeleton 2, and thus the hardness of the skeleton 2 (and thus the hardness of the porous structure 1), when used as a cushioning material, such as a seat cushion (particularly a vehicle seat cushion).

[0072] Here, the "apparent volume VS of the frame portion 2" refers to the entire internal space surrounded by the outer edge (outer contour) of the frame portion 2 (the volume occupied by the frame portion 2, the volume of the partial connection membrane 31 ( Figure 4 ), all connecting films 32 ( Figure 14 ) and the total volume occupied by voids).

[0073] When the materials constituting the skeleton 2 are assumed 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.

[0074] From the viewpoint that the reaction force generated by the skeleton part 2 when an external force is applied to the skeleton part 2, and therefore the hardness of the skeleton part 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 a vehicle), the proportion of the volume VB occupied by the skeleton part 2 in the apparent volume VS of the skeleton part 2 is more preferably 4% to 8%.

[0075] In addition, as a method for adjusting the ratio of the volume VB occupied by the skeleton part 2 in the apparent volume VS of the skeleton part 2, any method can be used, for example, a method of adjusting the thickness (cross-sectional area) of a part of the bone part 2B or all of the bone part 2B constituting the skeleton part 2 and / or the size (cross-sectional area) of a part of the joint part J or all of the joint part J constituting the skeleton part 2.

[0076] In each example described in this specification, the 25% hardness of the porous structure 1 is preferably 60N to 500N, more preferably 100N to 450N. The 25% hardness (N) of the porous structure 1 is a value measured using an inward-facing compression tester in an environment at 23°C and 50% relative humidity, measuring the load (N) required to compress the porous structure 25%. This ensures that the porous structure 1 has a satisfactory hardness for use as a cushioning material, such as a seat cushion (particularly a vehicle seat cushion).

[0077] like Figures 1 to 4 As shown, in this example, the skeleton portion 2 has a plurality (the number of unit holes C) of unit partitioning portions 21 that partition the unit holes C therein.

[0078] Figure 3 and Figure 4 A single unit division portion 21 is shown. Figure 3 For the sake of convenience, the illustration of the local connection film 31 is omitted. Figure 4 The figure shows a local connection film 31. The skeleton portion 2 of this example has a structure in which a large number of unit partitioning portions 21 are connected in the X, Y, and Z directions.

[0079] like Figures 1 to 4 As shown, each unit dividing portion 21 has a plurality of (14 in this example) annular portions 211. Each annular portion 211 is constructed in an annular shape, and a substantially flat imaginary surface V1 is divided by the inner peripheral side edge portion 2111 of each annular portion. The imaginary surface V1 is an imaginary plane (i.e., an imaginary closed plane) divided by the inner peripheral side edge portion 2111 of the annular portion 211. The plurality of annular portions 211 constituting the unit dividing portion 21 are connected to each other in such a manner that the imaginary surfaces V1 divided by their respective inner peripheral side edge portions 2111 do not intersect with each other. In addition, with respect to the imaginary surface V1, "substantially flat" is not limited to a strictly flat situation, as long as it is substantially flat, for example, it also includes a curved surface.

[0080] The unit holes C are formed by the plurality of annular portions 211 constituting the unit partitioning portion 21 and the plurality of imaginary surfaces V1 defined by each of the annular portions 211. Roughly speaking, the annular portions 211 define the sides of the three-dimensional shape formed by the unit holes C, while the imaginary surfaces V1 define the structural surfaces of the three-dimensional shape formed by the unit holes C.

[0081] 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.

[0082] The connection portion of the pair of ring-shaped portions 211 connected to each other is composed of a bone portion 2B and a pair of connecting portions 2J on both sides thereof, which are shared by the pair of ring-shaped portions 211. In other words, each bone portion 2B and each connecting portion 2J are shared by a plurality of adjacent ring-shaped portions 211.

[0083] Each imaginary surface V1 defines a portion of a unit cell C using one side of the imaginary surface V1 (the front surface of the imaginary surface V1), and defines a portion of another unit cell C using the other side of the imaginary surface V1 (the back surface of the imaginary surface V1). In other words, each imaginary surface V1 defines a portion of a different unit cell C using its front and back surfaces. In other words, each imaginary surface V1 is shared by a pair of unit cells C adjacent to the imaginary surface V1 (i.e., a pair of unit cells C sandwiched between the imaginary surface V1).

[0084] Each annular portion 211 is shared by a pair of adjacent unit partitioning portions 21 (i.e., a pair of unit partitioning portions 21 sandwiching the annular portion 211). In other words, each annular portion 211 constitutes a portion of each of the adjacent pair of unit partitioning portions 21.

[0085] exist Figures 1 and 2 In the example of FIG. 1 , a portion of the imaginary surface V1 of the porous structure 1 is not partially connected to the membrane 31 ( Figure 4 ) is not covered but is open, i.e., forms an opening. Therefore, the unit pores C are interconnected via the imaginary surface V1, enabling air permeability between the unit pores C. This improves the air permeability of the skeleton portion 2 and facilitates the compression and recovery of the skeleton portion 2 in response to the application and release of external forces.

[0086] like Figure 3 As shown in FIG. 1 , in this example, the skeleton line O of each unit partition 21 is in the shape of a polyhedron, and thus each unit hole C is in the shape of a substantially polyhedron. More specifically, Figures 1 to 4 In the example, the skeleton line O of each unit dividing portion 21 is 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. Roughly speaking, 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, in a manner that each unit hole C is filled without useless gaps between each other, in other words, in a manner that reduces the gaps (intervals) between the unit holes C).

[0087] By making the shape of the skeleton lines O of part or all (in this example, all) of the unit dividing portions 21 of the skeleton portion 2 (and thus the shape of part or all (in this example, all) of the unit pores C of the skeleton portion 2) a polyhedron as in this example, the gaps (intervals) between the unit pores C constituting the skeleton portion 2 can be further reduced, and more unit pores C can be formed inside the skeleton portion 2. Furthermore, as a result, the compression and recovery deformation behaviors of the skeleton portion 2 (and thus the porous structure 1) in response to the application and release of external forces are further improved when used as a cushioning material, for example, as a seat cushion (particularly a seat cushion for a vehicle).

[0088] The polyhedral shape formed by the skeleton lines O of the unit dividing portion 21 (and thus the polyhedral shape formed by the unit pores C) is not limited to this example and can be any shape. For example, it is preferable to set the shape of the skeleton lines O of the unit dividing portion 21 (and thus the shape formed by the unit pores C) to be approximately a tetrahedron, approximately an octahedron, or approximately a dodecahedron from the perspective of reducing the gap (interval) between the unit pores C. In addition, the shape of the skeleton lines O of a portion or all of the unit dividing portions 21 of the skeleton portion 2 (and thus the shape formed by a portion or all of the unit pores C of the skeleton portion 2) can also be a three-dimensional shape other than a roughly polyhedron (for example, a sphere, an ellipsoid, a cylinder, etc.). In addition, the skeleton portion 2 can have only one type of unit dividing portion 21 with the same skeleton line O shape as the unit dividing portion 21, or it can have multiple types of unit dividing portions 21 with different skeleton line O shapes as the unit dividing portion 21. Similarly, the skeleton portion 2 can have only one type of unit pores C with the same shape as the unit pores C, or it can have multiple types of unit pores C with different shapes as the unit pores C. In addition, when the shape of the skeleton line O of the unit dividing portion 21 (and therefore the shape of the unit hole C) is set to be roughly a Kelvin tetradecahedron (a truncated octahedron) as in this example, it is easier to reproduce the characteristics of a cushioning material equivalent to that of a conventional polyurethane foam manufactured through a foaming process utilizing a chemical reaction than other shapes.

[0089] like Figures 1 to 4As shown, in this example, the multiple (14 in this example) annular portions 211 constituting the unit dividing portion 21 each 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 uses its annular inner peripheral edge 2111 to divide a roughly flat small imaginary surface V1S. Each large annular portion 211L uses its annular inner peripheral edge 2111 to divide a roughly flat large imaginary surface V1L that is larger in area than the small imaginary surface V1S. The small imaginary surface V1S and the large imaginary surface V1L are respectively imaginary planes (i.e., imaginary closed planes). In addition, with respect to the small imaginary surface V1S and the large imaginary surface V1L, "roughly flat" is not limited to a strictly flat situation, as long as it is substantially flat, for example, it also includes a curved surface.

[0090] according to Figure 3 As can be seen, in this example, the skeleton line O of the large annular portion 211L forms a regular hexagon, and accordingly, the large imaginary surface V1L also forms a substantially regular hexagon. Furthermore, in this example, the skeleton line O of the small annular portion 211S forms a regular quadrilateral, and accordingly, the small imaginary surface V1S also forms a substantially regular quadrilateral. Thus, in this example, the small imaginary surface V1S and the large imaginary surface V1L differ not only in area but also in shape.

[0091] 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) connecting portions 2J that connect 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) connecting portions 2J that connect the ends 2Be of the plurality of bone portions 2B.

[0092] Moreover, in Figures 1 to 4 In the example, the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton part 2 are each in the form of a Kelvin tetradecahedron (a truncated octahedron). As described above, the Kelvin tetradecahedron (a truncated octahedron) is a polyhedron composed of six regular quadrilateral structural faces and eight regular hexagonal structural faces. Accordingly, the unit holes C divided by each unit dividing part 21 are also roughly in the form of a Kelvin tetradecahedron. 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. In other words, there are no gaps between the skeleton lines O of the multiple unit dividing parts 21.

[0093] Thus, in this example, the skeleton lines O of the multiple unit dividing portions 21 constituting the skeleton portion 2 are each polyhedron (in this example, a Kelvin tetrahedron), and accordingly, the unit pores C are roughly polyhedrons (in this example, a Kelvin tetrahedron). Therefore, 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 behavior of the porous structure 1 corresponding to the application and release of external forces become better when used as a cushioning material, such as a seat cushion (particularly a seat cushion for a vehicle). In addition, the gaps (intervals) between the unit pores C are equivalent to the wall portions (bone portion 2B, joint portion 2J) of the skeleton portion 2 that divide the unit pores C.

[0094] Furthermore, 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 properties of the porous structure as a cushioning material can be improved.

[0095] The polyhedron formed by the skeleton lines O of the unit partitioning portion 21 (and further, the substantially polyhedron formed by the unit holes C) is not limited to the examples shown in the drawings, and may be in any form.

[0096] For example, the polyhedron formed by the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton portion 2 (and then the roughly polyhedron formed by the unit pores C) is preferably able to fill the space (can be arranged without gaps). Thus, the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton portion 2 can be connected to each other in a space-filling manner, thereby improving the properties of the porous structure as a buffer material. In this case, the polyhedron formed by the skeleton lines O of the multiple unit dividing parts 21 constituting the skeleton portion 2 (and then the roughly polyhedron formed by the unit pores C) can either include only one type of polyhedron as in this example, or can include multiple types of polyhedrons. Here, with respect to a polyhedron, "type" refers to the 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. Regarding the polyhedron formed by the skeleton lines O of the multiple unit dividing parts 21 that constitute the skeleton part 2, examples of such polyhedrons that can fill space and only contain one type of polyhedron include, in addition to the Kelvin tetradecahedron, regular triangular prisms, regular hexagonal prisms, cubes, rectangular parallelepipeds, rhombic dodecahedrons, etc. Furthermore, when the shape of the skeleton lines O of the unit dividing parts 21 is set to a Kelvin tetradecahedron (a truncated octahedron) as in the examples of the various figures, it is easier to reproduce the properties of a cushioning material equivalent to conventional polyurethane foam manufactured through a foaming process utilizing a chemical reaction than other shapes. Furthermore, when the shape of the skeleton lines O of the unit dividing parts 21 is set to a Kelvin tetradecahedron (a truncated octahedron), it is possible to obtain equal mechanical properties in each of the X, Y, and Z directions. Examples of polyhedrons formed by the skeleton lines O of the plurality of unit dividing portions 21 constituting the skeleton portion 2, which can fill a space and include a plurality of types of polyhedrons, include a combination of a regular tetrahedron and a regular octahedron, a combination of a regular tetrahedron and a truncated tetrahedron, a combination of a regular octahedron and a truncated hexahedron, etc. These are examples of combinations of two polyhedrons, but combinations of three or more polyhedrons are also possible.

[0097] In addition, the polyhedron formed by the skeleton lines O of the multiple unit dividing parts 21 that constitute the skeleton part 2 (and thus the approximate polyhedron formed by the unit holes C) can be, for example, any regular polyhedron (a convex polyhedron in which all faces are congruent regular polygons and the number of faces touching at all vertices is equal), a semi-regular polyhedron (a polyhedron other than a regular polyhedron among convex polyhedrons in which all faces are regular polygons and all vertex shapes are congruent (the types and order of regular polygons gathered at the vertices are the same)), a prism, a pyramid, etc.

[0098] Furthermore, the skeleton lines O of some or all of the multiple unit dividing portions 21 constituting the skeleton portion 2 may be in a solid shape other than a polyhedron (e.g., a sphere, an ellipsoid, a cylinder, etc.). Furthermore, some or all of the multiple unit holes C constituting the skeleton portion 2 may be in a roughly solid shape other than a roughly polyhedron (e.g., a roughly sphere, a roughly ellipsoid, a roughly cylinder, etc.).

[0099] By including the small annular portions 211S and the large annular portions 211L of different sizes in the plurality of annular portions 211 constituting the unit partitioning portion 21, it is possible to further reduce the gaps (intervals) between the unit holes C constituting the skeleton portion 2. Furthermore, when the small annular portions 211S and the large annular portions 211L have different shapes as in this example, it is possible to further reduce the gaps (intervals) between the unit holes C constituting the skeleton portion 2.

[0100] However, the annular portions 211 constituting the unit partitioning portion 21 may be of the same size and / or shape. If the annular portions 211 constituting the unit partitioning portion 21 are of the same size and shape, equal mechanical properties can be obtained in the X, Y, and Z directions.

[0101] By making the skeleton lines O of part or all (in this example, all) of the annular parts 211 constituting the unit dividing part 21 (and furthermore, 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 spacing between the unit holes C constituting the skeleton part 2 can be further reduced. In addition, the behavior of the skeleton part 2 in compression and recovery deformation corresponding to the application and release of external forces becomes better when it is used as a seat cushion, especially as a seat cushion for vehicles. In addition, since the shape of the annular part 211 (and furthermore, the shape of the imaginary surface V1) becomes simpler, 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 furthermore, at least one imaginary surface V1 constituting the skeleton part 2) satisfies this structure, although there may be differences in degree, the same effect can be obtained.

[0102] Alternatively, 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 substantially polygonal shape other than a substantially regular hexagon or a substantially regular quadrilateral as in this example, or a planar shape other than a substantially polygonal shape (e.g., a circle (a perfect circle, an 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 circle (a perfect circle, an ellipse, etc.), the shape of the annular portion 211 (and furthermore, the shape of the imaginary surface V1) becomes simpler, thereby improving manufacturability and ease of adjusting characteristics, and achieving more uniform mechanical properties. 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 that is longer in a direction approximately perpendicular to the direction in which the load is applied (a horizontally long ellipse), the annular portion 211, and thus the skeleton portion 2 (and thus the porous structure 1) are easily deformed (become softer) relative to the input of the 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 that is longer in a direction approximately parallel to the direction in which the load is applied (a vertically long ellipse).

[0103] In this example, the skeleton portion 2 preferably has at least one unit pore C with a diameter of 5 mm or more. This facilitates the manufacture of the porous structure 1 using a 3D printer. If the diameter of each unit pore C of the skeleton portion 2 is less than 5 mm, the structure of the skeleton portion 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.

[0104] Furthermore, the porous structure constituting the conventional cushioning material is manufactured 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.

[0105] Furthermore, since the skeleton portion 2 has the unit pores C having a diameter of 5 mm or more, the air permeability and deformability of the skeleton portion 2 can be easily improved.

[0106] From this viewpoint, the diameters of all the unit pores C constituting the skeleton portion 2 are preferably 5 mm or more.

[0107] The larger the diameter of the unit pore 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 pores C of the skeleton portion 2 is more preferably 8 mm or more, and further preferably 10 mm or more.

[0108] On the other hand, if the unit pores C of the skeleton portion 2 are too large, it is difficult to neatly (smoothly) form the outer edge (outer contour) shape of the skeleton portion 2 (and thus the porous structure 1), and it is possible that the shape accuracy of the cushioning material (such as a seat cushion, in particular a seat cushion for a vehicle) decreases, and the appearance deteriorates. In addition, the properties of the cushioning material (such as a seat cushion, in particular 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, in particular a seat cushion for a vehicle), the diameter of each unit pore C of the skeleton portion 2 is preferably less than 30 mm, more preferably less than 25 mm, and further preferably less than 20 mm.

[0109] Furthermore, the more unit pores C that satisfy the aforementioned numerical ranges of diameters in the porous structure 1, the easier it is to achieve the aforementioned effects. From this perspective, the diameter of each unit pore C constituting the porous structure 1 preferably satisfies at least one of the aforementioned numerical ranges. Similarly, the average value of the diameters of each unit pore C constituting the porous structure 1 more preferably satisfies at least one of the aforementioned numerical ranges.

[0110] In addition, when the unit hole C has a shape different from a strict spherical shape as in this example, the diameter of the unit hole C refers to the diameter of the sphere circumscribing the unit hole C.

[0111] If the unit pores C of the skeleton portion 2 are too small, the structure of the skeleton portion 2 becomes too complicated. 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, and therefore 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 portion 2 is preferably 0.05 mm or more, 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, it is possible to use the resolution of a high-performance 3D printer for shaping. When the diameter of the unit pore C with the smallest diameter is 0.10 mm or more, it is possible to use not only the resolution of a high-performance 3D printer but also the resolution of a general-purpose 3D printer for shaping.

[0112] As mentioned above, Figure 1 、 Figure 2 、 Figure 4 As shown, the porous structure 1 includes one or more local connection membranes 31 in addition to the skeleton 2. At least a portion of one or more of the virtual surfaces V1 constituting the skeleton 2 is covered by one or more local connection membranes 31. Figure 5As shown in the enlarged view in the figure, the one or more partial connecting membranes 31 are connected only to a portion of the circumference of the annular portion 211. Specifically, each partial connecting membrane 31 is connected only to a portion of the circumference of the annular inner peripheral edge 2111 of the annular portion 211. The partial connecting membranes 31 are integrally formed with the skeleton portion 2.

[0113] Each partial connecting film 31 extends on the imaginary plane V1 defined by the inner peripheral edge 2111 of the annular portion 211 , thereby covering at least a portion of the imaginary plane V1 defined by the annular portion 211 .

[0114] Figure 6 Is to use along Figure 5 The cross section of the BB line is shown Figure 5 BB cross-sectional view of the annular portion 211 and the partial connecting film 31 . Figure 6 The annular portion 211 and the partial connecting membrane 31 are shown in a natural state in which no external force is applied to the porous structure 1 . Figure 7 is with Figure 6 The cross-sectional view at the corresponding position shows the annular portion 211 and the local connection membrane 31 in the state when the porous structure 1 is compressed and deformed or restored. Figures 6 and 7 As shown in the example, the local connection membrane 31 is only connected to the circumferential part of the annular portion 211, so when an external force is applied to the porous structure 1 and the porous structure 1 is compressed and deformed or restored ( Figure 7 ) The portion of the local connecting membrane 31 that is not connected to the annular portion 211 is bent due to being squeezed by the air, and the air passes through the gap between the local connecting membrane 31 and the annular portion 211 formed at this time. In this way, the air permeability between the two unit pores C sandwiched between the imaginary surface V1 covered by the local connecting membrane 31 is achieved. When the porous structure 1 is compressed and deformed or restored, the movement of air in and out of the gap between the local connecting membrane 31 and the annular portion 211, and the deformation movement of the local connecting membrane 31 and the annular portion 211 affect the dynamic characteristics of the porous structure 1 (specifically, the vibration attenuation characteristics (especially the viscosity attenuation characteristics)). By adjusting the structure of the local connecting membrane 31 and the annular portion 211, the movement of air in and out of the gap between the local connecting membrane 31 and the annular portion 211, and the deformation movement of the local connecting membrane 31 and the annular portion 211 can be adjusted, thereby achieving more diverse dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscosity attenuation characteristics)) as required. Therefore, it is possible to increase the degree of freedom in adjusting the dynamic characteristics of the porous structure 1. This is particularly preferred when the porous structure 1 is used for a vehicle seat cushion, particularly a vehicle seat cushion, which is input with vibration during use.

[0115] Furthermore, as previously mentioned, porous structures constituting cushioning materials are manufactured through a foaming process utilizing a chemical reaction. Therefore, it is difficult to form a membrane with interconnected pores that interconnect the individual units in the desired position, number, size, and shape. When the porous structure 1 is manufactured using a 3D printer, as in this example, by pre-incorporating information about the local interconnecting membrane 31 into the 3D modeling data read into the 3D printer, the local interconnecting membrane 31 can be reliably formed in the desired position, number, size, and shape.

[0116] The following, except Figures 1 to 7 In addition to the porous structure 1 of the first embodiment of the present invention shown in FIG. Figures 8 to 14 The porous structures 1 according to the second to eighth embodiments of the present invention will be described.

[0117] Figures 8 to 14 The porous structures 1 of the second to eighth embodiments shown are also similar to the porous structure 1 of the first embodiment. In addition to the skeleton portion 2, the porous structure 1 further includes one or more local connection membranes 31. At least a portion of each of one or more of the imaginary surfaces V1 constituting the skeleton portion 2 is covered by the one or more local connection membranes 31. The one or more local connection membranes 31 are each connected only to a portion of the circumference of the annular portion 211. Therefore, the porous structures 1 of the second to eighth embodiments also achieve the same effects as the porous structure 1 of the first embodiment.

[0118] In each embodiment described in this specification, one or more of the imaginary surfaces V1 constituting the skeleton portion 2 are respectively Figure 5 、 Figures 9 to 11 As in the embodiments of the present invention, only a local connection film 31 is covered, or it may be as Figure 8 、 Figures 12 and 13 In the case where the imaginary surface V1 is covered by a plurality of partial connecting films 31, the plurality of partial connecting films 31 are preferably as shown in FIG. Figure 8 、 Figures 12 and 13 As in the embodiments of the present invention, they do not overlap with each other when viewed from above.

[0119] By adjusting the number and size of the local connecting membranes 31 covering the imaginary surface V1, the movement of air in and out of the gap between the local connecting membrane 31 and the annular portion 211 and the deformation of the local connecting membrane 31 can be adjusted, thereby adjusting the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscosity attenuation characteristics)).

[0120] In each embodiment described in this specification, one or more local connection films are respectively, Figure 5 、 Figures 8 and 9、 Figures 11 to 13 As in the embodiments of the present invention, it is only connected to the circumferential part of the annular portion 211, or it can be connected as shown in FIG. Figure 10 As in the embodiment of the present invention, the plurality of circumferential portions of the annular portion 211 (in Figure 10 In the example, there are two parts) connected.

[0121] By adjusting the number and position of the connecting parts between the local connecting membrane 31 and the annular portion 211, the movement of air in and out of the gap between the local connecting membrane 31 and the annular portion 211, the deformation movement of the local connecting membrane 31 and the annular portion 211 can be adjusted, and the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscosity attenuation characteristics)) can be adjusted.

[0122] In each embodiment described in this specification, one or more local connection films 31 can be Figure 5 、 Figures 8 and 9 、 Figures 11 to 13 As in the embodiments of the present invention, only one bone portion 2B of the annular portion 211 is connected, or it may be connected as in Figure 10 As in the embodiment, it is connected only to multiple bone parts 2B in the annular part 211, or although not shown in the figure, it can also be connected to one or more bone parts 2B and one or more connecting parts 2J in the annular part 211.

[0123] By adjusting the position and length of the connection portion between the partial connection film 31 and the annular portion 211 , the deformation behavior of the partial connection film 31 and the annular portion 211 can be adjusted, thereby adjusting the dynamic characteristics (specifically, the vibration damping characteristics (especially the viscosity damping characteristics)).

[0124] In each embodiment described in this specification, one or more local connection films 31 may be respectively Figure 5 、 Figures 8 to 13 As in the embodiments of the present invention, only one or more bone parts 2B in the annular part 211 are connected to each other locally. Figure 5 、 Figures 8 and 9 、 Figures 11 to 13 In each embodiment, the local connection membrane 31 is connected only to a part of one bone portion 2B in the annular portion 211. Figure 10 In the embodiment, the local connection membrane 31 is connected only to the parts of each of the two bone parts 2B in the annular part 211. In these embodiments, the bone part 2B connected to the local connection membrane 31 includes the connection part 2BC connected to the local connection membrane 31 and the root part 3BR not connected to the local connection membrane 31. In this case, it is preferable to Figure 5 、 Figures 8 to 13As in the respective embodiments, the bone portion 2B connected to the partial connecting membrane 31 has a pair of root portions 3BR on both sides of the connecting portion 2BC in the extending direction of the bone portion 2B.

[0125] However, in each embodiment described in this specification, one or more local connecting membranes 31 may be connected to all of one or more bone portions 2B in the annular portion 211. In this case, the bone portion 2B connected to the local connecting membrane 31 includes only the portion connected to the local connecting membrane 31, namely the connecting portion 2BC, and does not include the portion not connected to the local connecting membrane 31, namely the root portion 3BR.

[0126] In these embodiments, when the porous structure 1 is compressed and deformed or restored, the root 3BR of the bone portion 2B is rotated around the skeleton line O( Figure 4 ) is twisted to play the role of hinge, so that the local connection film 31 and the connection part 2BC become one body around the skeleton line O( Figure 4 By adjusting the length of the connecting portion 2BC of the bone portion 2B (and thus the ratio of the length of the connecting portion 2BC to the overall length of the bone portion 2B), the deformation of the local connecting membrane 31 and the bone portion 2B can be adjusted, thereby adjusting the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscous attenuation characteristics)).

[0127] For example, in Figure 5 implementation methods and Figure 9 In the embodiment, although the size and shape of the local connecting membrane 31 are roughly the same, the length of the connecting portion 2BC of the bone portion 2B (and therefore the ratio of the length of the connecting portion 2BC to the overall length of the bone portion 2B) is different, and therefore the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscous attenuation characteristics)) are different.

[0128] In the image Figure 5 、 Figures 8 to 13 In the case where one or more local connection membranes 31 are respectively connected only to a part of one or more bone parts 2B in the annular portion 211 as in each embodiment, at least a part of the bone parts 2B in each bone part 2B connected to the one or more local connection membranes 31 is the cross-sectional area of the root 2BR that is not connected to the local connection membrane 31. Figure 5 、 Figures 8 to 10 、 Figures 12 and 13 The cross-sectional area of the connecting portion 2BC connected to the local connecting film 31 may be the same as in the embodiments of FIG. Figure 11 As in the embodiment of FIG, the cross-sectional area of the connecting portion 2BC may be smaller than that of the connecting portion 2BC, or although not shown in the figure, the cross-sectional area of the connecting portion BC may be larger.

[0129] By adjusting the cross-sectional area of the root 2BR of the bone portion 2B (and thus the ratio of the cross-sectional area of the root 3BR to the cross-sectional area of the connecting portion 2BC), the ease of twisting of the root 3BR around the skeleton line O (and thus the hinge function) can be adjusted, and thus the rotational movement of the local connecting membrane 31 and the connecting portion 2BC around the skeleton line O can be adjusted, and thus the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscous attenuation characteristics)) can be adjusted.

[0130] From the same point of view, Figure 5 、 Figures 8 to 13 In the case where one or more local connection membranes 31 are respectively connected only to a part of one or more bone parts 2B in the annular portion 211 as in each embodiment, at least a part of the bone parts 2B in each bone part 2B connected to the one or more local connection membranes 31 is the cross-sectional area of the root 2BR that is not connected to the local connection membrane 31. Figure 5 、 Figures 8 to 10 、 Figures 12 and 13 The cross-sectional area of the bone portion 2B not connected to the local connection membrane 31 may be the same as that of each embodiment, or it may be the same as that of Figure 11 As in the embodiment of FIG. 3 , the cross-sectional area of the bone portion 2B not connected to the local connecting membrane 31 may be smaller than that of the bone portion 2B, or although not shown in the figure, the cross-sectional area of the bone portion 2B not connected to the local connecting membrane 31 may be larger.

[0131] The cross-sectional areas of the connecting portion 2BC and the root portion 2BR refer to the cross-sectional areas of the connecting portion 2BC and the root portion 2BR, respectively, which are the areas of the connecting portion 2BC and the root portion 2BR that are connected to the skeleton line O( Figure 4 ) is the cross-sectional area of the perpendicular section.

[0132] In each embodiment described in this specification, the cross-sectional area of the connecting portion 2BC of the bone portion 2B can be as large as Figure 5 、 Figures 8 to 13 As in the various embodiments, the cross-sectional area of the bone portion 2B that is not connected to the local connecting membrane 31 may be the same as that of the bone portion 2B that is not connected to the local connecting membrane 31, or although not shown in the figure, it may be smaller than the cross-sectional area of the bone portion 2B that is not connected to the local connecting membrane 31, or although not shown in the figure, it may be larger than the cross-sectional area of the bone portion 2B that is not connected to the local connecting membrane 31.

[0133] The cross-sectional area of the connecting portion 2BC of the bone portion 2B tends to be less likely to affect the dynamic characteristics (specifically, the vibration damping characteristics (especially the viscous damping characteristics)).

[0134] In each embodiment described in this specification, the thickness T31 ( Figure 6 ) can be like Figure 6 The width W0 ( Figure 6) is smaller, or although not shown in the figure, it can be the same as the width W0 of the connecting portion 2BC of the bone portion 2B connected to the local connecting membrane 31, or although not shown in the figure, it can be larger than the width W0 of the connecting portion 2BC of the bone portion 2B connected to the local connecting membrane 31.

[0135] By adjusting the thickness T31 of the local connecting film 31 (and thus the ratio of the thickness T31 of the local connecting film 31 to the width W0 of the connecting portion 2BC), the deformation of the local connecting film 31 can be adjusted, and thus the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscosity attenuation characteristics)) can be adjusted.

[0136] From the same viewpoint, in each embodiment described in this specification, the thickness T31 ( Figure 6 ) can be greater than the width W0 of the bone portion 2B not connected to the local connection membrane 31 ( Figure 1 ) is smaller, or although not shown in the figure, it can be the same as the width W0 of the connection portion 2BC of the bone portion 2B that is not connected to the local connection membrane 31, or it can be larger than the width W0 of the connection portion 2BC of the bone portion 2B that is not connected to the local connection membrane 31.

[0137] In each embodiment described in this specification, one or more annular portions 211 may also be Figures 12 and 13 As in the embodiments of the present invention, each bone portion 2B of the annular portion 211 is connected to a local connection membrane 31 that is independent of each other. In this case, the local connection membranes 31 can be connected to each other as shown in FIG. Figures 12 and 13 A gap may be shown, or there may be no gap.

[0138] In such a case, as described above, by adjusting the length of the connecting portion 2BC of the bone portion 2B, the cross-sectional area of the root 2BR when the bone portion 2B has a root 2BR, the thickness T31 of the local connecting membrane 31, the gap between the local connecting membranes 31, etc., it is possible to adjust the gap between the local connecting membrane 31 and the annular portion 211, the movement of air in and out of the gap between the local connecting membranes 31, the deformation movement of the local connecting membrane 31 and the annular portion 211, and thus the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscosity attenuation characteristics)) can be adjusted.

[0139] In this case, one or more rings 211 may also be formed like Figure 13 As in the embodiment of the present invention, each bone portion 2B of the annular portion 211 is connected to a local connection membrane that is independent of each other, and the inner peripheral end of each local connection membrane 31 is used to define a hole (orifice) 5. The shape of the hole 5 can be as Figure 13By adjusting the size and shape of the hole 5, the air resistance of the air passing through the hole 5 and the deformation of the local connecting membrane 31 can be adjusted, thereby adjusting the dynamic characteristics (specifically, the vibration attenuation characteristics (especially the viscosity attenuation characteristics)).

[0140] In each embodiment described in this specification, the shape of the local connection film 31 may be any shape such as a triangle, a quadrilateral, a hexagon or other polygon, a circle or an ellipse. Figure 5 、 Figures 8 to 11 In each example, the shape of the local connection film 31 is hexagonal (in Figure 9 In the example, it is roughly hexagonal. In addition, Figures 12 and 13 In each example, the shape of the local connection film 31 is a triangle.

[0141] In each embodiment described in this specification, the shape of the local connection film 31 can be Figure 5 、 Figures 8 to 11 As in each example, the skeleton line O ( Figure 4 ) the shape formed (in Figure 5 、 Figures 8 to 11 In each case, it is a hexagon) or it can be roughly the same shape as Figures 12 and 13 As in each example, the shape formed by the skeleton line O of the annular portion 211 connected to the local connection film 31 (in Figures 12 and 13 In each case, it is a hexagonal shape).

[0142] In each embodiment described in this specification, when the porous structure 1 is in a natural state, one or more local connection membranes 31 covering the imaginary surface V1 can be Figure 5 、 Figures 8 to 13 As in the respective embodiments of the present invention, only a portion of the imaginary surface V1 may be covered, or the entire imaginary surface V1 may be covered.

[0143] In each embodiment described in this specification, any of the imaginary surfaces V1 constituting the skeleton portion 2 may be covered by one or more local connection films 31. At least one of the small imaginary surfaces V1S constituting the skeleton portion 2 may also be covered by one or more local connection films 31. And / or at least one of the large imaginary surfaces V1L constituting the skeleton portion 2 may also be covered by one or more local connection films 31.

[0144] In each embodiment described in this specification, it is possible to Figures 1 and 2As in the example of , the number, position, and structure of the local connection film 31 may be different in each unit dividing portion 21, or the number, position, and structure of the local connection film 31 may be the same in each unit dividing portion 21.

[0145] For example, at least one imaginary surface V1L of each cell partitioning portion 21 included in the porous structure 1 may be covered with one or more local connecting films 31 .

[0146] The porous structure 1 may also have the above-mentioned first to seventh embodiments ( Figure 5 、 Figures 8 to 13 ) in any number of embodiments.

[0147] The partial connecting film 31 is preferably made of the same material as the frame portion 2. However, the partial connecting film 31 may be made of a material different from that of the frame portion 2.

[0148] exist Figure 5 、 Figures 8 to 13 In each of the examples, the partial connecting film 31 is substantially flat, more specifically, flat. Regarding the partial connecting film 31, "substantially flat" is not limited to being strictly flat; it can be substantially flat, including, for example, a curved surface. When the partial connecting film 31 is curved, it can function as a diaphragm.

[0149] In each embodiment described in this specification, the porous structure 1 can also be as follows Figure 14 In addition to the skeleton portion 2 and the partial connecting membrane 31 , one or more full connecting membranes 32 are shown.

[0150] The entire connecting film 32 extends on the imaginary surface V1 divided by the annular inner peripheral side edge 2111 of the annular portion 211, thereby covering the imaginary surface V1 divided by the annular portion 211. The entire connecting film 32 is connected to the annular portion 211 in the circumferential direction. Specifically, the entire connecting film 32 is connected to the annular inner peripheral side edge 2111 of the annular portion 211 in the circumferential direction. The entire connecting film 32 is integrally formed with the skeleton portion 2. The entire connecting film 32 is preferably made of the same material as the skeleton portion 2. However, the entire connecting film 32 may also be made of a material different from that of the skeleton portion 2. In Figure 14 In the example shown, the entire connecting film 32 is substantially flat, more specifically, flat. Regarding the entire connecting film 32, "substantially flat" is not limited to being strictly flat; it can be substantially flat, including, for example, a curved surface. When the entire connecting film 32 is curved, the entire connecting film 32 can function as a diaphragm.

[0151] The entire connecting membrane 32 preferably has a width W0 ( Figure 1 ) Small thickness.

[0152] Due to the full coverage of the connecting membrane 32, the two unit pores C sandwiched between the imaginary surface V1 are no longer connected to each other via the imaginary surface V1, and air can no longer pass through the imaginary surface V1, thereby reducing the overall air permeability of the porous structure 1. By adjusting the number of imaginary surfaces V1 constituting the porous structure 1 that are fully covered by the connecting membrane 32, the overall air permeability of the porous structure 1 can be adjusted, and various air permeability levels can be achieved as required.

[0153] At least one of the small imaginary surfaces V1S constituting the skeleton portion 2 may be entirely covered by the connecting film 32 . Also, at least one of the large imaginary surfaces V1L constituting the skeleton portion 2 may be entirely covered by the connecting film 32 .

[0154] The number and position of all the connecting films 32 may be different in each cell partitioning portion 21 , or the number and position of all the connecting films 32 may be the same in each cell partitioning portion 21 .

[0155] In addition, the porous structure 1 may not include all the connecting membranes 32 .

[0156] [Seat cushion with porous structure]

[0157] 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).

[0158] Below, refer to Figure 15 An example of a seat pad 302 including the porous structure 1 according to any embodiment of the present invention will be described.

[0159] Figure 15 This is a perspective view schematically showing an example of a vehicle seat 300 including a seat cushion 302 (vehicle seat cushion) that can be formed of the porous structure 1 according to various embodiments of the present invention.

[0160] like Figure 15 As shown by the middle dotted line, the vehicle seat 300 includes a cushion 310 for seating the occupant and a backrest 320 for supporting the occupant's back. The cushion 310 and the backrest 320 are each formed of a seat cushion 302. Hereinafter, the cushion 310 or the backrest 320 may be referred to simply as "seat cushion 302." The cushion 310 and the backrest 320 can each be formed of the porous structure 1 of any embodiment described in this specification. An XYZ orthogonal coordinate system ( Figures 1 to 4) can point in any direction relative to the seat cushion 302. In addition to the seat cushion 302 that constitutes the cushion 310 and the backrest 320, the vehicle seat 300 can also include, for example, a skin 330 that covers the surface side (seat occupant side) of the seat cushion 302, a frame (not shown) that supports the cushion 310 from the bottom side, a frame (not shown) provided on the back side of the backrest 320, and a headrest 340 provided on the upper side of the backrest 320 and used to support the head of the seat occupant. The skin 330 is made of, for example, a material with good air permeability (cloth, etc.). In Figure 15 In the example shown in FIG. 3 , the cushion pad 310 and the backrest pad 320 are formed independently of each other, but they may be formed integrally with each other.

[0161] In addition, Figure 15 In the example shown in FIG, the headrest 340 is formed independently of the backrest cushion 320 , but the headrest 340 may be formed integrally with the backrest cushion 320 .

[0162] In this manual, if Figure 15 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 further the seat cushion 302) are abbreviated as "up", "down", "left", "right", "front" and "rear", respectively.

[0163] The cushion pad 310 includes a main cushion portion 311 configured to support the seated user's buttocks and thighs from below, and a pair of side cushion portions 312 located on the left and right sides of the main cushion portion 311. These side cushion portions 312 are raised upward relative to the main cushion portion 311 and configured to support the seated user from both sides. The main cushion portion 311 includes a lower leg portion 311t configured to support the seated user's thighs from below, and a lower buttock portion 311h located further back than the lower leg portion 311t and configured to support the seated user's buttocks from below.

[0164] The backrest cushion 320 includes a main cushion portion 321 configured to support the back of the seated person from the rear side, and a pair of side cushion portions 322 located on the left and right sides of the main cushion portion 321 and bulging forward relative to the main cushion portion 321 to support the seated person from the left and right sides.

[0165] In this specification, the "extension direction (LD) of the seat cushion (302)" is 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, it refers to the front-back direction ( Figure 15 ), 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 ( Figure 15 ).

[0166] 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. Figure 15 ), 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 seated person side surface (surface) FS of the main pad portion 321 of the backrest pad 320 to the back surface BS ( Figure 15 ).

[0167] In addition, the "surface (FS) on the seat occupant side" of the seat cushion (302) refers to the upper surface ( Figure 15 ), which refers to the front surface ( Figure 15 The "back side (BS)" of the seat cushion (302) is the side of the seat cushion (302) opposite to the seated person side surface (FS), and in the case of the cushion 310, it refers to the lower surface ( Figure 15 ), which refers to the rear surface ( Figure 15 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 pad 310, it refers to any one of the front surface, the back surface, the left surface, and the right surface ( Figure 15 ), in the case of the backrest pad 320, refers to any one of the lower surface, upper surface, left surface and right surface ( Figure 15 ).

[0168] In addition, Figure 15 In the illustrated example, the porous structure 1 constitutes the entirety of the cushion pad 310 and the back pad 320 of the seat cushion 302 .

[0169] 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 cushion 302 .

[0170] Alternatively, the porous structure 1 may constitute only a portion of the cushion pad 310 of the seat cushion 302, a portion of the backrest pad 320, and / or a portion of the headrest 340. This allows the size of the porous structure 1 to be reduced, enabling its manufacture using a relatively small 3D printer. In this case, the portions of the cushion pad 310, backrest pad 320, and headrest 340 of the seat cushion 302 other than those formed by the porous structure 1 can be manufactured, for example, by a foaming process utilizing a chemical reaction during mold forming or sheet forming, thereby forming the aforementioned conventional porous structure (foam). For example, although not shown in the figure, the cushion pad 310, backrest pad 320, and / or headrest 340 of the seat cushion 302 may each include a plurality of independently constructed cushioning portions, wherein only a portion (one or more) of the plurality of cushioning portions is formed of the porous structure 1, and the other cushioning portions are formed of a porous structure (foam) manufactured by a process of foaming using a chemical reaction during mold forming or sheet forming. More specifically, for example, the cushion pad 310, backrest pad 320, and / or headrest 340 of the seat cushion 302 may each include: one or more inserts formed of the porous structure 1; and a main body portion that is independently constructed relative to the one or more inserts and has a recess for accommodating the one or more inserts, and is, for example, formed of a porous structure (foam) manufactured by a process of foaming using a chemical reaction during mold forming or sheet forming.

[0171] Alternatively, the cushion pad 310, backrest pad 320, and / or headrest 340 of the seat cushion 302 may be composed of a plurality of independently constructed cushioning portions, each of which is composed of the porous structure 1. This can also reduce the size of the porous structure 1, and further enable its manufacture using a relatively small 3D printer.

[0172] The porous structure 1 preferably constitutes at least a portion of the main pad portion 311 or 321 of the cushion pad 310 or the back pad 320 .

[0173] [Method for producing porous structure]

[0174] Next, refer to Figure 16 The method for producing the porous structure 1 of the present invention will be described with examples. 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. Figure 16 A state of manufacturing the porous structure 1 constituting a seat cushion is shown.

[0175] First, three-dimensional shape data (for example, three-dimensional CAD data) representing the three-dimensional shape of the porous structure 1 is created in advance using a computer.

[0176] Next, the three-dimensional shape data is converted into 3D shaping data 500 using a computer. The 3D shaping data 500 is read into the control unit 410 of the 3D printer 400 when the shaping unit 420 of the 3D printer 400 performs shaping. The control unit 410 is configured to cause the shaping unit 420 to shape the porous structure 1. The 3D shaping data 500 includes, for example, slice data representing the two-dimensional shape of each layer of the porous structure 1.

[0177] 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. Figure 16 The following shows the case where the light shaping method is used for shaping.

[0178] The 3D printer 400 includes, for example, a control unit 410 composed of a CPU, a forming unit 420 that performs forming in accordance with the control of the control unit 410, a support table 430 for placing the formed object (i.e., the porous structure 1), and a storage body 440 that stores liquid resin LR, the support table 430, and the object. When using a light forming method as in this example, the forming unit 420 includes a laser irradiator 421 that is configured to irradiate ultraviolet laser light LL. The storage body 440 is filled with liquid resin LR. When the ultraviolet laser light LL emitted from the laser irradiator 421 hits the liquid resin LR, the liquid resin LR solidifies and becomes a flexible resin.

[0179] In the 3D printer 400 thus constructed, the control unit 410 first reads the 3D shaping data 500 and controls the shaping unit 420 to irradiate the ultraviolet laser LL based on the three-dimensional shape included in the read 3D shaping data 500, thereby shaping each layer in sequence.

[0180] 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.

[0181] By manufacturing the porous structure 1 using a 3D printer, the porous structure 1 including the partially connected membrane 31 as intended can be realized simply and accurately in a single step.

[0182] Furthermore, when the porous structure 1 is made of resin, the porous structure 1 as a formed object may be heated in a heating furnace after the forming is completed using the 3D printer 400. In this case, the bonding between the layers forming the porous structure 1 can be strengthened, thereby reducing the anisotropy of the porous structure 1, and thus further improving the cushioning properties of the porous structure 1.

[0183] 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 3D printer 400 has finished forming the porous structural body 1 .

[0184] Industrial applicability

[0185] 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, and are particularly suitable for use in vehicle seats and vehicle seat cushions.

[0186] Description of Reference Numerals

[0187] 1: porous structure; 2: skeleton; 2B: bone; 2Be: end of the bone; 2BC: connecting portion; 3BR: root; 2J: joint; 21: unit division; 211: annular portion; 211L: large annular portion; 211S: small annular portion; 2111: inner peripheral edge of the annular portion; 31: partial connecting membrane; 32: entire connecting membrane; 5: hole; C: unit hole; O: skeleton line; V1: imaginary surface; V1L: large imaginary surface; V1S: small imaginary surface; 300: vehicle seat; 302: seat cushion; 310: cushion; 311: main cushion Part (seating part); 311t: lower part of the legs; 311h: lower part of the buttocks; 312: side pad part, 320: back pad; 321: main pad part; 322: side pad part, 330: surface, 340: headrest, FS: surface on the side of the seated person; SS: side; BS: back; TD: thickness direction; LD: extension direction, 400: 3D printer; 410: control part; 420: forming part; 421: laser irradiator; 430: support table; 440: storage body; LL: ultraviolet laser; LR: liquid resin; 500: data for 3D forming.

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 portion includes a plurality of bone portions and a plurality of coupling portions for coupling ends of the plurality of bone portions to each other. The skeleton portion includes a plurality of annular portions each formed into an annular shape by a plurality of the bone portions and a plurality of the connecting portions. Each of the annular portions is divided into imaginary surfaces by its inner peripheral edge. At least a portion of each of one or more of the imaginary surfaces is covered by one or more local bonding films, The one or more local connection films are respectively connected only to a part of the circumference of the annular portion. The porous structure is used as a buffer material, The porous structure is formed by using a 3D printer.

2. The porous structure according to claim 1, wherein The one or more local connection membranes are respectively connected only to a part of the one or more bone parts in the annular part.

3. The porous structure according to claim 2, wherein In at least some of the bone parts among the bone parts connected to the one or more local connecting membranes, a cross-sectional area of a portion not connected to the local connecting membrane is smaller than a cross-sectional area of a portion connected to the local connecting membrane.

4. The porous structure according to any one of claims 1 to 3, wherein The one or more partial connecting films are respectively connected to a plurality of portions in the circumferential direction of the annular portion.

5. The porous structure according to any one of claims 1 to 3, wherein One or more of the annular portions are connected to the respective bone portions of the annular portions with the local connecting membranes independent of each other.

6. The porous structure according to any one of claims 1 to 3, wherein The one or more annular portions are connected to the bone portions of the annular portions respectively with the independent local connecting membranes, and the inner peripheral end portions of the local connecting membranes define a hole.

7. A method for producing a porous structure, wherein: This production method uses a 3D printer to produce the porous structure according to any one of claims 1 to 6.

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