Laminated plywood and chair using the same, and manufacturing method of laminated plywood

Abstract

To provide laminated plywood for improving rigidity of slit parts while reducing a sense of step caused by the slits for allowing bending.SOLUTION: Laminated plywood is curved laminated plywood formed by stacking a first layer 61 with one or more slits 61a, 61b, 61c and 61d and a second layer 62 with one or more slits 62a, 62b, 62c and 62d together, where the first layer 61 and the second layer 62 are stacked such that the slits 61a, 61b, 61c and 61d of the first layer 61 and the slits 62a, 62b, 62c and 62d of the second layer 62 are shifted.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a laminated plywood, a chair using the same, and a method for manufacturing the laminated plywood. [Background technology]

[0002] Traditionally, wood-based materials have been used for chair seats, backrests, armrests, etc. Wood-based materials include solid wood cut from natural trees and laminated plywood made by laminating veneers, and in recent years, a large amount of furniture manufactured at low cost using laminated plywood has been sold.

[0003] Laminated plywood is generally obtained by applying adhesive to multiple veneers, laminating them, and pressing them together using a mold, and is often formed into a shape that is at least partially curved in order to obtain a smooth curve. When forming curved laminated plywood, it has been disclosed that slits are provided in the laminated plywood to facilitate bending (see, for example, Patent Document 1).

[0004] However, laminated plywood with slits after bending has the problem that the slits create a sense of unevenness (uncomfortable feeling) and the slits can cause a lack of rigidity. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-83345 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a laminated plywood that can improve rigidity while reducing the sense of unevenness caused by slits that allow bending, a chair using the same, and a method for manufacturing the laminated plywood. [Means for solving the problem]

[0007] The laminated plywood of the present invention is a curved laminated plywood made by stacking a first layer having one or more slits and a second layer having one or more slits, and the first layer and the second layer are stacked so that the slits in the first layer and the slits in the second layer are misaligned.

[0008] The method for manufacturing a laminated plywood of the present invention includes a lamination step of forming a laminate by stacking a first layer having one or more slits and a second layer having one or more slits offset from the slits in the first layer, and a molding step of fitting the laminate into a mold and pressing it to form a curved laminated plywood.

[0009] According to the laminated plywood and its manufacturing method of the present invention, a portion of one of the first and second layers without a slit is arranged overlapping the slit of the other layer, so that the presence of the slit improves bending workability, while the depth of the step caused by the slit that appears on the surface of the plywood can be made shallower, reducing the feeling of a step and ensuring the rigidity of the slit portion.

[0010] In the laminated plywood of the present invention, a third layer may be laminated on the surface of the second layer opposite to the first layer.

[0011] According to this embodiment, the thickness of the laminated plywood can be increased to improve the strength and rigidity.

[0012] Furthermore, the third layer may be provided with one or more slits.

[0013] According to this embodiment, the bending workability of the third layer can be improved, and therefore the bending workability of the laminated plywood can be improved.

[0014] Furthermore, the slits in the third layer may be provided at the same positions as the slits in the first layer.

[0015] According to this embodiment, the slits in the second layer are covered by the non-slit portions of the first and third layers, and the slits in the third layer are covered by the non-slit portions of the second layer, thereby improving bending processability, reducing the sense of unevenness, and improving the rigidity of the slit portions. Furthermore, when forming the slits in the first and third layers, the slits can be formed in the first and third layers at once by performing the slit forming process on the first and third layers in a stacked state before the slits are formed, thereby improving productivity and reducing manufacturing costs.

[0016] The chair of the present invention is equipped with the laminated plywood of the present invention.

[0017] In the chair of the present invention, the laminated plywood of the present invention has slits that improve bending workability, reduce the sense of unevenness caused by the slits, and ensure rigidity in the slit areas, so it can be applied to various parts of the chair, such as the seat, backrest, armrests, headrest, and other body support parts that are subject to the pressure of the person's body.

[0018] For example, the chair of the present invention may be provided with a seat or backrest in which the laminated plywood is the core material and a surface material is provided on the surface of the core material.

[0019] According to this embodiment, the core material of the seat and backrest is made of laminated plywood, which reduces manufacturing costs and is environmentally friendly compared to using core materials made of synthetic resin. Furthermore, the laminated plywood of the present invention can form a core material with a three-dimensional curved shape that ensures rigidity of the slit parts while minimizing the sense of step caused by the slits, so it is possible to form a core material that fits well to the body. [Effects of the Invention]

[0020] The laminated plywood of the present invention, the chair using the same, and the method for manufacturing the laminated plywood can improve the rigidity of the slit portions while reducing the sense of unevenness caused by the slits that allow bending. [Brief explanation of the drawings]

[0021] [Figure 1] 1A and 1B are diagrams showing an embodiment of a chair, in which (A) is a plan view and (B) is a front view. [Figure 2] 1A is a left side view and FIG. 1B is a rear view of the same embodiment. [Figure 3] 1A is a bottom view of the embodiment, and FIG. 1B is a perspective view of the embodiment as seen from diagonally below on the left. [Figure 4] FIG. 2 is a perspective view of the cushion member of the embodiment, seen from diagonally above left, with the cushion member separated. [Figure 5] 1A and 1B are schematic diagrams showing a cushion member, in which (A) is a plan view and (B) is a perspective view. [Figure 6] 6A and 6B are longitudinal cross-sectional views taken along the lines AA and BB in FIG. 5. [Figure 7] FIG. [Figure 8] 1A and 1B are diagrams showing an embodiment of a core material, in which (A) is a plan view and (B) is a perspective view. [Figure 9] (A) is a plan view of the first and third layers before lamination, and (B) is a plan view of the second layer before lamination. [Figure 10] 1 shows a laminate obtained by laminating first to third layers, in which (A) is a plan view, (B) is a schematic side view seen from the direction of the arrow in (A), and (C) is an exploded perspective view. DETAILED DESCRIPTION OF THE INVENTION

[0022] Next, an embodiment of the present invention will be described with reference to the drawings. In the following description, the terms "front, back," "left, right," and "right" are used to specify directions, but these terms are based on a seated person. The front view direction is the direction facing the seated person, so left and right from a front view are opposite to left and right as seen from the seated person.

[0023] <Outline of chair configuration> 1 to 4, the chair of the embodiment includes a shell 1 on which a user sits, a support body 2 that supports the shell 1, and a cushion member 8 (an example of a seat) provided on a seat plate 11 of the shell 1. The shell 1, support body 2, and cushion member 8 are configured to be generally symmetrical with respect to a left-right center line extending in the front-to-rear direction in a plan view.

[0024] The shell 1 is formed by pressing synthetic fiber felt under heat. In this embodiment, the shell 1 includes an integrally molded seat panel 11, back panel 12, and left and right side panels 13. The shell 1 has a generally symmetrical configuration with a left-right center line extending in the front-to-rear direction in a plan view as the axis of symmetry.

[0025] The shell 1 is provided with outwardly extending flanges 111, 121, 131, and 141 at the edges of the seat panel 11, back panel 12, and left and right side panels 13. The flanges 111, 121, 131, and 141 are continuous in an annular shape along the edges of the shell 1.

[0026] The support body 2 includes a back and seat frame 21 made of a metal pipe provided along the flange portions 111, 121, 131, 141, a pair of left and right legs 22 supporting the back and seat frame 21, and a seat support plate 25.

[0027] The back and seat frame 21 has a seat frame portion 211 along the rear surface of the seat flange portion 111, a back frame portion 212 along the underside of the back flange portion 121, a front plate frame portion 213 along the rear surface of the front plate flange portion 131, and an upper plate frame portion 214 along the underside of the upper plate flange portion 141. The frame portions 211, 212, 213, and 214 are connected in an annular shape so as to follow the flange portions 111, 121, 131, and 141 of the shell 1. Reinforcing members 215 made of metal pipes extending in the left-right direction are provided inside the seat frame portion 211 and inside the back frame portion 212.

[0028] The leg body 22 is made of a single metal pipe having a generally W-shaped configuration in a side view, and includes generally V-shaped front leg portions 221 and rear leg portions 222, and a leg intermediate portion 223 that extends in the front-rear direction below the seat plate 11 and connects one end of the leg portions 221, 222. The other ends of the legs 221, 222 are connected to the front side plate frame portion 213 of the seat and back frame 21. The leg intermediate portions 223 of the left and right legs 22 are connected to a front leg connecting frame 23 and a rear leg connecting frame 24 that are made of metal round bars extending in the left-right direction.

[0029] The folded portions of the substantially V-shaped front leg portion 221 and rear leg portion 222 constitute a grounding portion 224 that is placed on the floor. In this embodiment, as shown in Fig. 3(B), a resin leg pad 226 is fixed to a nut member 225 that is fixed to the underside of the grounding portion 224 with a screw.

[0030] The pair of left and right seat support plates 25 are formed of approximately rectangular metal plates that are long in the front-to-rear direction, and are arranged spaced apart on the left and right sides of the center line of the seat plate 11 so as to fit along the lower left and right buttocks and thighs of a person seated on the seat plate 11.

[0031] Plate-shaped nut members 3 are attached by bonding to flange portions 111, 121, 131, and 141 of shell 1. A pair of plate-shaped seat nut members 4 are attached by bonding to the underside of seat plate 11. The nut members 3 and seat back frame 21 are connected by male screws 5. The seat nut members 4 and seat support plate 25 are connected by male screws 6.

[0032] As shown in Figures 1 to 4, the cushion member 8 is attached to the upper surface of the seat plate 11 of the shell 1. As shown in Figure 4, four screw insertion holes 16 are drilled in the seat plate 11. The cushion member 8 is detachably attached to the upper surface of the seat plate 11 by four male screws 9 that are screwed into nut members 89 of the cushion member 8 from below the seat plate 11 through the screw insertion holes 16.

[0033] <Configuration of cushion member> 5 to 7, the cushion member 8 includes a core material 60 made of laminated plywood and a surface material 70 provided on the surface of the core material 60. The cushion member 8 has a generally rectangular shape with rounded corners in a plan view, with a front end 8a that is open and concave facing upward, and left and right side end portions 8b and a rear end portion 8c that are curved upward.

[0034] The core material 60 is a component that forms the basis of the three-dimensional shape of the cushion member 8, and is formed from a laminated plywood consisting of three veneers, which are stacked in order from the top down: a first layer 61, a second layer 62, and a third layer 63. The core material 60 is made from a laminated plywood that is formed by applying adhesive to the first layer 61, the second layer 62, and the third layer 63 and stacking them to form a laminate 64 (see FIG. 10), which is then fitted into a mold having a three-dimensional curved surface and pressed to form the laminate.

[0035] As shown in Figure 8, the core 60 has a generally rectangular shape with rounded corners in a plan view. The core 60 has an open, upwardly concave front end 60a, and the left and right side end portions 60b and the rear end portion 60c have three-dimensional curved surfaces that curve upward. As shown in Figure 6(A), the front end portion 60a of the core 60 is gently curved upwardly convexly. Nut mounting holes 60d for mounting nut members 89 are drilled near the four corners of the core 60.

[0036] The surface material 70 has a structure in which three layers of cushioning material and upholstery are laminated, and includes, from the bottom up, a first cushion layer 71, a second cushion layer 72, a third cushion layer 73, and upholstery 74.

[0037] <Surface material composition> The first cushion layer 71 is formed, for example, from a sheet-like chip urethane (for example, about 10 mm thick) that is slightly smaller than the upper surface of the core material 60, and is adhered with an adhesive to the upper surface of the core material 60. For example, the first cushion layer 71 is sized so that, when attached to the core material 60, a gap equal to the thickness of the second cushion layer 72 is formed between a side peripheral end surface 71 a of the first cushion layer 71 and a side peripheral end surface of the core material 60.

[0038] The second cushion layer 72 is formed, for example, from a sheet-like sliced ​​urethane (for example, about 10 mm thick) having a size similar to that of the upper surface of the core material 60, and is bonded with an adhesive to the upper surface and side peripheral end surface 71a of the first cushion layer 71. As shown in Fig. 6, the peripheral end portion of the second cushion layer 72 is folded toward the upper surface of the core material 60, and the side peripheral end surface 72a of the second cushion layer 72 is bonded to the upper surface of the ends 60a, 60b, and 60c of the core material 60.

[0039] The third cushion layer 73 is formed, for example, from a sheet-like sliced ​​urethane (for example, about 5 mm thick) that is slightly larger than the upper surface of the core material 60, and is adhered to the upper surface of the second cushion layer 72 with an adhesive. An upholstery 74 is attached to the entire upper surface of the third cushion layer 73 with an adhesive. The peripheral edges of the third cushion layer 73 and the upholstery 74 are wrapped around the back surface of the core material 60 and fixed to the back surface of the peripheral edges of the core material 60 with an adhesive or a fixing device such as a tacker. Note that the adhesives are not shown in Figure 6.

[0040] As shown in Figure 6, the relatively hard first cushion layer 71 is not positioned at the peripheral edge of the core material 60, so when the third cushion layer 73 and upholstery 74 are wrapped around and fixed to the back side of the core material 60, the relatively soft second cushion layer 72 is compressed and deformed, making it possible to reduce the thickness of the peripheral edge of the cushion member 8.

[0041] In this way, the cushion member 8 has a first cushion layer 71 made of a relatively hard sheet-like elastic material attached to the center of the upper surface of the core material 60 at a distance from the peripheral edge surface of the core material 60, and a second cushion layer 72 made of a relatively soft sheet-like elastic material attached to the upper surface of the first cushion layer 71 and the upper surfaces of the peripheral edges (edges 60a, 60b, 60c) of the core material 60. Then, a third cushion layer 73 and upholstery 74 are attached to the second cushion layer 72 and the core material 60 so that their peripheral edges are rolled up onto the back surface of the core material 60. This allows the peripheral edges of the second cushion layer 72 to be compressed and deformed, making the peripheral edges of the cushion member 8 appear thinner, while forming a comfortable cushion member 8 with a thicker central portion that receives body pressure.

[0042] Furthermore, since the cushion layers 71, 72, and 73 are formed from sheet-like elastic bodies, a molding step using a mold is not required when producing the surface material 70, and the surface material 70 can be produced at low cost.

[0043] In the cushion member 8 of this embodiment, the entire periphery of the side peripheral end face of the first cushion layer 71 is disposed away from the side peripheral end face of the core material 60. However, a portion of the side peripheral end face of the first cushion layer 71 may be disposed close to the side peripheral end face of the core material 60. In this case, in a location where a portion of the side peripheral end face of the first cushion layer 71 is close to the side peripheral end face of the core material 60, the side peripheral end face of the second cushion layer 72 may be disposed close to the side peripheral end face of the first cushion layer 71. This makes it possible to make the thickness of the peripheral end of the cushion member 8 appear thicker in that location. Furthermore, the above embodiment does not exclude a configuration in which the entire periphery of the side peripheral end face of the first cushion layer 71 in the cushion member 8 is disposed close to the side peripheral end face of the core material 60.

[0044] <Core material composition> As shown in Figures 8 to 10, the first layer 61, second layer 62, and third layer 63 constituting the core material 60 each have one or more slits. Figure 9(A) shows a plan view of the first layer 61 and third layer 63 before lamination, and Figure 9(B) shows a plan view of the second layer 62 before lamination. Figure 10 shows a laminate 64 in which the first layer 61, second layer 62, and third layer 63 are laminated, with (A) being a plan view, (B) being a schematic side view seen from the direction of the arrow in (A), and (C) being an exploded perspective view. Note that the thickness of each layer is exaggerated in Figure 10(B).

[0045] 6 and 8, the core material 60 is made of curved laminated plywood made up of a first layer 61, a second layer 62, and a third layer 63, each having one or more slits. The core material 60 has an open, upwardly concave front end 60a, and left and right side end portions 60b and a rear end portion 60c, each having a three-dimensional curved surface that rises while curving upward.

[0046] The first layer 61 has a pair of first to third slits 61a to 61c provided at the left and right end portions, and a pair of fourth slits 61d provided at the rear end portion, in that order from the front. These slits 61a to 61d are connected to the left and right end faces or the rear end face and are spaced apart from each other. Similarly, the second layer 62 and the third layer 63 have a pair of first to third slits 62a to 62c, 63a to 63c provided at the left and right end portions and a pair of fourth slits 62d, 63d provided at the rear end portion, respectively. In other words, the first layer 61, the second layer 62, and the third layer 63 each have eight slits connected to the left and right end faces or the rear end faces.

[0047] The first to fourth slits 61a to 61d of the first layer 61 and the first to fourth slits 62a to 62d of the second layer 62 are provided at positions offset from each other (non-overlapping positions). The first slit 63a, the second slot 63b, the third slit 63c, and the fourth slit 63d of the third layer 63 are provided so as to overlap the first to fourth slots 61a to 61d of the first layer 61.

[0048] The first to fourth slits 61a to 61d and 63a to 63d in the first layer 61 and the third layer 63 overlap with portions of the second layer 62 where no slits are formed. Also, the first to fourth slits 62a to 62d in the second layer overlap with portions of the first layer 61 and the third layer 63 where no slits are formed.

[0049] 9 and 10, the first layer 61, the second layer 62, and the third layer 63 are made of a single sheet of beech wood with a thickness of, for example, 1.5 mm. The first layer 61, the second layer 62, and the third layer 63 have roughly the same outer shape, being approximately rectangular with rounded corners. An alignment slit 60e extending in the front-to-rear direction is formed at the front and rear ends of each of the first layer 61, the second layer 62, and the third layer 63.

[0050] 9(A), the first layer 61 has a pair of left and right slits: a first slit 61a opening toward the front of each of the left and right end faces, a second slit 61b opening toward the center of each of the left and right end faces, a third slit 61c opening toward the rear of each of the left and right end faces, and a fourth slit 61d opening toward the rear end face. These slits 61a to 61d are spaced apart from each other.

[0051] The first slit 61a has a linear shape extending in the left-right direction. The second slit 61b has a generally V-shape extending in the left-right direction at a position rearward of the first slit 61a. The third slit 61c has a generally V-shape extending diagonally backward at a position rearward of the second slit 61b. The fourth slit 61d has a generally V-shape extending diagonally backward at a position closer to the left-right center than the third slit 61c. The generally V-shaped slits 61b, 61c, and 61d are formed so that the side end faces of the first layer 61 are wider.

[0052] The third layer 63 has the same shape as the first layer 61. That is, the third layer 63 has first to fourth slits 63a to 63d at positions that overlap with the first to fourth slits 61a to 61d of the first layer when the third layer 63 is superimposed on the first layer 61.

[0053] As shown in Figure 9(B), the second layer 62, like the first layer 61, has a pair of linear first slits 62a opening at the front of the left and right end faces, a pair of approximately V-shaped second slits 62b opening at the center of the left and right end faces, a pair of approximately V-shaped third slits 62c opening at the rear of the left and right end faces, and a pair of approximately V-shaped fourth slits 62d opening at the rear end faces.

[0054] As can be seen from Figures 9 and 10, the first to fourth slits 62a to 62d of the second layer 62 are formed in positions (so as to be offset) so as not to overlap with the first to fourth slits 61a to 61d of the first layer 61 when the first layer 61 and the second layer 62 are superimposed.

[0055] In a laminate 64 formed by laminating a first layer 61, a second layer 62, and a third layer 63, the first to fourth slits 61a to 61d of the first layer 61 overlap with portions of the second layer 62 where no slits are formed. The first to fourth slits 63a to 63d of the third layer 63, which have the same shape as the first layer 61, also overlap with portions of the second layer 62 where no slits are formed. Furthermore, the first to fourth slits 62a to 62d of the second layer overlap with portions of the first layer 61 and the third layer 63 where no slits are formed. An adhesive (not shown) is applied between the first layer 61 and the second layer 62 and between the second layer 62 and the third layer 63.

[0056] <Manufacturing process of core material 60> To form the core material 60, as shown in Fig. 10, a first layer 61, a second layer 62, and a third layer 63 coated with adhesive are laminated to form a laminate 64 (laminating step). As shown in Fig. 9, the veneers of the first layer 61 and the third layer 63 have wood grain directions along the left-right direction, and the veneer of the second layer 62 has wood grain directions along the front-back direction. As a result, the first to third layers 61, 62, and 63 are laminated so that the wood grain directions alternately intersect (almost perpendicular).

[0057] Next, the laminate 64 is fitted into a mold (not shown) with a three-dimensional curved surface corresponding to the shape of the core material 60 and subjected to high-frequency heating while being pressed (molding process). As a result, the first layer 61, second layer 62, and third layer 63 are bonded and integrated to obtain the core material 60 made of laminated plywood with a three-dimensional curved shape. After the core material 60 is removed from the mold, nut mounting holes 60d are drilled near the four corners of the core material 60 (see FIG. 8). Nut members 89 are then attached to the nut mounting holes 60d (see FIG. 9).

[0058] In the forming process, when the laminate 64 is deformed into a three-dimensional curved shape, the first to third layers 61 to 63 are deformed such that the widths of the approximately V-shaped slits 61b to 61d, 62b to 62d, and 63b to 63d provided in the side and rear ends are narrowed. The first to third layers 61 to 63 are also deformed such that the widths of the linear slits 61a, 62a, and 63a provided in the side ends are widened. This prevents cracks in the layers 61 to 63, while forming the three-dimensional curved shape of the rising curved shapes of the side end 60b and rear end 60c and the upwardly convex curved shape of the front end 60a.

[0059] Note that, as long as the slits 61b-61d of the first layer and the slits 62b-62d of the second layer do not overlap in the molded core material 60, it is acceptable for portions of the slits 61b-61d of the first layer 61 to overlap portions of the slits 62b-62d of the second layer 62 in the laminate 64. For example, even if portions of the portions (wide portions) of the substantially V-shaped second slits 61b and 62b near the peripheral end faces overlap when the first layer 61 and the second layer 62 are laminated before molding, the groove widths of the second slits 61b and 62b may be narrowed in the molding process so that the second slits 61b and 62b do not overlap in the core material 60.

[0060] As shown in FIGS. 6 to 8, the core material 60 of this embodiment is formed from a curved laminated plywood consisting of a first layer 61 having one or more slits 61a to 61d and a second layer 62 having one or more slits 62a to 62d. The first layer 61 and the second layer 62 are laminated such that the slits 61a to 61d of the first layer 61 are offset from the slits 62a to 62d of the second layer 62. In this manner, a portion of one of the first layer 61 and the second layer 62 without a slit is arranged overlapping the slits 61a to 61d or 62a to 62d of the other layer. This configuration improves bending workability due to the presence of the slits 61a to 61d and 62a to 62d, while reducing the depth of any step caused by the slits that appears in the core material 60 made of laminated plywood, thereby reducing the sense of stepping. Furthermore, the core material 60 can ensure the rigidity of the slit portions (portions where the slits 61a to 61d and 62a to 62d are formed).

[0061] Furthermore, in the core material 60, the third layer 63 is laminated on the surface of the second layer 62 opposite to the first layer 61, thereby increasing the thickness of the core material 60 and improving its strength and rigidity. Furthermore, one or more slits 63a to 63d are provided in the third layer 63, thereby improving the bending processability of the third layer 63, and therefore the bending processability of the core material 60.

[0062] Furthermore, the slits 63a to 63d in the third layer 63 are provided in the same positions (overlapping positions) as the slits 61a to 61d in the first layer 61. That is, the slits 62a to 62d in the second layer 62 are covered by the non-slit portions of the first layer 61 and the third layer 63, and the slits 63a to 63d in the third layer 63 are covered by the non-slit portions of the second layer 62. This improves the bending processability of the core material 60, reduces unevenness, and improves the rigidity of the slit portions. Furthermore, when forming the slits in the first layer 61 and the third layer 63, the slits 61a to 61d and 63a to 63d can be formed in the first layer 61 and the third layer 63 at the same time by performing the slit forming process on the first layer 61 and the third layer 63 (see FIG. 9(A)) while they are overlapped before the slits are formed. This improves productivity and reduces manufacturing costs.

[0063] The core material 60 made of laminated plywood has improved bending workability due to the presence of slits 61a to 61d, 62a to 62d, and 63a to 63d, while reducing the sense of unevenness caused by slits 61a to 61d and ensuring rigidity in the slit portions, and therefore can be used, for example, as a cushion member 8 (an example of a seat) that bears the body pressure of a person in a chair.

[0064] As shown in Figures 1 to 6, cushion member 8 constitutes a seat with surface material 70 provided on the surface of core material 60 made of laminated plywood. Because cushion member 8 has core material 60 made of laminated plywood, it is possible to reduce manufacturing costs and is environmentally friendly compared to using a core material made of synthetic resin. Furthermore, core material 60 has a three-dimensional curved shape that ensures rigidity in the slit areas while minimizing the sense of stepping caused by slits 61a to 61d, 62a to 62d, and 63a to 63d, allowing for the formation of a core material that fits well to the body.

[0065] The above describes the embodiments and modifications, but the configurations, arrangements, numerical values, materials, etc. in the embodiments are merely examples, and the present invention is not limited to the above-described embodiments and can be embodied in various forms. The configurations of each part are not limited to the illustrated embodiments, and various modifications are possible within the scope of the spirit of the present invention. For example, the configurations described in the above-described embodiments and modifications (notes, etc.) may be combined, and additions, omissions, substitutions, and other modifications of the configurations are possible.

[0066] For example, in the above embodiment, the laminated plywood of the present invention is applied to the core material 60 of the cushion member 8, but the laminated plywood of the present invention can also be applied to the core material of body support parts such as the backrest, armrests, and headrest that receive body pressure in a chair. Furthermore, the configuration of the surface material that covers the surface of the core material 60 is not limited to the surface material 70 of the above embodiment, and can be changed as appropriate.

[0067] In the core material 60, the first to third layers 61, 62, and 63 may have different thicknesses. The number of layers (single sheets) constituting the core material 60 may be two or four or more. The slits 63a to 63d of the third layer 63 may be arranged so as not to overlap with the slits 62a to 62d of the second layer 62, and so as not to overlap with the slits 61a to 61d of the first layer 61 either.

[0068] Furthermore, the core material 60 may have portions where the slits 61a to 61d of the first layer 61 overlap with the slits 62a to 62d of the second layer 62. For example, the core material 60 may have the slits 61a and 62a formed at positions where they intersect (shifted positions). Similarly, the core material 60 may have portions where the slits 62a to 62d of the second layer 62 overlap with the slits 63a to 63d of the third layer 63.

[0069] The arrangement, length, and shape of the slits 61a-61d, 62a-62d, and 63a-63d can be changed as appropriate depending on the desired three-dimensional shape (for example, a three-dimensional curved surface shape). The number of slits formed in each layer (single board) may be 1 to 3, or may be 5 or more. The core material 60 without the surface material 70 can also be used as a body support part of a chair (for example, a seat, backrest, armrests, headrest, etc.). [Explanation of symbols]

[0070] 8 Cushion member (example of seat) 60 Core material (an example of laminated plywood) 61 1st layer 62 2nd layer 63 3rd layer 61a, 62a, 63a First slit 61b, 62b, 63b Second slit 61c, 62c, 63c 3rd slit 61d, 62d, 63d 4th slit 64 Laminate 70 Surface material 71 First cushion layer 72 Second cushion layer 73 Third cushion layer 74 Upholstery

Claims

1. A curved laminated plywood comprising a first layer having one or more slits and a second layer having one or more slits laminated thereon, The first layer and the second layer are laminated such that the slits in the first layer and the slits in the second layer are misaligned. Laminated plywood.

2. a third layer is laminated on a surface of the second layer opposite to the first layer, the third layer covering the slits of the second layer; The laminated plywood according to claim 1.

3. The third layer has one or more slits. The laminated plywood according to claim 2.

4. The slits in the third layer are provided at the same positions as the slits in the first layer. The laminated plywood according to claim 3.

5. A chair comprising the laminated plywood according to any one of claims 1 to 4.

6. The laminated plywood is a core material, The seat or backrest has a surface material provided on the surface of the core material.

6. The chair of claim 5.

7. a lamination step of laminating a first layer having one or more slits and a second layer having one or more slits offset from the slits in the first layer to form a laminate; a molding step of pressing the laminate into a mold to form a curved laminated plywood; A method for producing laminated plywood, comprising:

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