Protector

Abstract

To provide a protector capable of striking a balance between improvement of design and continuous impact absorbability.SOLUTION: A protector includes an impact absorption material 10 comprising a resin hollow plate material. The hollow plate material includes a hollow plate-like core layer in which multiple cells are juxtaposed, which are partitioned by a side wall part extending in a thickness direction, and a skin layer bonded to a principal surface of the core layer. On the front side surface of the impact absorption material 10, which is a surface on the side on which an object collides, a recess pattern formed by a recess 14 recessed in the thickness direction is provided partially, and in a side wall part positioned on the recess 14, a cross-sectional shape along the thickness direction of the impact absorption material 10 has a curved shape.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a protector. [Background technology]

[0002] Patent Document 1 discloses a hollow resin plate having a plurality of cells arranged side by side. The hollow structure of Patent Document 1 is used as a chest protector that protects the chest of a wearer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-154947 A Summary of the Invention [Problem to be solved by the invention]

[0004] The protector disclosed in Patent Document 1 has room for improvement in terms of design. The object of the present invention is to achieve both improved design and continuous shock absorption for a protector using a hollow resin plate material. [Means for solving the problem]

[0005] The protector that solves the above problem is a protector for protecting the body of a user, and comprises an impact absorbing material made of a hollow resin plate, the hollow plate comprising a hollow plate-shaped core layer consisting of a plurality of cells arranged side by side and partitioned by side wall portions extending in the thickness direction, and a skin layer joined to at least one main surface of the core layer, the front surface of the impact absorbing material being provided with a recess pattern formed by recesses that are partially recessed in the thickness direction, and the side wall portions located in the recesses have a curved cross-sectional shape along the thickness direction of the impact absorbing material.

[0006] According to the above configuration, by arranging the recesses on the front surface of the shock absorbing material, a predetermined recess pattern can be added to the front surface of the shock absorbing material, improving the design of the protector. In addition, by making the side wall portion located in the recess have a curved cross section, that is, by forming the recess by curving the side wall portion to a degree that does not buckle, when an impact is applied to the shock absorbing material that is strong enough to buckle and crush the side wall portion, a restoring force is generated in the side wall portion to return it to its original state. This prevents a significant decrease in the shock absorbing property of the shock absorbing material due to the application of an impact, and ensures continuous shock absorbing property.

[0007] In the above protector, it is preferable that the impact absorbing material has a curved shape so as to protrude toward the front side where an object hits. According to the above configuration, when an object collides with the curved portion of the impact absorbing material, the object slides along the outer surface of the impact absorbing material in accordance with the shape of the impact absorbing material, thereby diverting part of the impact force acting on the impact absorbing material. Effect of the Invention

[0008] According to the protector of the present invention, it is possible to achieve both improved design and continuous shock absorption properties. [Brief description of the drawings]

[0009] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] 3 is a cross-sectional view taken along line 3-3 in FIG. 1. [Figure 4] 4 is a cross-sectional view taken along line 4-4 of FIG. 2. [Diagram 5] FIG. [Figure 6] FIG. 1(a) is an explanatory diagram of a sheet material forming process, and (b) and (c) are explanatory diagrams of a folding process. [Figure 7] 1A is a partial perspective view of the core layer, FIG. 1B is a β-β line cross-sectional view of FIG. 1A, and FIG. 1C is a γ-γ line cross-sectional view of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a specific embodiment of a protector according to the present invention will be described. The protector of this embodiment is a protector for protecting the body of a user, and is used as protective gear for sports or protective gear for workers, such as a chest guard, a body protector, a foot guard, a shin guard, a knee guard, etc. In this embodiment, a protector applied as a chest guard will be described as an example.

[0011] 1 to 3, the protector includes an impact absorbing material 10 made of a single hollow plate material. The impact absorbing material 10 is manufactured by performing bending and compression processes on a single flat hollow plate material.

[0012] As shown in FIG. 5, the hollow plate material 10a includes a core layer 20 in which a plurality of cells S are arranged side by side, and a skin layer 30 bonded to both the upper and lower surfaces of the core layer 20. The core layer 20 includes a side wall portion 23 that divides the plurality of cells S, an upper wall portion 21 that is bonded to the upper edge of the side wall portion 23 to close the upper end of the cell S, and a lower wall portion 22 that is bonded to the lower edge of the side wall portion 23 to close the lower end of the cell S. The plurality of cells S are divided by the side wall portion 23 to form a hexagonal column extending in the thickness direction of the hollow plate material 10a. The core layer 20 includes the upper wall portion 21 and the lower wall portion 22, and is hollow, containing the plurality of cells S. The skin layer 30 bonded to the upper surface of the core layer 20 is bonded to the upper wall portion 21 of the core layer 20 via an adhesive layer (not shown). The skin layer 30 bonded to the lower surface of the core layer 20 is bonded to the lower wall portion 22 of the core layer 20 via an adhesive layer (not shown).

[0013] The core layer 20, the skin layer 30, and the adhesive layer are made of a thermoplastic resin. The thermoplastic resin constituting the core layer 20 and the skin layer 30 is a conventionally known one, and the material is not particularly limited. For example, polypropylene resin, polyamide resin, polyethylene resin, acrylonitrile-butadiene-styrene copolymer resin, acrylic resin, polybutylene terephthalate resin, etc. are included. The thermoplastic resin constituting the core layer 20 and the skin layer 30 is preferably made of the same material. In this embodiment, both are made of polypropylene resin. The above-mentioned thermoplastic resin may contain additives such as elastomer and butadiene.

[0014] The thermoplastic resin constituting the adhesive layer that bonds the core layer 20 and the skin layer 30 is also a conventionally known one, and its material is not particularly limited. Examples include olefin-based, polyester-based, and urethane-based resins. The adhesive layer is preferably a resin with a lower melting point than the thermoplastic resins constituting the core layer 20 and the skin layer 30. In this embodiment, the adhesive layer is made of a modified polyolefin-based resin (modified resin) such as modified polyethylene or modified polypropylene, which is provided with adhesiveness by introducing a functional group into polyolefin.

[0015] The thickness of the hollow plate material 10a is not particularly limited, but is preferably 5 to 30 mm. The thickness of each of the upper wall portion 21, the lower wall portion 22, and the side wall portion 23 that constitute the core layer 20 is preferably 0.2 to 0.3 mm.

[0016] The thickness of the skin layer 30 is preferably 0.2 to 1.0 mm. When the thicknesses of the core layer 20 and the skin layer 30 are within this range, the formability during bending can be improved. In addition, it is preferable that the thicknesses of the walls of the core layer 20 and the skin layer 30 are approximately the same thickness, or that the core layer 20 is thinner. The thicknesses of the walls of the core layer 20 and the skin layer 30 are the thicknesses of the resin sheet material 100 forming the core layer 20 and the sheet constituting the skin layer 30, respectively, which will be described later.

[0017] As shown in Fig. 2, the impact absorbing material 10 has a generally polygonal shape with a wide upper side, with the upper side 11 as the upper base and the lower side 12 as the lower base, when viewed from the front, and the center side in the direction along the upper side 11 or the lower side 12 is curved so as to protrude toward the front side (the front side of the paper in Fig. 2). In addition, the corners of the polygonal shape when viewed from the front in the impact absorbing material 10 are rounded and configured into a curved shape. In the following description, the front side of the paper in Fig. 2 is the front side of the protector, and the surface located on the back side of the paper is the back side of the protector.

[0018] 2 and 3, a thin peripheral portion 13 is formed on both the front and back sides of the periphery of the impact absorbing material 10. The peripheral portion 13 is a thin portion of a hollow structure formed by partially compressing the hollow plate material 10a constituting the impact absorbing material 10. The thickness of the peripheral portion 13 is thinner than the general portion of the impact absorbing material 10, i.e., the portion excluding the peripheral portion 13 and a recessed portion 14 described later, for example, by 0.1 to 0.7 mm.

[0019] Here, the impact absorbing material 10 of this embodiment is attached so that the back side faces the user, and is used in a state in which the portion of the front surface except for the peripheral edge portion 13 is exposed to the outer surface. Hereinafter, the portion of the front surface of the impact absorbing material 10 except for the peripheral edge portion 13, i.e., the portion of the impact absorbing material 10 exposed to the outer surface, will be referred to as the exposed portion.

[0020] As shown in Figures 2 and 3, the exposed portion of the impact absorbing material 10 is provided with a recess pattern formed by recesses 14 that are partially recessed in the thickness direction. The recesses 14 are grooves that extend linearly along the surface of the exposed portion of the impact absorbing material 10 in a front view. Examples of the recess pattern include a honeycomb pattern, a lattice pattern, a striped pattern, a wave pattern, and letters. The drawings show, as an example, a case in which the groove-shaped recesses 14 are formed across multiple cells S of the core layer 20 and are arranged to form a honeycomb pattern as a whole.

[0021] As shown in Fig. 4, the recess 14 has vertical walls 15a extending parallel to the thickness direction of the impact absorbing material 10, and a bottom wall 15b connecting the vertical walls 15a. The bottom wall 15b is a plane parallel to the surface of the impact absorbing material 10, that is, a curved plane having the same curvature as the surface of the impact absorbing material 10 having a curved shape. In Fig. 4, the impact absorbing material 10 is illustrated as a flat plate for ease of understanding. The vertical walls 15a and the bottom wall 15b of the recess 14 are composed of the upper wall portion 21 or the lower wall portion 22 of the core layer 20 of the hollow plate material 10a described above, and the skin layer 30.

[0022] As shown in Figure 4, the side wall portion 23 constituting the core layer 20 of the hollow plate material 10a has a side wall portion 23 located in the general part of the impact absorbing material 10 (hereinafter referred to as general side wall portion 23A) and a side wall portion 23 where the recess 14 is located (hereinafter referred to as recess side wall portion 23B).

[0023] The general side wall portion 23A is a side wall portion 23 supporting the upper wall portion 21 constituting the surface of the general portion of the impact absorbing material 10, and has a linear cross-sectional shape along the thickness direction of the impact absorbing material 10. The recess side wall portion 23B is a side wall portion 23 supporting the bottom wall 15b of the recess 14 of the impact absorbing material 10, and has a curved cross-sectional shape along the thickness direction of the impact absorbing material 10, and is formed into a continuous curved shape with no buckling portions along the way.

[0024] Next, the shape of the recess side wall 23B will be described, with the recess side wall 23B constituting one side of one cell S being one block, and a group of multiple blocks of recess side wall 23B surrounding one cell S being one cell unit of recess side wall 23B. In the present embodiment having a hexagonal columnar cell S, six blocks of recess side wall 23B constitute one cell unit of recess side wall 23B. The following description relates to the cross-sectional shape along the thickness direction of the impact absorbing material 10.

[0025] The curved direction of the curved shape of the recess side wall 23B of each block is not particularly limited. For example, the recess side wall 23B of two opposing blocks of one set of recess side wall 23B may be curved in opposite directions so that the central portions in the thickness direction are separated or so that the central portions in the thickness direction are closer to each other, or may be curved in the same direction. FIG. 4 illustrates, as an example, a case in which the recess side wall 23B of the opposing two blocks is curved so that the central portions in the thickness direction are separated.

[0026] The recess side wall portion 23B of one block may be configured to consist only of curved portions, or may be configured to have some straight portions provided within the recess side wall portion 23B of one block, resulting in a mixture of curved and straight portions.

[0027] The recess side wall 23B of one cell unit may be configured only of blocks of recess side wall 23B having the same shape, or may be configured of a combination of blocks of recess side wall 23B having different shapes. From the viewpoint of further improving the continuous shock absorption, it is preferable that the recess side wall 23B of one cell unit is configured of a combination of blocks of recess side wall 23B having different shapes.

[0028] The depth D of the recess 14, i.e., the distance between the surface of the general part of the impact absorbing material 10 and the bottom wall 15b of the recess 14, is, for example, 0.2 to 2.0 mm, preferably 0.5 to 1.0 mm, when the thickness of the part of the exposed part other than the recess 14 (hereinafter simply referred to as the thickness of the exposed part) is 5 to 30 mm. The depth D is, for example, 3 to 50% of the thickness of the exposed part, preferably 5 to 40%, more preferably 10 to 30%. The width H of the groove-shaped recess 14 is, for example, 1 to 10 mm, preferably 2 to 5 mm. The depth D and width H of each recess 14 may be constant, may be different for each recess 14, or may vary for each part in one recess 14.

[0029] The area ratio of the recesses 14 to the exposed portion of the impact absorbing material 10 is, for example, 3 to 50%, preferably 5 to 40%, and more preferably 10 to 30%. Moreover, the recesses 14 are provided so as to be distributed uniformly without bias in the portion on the surface of the impact absorbing material 10 excluding the peripheral edge portion 13.

[0030] 1 to 3, the impact absorbing material 10 is provided with two hinge portions 17 that extend linearly from the upper side 11 to the lower side 12. The two hinge portions 17 are disposed at an angle with respect to a vertical line L1 so that the distance between them gradually narrows from the upper side 11 to the lower side 12.

[0031] The hinge portion 17 is a thin-walled portion formed by partially compressing the hollow plate material 10a constituting the impact absorbing material 10. The thickness of the hinge portion 17 is set to a thickness that allows the impact absorbing material 10 to bend at the hinge portion 17. The thickness of the hinge portion 17 is, for example, 0.2 to 0.7 mm, and preferably 0.4 to 0.6 mm.

[0032] 1 to 3, a covering material 16 having a U-shaped cross section is attached to the entire periphery of the peripheral portion 13 of the impact absorbing material 10. When the covering material 16 is attached to the peripheral portion 13, the surface of the general part of the impact absorbing material 10 and the surface of the covering material 16 are substantially flush with each other.

[0033] The covering material 16 is provided for the purpose of protecting the edges of the impact absorbing material 10 and improving the design. As the covering material 16, for example, a cloth material such as a woven fabric, a nonwoven fabric, or a mesh fabric, or a sheet-like material such as leather, rubber, or resin can be used.

[0034] The fabric material may be made of either natural or synthetic fibers. Examples of natural fibers include cotton, hemp, linen, silk, and cashmere. Examples of synthetic fibers include nylon, polyester, polyacrylonitrile, and vinylon. The leather may be made of either natural or synthetic leather.

[0035] There is no particular limitation on the method of attaching the covering material 16 to the peripheral portion 13 of the impact absorbing material 10. For example, the covering material 16 may be sewn using thread, the covering material 16 may be adhered using an adhesive, or the covering material 16 may be welded. In the drawings, as an example, the covering material 16 is shown sewn to the peripheral portion 13 using thread.

[0036] Next, a method for manufacturing the protector will be described. The manufacturing method of the protector includes a plate manufacturing process for manufacturing the impact absorbing material 10 composed of a hollow plate material 10a, and a covering process for attaching a covering material 16 to the peripheral portion 13 of the impact absorbing material 10 obtained in the plate manufacturing process.

[0037] (Plate manufacturing process) The plate manufacturing process includes a sheet material forming step, a folding step, a joining step, a shaping step, and a cutting step.

[0038] [Sheet material forming process] As shown in FIG. 6(a), in the sheet material forming process, a resin sheet material 100 is formed by hot-molding a sheet made of a thermoplastic resin into a predetermined shape. In the resin sheet material 100, a band-shaped planar region 110 and a bulging region 120 are alternately arranged in the width direction (X direction) of the resin sheet material 100. In the bulging region 120, a first bulging portion 121 having a cross section of a downward groove shape composed of an upper surface and a pair of side surfaces is formed over the entire extension direction (Y direction) of the bulging region 120. Note that the angle between the upper surface and the side surface of the first bulging portion 121 is preferably 90 degrees, and as a result, the cross section of the first bulging portion 121 is a downward U-shape. In addition, the width of the first bulging portion 121 (the length of the short side of the upper surface) is set to be equal to the width of the planar region 110 and twice the length of the bulging height of the first bulging portion 121 (the length of the short side of the side surface).

[0039] In addition, in the bulging region 120, a plurality of second bulging portions 122, each of which has a cross-sectional shape that is a trapezoid obtained by bisecting a regular hexagon at its longest diagonal, are formed so as to be perpendicular to the first bulging portion 121. The bulging height of the second bulging portion 122 is set to be equal to the bulging height of the first bulging portion 121. In addition, the interval between adjacent second bulging portions 122 is equal to the width of the upper surface of the second bulging portion 122.

[0040] The first bulge 121 and the second bulge 122 are formed by partially bulging the sheet upwards by utilizing the plasticity of the sheet. The resin sheet material 100 can be molded from a single sheet by a known molding method such as vacuum molding or compression molding.

[0041] [Folding process] As shown in FIG. 6(b) and FIG. 6(c), in the folding process, the resin sheet material 100 configured as described above is folded along the boundary lines P and Q to form the core layer 20. Specifically, the resin sheet material 100 is valley-folded at the boundary line P between the flat area 110 and the bulging area 120, and mountain-folded at the boundary line Q between the top surface and side surface of the first bulging portion 121 to compress in the X direction. Then, the top surface and side surface of the first bulging portion 121 are folded over, and the end surface of the second bulging portion 122 and the flat area 110 are folded over, thereby forming one rectangular column-shaped partition body 130 extending in the Y direction for one bulging area 120. The partition bodies 130 are continuously formed in the X direction to form the core layer 20. The thickness of the resin sheet material 100 forming the core layer 20 is formed to be approximately the same as or thinner than the thickness of the skin layer 30.

[0042] As shown in Figure 6 (c), when the resin sheet material 100 is compressed, the upper wall portion 21 of the core layer 20 is formed by the upper surface and side surfaces of the first bulge portion 121, and the lower wall portion 22 of the core layer 20 is formed by the end surface of the second bulge portion 122 and the flat area 110.

[0043] As shown in Fig. 7(a), the cells S formed inside the core layer 20 by the folding process include a first cell S1 and a second cell S2 having different structures. As shown in Fig. 7(b), in the first cell S1, a two-layered upper wall portion 21 is provided on the upper part of the side wall portion 23. The layers of this two-layered upper wall portion 21 are joined to each other. In the first cell S1, a one-layered lower wall portion 22 is provided on the lower part of the side wall portion 23.

[0044] 7(b), the boundary portion between the side wall portion 23 and the upper wall portion 21 of the first cell S1 is, microscopically, in a state where the side wall portion 23 extends upward in a straight line and curves to connect to the upper wall portion 21. In other words, a curved portion 23e is formed between the side wall portion 23 and the upper wall portion 21.

[0045] 7(c), in the second cell S2, an upper wall portion 21 having a single layer structure is provided on the upper part of the side wall portion 23. In addition, in the second cell S2, a lower wall portion 22 having a two-layer structure is provided on the lower part of the side wall portion 23. The layers of the lower wall portion 22 having the two-layer structure are joined to each other.

[0046] 7(c), the boundary between the side wall portion 23 and the upper wall portion 21 of the first cell S1 is, microscopically, in a state where the side wall portion 23 extends upward in a straight line and curves to connect to the upper wall portion 21. In other words, a curved portion 23e is formed between the side wall portion 23 and the upper wall portion 21.

[0047] As shown in FIG. 7(c), the portion where the upper surface and side surface of the first bulge portion 121 in the upper wall portion 21 are folded to form a two-layer structure, and the portion where the end surface of the second bulge portion 122 in the lower wall portion 22 is folded to form a two-layer structure and the flat area 110 are folded to form an overlapping portion 131.

[0048] Moreover, the hexagonal columnar region formed as a partition block by folding the second bulging portion 122 becomes the second cell S2, and the hexagonal columnar region formed as a partition block between a pair of adjacent partitions 130 becomes the first cell S1. In this embodiment, the upper surface and side surface of the second bulging portion 122 constitute the side wall portion 23 of the second cell S2, and the side surface of the second bulging portion 122 and the flat portion located between the second bulging portions 122 in the bulging region 120 constitute the side wall portion 23 of the first cell S1. The contact portion between the upper surfaces of the second bulging portions 122 and the contact portion between the flat portions in the bulging region 120 constitute the side wall portion 23 having a two-layer structure consisting of the first side wall portion 23b and the second side wall portion 23c. When carrying out such a folding process, it is preferable to heat-treat the resin sheet material 100 to soften it.

[0049] As shown in FIG. 7(b) and FIG. 7(c), the adjacent first cells S1 and the adjacent second cells S2 are partitioned by the side wall 23 (the first side wall 23b and the second side wall 23c) having a two-layer structure. The two-layer side wall 23 has a non-bonded portion 23d, which is a portion that is not heat-welded to each other, in the center of the thickness direction of the core layer 20. Therefore, the internal space of each cell S of the core layer 20 communicates with the internal space of the other cell S through the non-bonded portion 23d between the first side wall 23b and the second side wall 23c. The non-bonded portion 23d is provided in the center of the thickness direction of the core layer 20, that is, in the center of the height direction of the side wall 23, and the first side wall 23b and the second side wall 23c having the two-layer structure are heat-welded to each other at the upper end and the lower end of the side wall 23.

[0050] As shown in Fig. 7(a), the first cells S1 are arranged in a row along the X direction. Similarly, the second cells S2 are arranged in a row along the X direction. The rows of the first cells S1 and the rows of the second cells S2 are alternately arranged in the Y direction perpendicular to the X direction. The first cells S1 and the second cells S2 form a honeycomb structure as a whole in the core layer 20.

[0051] [Joining process] In the joining step, the skin layer 30 is joined to the upper surface 20a of the core layer 20, and the skin layer 30 is joined to the lower surface 20b of the core layer. In the joining step, a flat sheet that has not been subjected to secondary processing (press molding) is joined as the skin layer 30. It is preferable that the thickness of the sheet constituting the skin layer 30 is approximately the same as the thickness of the resin sheet material 100 that forms the core layer 20, or is thicker than the resin sheet material 100 that forms the core layer 20.

[0052] The bonding step is performed by forming an adhesive layer between the core layer 20 and the skin layer 30, and then heating the core layer 20 and the skin layer 30 to a predetermined temperature. The heating temperature is set to a temperature several degrees Celsius to several tens of degrees Celsius higher than the melting point of the adhesive layer in the skin layer 30. Specifically, the heating temperature is set to a temperature several degrees Celsius higher than the melting point of the modified polyolefin adhesive (modified resin) constituting the adhesive layer. This heating temperature is set sufficiently lower than the molding temperature for softening the polyamide resin constituting the skin layer 30. In addition, the heating time for heat welding to the skin layer 30 is set to several seconds to several tens of seconds so that the same part of the skin layer 30 is not heated for an excessively long time. Therefore, the skin layer 30 does not reach a high temperature at which it is softened and melted, and only the adhesive layer can be softened and melted without strictly controlling the heating temperature.

[0053] The skin layer 30 is aligned with the core layer 20, temporarily joined by applying a predetermined pressure, and then cooled, to obtain a flat hollow plate 10a in which the skin layer 30 is heat-welded to the core layer 20.

[0054] [Molding process] In the molding process, the flat hollow plate 10a is press molded into a predetermined shape. The press molding is performed by placing a pair of dies on both the front and back sides of the hollow plate 10a and sandwiching the hollow plate 10a between the pair of dies from above and below. The temperature of the dies is set to a temperature at which the thermoplastic resin constituting the core layer 20 and the skin layer 30 can be softened and bent into a predetermined shape.

[0055] In the press molding, the hollow plate material 10a is subjected to bending and compression to form a thin peripheral portion 13, a recess 14, and a hinge portion 17. Note that a cutting allowance that will be cut in a cutting process is formed on the outer periphery side of the peripheral portion 13 of the hollow plate material 10a after the press molding. The thickness of the cutting allowance is configured to be thinner than the thickness of the peripheral portion 13.

[0056] The peripheral portion 13, the recessed portion 14, and the hinge portion 17 of the hollow plate material 10a are compressed by a pair of dies so that they are thinner than the other portions. Therefore, the peripheral portion 13, the recessed portion 14, and the hinge portion 17 have a higher density than the other portions by the amount of the thinner thickness. The high density of the peripheral portion 13 makes it possible to stably pass a needle through the peripheral portion 13 when sewing the covering material 16 with thread in the covering process described below. Therefore, the covering material 16 can be efficiently sewn to the shock absorbing material 10. In addition, when the hollow plate material 10a is curved to have a three-dimensional structure by bending and compressing, the skin layer 30 is stretched and thinned, so that the resistance when passing a needle through the peripheral portion 13 is reduced.

[0057] [Cutting process] In the cutting process, a cutting tool with an annular cutting blade is used. The outer shape of the cutting blade is configured to be approximately the same as the outer shape of the impact absorbing material 10. The cutting tool is pressed from above against the cutting margin of the hollow plate material 10a after the bending process, and the cutting tool is pressed downward to cut the hollow plate material 10a along the cutting margin. The part cut out by the cutting blade becomes the impact absorbing material 10. Since the cutting margin is provided on the hollow plate material 10a to be subjected to the cutting process, the hollow plate material 10a can be easily cut. In the cutting process, instead of using a cutting tool with a cutting blade, a laser, a water jet, or an ultrasonic cutter may be used, or the hollow plate material 10a may be cut by pressing and punching with a metal mold. In addition, the cutting process may be a process of cutting out the impact absorbing material 10 simultaneously with the molding process.

[0058] (Coating process) In the covering step, a covering material 16 is attached to the peripheral edge portion 13 of the impact absorbing material 10 cut out in the cutting step. Here, as an example, a method of attaching the covering material 16 by sewing will be specifically described.

[0059] Both ends in the width direction of the strip-shaped covering material 16 are placed on the peripheral portion 13 of the impact absorbing material 10. In this state, the covering material 16 is sewn to the peripheral portion 13 using a needle with a thread passing through the needle hole. By sewing while passing the needle through the peripheral portion 13 in the thickness direction, the covering materials 16 placed on both the front and back sides of the peripheral portion 13 are sewn simultaneously. By attaching the covering material 16 to the thin peripheral portion 13, it is possible to reduce the height at which the covering material 16 protrudes from the front and back sides of the impact absorbing material 10 in the thickness direction of the impact absorbing material 10. By attaching the covering material 16 to the peripheral portion 13 of the impact absorbing material 10, the protector of this embodiment is obtained.

[0060] Next, the operation of this embodiment will be described. The surface of the impact absorbing material 10 of the protector is provided with recesses 14 that are partially recessed in the thickness direction. Depending on the arrangement of these recesses 14, a predetermined recess pattern can be added to the front surface of the impact absorbing material 10, improving the design of the protector.

[0061] The side wall portion 23 located in the recess 14 has a curved cross-sectional shape along the thickness direction of the shock absorbing material 10. That is, the recess 14 is formed by curving the side wall portion 23 to a degree that does not cause buckling. As a result, when an impact is applied to the shock absorbing material 10 to the extent that the side wall portion 23 buckles and collapses, a restoring force is generated in the side wall portion 23 to return to its original state. As a result, a significant decrease in the shock absorbing ability of the shock absorbing material 10 due to the application of an impact is suppressed, and continuous shock absorbing ability can be ensured. Specifically, compared to the shock absorbing ability for the first impact, the shock absorbing ability for the second impact is slightly decreased, but the shock absorbing ability for the third and subsequent impacts is maintained at the same level as the shock absorbing ability for the second impact.

[0062] Furthermore, when a set of recess sidewalls 23B surrounding one cell S is configured to be a combination of blocks of recess sidewalls 23B with different shapes, the blocks of recess sidewalls 23B have different shapes, so that the degree and direction of deformation of each block of recess sidewalls 23B when an impact is applied is suppressed. As a result, the effect of maintaining the impact absorption against the third and subsequent impacts at the same level as the impact absorption against the second impact can be more stably obtained.

[0063] In fact, a test was conducted in which a spherical weight at a speed of 150 km / h was repeatedly collided three times against the impact absorbing material 10 attached to the impact force evaluation device, which was launched from the impact force loading device. The impact absorbing material 10 used was a flat hollow plate material 10a having a structure shown in FIG. 5 with a recess 14. This hollow plate material 10a has a core layer 20 and a skin layer 30 made of polypropylene. As a result of the test, it was confirmed that the impact absorbing effect was exerted even at the second and third collisions. In addition, when the state of the impact absorbing material 10 when hit by a hardball was observed using a high-speed camera, it was confirmed that the impact absorbing material 10 was instantly compressed to such an extent that the side wall portion 23 at the impact portion buckled and collapsed.

[0064] Next, the effects of this embodiment will be described. (1) The protector includes an impact absorbing material 10 made of a resin hollow plate material 10a. The hollow plate material 10a includes a hollow plate-shaped core layer 20 formed by arranging a plurality of cells S separated by side walls 23 extending in the thickness direction, and a skin layer 30 joined to the main surface of the core layer 20. The front surface of the impact absorbing material 10, which is the surface on the side against which an object collides, is provided with a recess pattern formed by recesses 14 that are partially recessed in the thickness direction, and the side walls 23 located at the recesses 14 have a curved cross-sectional shape along the thickness direction of the impact absorbing material 10.

[0065] According to the above-mentioned configuration, it is possible to achieve both improved design and continuous shock absorption. In addition, the shock absorbing material 10 that constitutes the majority of the protector is made of a hollow plate material 10a, so it is lightweight and capable of shock absorption.

[0066] (2) The impact absorbing material 10 has a curved shape that protrudes toward the front side where an object collides. According to the above configuration, when an object collides with the curved portion of the impact absorbing material 10, the object slides along the front surface of the impact absorbing material 10 along the curved shape of the impact absorbing material 10, thereby diverting part of the impact force acting on the impact absorbing material 10. Note that depending on the shape and impact angle of the object colliding with the impact absorbing material 10, the effect of diverting part of the impact force acting on the impact absorbing material 10 may be obtained even if the object does not slide along the surface of the impact absorbing material 10.

[0067] (3) The impact absorbing material 10 is provided with a thin hinge portion 17 for bending the impact absorbing material 10 . According to the above configuration, the impact absorbing material 10 can be easily folded to the back side at each hinge portion 17. This allows the shape of the impact absorbing material 10 to be changed to suit the physique of the user, for example, by reducing the degree of folding of the hinge portion 17 when the mounting portion of the user, such as the chest, is large, and by increasing the degree of folding of the hinge portion 17 when the mounting portion is small. This makes it easy to fit the impact absorbing material 10 to various users with different physiques, improving adhesion when worn.

[0068] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs. The shape of the groove-shaped recess 14 may be changed. For example, the vertical wall 15a of the recess 14 may be a wall portion parallel to the thickness direction of the impact absorbing material 10, or may be a wall portion having a gradient of, for example, 0.5 to 1.5 degrees with respect to the thickness direction so that the cross-sectional area of ​​the recess 14 becomes smaller toward the bottom wall 15b side. FIG. 4 illustrates a case where the vertical wall 15a is parallel to the thickness direction. When the gradient of the vertical wall 15a is set to 1.5 degrees or less, the visibility of the recess pattern formed by the recess 14 is improved and it can be seen more clearly. When the vertical wall 15a is set to have a right angle with the surface of the general part of the impact absorbing material 10, the visibility of the recess pattern formed by the recess 14 is improved and it can be seen more clearly. In addition, the cross-sectional shape of the recess 14 may be a V-shaped or U-shaped cross section without the bottom wall 15b. In this case, the recess side wall portion 23B becomes a wall portion supporting the vertical wall 15a of the recess 14.

[0069] Instead of the groove-shaped recesses 14, planar (bottomed hole-shaped) recesses 14 having a bottom wall 15b with a polygonal or circular shape when viewed from the front may be used. The planar recesses 14 may all have the same shape, or some or all of them may be different. The arrangement of the planar recesses 14 in the exposed portion is not particularly limited, but it is preferable that they are provided so as to be uniformly distributed without bias. In addition, both groove-shaped recesses 14 and planar recesses 14 may be provided.

[0070] Among the blocks of the recess side wall portion 23B, blocks of a non-curved shape, such as a cross-sectional shape along the thickness direction of the impact absorbing material 10 that is all linear, may be mixed. That is, at least one block of the blocks of the recess side wall portion 23B may have a curved shape as in the above embodiment. For example, the recess side wall portion 23B of one cell unit may be composed of a block of the recess side wall portion 23B of a curved shape and a block of the recess side wall portion 23B of a non-curved shape, or a recess side wall portion 23B of one cell unit consisting only of a block of the recess side wall portion 23B of a non-curved shape may be partially provided.

[0071] Buckling may occur in the connection portions between the upper wall portion 21 and the lower wall portion 22 and the recess side wall portion 23B. The hinge portion 17 may be provided with continuous holes such as perforations.

[0072] The number of hinge portions 17 provided on the impact absorbing material 10 is not particularly limited, and may be one, or three or more. When multiple hinge portions 17 are provided, the direction in which each hinge portion 17 extends is not particularly limited, and some or all of the hinge portions 17 may extend in different directions, all may extend in the same direction, or may intersect. For example, the multiple hinge portions 17 may be arranged in parallel, or the multiple hinge portions 17 may be arranged to intersect in a grid or cross shape.

[0073] Furthermore, the hinge portion 17 may have a curved shape in a cross section parallel to the extending direction of the hinge portion 17. For example, the hinge portion 17 may extend linearly in the plan view shown in Fig. 2 and have a curved shape that conforms to the three-dimensional shape of the impact absorbing material 10 in a cross section taken along the linear shape.

[0074] The thin hinge portion 17 is not limited to a configuration in which the hollow plate material 10a is partially compressed. For example, the hinge portion 17 may be formed by partially cutting out the hollow plate material 10a along the line where the hinge portion 17 is formed. As a specific example, a part of the hollow plate material 10a is cut out along the line where the hinge portion 17 is formed so as to leave the skin layer 30 on one side of the hollow plate material 10a, and the remaining skin layer 30 is used as the hinge portion 17.

[0075] The width of the hinge portion 17 may be constant or may vary depending on the location. For example, the hinge portion 17 is formed so that the width above the vertical line L1 is wider than the width below.

[0076] The width of the peripheral edge 13 of the impact absorbing material 10 can be changed as desired. The peripheral portion 13 of the impact absorbing material 10 may be the same thickness as the general portion of the impact absorbing material 10, or may be formed to be thicker than the general portion. Also, the thickness of the peripheral portion 13 may vary depending on the portion in the circumferential direction.

[0077] The skin layer 30 of the hollow plate material 10a is not limited to a single layer. The skin layer 30 may be a laminate of two or more layers. It is sufficient that the skin layer 30 is bonded to at least the front side.

[0078] The core layer 20 and the skin layer 30 of the hollow plate material 10a may be transparent or colored. When the impact absorbing material 10 is subjected to an impact strong enough to crush the side wall portion 23, the core layer 20 of the impact absorbing material 10 turns white due to the buckling of the side wall portion 23. On the other hand, the skin layer 30 does not turn white because it only extends in the planar direction. Therefore, when the skin layer 30 is colored in a color that makes the core layer 20 invisible through the skin layer 30, for example, a dark color such as black, dark gray, or dark navy blue, the skin layer 30 can make the whitening of the core layer 20 less noticeable, which is preferable in terms of design.

[0079] The core layer 20 and the skin layer 30 of the hollow plate material 10a do not have to be bonded together via an adhesive layer. The core layer 20 and the skin layer 30 may be bonded together directly without using an adhesive layer.

[0080] The core layer 20 of the hollow plate material 10a is not limited to a form formed by folding one sheet made of thermoplastic resin. The core layer 20 may be formed by using a plurality of sheets.

[0081] The core layer 20 of the hollow plate material 10a is not limited to an embodiment having an upper wall portion 21, a lower wall portion 22, and a side wall portion 23. As long as a plurality of cells S are arranged side by side, the core layer does not need to have at least one of the upper wall portion 21 and the lower wall portion 22.

[0082] Another layer may be provided on the skin layer 30 of the hollow plate material 10a. Examples of the another layer include a synthetic resin fiber sheet such as a polypropylene fiber sheet, and a laminate sheet. Also, the skin layer 30 may be omitted and another layer may be provided on the core layer 20. In this case, by covering the peripheral portion 13 of the impact absorbing material 10 with the covering material 16 so as to include the edge of the another layer, it is possible to prevent the layer from turning over.

[0083] The shape of the cells S of the hollow plate material 10a is not limited to a hexagonal prism. It may be a polygonal shape such as a square prism or an octagonal prism, or a cylindrical shape. Cells S of different shapes may be mixed. The cells S do not have to be adjacent to each other, and there may be a gap (space) between the cells S.

[0084] The hollow plate 10a having a plurality of cells S arranged in parallel therein is not limited to the embodiment of the present invention. For example, it may be a hollow plate made of corrugated plastic having a plurality of cells S in a harmonica shape, or a hollow plate having a plurality of cells S formed by sandwiching a sheet having cylindrical or conical protrusions from above and below with other sheets. It may also be a hollow plate having a plurality of cells S in a honeycomb shape. In the case of a hollow plate having a plurality of cells S formed by sandwiching a sheet having cylindrical or conical protrusions from above and below with other sheets, the cross-sectional shape of the recess side wall 23B is curved so as to bulge outward from the cells S.

[0085] The shape of the impact absorbing material 10 can be appropriately selected. For example, it may be a flat plate, or may have a shape having a flat portion and a curved portion. The covering material 16 is not limited to being sewn around the entire periphery of the periphery 13 of the impact absorbing material 10. It may be sewn partially around the periphery 13 of the impact absorbing material 10.

[0086] Also, the covering material 16 may be omitted. In this case, instead of providing the peripheral portion 13, it is preferable to perform terminal processing to round the end face of the impact absorbing material 10. Examples of the method of terminal processing include processing to bend the upper wall portion 21 and the lower wall portion 22 at the peripheral portion of the impact absorbing material 10 so that their tips face each other and round the end face of the impact absorbing material 10 into a semicircular cross section, and processing to bend one of the upper wall portion 21 and the lower wall portion 22 at the peripheral portion of the impact absorbing material 10 to the other side and round the end face of the impact absorbing material 10 into a quarter-circular cross section.

[0087] One covering material 16 may be attached to each of the front and back surfaces of the impact absorbing material 10. In this case, each covering material 16 may be the same or different. In the forming process, the method of press-forming the flat hollow plate material 10a into a predetermined shape is not limited to the method of this embodiment. For example, the flat hollow plate material 10a may be softened by heating it with a heater or the like, and then molded by sandwiching the hollow plate material 10a from above and below with unheated dies. At this time, vacuum holes may be provided in the die to perform vacuum forming.

[0088] The shape and thickness of the impact absorbing material 10 are not particularly limited. For example, the thickness of the impact absorbing material 10 may be gradually reduced from the center toward the periphery, so that the impact absorbing material 10 is curved so that the center protrudes toward the surface. Impact absorbing material 10 of this shape can be formed, for example, by deforming the impact absorbing material 10 so that the periphery is stretched more than the center when the impact absorbing material 10 is heated and deformed into a desired curved shape.

[0089] The impact absorbing material 10 thus formed has one or more of the following configurations. The thickness of the core layer 20 gradually decreases from the center toward the periphery. The thickness of the skin layer 30 gradually decreases from the center toward the periphery. The area of ​​the upper wall portion 21 of each cell S gradually increases from the center toward the periphery. The area of ​​the upper wall portion 21 is larger than the area of ​​the lower wall portion 22. The side wall portions 23 of the cells S of the core layer 20 are formed perpendicular to the surface of the impact absorbing material 10 that constitutes the surface of the protector.

[0090] Next, technical ideas that can be understood from the above embodiment and modified examples will be described below. (i) The protector, wherein the concave portions account for 3 to 50% of the surface area of ​​the portion of the impact absorbing material exposed to the outer surface.

[0091] (b) The protector, wherein the depth of the recess is 3 to 50% of the thickness of the exposed portion of the impact absorbing material. (c) The protector, wherein the hollow plate material has a core layer in which a plurality of the cells having a polygonal columnar or cylindrical shape are arranged side by side.

[0092] (ii) The protector in which the impact absorbing material is provided with a thin hinge portion for bending the impact absorbing material. [Explanation of symbols]

[0093] S: Cell 10...Shock absorbing material 10a…Hollow plate material 13...Periphery 14…Recess 20…Core layer 23...Side wall 30…Skin layer

Claims

1. A protector for protecting a user's body, Equipped with shock absorbing material made of hollow resin plate material, The hollow plate material includes a hollow plate-shaped core layer having a plurality of cells arranged in parallel and partitioned by side walls extending in a thickness direction, and a skin layer joined to at least one main surface of the core layer, The front surface of the impact absorbing material is provided with a recess pattern formed by recesses that are partially recessed in the thickness direction, A protector, wherein the side wall portion located in the recess has a curved cross-sectional shape along a thickness direction of the impact absorbing material.

2. 2. The protector according to claim 1, wherein the shock absorbing material is curved so as to protrude toward a front side where an object strikes.

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