Seat pad, and method for manufacturing a seat pad

Abstract

To provide a seat pad that can obtain a dynamic characteristic different from a dynamic characteristic that can obtain when the seat pad is composed of a single unit made of a porous structure, and to provide a manufacturing method of such seat pad.SOLUTION: A seat pad 302 of the present invention includes; an engaging member 51 having an engagement part 510; and an engaged member 52 having an engaged part 520 composed for engaging with the engagement part. The engaging member and the engaged member are each composed of a porous structure 1 which is composed of a flexible resin or rubber. The porous structure, in almost its entirety, is provided with a skeleton part 2, and the skeleton part is equipped with a plurality of bone parts 2B and a plurality of connection parts 2J which connect the respective ends of the plurality of bone parts.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a seat pad and a method for manufacturing the seat pad.

Background Art

[0002] Conventionally, a cushioning porous structure (for example, urethane foam) has been manufactured through a process of foaming by a chemical reaction in, for example, mold forming. On the other hand, in recent years, a porous structure that enables easy production of a cushioning porous structure by a 3D printer has been proposed (for example, Patent Document 1, Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventors of the present invention earnestly studied a seat pad capable of obtaining dynamic characteristics different from those obtained when a seat pad is constituted by a single member made of a porous structure as described above, and arrived at the present invention.

[0005] An object of the present invention is to provide a seat pad capable of obtaining dynamic characteristics different from those obtained when a seat pad is constituted by a single member made of a porous structure, and a method for manufacturing a seat pad capable of obtaining a seat pad capable of obtaining dynamic characteristics different from those obtained when a seat pad is constituted by a single member made of a porous structure.

Means for Solving the Problems

[0006] The seat pad of the present invention A fitting member having a fitting portion, A fitted member having a fitted portion configured to fit with the aforementioned fitting portion, Equipped with, The fitting member and the fitted member are each composed of a porous structure. The porous structure is made of a flexible resin or rubber. The porous structure has a skeletal structure extending almost entirely over its entirety. The aforementioned skeletal part is, Multiple bones, Each of the aforementioned multiple bone portions connects the ends of the bones, It is equipped with. According to the sheet pad of the present invention, it is possible to obtain dynamic characteristics that are different from those obtained when the sheet pad is constructed using only a member made of a porous structure.

[0007] In the sheet pad of the present invention, It is preferable that the fitting portion and the fitted portion are located on the main pad portion of the seat pad. This improves the grip.

[0008] In the sheet pad of the present invention, Preferably, the fitting member and the fitted member face each other in a direction perpendicular to the thickness direction of the sheet pad. This improves the grip.

[0009] In the sheet pad of the present invention, In a cross-section perpendicular to the opposing direction of the fitting portion and the fitted portion, the fitting portion and the fitted portion may extend over the entire length of the sheet pad.

[0010] In the sheet pad of the present invention, At least one of the fitting portion and the fitted portion has a plurality of protrusions, The widths of the plurality of convex portions may be non-uniform.

[0011] In the seat pad of the present invention, At least one of the fitting portion and the fitted portion has a plurality of convex portions, The extending lengths of the plurality of convex portions may be non-uniform.

[0012] In the seat pad of the present invention, Among the bone portions constituting the fitting portion of the fitting member, each bone portion configured to contact the fitted portion of the fitted member is thicker than each bone portion constituting a portion of the fitting member other than the fitting portion, Among the bone portions constituting the fitted portion of the fitted member, each bone portion configured to contact the fitting portion of the fitting member may be thicker than each bone portion constituting a portion of the fitted member other than the fitted portion. Thereby, dynamic characteristics different from those obtained when the seat pad is constituted by a single member made of a porous structure are more likely to be obtained.

[0013] In the seat pad of the present invention, The seat pad is preferably a vehicle seat pad.

[0014] In the seat pad of the present invention, The fitting member and the fitted member are preferably formed by a 3D printer.

[0015] A method for manufacturing the seat pad of the present invention is A method for manufacturing a seat pad for manufacturing the above seat pad, A shaping step of shaping the fitting member and the fitted member using a 3D printer, A fitting step of fitting the fitting portion of the fitting member and the fitted portion of the fitted member, and includes. According to the method for manufacturing a seat pad of the present invention, it is possible to obtain a seat pad having dynamic characteristics different from those obtained when the seat pad is constituted by a single member made of a porous structure.

Advantages of the Invention

[0016] According to the present invention, it is possible to provide a seat pad capable of obtaining dynamic characteristics different from those obtained when the seat pad is constituted by a single member made of a porous structure, and a method for manufacturing a seat pad capable of obtaining a seat pad capable of obtaining dynamic characteristics different from those obtained when the seat pad is constituted by a single member made of a porous structure.

Brief Description of the Drawings

[0017] [Figure 1] It is a perspective view schematically showing an example of a vehicle seat that can be provided with a seat pad according to any embodiment of the present invention. [Figure 2] It is a cross-sectional view in the pad width direction schematically showing the seat pad according to the first embodiment of the present invention by a cross-section along the pad width direction. [Figure 3] It is a B-B cross-sectional view schematically showing the seat pad of FIG. 2 by a cross-section along the line B-B in FIG. 2 and parallel to the pad extending direction. [Figure 4] It is a drawing for explaining an example of a porous structure constituting a fitting member and a fitted member that can be used for the seat pad according to any embodiment of the present invention. [Figure 5] It is a drawing for explaining the operation and effect of the seat pad of FIG. 2. [Figure 6] [[ID=�0]]It is a cross-sectional view in the pad extending direction schematically showing the seat pad according to the second embodiment of the present invention by a cross-section along the pad extending direction. [Figure 7] It is a C-C cross-sectional view schematically showing the seat pad of FIG. 6 by a cross-section along the line C-C in FIG. 6 and parallel to the pad width direction. [Figure 8]This is a drawing illustrating a seat pad according to a third embodiment of the present invention. [Figure 9] This is a cross-sectional view in the width direction of the pad, schematically showing a sheet pad according to the fourth embodiment of the present invention, with a cross section along the pad width direction. [Figure 10] Figure 9 is a schematic cross-sectional view of the seat pad, shown along the DD line in Figure 9 and parallel to the pad's extending direction. [Figure 11] This is a cross-sectional view in the width direction of the pad, schematically showing a sheet pad according to the fifth embodiment of the present invention, with a cross section along the pad width direction. [Figure 12] This is an EE cross-sectional view schematically showing the sheet pad in Figure 11, along the EE line in Figure 11 and parallel to the pad's extending direction. [Figure 13] This is a cross-sectional view in the width direction of the pad, schematically showing a sheet pad according to the sixth embodiment of the present invention, with a cross section along the pad width direction. [Figure 14] Figure 13 is a cross-sectional view of the seat pad, schematically showing a cross-section along the FF line in Figure 13 and parallel to the pad's extension direction. [Figure 15] This is a cross-sectional view in the width direction of the pad, schematically showing a sheet pad according to the seventh embodiment of the present invention, with a cross section along the pad width direction. [Figure 16] Figure 15 shows the seat pad schematically in a cross-sectional view along the GG line and parallel to the pad's extension direction. [Figure 17] These drawings illustrate other examples of porous structures constituting fitting members and fitted members that can be used in a sheet pad according to any embodiment of the present invention. [Figure 18] These drawings illustrate a method for manufacturing a sheet pad according to one embodiment of the present invention, which can be used to manufacture a sheet pad according to any embodiment of the present invention. [Figure 19] This is a perspective view showing an example of a porous structure that can constitute a fitting member and a fitted member of a sheet pad according to any embodiment of the present invention. [Figure 20] This is a view of the porous structure shown in Figure 19, as seen from the direction of arrow A in Figure 19. [Figure 21] Figure 19 is a perspective view showing the cell compartments of the porous structure. [Figure 22] This diagram corresponds to Figure 21 and is intended to illustrate a modified example of the cell partitioning section. [Figure 23] This is a plan view showing another example of a porous structure that can constitute a fitting member and a fitted member of a sheet pad according to any embodiment of the present invention. [Figure 24] Figure 24(a) is a perspective view showing the bone structure of the porous structure in Figure 23 when no external force is applied, and Figure 24(b) is a perspective view showing the bone structure of Figure 23(a) when an external force is applied. [Modes for carrying out the invention]

[0018] The seat pad and method for manufacturing the seat pad of the present invention are suitable for use in seat pads for any vehicle, and are particularly suitable for use in vehicle seat pads.

[0019] Hereinafter, embodiments of the sheet pad and the method for manufacturing the sheet pad according to the present invention will be described with reference to the drawings. Common components in each figure are denoted by the same reference numerals.

[0020] [Seat pad] The seat pads 302 of each embodiment described herein are suitable for use in any vehicle seat pad, and are particularly suitable for use in a vehicle seat pad.

[0021] Figure 1 shows an example of a vehicle seat 300 that may include a seat pad 302 according to any embodiment of the present invention. As shown by the dashed line in Figure 1, the vehicle seat 300 includes a cushion pad 310 for the occupant to sit on and a back pad 320 for supporting the occupant's back. The cushion pad 310 and the back pad 320 are each composed of a seat pad 302. The cushion pad 310 is the seat pad 302 for sitting. In this example, the seat pad 302 is configured as a vehicle seat pad. In addition to the seat pads 302 that make up the cushion pad 310 and the back pad 320, the vehicle seat 300 may also include, for example, a surface 330 that covers at least the front side (occupant side) of the seat pad 302, a frame (not shown) that supports the cushion pad 310 from below, a frame (not shown) installed on the back of the back pad 320, and a headrest 340 installed on the upper side of the back pad 320 to support the occupant's head. The surface 330 is made of, for example, a breathable material (cloth, etc.). The surface material 330 may cover the entire seat pad 302. In the example in Figure 1, the cushion pad 310 and the back pad 320 are constructed separately from each other, but they may be constructed as a single unit. Furthermore, in the example shown in Figure 1, the headrest 340 is configured separately from the back pad 320, but the headrest 340 may be configured integrally with the back pad 320. In this specification, as shown in Figure 1, the directions "up," "down," "left," "right," "front," and "rear" as viewed from the perspective of a person seated in the vehicle seat 300 (and consequently the seat pad 302) are simply referred to as "up," "down," "left," "right," "front," and "rear," respectively.

[0022] The cushion pad 310 includes a main pad portion 3MP configured to support the seated person's buttocks and thighs from below, a pair of side pad portions 3SP located on both the left and right sides of the main pad portion 3MP, which are raised above the main pad portion 3MP and configured to support the seated person from both sides, and a back pad opposing portion 3BF located behind the main pad portion 3MP and configured to face the back pad 320.

[0023] The back pad 320 has a main pad section 3MP configured to support the sitter's back from the rear, and a pair of side pad sections 3SP located on both the left and right sides of the main pad section 3MP, which are raised in front of the main pad section 3MP and configured to support the sitter from both sides.

[0024] In this specification, "width direction WD of the seat pad 302" (hereinafter sometimes referred to as "pad width direction WD") refers to the left-right direction of the seat pad 302 (Figure 1). In this specification, the "extension direction LD of the seat pad 302" (hereinafter sometimes referred to as the "pad extension direction LD") is the direction perpendicular to the width direction WD and thickness direction TD of the seat pad 302. In the case of the cushion pad 310, it refers to the front-to-back direction (Figure 1), and in the case of the back pad 320, it refers to the direction in which the main pad portion 3MP extends from the lower surface to the upper surface of the main pad portion 3MP of the back pad 320 (Figure 1). Furthermore, the "thickness direction TD of the seat pad 302" (hereinafter sometimes referred to as "pad thickness direction TD") refers to the vertical direction in the case of the cushion pad 310 (Figure 1), and in the case of the back pad 320, it is the direction in which the main pad portion 3MP of the back pad 320 extends from the seated side surface (front surface) FS to the back surface BS (Figure 1). The seat pad 302 is configured so that the load is mainly input in the pad thickness direction TD. Furthermore, the "seater-side surface (front surface) FS" of the seat pad 302 refers to the top surface in the case of the cushion pad 310 (Figure 1), and to the front surface in the case of the back pad 320 (Figure 1). The "back surface BS" of the seat pad 302 is the surface opposite to the seater-side surface FS of the seat pad 302, and refers to the bottom surface in the case of the cushion pad 310 (Figure 1), and to the rear surface in the case of the back pad 320 (Figure 1). The "side surface SS" of the seat pad 302 is the surface between the seater-side surface FS and the back surface BS of the seat pad 302, and refers to one of the front, rear, left, and right surfaces in the case of the cushion pad 310 (Figure 1), and to one of the bottom, top, left, and right surfaces in the case of the back pad 320 (Figure 1).

[0025] The following describes the seat pads 302 according to various embodiments of the present invention with reference to Figures 2 to 17. The seat pads 302 according to each embodiment of the present invention can be used in any vehicle seat configuration, including the vehicle seat 300 described above with reference to Figure 1. The seat pads 302 according to each embodiment of the present invention are preferably configured as cushion pads 310, but may also be configured as back pads 320.

[0026] Figures 2 and 3 show a seat pad 302 according to the first embodiment of the present invention. Figure 2 schematically shows the seat pad 302 according to the first embodiment of the present invention in cross-section along the pad width direction WD. Figure 3 schematically shows the seat pad 302 of Figure 2 in cross-section along the BB line of Figure 2 and parallel to the pad extension direction LD. In the example of Figures 2 and 3, the seat pad 302 is configured as a cushion pad 310. The seat pad 302 of this embodiment comprises a fitting member 51 and a fitted member 52. The fitting member 51 and the fitted member 52 are configured as separate components. The fitting member 51 has a fitting portion 510. The fitted member 52 has a fitted portion 520 configured to fit with the fitting portion 510. In this specification, "fitting" is not limited to cases where no gap is formed between two fitting members, but also includes cases where a gap is formed between two fitting members. That is, when the fitting portion 510 and the fitted portion 520 are fitted together, there may or may not be a gap between the fitting portion 510 and the fitted portion 520.

[0027] The mating portion 510 and the mated portion 520 may have any concave or concave shape, as long as they are configured to fit together. As shown in the examples in Figures 2 and 3, it is preferable that the mating portion 510 and the mated portion 520 each have one or more convex portions Q and one or more concave portions R. In this case, each convex portion Q (Q1) of the mating portion 510 is configured to fit into the corresponding concave portion R (R2) of the mated portion 520. Similarly, each convex portion Q (Q2) of the mated portion 520 is configured to fit into the corresponding concave portion R (R1) of the mating portion 510. Each of the protrusions Q and recesses R constituting the fitting member 51 and the fitted member 52 extends in the direction FD in which the fitting member 51 and the fitted member 52 face each other (this is also the direction in which the fitting portion 510 and the fitted portion 520 face each other; hereinafter also referred to as the "facing direction FD").

[0028] As shown in Figure 4, the fitting member 51 and the fitted member 52 are each composed of a porous structure 1. The porous structure 1 has a large number of cell pores C. As will be described later, the porous structure 1 has a skeletal section 2 that extends over almost its entire length, and the skeletal section 2 comprises a plurality of bone sections 2B and a plurality of connecting sections 2J that connect the ends 2Be of each of the plurality of bone sections 2B (Figures 4 and 20). The skeletal section 2 has a plurality of cell compartment sections 21 (as many as there are cell pores C) that partition the cell pores C inside. The cell compartment section 21 consists of a plurality of bone sections 2B and a plurality of connecting sections 2J that connect the ends 2Be of each of the plurality of bone sections 2B. The porous structure 1 is made of a flexible resin or rubber. Here, "flexible resin" refers to a resin that can deform when an external force is applied. For example, elastomer-based resins are preferred, and polyurethane is more preferred. Examples of rubber include natural rubber or synthetic rubber. Since the porous structure 1 is made of flexible resin or rubber, it can be compressed and restored in response to the application and release of external force from the user, thus providing cushioning properties. The preferred structure of the porous structure 1 will be described in detail later with reference to Figures 19 to 24.

[0029] The fitting member 51 and the fitted member 52 (and consequently the porous structure 1) are preferably fabricated by a 3D printer, as will be described later with reference to Figure 18. By manufacturing the mating member 51 and the mated member 52 (and consequently the porous structure 1) using a 3D printer, manufacturing becomes simpler and the desired configuration can be obtained. Furthermore, with future advancements in 3D printer technology, it is expected that 3D printing will become possible in a shorter time and at a lower cost. In addition, by manufacturing the mating member 51 and the mated member 52 (and consequently the porous structure 1) using a 3D printer, configurations of the mating member 51 and the mated member 52 (and consequently the porous structure 1) that meet various required characteristics can be easily realized as intended. When the porous structure 1 is manufactured using a 3D printer, a flexible resin or rubber is preferred as the material constituting the porous structure 1. For example, a resin made from photocurable polyurethane (especially UV-curable polyurethane) can be used. As the photocurable polyurethane (especially UV-curable polyurethane), a resin made from urethane acrylate or urethane methacrylate can be used. Examples of such resins include those described in US4337130.

[0030] In the first embodiment of the present invention described above, the sheet pad 302 is equipped with a fitting member 51 and a fitted member 52 that fit together. As a result, the fitting portion of the sheet pad 302 between the fitting member 51 and the fitted member 52 (fitting portion 510 and fitted portion 520) is more flexible than the surrounding portion. Therefore, when a load from the user is applied to the sheet pad 302, as shown in Figure 5, the fitting portion of the sheet pad 302 between the fitting member 51 and the fitted member 52 (fitting portion 510 and fitted portion 520) will bend relatively more than the surrounding portion. Thus, the sheet pad 302 of this embodiment can obtain dynamic characteristics different from those obtained when the sheet pad is constructed using only a porous structure. Furthermore, when a load from the user is applied to the seat pad 302, the user is effectively held by the parts of the seat pad 302 around the relatively large-flexible fitting portion 510 and fitted portion 520, thereby improving the holding performance.

[0031] In the first embodiment described above, the seat pad 302 consists of only two members, a fitting member 51 and a fitted member 52. However, in each embodiment described herein, the seat pad 302 may include three or more members configured to fit together. In this case, it is preferable that each pair of any two members configured to fit together satisfies any configuration of the fitting member 51 and fitted member 52 described herein.

[0032] Furthermore, in the first embodiment described above, the fitting member 51 and the fitted member 52 constitute the entirety of the seat pad 302. However, in each embodiment described herein, the fitting member 51 and the fitted member 52 may constitute only a part of the seat pad 302. In that case, the other parts of the seat pad 302 may be made up of any other material.

[0033] In each embodiment described herein, as in the embodiments shown in Figures 2 to 3 and Figures 6 to 16, it is preferable that at least a portion of the fitting portion 510 and the fitted portion 520 are located on the main pad portion 3MP of the seat pad 302. Generally, the seat pad 302 is configured such that the load from the user is mainly applied to the main pad portion 3MP. Because the fitting portion 510 and the fitted portion 520 are located on the main pad portion 3MP, when a load is applied to the main pad portion 3MP, the fitting portion (fitting portion 510 and fitted portion 520) of the main pad portion 3MP flexes relatively more than the surrounding portion, thus improving the holding performance. From a similar viewpoint, in each embodiment described herein, it is more preferable that the mating portion 510 and the mated portion 520 are located on the center of the pad width direction WD of the main pad portion 3MP.

[0034] In each embodiment described herein, it is preferable that the fitting member 51 and the fitted member 52 face each other in a direction perpendicular to the thickness direction (pad thickness direction) TD of the sheet pad 302, as shown in the embodiments of Figures 2 to 3 and Figures 6 to 16. Generally, the seat pad 302 is configured such that the load from the user is mainly applied in the pad thickness direction TD. Because the fitting member 51 and the fitted member 52 face each other in a direction perpendicular to the pad thickness direction TD, when a load from the user is applied in the pad thickness direction TD, the fitting portions (fitting portion 510 and fitted portion 520) of the fitting member 51 and the fitted member 52 can effectively flex. This improves the holding performance. For example, as shown in the embodiments of Figures 2-3 and 8-16, the fitting member 51 and the fitted member 52 may face each other in the pad width direction WD. Alternatively, as shown in the embodiments of Figures 6-7, the fitting member 51 and the fitted member 52 may face each other in the pad extending direction LD. Furthermore, when the fitting member 51 and the fitted member 52 face each other in a direction perpendicular to the pad thickness direction TD, the convex portion Q(Q1) and concave portion R(R1) constituting the fitting portion 510 are arranged alternately along the pad thickness direction TD, and the convex portion Q(Q2) and concave portion R(R2) constituting the fitted portion 520 are arranged alternately along the pad thickness direction TD.

[0035] In each embodiment described herein, as in the embodiments shown in Figures 2-3, 6-7, and 9-16, the fitting member 51 and the fitted member 52 (and consequently, the fitting portion 510 and the fitted portion 520) do not need to be bonded to each other. In this case, the seat pad 302 is covered by the surface 330 (Figure 1), which prevents the fitting of the fitting member 51 and the fitted member 52 from being released. Alternatively, in each embodiment described herein, as in the embodiment of Figure 8, the fitting member 51 and the fitted member 52 (and consequently the fitting portion 510 and the fitted portion 520) may be bonded to each other at least partially. In this case, the adhesive G is preferably placed at least between the tip surface Qt of each protrusion Q of the fitting portion 510 and the fitted portion 520 and the bottom surface Rb of each recess R of the fitting portion 510 and the fitted portion 520 (the surface opposite to the opening surface of the recess R), and more preferably only between the tip surface Qt of each protrusion Q of the fitting portion 510 and the fitted portion 520 and the bottom surface Rb of each recess R of the fitting portion 510 and the fitted portion 520.

[0036] In each embodiment described herein, as in the embodiments of Figures 2-3, 6-7, and 13-16, the fitting portion 510 and the fitted portion 520 (and by extension, the convex portion Q constituting them) may extend over the entire length of the sheet pad 302 in a cross section perpendicular to the opposing direction FD between the fitting portion 510 and the fitted portion 520 (Figures 3, 7, 14, and 16). In this case, since the fitting portion 510 and the fitted portion 520 are present over a wider area, it becomes easier to obtain dynamic characteristics that differ from those obtained when the sheet pad is constructed from a single porous structure. For example, when the fitting member 51 and the fitted member 52 face each other in a direction perpendicular to the pad thickness direction TD, the fitting portion 510 and the fitted portion 520 (and by extension, the convex portion Q that constitutes them) may extend along the entire length of the sheet pad 302 in a direction perpendicular to both the pad thickness direction TD and the opposing direction FD, as shown in the embodiments of Figures 2-3, 6-7, and 13-16. Alternatively, in each embodiment described herein, as in the fitted portion 520 of each embodiment in Figures 9 to 12, at least one of the fitted portion 510 and the fitted portion 520 (and thus the convex portion Q constituting them) may extend over only a portion of the sheet pad 302 in a cross section perpendicular to the opposing direction FD between the fitted portion 510 and the fitted portion 520 (Figures 10 and 12). For example, when the fitted member 51 and the fitted member 52 face each other in a direction perpendicular to the pad thickness direction TD, at least one of the fitted portion 510 and the fitted portion 520 (and thus the convex portion Q constituting them) may extend over only a portion of the sheet pad 302 in a direction perpendicular to both the pad thickness direction TD and the opposing direction FD.

[0037] In each embodiment described herein, the protrusions Q and recesses R constituting the fitting portion 510 and the fitted portion 520 may have any shape. By adjusting the shape of the protrusions Q and recesses R constituting the fitting portion 510 and the fitted portion 520, the dynamic characteristics of the seat pad 302 can be adjusted. For example, the protrusions Q and recesses R constituting the fitting portion 510 and the fitted portion 520 may form a rectangle in cross-section in the opposing direction FD (and thus in the direction in which the protrusions Q and recesses R extend), as in the embodiments of Figures 2, 6, 8, 9, 11, and 13; or they may form a triangle, as in the embodiment of Figure 15 with protrusions Q2 and recesses R1; or they may form a trapezoid, as in the embodiment of Figure 15 with protrusions Q1 and recesses R2; or they may have any other shape. Furthermore, the protrusions Q and recesses R constituting the fitting portion 510 and the fitted portion 520 may each have a plate shape with a uniform thickness along the width direction of the protrusions Q and recesses R in a cross-section perpendicular to the opposing direction FD (and thus perpendicular to the direction in which the protrusions Q and recesses R extend), as in the embodiments of Figures 3, 7, 14, and 16; or they may be circular, as in the embodiment of Figure 10 with protrusions Q2 and recesses R1; or they may be rectangular, as in the embodiment of Figure 12 with protrusions Q2 and recesses R1; or they may be other shapes (for example, triangles, trapezoids, other polygons, etc.). The width direction of the protrusions Q is perpendicular to the direction in which the protrusions Q are arranged (in the embodiment of Figure 3, the pad thickness direction TD) in a cross-section perpendicular to the opposing direction FD (and therefore perpendicular to the extension direction of the protrusions Q) (in the embodiment of Figure 3, the pad extension direction LD). Similarly, the width direction of the recesses R is perpendicular to the direction in which the recesses R are arranged (in the embodiment of Figure 3, the pad thickness direction TD) in a cross-section perpendicular to the opposing direction FD (and therefore perpendicular to the extension direction of the recesses R) (in the embodiment of Figure 3, the pad extension direction LD).

[0038] Furthermore, the dynamic characteristics of the seat pad 302 can be adjusted by adjusting the dimensions of the protrusions Q and recesses R that constitute the fitting portion 510 and the fitted portion 520.

[0039] In each embodiment described herein, as in the fitted portion 520 of the embodiment in Figure 10, at least one of the fitted portion 510 and the fitted portion 520 may have a plurality of protrusions Q, and the widths of these protrusions Q may be uniform (i.e., the same as each other). In this case, as in the fitted portion 520 of the embodiment in Figure 10, it is preferable that in a cross section perpendicular to the opposing direction FD between the fitted portion 510 and the fitted portion 520 (Figure 10), at least one of the fitted portion 510 and the fitted portion 520 (and thus the protrusions Q constituting them) extends over only a portion of the sheet pad 302. Alternatively, in each embodiment described herein, as in the fitted portion 520 of the embodiment in Figure 12, at least one of the fitted portion 510 and the fitted portion 520 may have a plurality of protrusions Q, and the widths of these plurality of protrusions Q may be non-uniform (i.e., different from each other). In this case, as in the fitted portion 520 of the embodiment in Figure 12, it is preferable that the width of these plurality of protrusions Q is smaller for the protrusions Q closer to the back surface BS side of the seat pad 302. This can improve seating comfort. Also, in this case, as in the fitted portion 520 of the embodiment in Figure 12, it is preferable that in a cross section perpendicular to the opposing direction FD between the fitted portion 510 and the fitted portion 520 (Figure 12), at least one of the fitted portion 510 and the fitted portion 520 (and thus the protrusions Q constituting them) extends over only a portion of the seat pad 302. Here, the width of the protrusion Q refers to the dimension in the width direction of the protrusion Q, and the width direction of the protrusion Q is the direction perpendicular to the direction in which the protrusions Q are arranged (in the embodiments of Figures 10 and 12, the pad thickness direction TD) (in the embodiments of Figures 10 and 12, the pad extension direction LD) in a cross-section perpendicular to the opposing direction FD (and thus perpendicular to the extension direction of the protrusion Q).

[0040] In each embodiment described herein, as in the fitting portion 510 and the fitted portion 520 of the embodiments in Figures 2, 6, 8, 9, 11, and 15, at least one of the fitting portion 510 and the fitted portion 520 has a plurality of protrusions Q, and the extending lengths of these plurality of protrusions Q may be uniform (i.e., the same as each other). Alternatively, in each embodiment described herein, as in the fitted portion 510 and fitted portion 520 of the embodiment in Figure 13, at least one of the fitted portion 510 and fitted portion 520 may have a plurality of protrusions Q, and the extension lengths of these plurality of protrusions Q may be non-uniform (i.e., different from each other). In this case, as in the fitted portion 510 and fitted portion 520 of the embodiment in Figure 13, it is preferable that the extension length of these plurality of protrusions Q is smaller for the protrusions Q closer to the back surface BS side of the seat pad 302. This can improve seating comfort. Here, the extension length of the convex portion Q refers to the dimension in the extension direction of the convex portion Q, and the extension direction of the convex portion Q is the same as the opposing direction FD.

[0041] In each embodiment described herein, from the viewpoint of obtaining dynamic characteristics different from those obtained when a sheet pad is constructed using only a porous structure member, the fitting portion 510 and the fitted portion 520 are preferably such that the extended length of each protrusion Q is 1 cm or more, more preferably 5 cm or more, and even more preferably 10 cm or more. Furthermore, in each embodiment described herein, the fitting portion 510 and the fitted portion 520 are preferably such that the extended length of each protrusion Q is 60 cm or less, more preferably 40 cm or less, and even more preferably 30 cm or less. In each embodiment described herein, from the viewpoint of obtaining dynamic characteristics different from those obtained when a sheet pad is constructed using only a porous structure, it is preferable that each protrusion Q of the fitting portion 510 and the fitted portion 520 has one or more cell compartments 21 (Figure 4) arranged along the extending direction of the protrusion Q, more preferably five or more, and even more preferably ten or more.

[0042] In each embodiment described herein, at least one of the fitting portion 510 and the fitted portion 520 has a plurality of protrusions Q, the thickness of which these protrusions Q may be uniform (i.e., the same as each other) or non-uniform (i.e., different from each other). Here, the thickness of the protrusion Q refers to the dimension in the thickness direction of the protrusion Q, and the thickness direction of the protrusion Q is the same as the direction in which the protrusions Q are arranged in a cross-section perpendicular to the opposing direction FD (and thus perpendicular to the extension direction of the protrusion Q) (in the embodiments of Figures 10 and 12, this is the pad thickness direction TD). In each embodiment described herein, each protrusion Q of the fitting portion 510 and the fitted portion 520 may have only one cell partition portion 21 (Figure 4) constituting the protrusion Q, as in the embodiment of Figure 4, or multiple cells may be arranged along the thickness direction of the protrusion Q.

[0043] In each embodiment described herein, from the viewpoint of obtaining dynamic characteristics different from those obtained when a sheet pad is constructed using only a porous structure, the number of protrusions Q on the fitting portion 510 and the fitted portion 520 is preferably one or more, and more preferably two or more. The number of protrusions Q on the fitting portion 510 and the fitted portion 520 is preferably eight or less, and more preferably six or less. In each embodiment described herein, from the viewpoint of obtaining dynamic characteristics different from those obtained when a sheet pad is constructed using only a porous structure, the number of recesses R in the fitting portion 510 and the fitted portion 520 is preferably one or more, and more preferably two or more. The number of recesses R in the fitting portion 510 and the fitted portion 520 is preferably eight or less, and more preferably six or less.

[0044] In each embodiment described herein, the thickness (cross-sectional area) of each bone portion 2B constituting the fitting member 51 may be uniform (i.e., the same as each other), as in the example fitting member 51 shown in Figure 4. Similarly, in each embodiment described herein, the thickness (cross-sectional area) of each bone portion 2B constituting the fitted member 52 may be uniform (i.e., the same as each other), as in the example fitted member 52 shown in Figure 4. The thickness (cross-sectional area) of each bone portion 2B constituting the fitting member 51 and the thickness (cross-sectional area) of each bone portion 2B constituting the fitted member 52 may be the same as each other, or they may be different, as in the example shown in Figure 4. Alternatively, in each embodiment described herein, the thickness (cross-sectional area) of each bone portion 2B constituting the fitting member 51 may be non-uniform (i.e., different from each other), as in the example fitting member 51 shown in Figure 17. Also, in each embodiment described herein, the thickness (cross-sectional area) of each bone portion 2B constituting the fitted member 52 may be non-uniform (i.e., different from each other), as in the example fitted member 52 shown in Figure 17. For example, as shown in the example of the fitting member 51 in Figure 17, each bone portion 2B(2Ba) of the fitting member 52 that is configured to contact the fitting portion 520 of the fitted member 51 may be thicker (have a larger cross-sectional area) than each bone portion 2B(2Bb) of the fitting member 51 that is configured to contact the fitting portion 520 of the fitted member 52. Also, as shown in the example of the fitted member 52 in Figure 17, each bone portion 2B(2Bm) of the fitting member 52 that is configured to contact the fitting portion 510 of the fitting member 51 may be thicker (have a larger cross-sectional area) than each bone portion 2B(2Bn) of the fitting member 52 that is configured to contact the fitting portion 520 of the fitting member 51. In this case, compared to the example shown in Figure 4 where the thickness (cross-sectional area) of each bone portion 2B of the fitting member 51 and the fitted member 52 is uniform, the frictional force (and thus viscosity) acting between the fitting portion 510 and the fitted portion 520 when a load is applied can be changed. Therefore, it becomes easier to obtain dynamic characteristics that are different from those obtained when a sheet pad is constructed using only a porous structure. If, among the bone portions 2B constituting the fitting portion 510 of the fitting member 51, each bone portion 2B(2Ba) configured to contact the fitted portion 520 of the fitted member 52 is thicker (has a larger cross-sectional area) than each bone portion 2B(2Bb) constituting the part of the fitting member 51 other than the fitting portion 510, then, as in the example fitting member 51 shown in Figure 17, each bone portion 2B(2Ba) configured to contact the fitted portion 520 among the bone portions 2B constituting the fitting portion 510 may be thicker (has a larger cross-sectional area) than each bone portion 2B(2Bc) constituting the fitting portion 510 that is not configured to contact the fitted portion 520, or the thickness (cross-sectional area) of each bone portion 2B constituting the fitting portion 510 may be uniform. Furthermore, if each of the bone portions 2B (2Bm) that constitute the fitting portion 520 of the fitting member 52 is configured to contact the fitting portion 510 of the fitting member 51, then, as in the example fitting member 52 shown in Figure 17, each of the bone portions 2B (2Bm) that constitute the fitting portion 520 is thicker (has a larger cross-sectional area) than each of the bone portions 2B (2Bn) that constitute the part of the fitting member 52 other than the fitting portion 520, then, as in the example fitting member 52 shown in Figure 17, each of the bone portions 2B (2Bm) that constitute the fitting portion 520 is configured to contact the fitting portion 510, and it is also possible that the thickness (cross-sectional area) of each of the bone portions 2B that constitute the fitting portion 520 is uniform. Here, "contact" includes not only direct contact without anything in between, but also contact with an adhesive in between.

[0045] [Method for manufacturing a seat pad] Next, with reference to Figure 18, an embodiment of the method for manufacturing the sheet pad of the present invention will be illustrated. The method described below can be suitably used to manufacture the sheet pad 302 of any embodiment described herein.

[0046] First, using a computer, three-dimensional shape data (e.g., three-dimensional CAD data) representing the three-dimensional shapes of the fitting member 51 and the fitted member 52 (i.e., the porous structure 1 that constitutes them) in the sheet pad 302 is created in advance (three-dimensional shape data creation step). In other words, in the 3D shape data creation step, separate 3D shape data is created for each fitting member 51 and fitted member 52 (i.e., for each porous structure 1).

[0047] Next, a computer is used to convert each of the above 3D shape data into 3D modeling data 500 (500a to 500b) (Figure 18(a), 3D modeling data conversion step). 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 performs modeling. The control unit 410 is configured to cause the modeling unit 420 to model an object with the shape represented by the three-dimensional shape data. The 3D modeling data 500 includes, for example, slice data representing the two-dimensional shape of each layer of the object with the shape represented by the three-dimensional shape data.

[0048] Next, the 3D printer 400 is used to fabricate the fitting member 51 and the fitted member 52 of the sheet pad 302, for each fitting member 51 and fitted member 52 (i.e., each porous structure) (Figure 18(b), fabrication step). The 3D printer 400 may use any manufacturing method, such as stereolithography, powder bed fusion (FDM), fused deposition modeling (FDM), or inkjet. From a productivity standpoint, stereolithography is preferred. Figure 18 shows the manufacturing process using stereolithography. The 3D printer 400 comprises, for example, a control unit 410 configured by a CPU, a molding unit 420 that performs molding according to the control of the control unit 410, a support base 430 for placing the molded object (i.e., the above-mentioned part), and a liquid resin LR, a support base 430, and a container 440 that houses the molded object. When the stereolithography method is used as in this example, the molding unit 420 has a laser irradiator 421 configured to irradiate ultraviolet laser light LL. The container 440 is filled with liquid resin LR. When the liquid resin LR is exposed to ultraviolet laser light LL irradiated from the laser irradiator 421, it hardens and becomes a flexible resin. In the 3D printer 400 configured in this way, the control unit 410 first reads the 3D modeling data 500, and then sequentially builds each layer while controlling the irradiation of the building section 420 with ultraviolet laser light LL based on the three-dimensional shape contained in the read 3D modeling data 500. After the 3D printing process by the 3D printer 400 is complete, the printed object (porous structure 1) is removed from the housing 440. This yields the fitting member 51 and the fitted member 52 (i.e., the porous structure 1 that constitutes them) (Figure 18(c)).

[0049] Subsequently, the fitting portion 510 of the fitting member 51 and the fitted portion 520 of the fitted member 52 are fitted together (fitting step). This results in the sheet pad 302. In the mating step, adhesive may or may not be placed between the mating portion 510 and the mated portion 520.

[0050] [Porous structure] Next, the porous structure 1 described above will be explained in detail with reference to Figures 19 to 24. The porous structure 1 described below can be used as the fitting member 51 and the fitted member 52 of the sheet pad 302 according to any embodiment described herein. The configurations of each porous structure 1 constituting the fitting member 51 and the fitted member 52 may be the same or different. In Figures 19 to 22, the orientation of the XYZ Cartesian coordinate system fixed to the porous structure 1 is shown to make it easier to understand the orientation of the porous structure 1.

[0051] Figures 19 and 20 show a portion of the porous structure 1, which has a roughly rectangular outer shape, viewed from different angles. Figure 19 is a perspective view showing the portion of the porous structure 1 in question. Figure 20 is a view from arrow A, showing the portion of the porous structure 1 in Figure 19 viewed from the direction of arrow A (Y direction).

[0052] The porous structure 1 in this example was fabricated using a 3D printer. By manufacturing the porous structure 1 using a 3D printer, the manufacturing process is simpler compared to the conventional method of foaming through chemical reactions, and the desired configuration can be obtained. Furthermore, with future advancements in 3D printer technology, it is expected that 3D printing will become possible in a shorter time and at a lower cost. In addition, by manufacturing the porous structure 1 using a 3D printer, it is possible to easily and precisely realize the desired configuration of the porous structure 1 that meets various required characteristics.

[0053] As described above, the porous structure 1 is made of a flexible resin or rubber. Furthermore, from the standpoint of ease of manufacturing with a 3D printer, it is preferable for the porous structure 1 to be made of a flexible resin rather than rubber. Furthermore, from the standpoint of ease of manufacturing with a 3D printer, it is preferable that the porous structure 1 is composed entirely of a material with the same composition. However, the porous structure 1 may be composed of materials with different compositions depending on the part.

[0054] As mentioned above, the porous structure 1 in this example was fabricated using a 3D printer. The porous structure 1 is constructed as a single, integrated unit. The porous structure 1 is made of a flexible resin or rubber. More specifically, the porous structure 1 includes a skeletal portion 2 that forms the framework of the porous structure 1. The skeletal portion 2 partitions a large number of cellular pores C. The skeletal portion 2 is present throughout almost the entire porous structure 1 and is made of a flexible resin or rubber. In this example, the part of the porous structure 1 other than the skeletal portion 2 is void; in other words, the porous structure 1 consists only of the skeletal portion 2.

[0055] As shown in Figures 19 to 21, the skeletal structure 2 of the porous structure 1 is composed of multiple bone sections 2B and multiple connecting sections 2J, and the entire skeletal structure 2 is integrally constructed. In this example, each bone section 2B is columnar in shape and extends in a straight line. Each connecting section 2J connects the ends 2Be of multiple (for example, four) bone sections 2B that extend in different directions to each other at the points where these ends 2Be are adjacent to each other. Figures 19 to 21 show the skeletal lines O of the skeletal section 2 in a portion of the porous structure 1, indicated by dashed lines. The skeletal lines O of the skeletal section 2 consist of the skeletal lines O of each bone section 2B and the skeletal lines O of each joint section 2J. The skeletal line O of the bone section 2B is the central axis of the bone section 2B. The skeletal line O of the joint section 2J is an extended line portion formed by smoothly extending the central axes of each bone section 2B connected to the joint section 2J into the joint section 2J and connecting them to each other. The central axis of the bone section 2B is a line formed by connecting the centroid points of the shape formed by the bone section 2B in a cross section perpendicular to the direction of extension of the bone section 2B at each point in the direction of extension of the bone section 2B. The direction of extension of bone portion 2B is the direction of extension of the skeletal line O of bone portion 2B (the portion of the skeletal line O that corresponds to bone portion 2B; the same applies hereinafter). Since the porous structure 1 is equipped with a skeletal structure 2 throughout almost its entire length, it ensures breathability while allowing for compression and recovery deformation in response to the application and release of external forces, resulting in good characteristics as a sheet pad. In addition, the structure of the porous structure 1 is simple, making it easier to fabricate using a 3D printer. Furthermore, some or all of the bone portions 2B constituting the skeletal structure 2 may extend while curving. In this case, the curvature of some or all of the bone portions 2B prevents abrupt shape changes of the bone portions 2B and, consequently, the porous structure 1 when a load is applied, thereby suppressing localized buckling.

[0056] In this example, each bone portion 2B constituting the skeletal structure 2 has approximately the same shape and length. However, not limited to this example, the shapes and / or lengths of each bone portion 2B constituting the skeletal structure 2 do not necessarily have to be the same. For example, the shape and / or length of some bone portions 2B may differ from those of other bone portions 2B. In this case, by making the shape and / or length of the bone portions 2B of a specific part of the skeletal structure 2 different from those of other parts, different mechanical properties can be intentionally obtained.

[0057] In this example, the width W0 (Figure 19) and cross-sectional area of ​​each bone portion 2B are constant along the entire length of the bone portion 2B (i.e., uniform along the direction of extension of the bone portion 2B). Here, the cross-sectional area of ​​bone portion 2B refers to the cross-sectional area of ​​the bone portion 2B perpendicular to the skeletal line O. Also, the width W0 of bone portion 2B (Figure 19) refers to the maximum width in the cross-section when measured along the cross-section perpendicular to the skeletal line O of bone portion 2B. However, in each example described herein, some or all of the bone portions 2B constituting the skeletal portion 2 may have non-uniform width W0 and / or cross-sectional area along the extending direction of the bone portion 2B. For example, in some or all of the bone portions 2B constituting the skeletal portion 2, the width W0 of the bone portion 2B may gradually increase or decrease towards both ends in the extending direction of the bone portion 2B in the portion including the ends 2Be on both sides in the extending direction of the bone portion 2B. Also, in some or all of the bone portions 2B constituting the skeletal portion 2, the cross-sectional area of ​​the bone portion 2B may gradually increase or decrease towards both ends in the extending direction of the bone portion 2B in the portion including the ends 2Be on both sides in the extending direction of the bone portion 2B.

[0058] In each example described herein, from the viewpoint of simplifying the structure of the skeletal part 2 and, consequently, the ease of manufacturing the porous structure 1 by 3D printing, the width W0 (Figure 19) of the skeletal part 2B is preferably 0.05 mm or more, and more preferably 0.10 mm or more. When the width W0 is 0.05 mm or more, it can be fabricated at the resolution of a high-performance 3D printer, and when it is 0.10 mm or more, it can be fabricated not only at the resolution of a high-performance 3D printer but also at the resolution of a general-purpose 3D printer. On the other hand, from the viewpoint of improving the accuracy of the outer edge (outer contour) shape of the skeletal part 2, reducing the gap (spacing) between cell holes C, and improving the characteristics as a sheet pad, it is preferable that the width W0 of the skeletal part 2B be 2.0 mm or less. It is preferable that each bone portion 2B constituting the skeletal part 2 satisfies these requirements, but it is also acceptable if only some of the bone portions 2B constituting the skeletal part 2 satisfy these requirements. In that case, similar effects can be obtained, although there may be differences in degree.

[0059] In this example, each bone portion 2B constituting the skeletal portion 2 is columnar, and each has a circular (perfectly circular) cross-sectional shape. This simplifies the structure of the skeletal part 2, making it easier to fabricate using a 3D printer. It also makes it easier to reproduce the mechanical properties of general polyurethane foam manufactured through a chemical reaction foaming process. Therefore, the properties of the porous structure 1 as a sheet pad can be improved. Furthermore, by configuring the skeletal part 2B in a columnar shape in this way, the durability of the skeletal part 2 can be improved compared to when the skeletal part 2B is replaced with a thin membrane-like portion. The cross-sectional shape of each bone portion 2B is the shape of the cross-section perpendicular to the central axis (skeletal line O) of the bone portion 2B. It should be noted that, not limited to this example, only some of the bone parts 2B constituting the skeletal part 2 may satisfy this configuration, and even in that case, a similar effect can be obtained, albeit to varying degrees. For example, in each example described herein, all or some of the bone parts 2B constituting the skeletal part 2 may have a polygonal cross-sectional shape (equilateral triangle, triangle other than equilateral triangle, quadrilateral, etc.) or a circular shape other than a perfect circle (ellipse, etc.), and in such cases, the same effect as in this example can be obtained. Furthermore, the cross-sectional shape of each bone part 2B may be uniform along its extension direction, or it may be non-uniform along its extension direction. Also, the cross-sectional shapes of each bone part 2B may differ from each other.

[0060] In each example described herein, the ratio of the volume VB occupied by the frame 2 to the apparent volume VS of the frame 2 (VB × 100 / VS [%]) is preferably 3 to 10%. This configuration makes it possible to achieve a good reaction force generated in the frame 2 when an external force is applied to the frame 2, and consequently, the hardness of the frame 2 (and consequently the hardness of the porous structure 1) for use as a seat pad (particularly a seat pad for a vehicle). Here, "apparent volume VS of the skeletal part 2" refers to the total volume of the internal space enclosed by the outer edge (outer contour) of the skeletal part 2 (the sum of the volume occupied by the skeletal part 2, the volume occupied by the membrane 3 (Figure 22) if one is provided, and the volume occupied by the voids). Assuming the same material constitutes the skeletal structure 2, the higher the proportion of volume VB occupied by the skeletal structure 2 to its apparent volume VS, the harder the skeletal structure 2 (and consequently the porous structure 1) becomes. Conversely, the lower the proportion of volume VB occupied by the skeletal structure 2 to its apparent volume VS, the softer the skeletal structure 2 (and consequently the porous structure 1) becomes. From the viewpoint of ensuring that the reaction force generated in the frame 2 when an external force is applied to the frame 2, and consequently the hardness of the frame 2 (and thus the porous structure 1), is good for a seat pad (especially a seat pad for a vehicle), it is more preferable that the ratio of the volume VB occupied by the frame 2 to the apparent volume VS of the frame 2 is 4 to 8%. Furthermore, any method may be used to adjust the ratio of the volume VB occupied by the skeleton 2 to the apparent volume VS of the skeleton 2. For example, this could involve adjusting the thickness (cross-sectional area) of some or all of the bone parts 2B that make up the skeleton 2, and / or the size (cross-sectional area) of some or all of the connecting parts J that make up the skeleton 2.

[0061] In each example described herein, the 25% hardness of the porous structure 1 is preferably 60 to 500 N, and more preferably 100 to 450 N. 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 Instron type compression tester. This makes the hardness of the porous structure 1 suitable for use as a seat pad (particularly a seat pad for vehicles).

[0062] As shown in Figures 19 to 21, in this example, the skeletal part 2 has multiple cell compartments 21 (as many as there are cell holes C) that partition the cell holes C inside. Figure 21 shows a single cell compartment 21 in isolation. The skeletal structure 2 in this example has a structure in which numerous cell compartments 21 are connected in the X, Y, and Z directions. As shown in Figures 19 to 21, each cell partition 21 has multiple (14 in this example) annular portions 211. Each annular portion 211 is configured in an annular shape, and a flat virtual surface V1 is partitioned by the inner circumferential edge portions 2111 of each annular portion. The virtual surface V1 is a virtual plane (i.e., a virtual closed plane) partitioned by the inner circumferential edge portions 2111 of the annular portions 211. The multiple annular portions 211 constituting the cell partition 21 are connected to each other such that the virtual surfaces V1 partitioned by their respective inner circumferential edge portions 2111 do not intersect. The cell hole C is demarcated by a plurality of annular portions 211 that constitute the cell compartment 21, and a plurality of virtual surfaces V1 that are each demarcated by these annular portions 211. Roughly speaking, the annular portions 211 are parts that demarcate the edges of the three-dimensional shape formed by the cell hole C, and the virtual surfaces V1 are parts that demarcate the constituent surfaces of the three-dimensional shape formed by the cell hole C. Each annular portion 211 is composed of a plurality of bone portions 2B and a plurality of connecting portions 2J that connect the ends 2Be of these bone portions 2B. The connecting portion between a pair of interconnected annular sections 211 consists of a single bone section 2B and a pair of connecting sections 2J on either side of it, which are shared by the pair of annular sections 211. That is, each bone section 2B and each connecting section 2J are shared by multiple adjacent annular sections 211. Each virtual surface V1 partitions a portion of one cell hole C with one side of the virtual surface V1 (the front surface of the virtual surface V1), and partitions a portion of another cell hole C with the other side of the virtual surface V1 (the back surface of the virtual surface V1). In other words, each virtual surface V1 partitions a portion of a different cell hole C with both its front and back surfaces. To put it another way, each virtual surface V1 is shared by a pair of cell holes C adjacent to it (i.e., a pair of cell holes C with the virtual surface V1 in between). Furthermore, each annular portion 211 is shared by a pair of cell compartments 21 adjacent to it (i.e., a pair of cell compartments 21 with the annular portion 211 in between). In other words, each annular portion 211 constitutes a part of each of the pairs of cell compartments 21 adjacent to each other. In the examples shown in Figures 19 to 20, some virtual surfaces V1 in the porous structure 1 are not covered by the membrane 3 (Figure 22) described later, but are open, i.e., they form openings. As a result, the cell pores C are connected to each other through these virtual surfaces V1, and ventilation between the cell pores C is possible. This improves the air permeability of the skeletal structure 2 and facilitates the compression and recovery deformation of the skeletal structure 2 in response to the application and release of external forces.

[0063] As shown in Figure 21, in this example, the skeletal lines O of each cell compartment 21 form a polyhedron shape, and as a result, each cell hole C forms a roughly polyhedron shape. More specifically, in the examples in Figures 19 to 21, the skeletal lines O of each cell compartment 21 form a Kelvin 14-hedron (truncated octahedron) shape, and as a result, each cell hole C forms a roughly Kelvin 14-hedron (truncated octahedron) shape. A Kelvin 14-hedron (truncated octahedron) is a polyhedron composed of six quadrilateral faces and eight hexagonal faces. The cell holes C constituting the skeletal part 2 are arranged in a regular manner so as to fill the internal space enclosed by the outer edge (outer contour) of the skeletal part 2 (that is, so that each cell hole C is tiled without any wasted gaps, or in other words, so that the gaps (spacing) between the cell holes C are small). As in this example, by making the shape of the skeletal lines O of the cell compartments 21 of part or all (in this example, all) of the skeletal part 2 (and consequently the shape of the cell holes C of part or all (in this example, all) of the skeletal part 2) a polyhedron, it becomes possible to reduce the gaps (spacing) between the cell holes C that constitute the skeletal part 2, and to form more cell holes C inside the skeletal part 2. Furthermore, this improves the compression and recovery deformation behavior of the skeletal part 2 (and consequently the porous structure 1) in response to the application and release of external forces, making it suitable as a seat pad (especially a seat pad for vehicles). The polyhedron shape formed by the skeletal lines O of the cell compartment 21 (and consequently, the polyhedron shape formed by the cell holes C) is not limited to this example and can be any shape. For example, when the shape of the skeletal lines O of the cell compartment 21 (and consequently the shape formed by the cell holes C) is approximately a tetrahedron, approximately an octahedron, or approximately a dodecahedron, it is also preferable from the viewpoint of reducing the gap (spacing) between the cell holes C. Furthermore, the shape of the skeletal lines O of some or all of the cell compartment 21 of the skeleton 2 (and consequently the shape formed by some or all of the cell holes C of the skeleton 2) may be a three-dimensional shape other than an approximately polyhedron (for example, a sphere, ellipsoid, cylinder, etc.). Also, the skeleton 2 may have only one type of cell compartment 21 with the same shape of skeletal lines O, or it may have multiple types of cell compartment 21 with different shapes of skeletal lines O. Similarly, the skeletal portion 2 may have only one type of cell pore C with the same shape, or it may have multiple types of cell pores C with different shapes. In this example, when the shape of the skeletal line O of the cell compartment portion 21 (and therefore the shape of the cell pore C) is approximately a Kelvin 14-hedron (truncated octahedron), it is easiest to reproduce the characteristics of a sheet pad equivalent to those of a general polyurethane foam manufactured through a foaming process by chemical reaction, compared to other shapes.

[0064] As shown in Figures 19 to 21, in this example, the multiple (14 in this example) annular portions 211 constituting the cell partition portion 21 each contain 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 partitions a flat small virtual surface V1S by its annular inner circumferential edge portion 2111. Each large annular portion 211L partitions a flat large virtual surface V1L with a larger area than the small virtual surface V1S by its annular inner circumferential edge portion 2111. The small virtual surface V1S and the large virtual surface V1L are each virtual planes (i.e., virtual closed planes). As can be seen from Figure 21, in this example, the large annular portion 211L has a skeletal line O that is a regular hexagon, and consequently, the large virtual surface V1L is also approximately a regular hexagon. In addition, in this example, the small annular portion 211S has a skeletal line O that is a regular quadrilateral, and consequently, the small virtual surface V1S is also approximately a regular quadrilateral. Thus, in this example, the small virtual surface V1S and the large virtual surface V1L differ not only in area but also in shape. Each large annular section 211L is composed of multiple (six in this example) bone sections 2B and multiple (six in this example) connecting sections 2J that connect the ends 2Be of these bone sections 2B. Each small annular section 211S is composed of multiple (four in this example) bone sections 2B and multiple (four in this example) connecting sections 2J that connect the ends 2Be of these bone sections 2B. In the examples shown in Figures 19 to 21, the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 each form a Kelvin tetrahedron (truncated octahedron). As mentioned above, a Kelvin tetrahedron (truncated octahedron) is a polyhedron composed of six quadrilateral faces and eight hexagonal faces. Accordingly, the cell holes C partitioned by each cell compartment 21 also form approximately a Kelvin tetrahedron. The skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 are connected to each other in a space-filling manner. That is, there are no gaps between the skeletal lines O of the multiple cell compartments 21.

[0065] Thus, in this example, the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 each form a polyhedron (in this example, a Kelvin 14-sided polyhedron), and consequently, the cell pores C also form a roughly polyhedron (in this example, a roughly Kelvin 14-sided polyhedron), making it possible to reduce the gaps (spacing) between the cell pores C constituting the porous structure 1, and allowing more cell pores C to be formed inside the porous structure 1. Furthermore, this improves the compression and recovery deformation behavior of the porous structure 1 in response to the application and release of external forces, making it suitable as a seat pad (especially a seat pad for vehicles). The gaps (spacing) between the cell pores C correspond to the fleshy parts (bone parts 2B and joint parts 2J) of the skeletal part 2 that partition the cell pores C. Furthermore, in this example, the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 are connected to each other in a way that fills the space, making it possible to further reduce the gaps (spacing) between the cell pores C constituting the porous structure 1. Therefore, the properties of the porous structure as a sheet pad can be improved.

[0066] The polyhedron formed by the skeletal lines O of the cell compartment 21 (and consequently, the approximate polyhedron formed by the cell holes C) is not limited to the examples shown in each figure, but can be any shape. For example, the polyhedron formed by the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 (and consequently, the approximate polyhedron formed by the cell pores C) is preferably such that it can fill the space (can be arranged without gaps). This allows the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 to be connected to each other in a way that fills the space, thereby improving the properties of the porous structure as a sheet pad. In this case, the polyhedron formed by the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 (and consequently, the approximate polyhedron formed by the cell pores C) may include only one type of polyhedron, as in this example, or it may include multiple types of polyhedra. Here, with respect to polyhedra, "type" refers to the shape (number and shape of constituent faces), and specifically, two polyhedra with different shapes (number and shape of constituent faces) are treated as two types of polyhedra, while two polyhedra with the same shape but different dimensions are treated as the same type of polyhedron. When the polyhedron formed by the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 can fill space and contains only one type of polyhedron, examples of such polyhedra include, in addition to the Kelvin 14-hedron, regular triangular prisms, regular hexagonal prisms, cubes, rectangular prisms, rhombic dodecahedrons, etc. As shown in the examples in each figure, when the shape of the skeletal line O of the cell compartment 21 is a Kelvin 14-hedron (truncated octahedron), it is easiest to reproduce the characteristics of a sheet pad equivalent to that of a sheet pad made of general polyurethane foam manufactured through a process of foaming by chemical reaction, compared to other shapes. Furthermore, when the shape of the skeletal line O of the cell compartment 21 is a Kelvin 14-hedron (truncated octahedron), equal mechanical properties can be obtained in each of the X, Y, and Z directions. Examples of polyhedra formed by the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 that can fill space and include multiple types of polyhedra include combinations of a regular tetrahedron and a regular octahedron, a regular tetrahedron and a truncated tetrahedron, and a regular octahedron and a truncated hexahedron. These are examples of combinations of two types of polyhedra, but combinations of three or more types of polyhedra are also possible. Furthermore, the polyhedra formed by the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 (and consequently, the approximate polyhedra formed by the cell 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 convex polyhedron other than a regular polyhedron in which all faces are regular polygons and all vertex shapes are congruent (the type and order of regular polygons meeting at the vertices are the same)), a prism, a pyramid, etc. Furthermore, the skeletal lines O of some or all of the multiple cell compartments 21 constituting the skeletal part 2 may form a three-dimensional shape other than a polyhedron (for example, a sphere, ellipsoid, cylinder, etc.). Consequently, some or all of the multiple cell holes C constituting the skeletal part 2 may form a substantially three-dimensional shape other than a substantially polyhedron (for example, a substantially sphere, a substantially ellipsoid, a substantially cylinder, etc.).

[0067] By including small annular sections 211S and large annular sections 211L of different sizes among the multiple annular sections 211 constituting the cell compartment 21, it becomes possible to further reduce the gaps (spacing) between the cell holes C constituting the skeletal section 2. Furthermore, as in this example, if the shapes of the small annular sections 211S and the large annular sections 211L are different, it becomes possible to further reduce the gaps (spacing) between the cell holes C constituting the skeletal section 2. However, the multiple annular portions 211 constituting the cell compartment 21 may each have the same size and / or shape. If the size and shape of each annular portion 211 constituting the cell compartment 21 are the same, equal mechanical properties can be obtained in the X, Y, and Z directions.

[0068] As in this example, if the skeletal lines O of some or all (all in this example) of the annular parts 211 constituting the cell compartment 21 (and consequently, some or all (all in this example) of the virtual surfaces V1 constituting the cell compartment 21) form a substantially polygonal shape, it becomes possible to reduce the spacing between the cell holes C constituting the skeletal part 2. In addition, the compression and recovery deformation behavior of the skeletal part 2 in response to the application and release of external force becomes better as a seat pad, especially as a seat pad for vehicles. Furthermore, since the shape of the annular parts 211 (and consequently the shape of the virtual surfaces V1) becomes simpler, manufacturability and ease of adjusting characteristics can be improved. Note that if at least one of the annular parts 211 constituting the skeletal part 2 (and consequently at least one of the virtual surfaces V1 constituting the skeletal part 2) satisfies this configuration, similar effects can be obtained, albeit to varying degrees. Furthermore, the skeletal line O of at least one of the annular parts 211 constituting the skeletal part 2 (and consequently, at least one virtual surface V1 among the virtual surfaces V1 constituting the skeletal part 2) may be any approximate polygon shape other than the approximate regular hexagon or approximate regular quadrilateral as in this example, or a planar shape other than an approximate polygon (for example, a circle (perfect circle, ellipse, etc.)). When the shape of the skeletal line O of the annular part 211 (and consequently the shape of the virtual surface V1) is a circle (perfect circle, ellipse, etc.), the shape of the annular part 211 (and consequently the shape of the virtual surface V1) becomes simpler, which improves manufacturability and ease of adjusting properties, and also allows for more homogeneous mechanical properties to be obtained. For example, if the shape of the skeletal line O of the annular portion 211 (and consequently the shape of the virtual surface V1) is an elongated ellipse (horizontally elongated ellipse) in a direction approximately perpendicular to the direction of the applied load, the annular portion 211, and consequently the skeletal portion 2 (and consequently the porous structure 1), will deform more easily (become softer) in response to the input load compared to the case where the ellipse is elongated in a direction approximately parallel to the direction of the applied load (vertically elongated ellipse).

[0069] In this example, it is preferable that the skeletal part 2 has at least one cell pore C with a diameter of 5 mm or more. This makes it easier to manufacture the porous structure 1 using a 3D printer. If the diameter of each cell pore C in the skeletal part 2 is less than 5 mm, the structure of the skeletal part 2 becomes too complex, which may make it difficult to generate 3D shape data (CAD data, etc.) representing the three-dimensional shape of the porous structure 1, or 3D modeling data generated based on that 3D shape data, on a computer. Furthermore, conventional porous structures were manufactured through a process of foaming by chemical reactions, making it difficult to form cell pores C with a diameter of 5 mm or more. Furthermore, having cell pores C with a diameter of 5 mm or more in the skeletal part 2 makes it easier to improve the breathability and deformability of the skeletal part 2. From this perspective, it is preferable that the diameter of all cell pores C constituting the skeletal part 2 is 5 mm or more. The larger the diameter of the cell pores C, the easier it becomes to manufacture the porous structure 1 using a 3D printer, and the easier it becomes to improve breathability and deformability. From this perspective, the skeletal part 2 should have at least one (preferably all) cell pores C with a diameter of 8 mm or more, and even more preferably 10 mm or more. On the other hand, if the cell pores C of the skeletal part 2 are too large, it becomes difficult to form a clean (smooth) outer edge (outer contour) shape of the skeletal part 2 (and consequently the porous structure 1), which may reduce the shape accuracy of the porous structure 1 and worsen its appearance. Furthermore, the characteristics of the seat pad (especially a seat pad for a vehicle) may not be sufficiently good. Therefore, from the viewpoint of improving the appearance and the characteristics of the seat pad (especially a seat pad for a vehicle), the diameter of at least one (preferably all) cell pores C of the skeletal part 2 is preferably less than 30 mm, more preferably 25 mm or less, and even more preferably 20 mm or less. Furthermore, the more cell pores C that satisfy the above-mentioned numerical range of diameters the porous structure 1 has, the easier it is to obtain the above-mentioned effects. From this viewpoint, it is preferable that the diameter of each cell pore C constituting the porous structure 1 satisfies at least one of the above-mentioned numerical ranges. Similarly, it is even more preferable that the average value of the diameters of each cell pore C constituting the porous structure 1 satisfies at least one of the above-mentioned numerical ranges. Note that, in cases where the cell hole C has a shape different from a strictly spherical shape, as in this example, the diameter of the cell hole C refers to the diameter of the circumscribed sphere.

[0070] If the cell pores C of the skeletal part 2 are too small, the structure of the skeletal part 2 becomes too complex, which may make it difficult to generate 3D shape data (CAD data, etc.) representing the three-dimensional shape of the porous structure 1, or 3D modeling data generated based on that 3D shape data, on a computer. This makes it difficult to manufacture the porous structure 1 using a 3D printer. From the viewpoint of facilitating the manufacture of the porous structure 1 using a 3D printer, it is preferable that the diameter of the smallest cell pore C among the cell pores C constituting the skeletal part 2 is 0.05 mm or larger, and more preferably 0.10 mm or larger. When the diameter of the smallest cell pore C is 0.05 mm or larger, it can be fabricated at the resolution of a high-performance 3D printer, and when it is 0.10 mm or larger, it can be fabricated not only at the resolution of a high-performance 3D printer but also at the resolution of a general-purpose 3D printer.

[0071] Figure 22 is a diagram illustrating a modified example of the cell compartment 21 of the porous structure 1, and is a diagram corresponding to Figure 21. In each example described herein, the porous structure 1 may include one or more membranes 3 in addition to the skeletal portion 2, as shown in the modified example in Figure 22. The membrane 3 extends over a virtual surface V1 defined by the annular inner circumferential edge 2111 of the annular portion 211, thereby covering the virtual surface V1 defined by the annular portion 211. In the porous structure 1 of the example in Figure 22, at least one of the virtual surfaces V1 constituting the skeletal portion 2 is covered by the membrane 3. The membrane 3 is made of the same material as the skeletal portion 2 and is integrally constructed with the skeletal portion 2. In the example in Figure 22, the membrane 3 is configured to be flat. However, the membrane 3 may be configured to be non-flat (for example, curved). It is preferable that the membrane 3 has a thickness smaller than the width W0 of the bone portion 2B (Figure 19). The membrane 3 prevents communication between two cell pores C separated by the virtual surface V1, thus preventing airflow through the virtual surface V1. Consequently, the overall air permeability of the porous structure 1 decreases. By adjusting the number of virtual surfaces V1 constituting the porous structure 1 that are covered by the membrane 3, the overall air permeability of the porous structure 1 can be adjusted, and various levels of air permeability can be achieved according to requirements. From the viewpoint of facilitating the compression and recovery deformation of the porous structure 1, it is undesirable for all virtual surfaces V1 constituting the porous structure 1 to be covered by the membrane 3. In other words, it is preferable that at least one of the virtual surfaces V1 constituting the porous structure 1 is not covered by the membrane 3 and is open, and it is more preferable that all virtual surfaces V1 constituting the porous structure 1 are not covered by the membrane 3 and are open. Furthermore, as mentioned above, conventional porous structures were manufactured through a process of foaming by chemical reaction, making it difficult to form the membranes in the connecting pores between cells in the desired positions and quantities. In this example, when manufacturing the porous structure 1 with a 3D printer, it is possible to reliably form the membranes 3 in the desired positions and quantities by including information about the membranes 3 in the 3D modeling data loaded into the 3D printer beforehand. At least one of the small virtual surfaces V1S constituting the skeletal part 2 may be covered with the film 3, and / or at least one of the large virtual surfaces V1L constituting the skeletal part 2 may be covered with the film 3.

[0072] Next, with reference to Figures 23 to 24, other examples of porous structures 1 that can be used in the fitting member 51 and fitted member 52 of the sheet pad 302 according to any embodiment of the present invention will be described, focusing on the differences from the examples in Figures 19 to 21. In the examples shown in Figures 23 to 24, only the configuration of the bone portion 2B of the skeletal portion 2 of the porous structure 1 differs from the examples shown in Figures 19 to 21. The porous structure 1 may or may not have the membrane 3 (Figure 22) described above. In the example in Figure 23, the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 each form a Kelvin tetrahedron, and consequently, the cell holes C form approximately a Kelvin tetrahedron. However, as described in the explanation of the examples in Figures 19 to 21, in the example in Figure 23 as well, the skeletal lines O of the multiple cell compartments 21 constituting the skeletal part 2 may each have any shape, and consequently, the cell holes C may also have any shape.

[0073] Figure 23 is a plan view, corresponding to Figure 20, showing another example of a porous structure 1 that can be used in the fitting member 51 and fitted member 52 of a sheet pad 302 according to any embodiment of the present invention. Figure 24 shows the bone portion 2B of this example by itself. Figure 24(a) shows the bone portion 2B in its natural state with no external force applied, and Figure 24(b) shows the bone portion 2B with an external force applied. Figures 23 and 24 show the central axis (skeletal line O) of the bone portion 2B. As shown in Figures 23 and 24(a), each bone portion 2B of the skeletal portion 2 is composed of a constant bone portion 2B1 that extends while maintaining a constant cross-sectional area, and a pair of bone variation portions 2B2 that extend from the constant bone portion 2B1 to the joint portion 2J on both sides in the direction of extension of the constant bone portion 2B1, gradually changing their cross-sectional area. In this example, each bone variation portion 2B2 extends from the constant bone portion 2B1 to the joint portion 2J while gradually increasing its cross-sectional area. It should be noted that even if only some of the bone portions 2B of the skeletal portion 2 are satisfied with this configuration, the same effect can be obtained. Furthermore, some or all of the bone portions 2B of the skeletal portion 2 may have a bone variation portion 2B2 only at one end of the constant bone portion 2B1, with the other end of the constant bone portion 2B1 directly connected to the joint portion 2J, and in this case as well, the same effect can be obtained, although to a different degree. Here, the cross-sectional areas of the bone-fixed portion 2B1 and the bone-transformed portion 2B2 refer to the cross-sectional areas of the bone-fixed portion 2B1 and the bone-transformed portion 2B2 perpendicular to the skeletal line O, respectively. In this example, each bone portion 2B constituting the porous structure 1 consists of a fixed bone portion 2B1 and a deformed bone portion 2B2. As the deformed bone portion 2B2 gradually increases in cross-sectional area from the fixed bone portion 2B1 towards the joint portion 2J, the bone portion 2B has a constricted shape near the boundary between the fixed bone portion 2B1 and the deformed bone portion 2B2, becoming thinner towards the fixed bone portion 2B1. Therefore, when an external force is applied, the bone portion 2B is more susceptible to buckling deformation at its constricted portion and the intermediate portion of the fixed bone portion 2B1, and consequently, the porous structure 1 becomes more susceptible to compressive deformation. This results in behavior and properties equivalent to those of general polyurethane foam manufactured through a foaming process using chemical reactions. Furthermore, this makes the surface of the porous structure 1 feel softer to the touch. Therefore, for example, when sitting down, especially at the beginning of sitting, it provides a softer feel to the sitter. This kind of soft feel is generally widely preferred, and is also favored by those who sit in the seats of luxury cars (for example, those sitting in the back seat when a chauffeur is present).

[0074] As in this example, when the bone portion 2B has a bone-fixed portion 2B1 in at least a part thereof, the ratio A0 / A1 of the cross-sectional area A0 (Figure 24(a)) of the bone-fixed portion 2B1 to the cross-sectional area A1 (Figure 24(a)) of either end 2B21 of the bone portion 2B (preferably both ends) is: 0.15 ≤ A0 / A1 ≤ 2.0 It is preferable if the following conditions are met. This makes it possible to make the touch feel of the surface of the porous structure 1 just right, neither too soft nor too hard, as a characteristic of a seat pad (especially a vehicle seat pad). Therefore, for example, when sitting down, especially at the beginning of sitting down, the sitter will be given a feeling of just the right firmness. The smaller the ratio A0 / A1, the softer the touch feel of the surface of the porous structure 1 becomes. If the ratio A0 / A1 is less than 0.15, the touch feel of the surface of the porous structure 1 may become too soft, which may be undesirable as a characteristic of a seat pad (especially a vehicle seat pad), and it may also become difficult to manufacture with a 3D printer, making it undesirable from a manufacturability standpoint. If the ratio A0 / A1 is greater than 2.0, the touch feel of the surface of the porous structure 1 may become too hard, which may be undesirable as a characteristic of a seat pad (especially a vehicle seat pad). Furthermore, a ratio of A0 / A1 of 0.5 or higher is more preferable. More specifically, in the example shown in Figures 23-24, the bone portion 2B has a fixed bone portion 2B1 and a pair of continuous bone variation portions 2B2 on both sides, with each bone variation portion 2B2 extending from the fixed bone portion 2B1 to the joint portion 2J, gradually increasing in cross-sectional area, and the ratio A0 / A1 is less than 1.0. This makes the touch feel of the surface of the porous structure 1 relatively soft, as a characteristic of seat pads (especially vehicle seat pads). Such a soft feel is generally widely preferred and is also preferred by occupants of luxury car seat pads (for example, occupants in the back seat when there is a driver and passengers in the back seat). Furthermore, each bone portion 2B constituting the skeletal part 2 may satisfy this configuration, or only some of the bone portions 2B constituting the skeletal part 2 may satisfy this configuration. In either case, similar effects can be obtained, although there may be differences in degree.

[0075] Alternatively, instead of the examples in Figures 23-24, the bone deformation section 2B2 may extend from the bone fixed section 2B1 to the joint section 2J, gradually decreasing in cross-sectional area. In this case, the bone fixed section 2B1 will have a larger (thicker) cross-sectional area than the bone deformation section 2B2. As a result, when an external force is applied, the bone fixed section 2B1 becomes less prone to deformation, and instead, the bone deformation section 2B2 (especially the part on the joint section 2J side) becomes more susceptible to buckling, and consequently, the porous structure 1 becomes less prone to compressive deformation. This results in a harder touch feel on the surface of the porous structure 1 and provides high-hardness mechanical properties. Therefore, for example, when sitting down, especially at the beginning of sitting, the sitter will feel a harder sensation. Such behavior is not easily obtained with general polyurethane foam manufactured through a foaming process by chemical reaction. This configuration can accommodate users who prefer a firmer feel. This firm feel is preferred by occupants, for example, in the seat pads of sports cars that perform rapid acceleration, deceleration, and lane changes. Furthermore, if the bone alteration portion 2B2 extends from the bone solid portion 2B1 to the joint portion 2J while gradually decreasing in cross-sectional area, the ratio A0 / A1 will be greater than 1.0. Furthermore, each bone portion 2B constituting the skeletal part 2 may satisfy this configuration, or only some of the bone portions 2B constituting the skeletal part 2 may satisfy this configuration. In either case, similar effects can be obtained, although there may be differences in degree.

[0076] In the examples shown in Figures 19 to 21 above, the bone portion 2B consists only of the constant bone portion 2B1, without the bone variation portion 2B2. In this case, the cross-sectional area of ​​the bone portion 2B is constant along its entire length. The touch feel of the surface of the porous structure 1 when external force is applied is moderately hard. This configuration can accommodate users who prefer a moderately hard feel. Furthermore, it can be suitably applied to seat pads in all types of vehicles, including luxury cars and sports cars. In this case, the ratio A0 / A1 is 1.0. Furthermore, each bone portion 2B constituting the skeletal part 2 may satisfy this configuration, or only some of the bone portions 2B constituting the skeletal part 2 may satisfy this configuration. In either case, similar effects can be obtained, although there may be differences in degree.

[0077] Returning to the example in Figures 23-24, in this example, each bone portion 2B constituting the skeletal portion 2 has a smaller cross-sectional area at the bone fixed portion 2B1 than at the bone transformation portion 2B2 and the joint portion 2J. More specifically, the cross-sectional area of ​​the bone fixed portion 2B1 is smaller than the cross-sectional area of ​​any part of the bone transformation portion 2B2 and the joint portion 2J (excluding the boundary portion between the bone fixed portion 2B1 and the bone transformation portion 2B2). In other words, the bone fixed portion 2B1 is the part with the smallest (thinnest) cross-sectional area in the skeletal portion 2. As a result, as described above, when an external force is applied, the bone fixed portion 2B1 is more easily deformed, and consequently, the porous structure 1 is more easily compressed and deformed. This makes the surface of the porous structure 1 feel softer to the touch. Note that the cross-sectional area of ​​the joint 2J refers to the cross-sectional area of ​​the joint 2J perpendicular to the skeletal line O. It should be noted that, not limited to this example, only some of the bone parts 2B constituting the skeletal part 2 may satisfy this configuration, and even in that case, a similar effect can be obtained, albeit to varying degrees.

[0078] Similarly, in the examples shown in Figures 23 and 24, each bone portion 2B constituting the skeletal structure 2 has a bone fixed portion 2B1 that is narrower than the bone deformation portion 2B2 and the joint portion 2J. More specifically, the width of the bone fixed portion 2B1 is narrower than the width of any part of the bone deformation portion 2B2 and the joint portion 2J (excluding the boundary portion between the bone fixed portion 2B1 and the bone deformation portion 2B2). In other words, the bone fixed portion 2B1 is the narrowest (thinnest) part of the skeletal structure 2. This also makes the bone fixed portion 2B1 more easily deformed when external force is applied, thereby making the surface of the porous structure 1 feel softer to the touch. Note that the widths of the fixed bone portion 2B1, the altered bone portion 2B2, and the joint portion 2J refer to the maximum width in the respective cross-sections when measured along the cross-section perpendicular to the skeletal line O of the fixed bone portion 2B1, the altered bone portion 2B2, and the joint portion 2J. The skeletal line O of the joint portion 2J is the portion of the skeletal line O that corresponds to the joint portion 2J. For reference, Figure 24(a) shows the width W0 of the fixed bone portion 2B1 and the width W1 of the altered bone portion 2B2. It should be noted that, not limited to this example, only some of the bone parts 2B constituting the skeletal part 2 may satisfy this configuration, and even in that case, a similar effect can be obtained, albeit to varying degrees.

[0079] In each of the above examples, from the viewpoint of simplifying the structure of the porous structure 1 and, consequently, the ease of manufacturing with a 3D printer, the width W0 (Figure 24) of the bone-like portion 2B1 is preferably 0.05 mm or more, and more preferably 0.10 mm or more. When the width W0 is 0.05 mm or more, it can be fabricated with the resolution of a high-performance 3D printer, and when it is 0.10 mm or more, it can be fabricated not only with a high-performance 3D printer but also with the resolution of a general-purpose 3D printer. On the other hand, from the viewpoint of improving the accuracy of the outer edge (outer contour) shape of the porous structure 1, reducing the gap (spacing) between cell pores C, and improving the characteristics as a sheet pad, the width W0 (Figure 24) of the bone fixed portion 2B1 is preferably 0.05 mm or more and 2.0 mm or less. It is preferable that each bone portion 2B constituting the skeletal part 2 satisfies this configuration, but it is also acceptable if only some of the bone portions 2B constituting the skeletal part 2 satisfy this configuration, and even in that case, similar effects can be obtained, although to varying degrees.

[0080] As shown in Figure 24, in this example, each bone portion 2B constituting the skeletal portion 2 has one or more (three in this example) inclined surfaces 2B23 on its side surface, where the bone transformation portion 2B2 has a bone transformation portion 2B2 and the width W2 gradually increases from the bone fixed portion 2B1 toward the joint portion 2J. As a result, when an external force is applied, the bone portion 2B becomes more susceptible to buckling deformation at the constricted portion near the boundary between the bone solid portion 2B1 and the bone deformation portion 2B2, and consequently, the porous structure 1 becomes more susceptible to compressive deformation. This makes the surface of the porous structure 1 feel softer to the touch. Here, the extension direction of the bone transformation portion 2B2 is the extension direction of the central axis (skeletal line O) of the bone transformation portion 2B2. Also, the width W2 of the inclined surface 2B23 of the bone transformation portion 2B2 refers to the width of the inclined surface 2B23 when measured along a cross section perpendicular to the skeletal line O of the bone transformation portion 2B2. It should be noted that, not limited to this example, only some of the bone parts 2B constituting the skeletal part 2 may satisfy this configuration, and even in that case, a similar effect can be obtained, albeit to varying degrees.

[0081] In the examples shown in Figures 23 and 24, each bone portion 2B constituting the skeletal portion 2 is columnar, and the bone fixed portion 2B1 and the bone modified portion 2B2 have equilateral triangular cross-sectional shapes. This simplifies the structure of the porous structure 1, making it easier to fabricate using a 3D printer. Furthermore, it facilitates the reproduction of the mechanical properties of typical polyurethane foam manufactured through a chemical reaction foaming process. Therefore, the properties of the porous structure 1 as a sheet pad can be improved. Additionally, by configuring the frame 2B in a columnar shape, the durability of the porous structure 1 can be improved compared to a case where the frame 2B were replaced with a thin, membrane-like portion. The cross-sectional shapes of the fixed bone portion 2B1 and the altered bone portion 2B2 are, respectively, the shapes in a cross-section perpendicular to the central axis (skeletal line O) of the fixed bone portion 2B1 and the altered bone portion 2B2. It should be noted that, not limited to this example, only some of the bone parts 2B constituting the skeletal part 2 may satisfy this configuration, and even in that case, a similar effect can be obtained, albeit to varying degrees. Furthermore, in all or some of the bone parts 2B that constitute the skeletal part 2, the bone fixed part 2B1 and the bone variation part 2B2 may have cross-sectional shapes other than equilateral triangles (triangles other than equilateral triangles, quadrilaterals, etc.), or they may be circular (perfect circles, ellipses, etc.), and in such cases, the same effect as in this example can be obtained. Also, the bone fixed part 2B1 and the bone variation part 2B2 may have different cross-sectional shapes from each other. In addition, the cross-sectional shape of each bone part 2B may be uniform along its extension direction, or it may be non-uniform along its extension direction. Furthermore, the cross-sectional shapes of each bone part 2B may be different from each other. [Industrial applicability]

[0082] The seat pad and method for manufacturing the seat pad of the present invention are suitable for use in seat pads for any vehicle, and are particularly suitable for use in vehicle seat pads. [Explanation of symbols]

[0083] 300: Vehicle seats, 302: Seat pad, 310: Cushion pad, 320: Back pad, 3MP: Main pad section, 3SP: Side pad section, 3BF: Back pad opposing section, 330: Epidermis, 340: Headrest, FS: Side facing the seated person (front), SS: Side, BS: Back TD: Pad thickness direction, LD: Pad extension direction, WD: Pad width direction, 51: Fitting member, 510: Fitting part 52: Fitting member, 520: Fitting part FD: Opposite direction, Q, Q1, Q2: convex part, Qt: tip surface, R, R1, R2: recessed surface, Rb: bottom surface, G: Adhesive, 1: porous structure, 2: Skeletal part, 2B, 2Ba, 2Bb, 2Bc, 2Bm, 2Bn, 2Bo: Bone part, 2Be: End of bone part, 2B1: Bone fixed part, 2B2: Bone transformation part, 2B21: End of bone transformation part on the joint side, 2B22: End of bone transformation part on the bone fixed part side, 2B23: Inclined surface of bone transformation part, 2J: Joint, 21: Cell compartment part, 211: Ring part, 211L: Large ring part, 211S: Small ring part, 2111: Inner circumferential edge of ring part, 3: Membrane, C: Cell hole, O: Skeletal line, V1: Virtual plane, V1L: Large virtual plane, V1S: Small virtual plane 400: 3D printer, 410: control unit, 420: molding unit, 421: laser irradiator, 430: support base, 440: housing, LL: ultraviolet laser light, LR: liquid resin, 500, 500a, 500b: 3D modeling data

Claims

1. It is a seat pad, A fitting member having a fitting portion, A fitted member having a fitted portion configured to fit with the aforementioned fitting portion, Equipped with, The fitting member and the fitted member are each composed of a porous structure. The porous structure is made of a flexible resin or rubber. The porous structure has a skeletal structure extending almost entirely over its entirety. The aforementioned skeletal part is, Multiple bones and Each of the aforementioned multiple bone portions connects the ends of the multiple bone portions, Equipped with, At least one of the fitting portion and the fitted portion has a plurality of protrusions arranged in the thickness direction of the sheet pad, In a cross-section perpendicular to the opposing direction of the fitting portion and the fitted portion, the fitting portion and the fitted portion extend along the entire length of the seat pad. The fitting portion and the fitted portion are further located on the center in the width direction of the seat pad, the seat pad.

2. The seat pad according to claim 1, wherein the fitting portion and the fitted portion are arranged on the main pad portion of the seat pad.

3. The sheet pad according to claim 1 or 2, wherein the fitting member and the fitted member face each other in a direction perpendicular to the thickness direction of the sheet pad.

4. The sheet pad according to any one of claims 1 to 3, wherein the widths of the plurality of protrusions are non-uniform.

5. The sheet pad according to any one of claims 1 to 4, wherein the extension lengths of the plurality of protrusions are non-uniform.

6. Of the bones that constitute the fitting portion of the fitting member, each bone configured to contact the fitting portion of the fitted member is thicker than each bone that constitutes the portion of the fitting member other than the fitting portion. The seat pad according to any one of claims 1 to 5, wherein each of the bones constituting the fitting portion of the fitting member that is configured to contact the fitting portion of the fitting member is thicker than each of the bones constituting the portion of the fitting member other than the fitting portion.

7. The seat pad is a seat pad for a vehicle, as described in any one of claims 1 to 6.

8. A method for manufacturing a seat pad according to any one of claims 1 to 7, A fabrication step involves fabricating the fitting member and the fitted member using a 3D printer, A fitting step of fitting the fitting portion of the fitting member and the fitted portion of the fitted member, A method for manufacturing a seat pad, including the method described above.

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