cushion

Abstract

To provide a cushion that is thin and lightweight while offering a high-quality, comfortable seating experience. [Solution] The cushion 10 comprises a cushion body 20, which is formed at least in part from an elastic foam and has an internal space 23, and a wave spring 30 disposed within the space 23 and having elastic force in the thickness direction of the cushion body 20. The wave spring 30 is formed as an annular or cylindrical shape overall and is formed in a wave shape along its circumferential direction, thereby generating an elastic restoring force against a compressive load in the thickness direction, and consists of a linear elastic body 31.

Description

Technical Field

[0001] This invention relates to a cushion.

Background Art

[0002] Patent Document 1 discloses a cushion. The cushion disclosed in Patent Document 1 includes a cushion body formed of an elastic foam and provided with a storage space inside, and a coil spring stored inside the storage space and having an elastic force in the thickness direction of the cushion body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such conventional cushions, the following problems exist. That is, in order for the coil spring to secure a stroke for supporting a load, the spring itself requires a certain "coil height". Therefore, the thickness of the entire cushion increases, and it is difficult to arrange the cushion in a limited space such as furniture with a thin and stylish design or vehicle seats.

[0005] In addition, when arranging a large number of coil springs to support the entire surface uniformly, the amount of steel used increases, and the weight of the entire cushion increases. Therefore, it has become a factor that reduces the transportation efficiency and handling performance of the product.

Means for Solving the Problems

[0006] Each aspect of the cushion for solving the above problems will be described. [Aspect 1] A cushion body, in which at least a portion is formed of elastic foam and an internal space for arrangement is formed, The cushion body is provided with a wave spring, which is arranged within the aforementioned space and has elastic force in the thickness direction, The wave spring is formed as an annular or cylindrical shape overall, and is made of a linear elastic body that is formed in a wave-like shape along its circumferential direction, thereby generating an elastic restoring force against the compressive load in the thickness direction. cushion.

[0007] Because wave springs have a structure that undulates up and down along the circumference, rather than being coil springs, they can generate a strong restoring force by utilizing the bending elasticity of metal wire, even with an extremely low overall height (thickness). This allows for thinning and weight reduction that was impossible with conventional coil springs. Furthermore, because they are annular or cylindrical, they form a circumferential support line against the load. As a result, the load does not concentrate at a specific point, dramatically improving the stability of the seat surface even with a thin cushion.

[0008] [Aspect 2] The cushion body is A first layer made of elastic foam having recesses or through holes forming the aforementioned space, The first layer is laminated with a second layer made of elastic foam that covers the recess or the opening of the through hole, The wave spring is positioned between the first layer and the second layer. The cushion described in Embodiment 1.

[0009] According to this configuration, the recesses or through holes formed in the first layer restrain the annular or cylindrical wave spring from its outer circumference, physically suppressing lateral displacement and distortion of the wave spring due to the load when seated. In this way, the wave spring is always held in the correct position within the installation space, so the cushioning performance does not change easily even with long-term use, and it exhibits high durability. In addition, since the entire wave spring is sandwiched between the first and second layers formed of elastic foam, metal-to-metal contact and the vibration noise characteristic of springs are blocked and absorbed, providing a quiet user experience.

[0010] [Aspect 3] The second layer is positioned on the side of the load-receiving surface relative to the first layer. The hardness of the elastic foam constituting the second layer is set to be greater than or equal to the hardness of the elastic foam constituting the first layer. The cushion described in Embodiment 2.

[0011] In this configuration, the second layer on the load-receiving surface has a hardness equal to or greater than that of the base first layer, which suppresses the deflection of the cushion surface under load. Therefore, when a load is applied by the user, the load is not locally compressed in the second layer, but rather distributed widely to the surrounding area. This prevents pressure from concentrating at a specific apex of the annular or cylindrical wave spring, so that even with a thin structure, it can provide a flat and stable seating experience without any jarring sensation.

[0012] Furthermore, with the above configuration, the second layer has high rigidity, which suppresses the rapid compression of the cushion in response to the initial load. Therefore, even when a relatively large load is applied, it is possible to prevent the wave spring from being crushed to its limit. This prevents the bottoming-out phenomenon, where the wave spring completely compresses and a hard feeling is transmitted, by limiting the amount of physical deformation.

[0013] [Aspect 4] The second layer is positioned on the side of the load-receiving surface relative to the first layer. The hardness of the elastic foam constituting the second layer is set lower than the hardness of the elastic foam constituting the first layer. The cushion according to Embodiment 2.

[0014] According to this configuration, by setting the second layer on the pressure-receiving surface side to have a low hardness and the first layer holding the wave spring to have a high hardness, multi-stage support characteristics that change from "soft" to "rigid" with respect to the load are generated. For this reason, the low-hardness second layer diffusely spreads in a planar manner the sharp restoring force generated from the "circumferential apex" of the annular or cylindrical wave spring. As a result, a smooth and comfortable feeling on the surface can be realized without making the user feel the hardness of the spring.

[0015] In particular, when a recess for forming a placement space is formed in the first layer, the initial load is absorbed by the second layer, and a large load is received by the high-hardness first layer and the wave spring. Due to this synergistic effect, the "bottom feeling", which is a weakness of the thin structure, can be eliminated. Furthermore, since the high-hardness first layer serves as the base of the spring, the energy of the spring can be concentrated in the vertical direction without being dissipated, and a strong elastic force can be generated.

Effect of the Invention

[0016] According to the present invention, while achieving thinning and weight reduction, a high-quality sitting comfort can be provided.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a perspective view of a cushion according to an embodiment. [Figure 2] FIG. 2 is a perspective view of the cushion of FIG. 1 with the upper second layer removed. [Figure 3] FIG. 3 is a cross-sectional view of the cushion of FIG. 1. [Figure 4] FIG. 4 is a perspective view of the wave spring provided in the cushion of FIG. 1.

Mode for Carrying Out the Invention

[0018] An embodiment will be described below with reference to Figures 1 to 4. As shown in Figures 1 and 2, the cushion 10 comprises a cushion body 20, which is formed at least in part from an elastic foam and has a space 23 formed inside, and a wave spring 30 which is placed in the space 23 and has elastic force in the thickness direction of the cushion body 20.

[0019] <Cushion body> As shown in Figures 1 to 3, the cushion body 20 has a first layer 21 in which through holes 24 forming the installation space 23, and a second layer 22 which is laminated on the first layer 21 and covers the opening of the through holes 24.

[0020] The cushion body 20 of this embodiment is rectangular in shape. Note that the term "rectangle" also includes a square. Hereafter, the direction in which the first side of the rectangle of the cushion body 20 extends will be referred to as the first direction, and the direction perpendicular to both the first direction and the thickness direction of the cushion body 20 will be referred to as the second direction.

[0021] The first layer 21 is formed of an elastic foam. The elastic foam is, for example, a flexible polyurethane foam. The first layer 21 of this embodiment is in the shape of a rectangular plate.

[0022] The multiple through holes 24 are circular holes that penetrate the first layer 21 in the thickness direction. The multiple through holes 24 are provided at equal intervals along the first direction and also at equal intervals along the second direction.

[0023] The second layer 22 is formed of an elastic foam. The elastic foam is, for example, a flexible polyurethane foam. In this embodiment, the hardness of the elastic foam constituting the second layer 22 is set higher than the hardness of the elastic foam constituting the first layer 21. Here, hardness refers to the 25% hardness measured in accordance with, for example, JIS K 6400-2. For example, by setting the hardness of the second layer 22 to 150N or higher and the hardness of the first layer 21 to less than 100N, it is possible to achieve both a stable seating experience and the prevention of bottoming out. However, it is sufficient that the difference in hardness between the two can be confirmed using the same standard, and the method of measuring hardness is not limited to this.

[0024] The second layer 22 in this embodiment is rectangular in shape. The second layer 22 has a main surface of the same size and shape as the first layer 21. The through hole 24 has a pair of openings that open to both main surfaces of the first layer 21.

[0025] In this embodiment, a pair of second layers 22 are provided so as to cover each of the pair of openings of the through hole 24. That is, the second layers 22 are positioned on the side of the load-receiving pressure surface 11 relative to the first layer 21.

[0026] The thickness of the second layer 22 is preferably smaller than the thickness of the first layer 21. The first layer 21 and the second layer 22 are bonded together via an adhesive (not shown). <Wave Spring> As shown in Figures 3 and 4, the wave spring 30 is formed in a cylindrical shape overall and consists of a linear elastic body 31 that is formed in a wave-like shape along its circumferential direction, thereby generating an elastic restoring force against compressive loads in the thickness direction.

[0027] The wave spring 30 is made of metal. In this embodiment, the wave spring 30 is made of steel. The wave spring 30 is positioned between the first layer 21 and a pair of second layers 22.

[0028] As described above, the cushion 10 of this embodiment has a symmetrical shape and structure in the thickness direction. The cushion 10 may also be equipped with a cover that covers the cushion body 20. The material of the cover is not particularly limited, but it is preferable to use a waterproof cover or the like.

[0029] <Operation of this embodiment> Because the wave spring 30 is not a coil spring but has a structure that undulates up and down along the circumference, it can generate a strong restoring force by utilizing the bending elasticity of the metal wire, even with an extremely low overall height (thickness). As a result, it is possible to achieve a thinner and lighter design that was impossible with conventional coil springs. In addition, because the wave spring 30 is cylindrical, it forms a circumferential support line against the load. This prevents the load from concentrating at a specific point, so the stability of the seat surface can be dramatically improved even with a thin cushion.

[0030] Furthermore, while the cushion body 20, made of elastic foam, is prone to sagging, the wave spring 30 acts as a core material, reinforcing its elastic restorative force. On the other hand, the wave spring 30 alone would be lumpy, but the cushion body 20, made of elastic foam, encases the wave spring 30, achieving an ideal overall resilience.

[0031] <Effects of this embodiment> (1) The cushion 10 comprises a cushion body 20, which is formed at least in part from an elastic foam and has a space 23 formed inside it, and a wave spring 30 which is disposed in the space 23 and has elastic force in the thickness direction of the cushion body 20. The wave spring 30 is formed as a whole in a cylindrical shape and is formed in a wave shape along its circumferential direction, and consists of a linear elastic body 31 which generates an elastic restoring force against a compressive load in the thickness direction.

[0032] This configuration achieves the effects described above, allowing for a thinner and lighter design while providing a high-quality, comfortable seating experience. (2) The cushion body 20 has a first layer 21 made of elastic foam with through holes 24 forming the installation space 23, and a second layer 22 made of elastic foam laminated on the first layer 21 and covering the openings of the through holes 24. The wave spring 30 is positioned between the first layer 21 and the second layer 22.

[0033] With this configuration, the through-holes 24 formed in the first layer 21 restrain the cylindrical wave spring 30 from its outer circumference, physically suppressing lateral displacement and distortion of the wave spring 30 due to the load when seated. In this way, the wave spring 30 is always held in the correct position within the installation space 23, so the cushioning performance does not change easily even with long-term use, and it exhibits high durability. In addition, since the entire wave spring 30 is sandwiched between the first layer 21 and the second layer 22, which are made of elastic foam, metal-to-metal contact and vibration noise characteristic of springs are blocked and absorbed, providing a quiet user experience.

[0034] (3) The second layer 22 is positioned on the side of the load-receiving surface 11 relative to the first layer 21. The hardness of the elastic foam constituting the second layer 22 is set higher than the hardness of the elastic foam constituting the first layer 21.

[0035] With this configuration, the second layer 22 on the pressure-receiving surface 11 side has a hardness equal to or greater than that of the base layer 21, thereby suppressing the deflection of the cushion surface under load. As a result, when a load is applied by the user, the second layer 22 does not sink locally, but rather the load is distributed over a wide area. This prevents pressure from concentrating at a specific point in the cylindrical wave spring 30, so that even with a thin structure, it can provide a flat and stable seating experience without any jarring sensation.

[0036] Furthermore, because the second layer 22 has high rigidity, the rapid compression of the cushion 10 in response to the initial load is suppressed. Therefore, even when a relatively large load is applied, the wave spring 30 is prevented from being crushed to its limit. This prevents the bottoming-out phenomenon, where the wave spring 30 completely compresses and a hard feeling is transmitted, by limiting the amount of physical deformation.

[0037] <Variation> This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0038] The cushion body 20 is not limited to a rectangular shape, but may have other polygonal shapes, or it may be changed to an elliptical or circular shape as appropriate. The cross-section of the through-hole 24 is not limited to a circular shape, but may also be a regular polygon such as a square.

[0039] The second layer 22 does not need to be bonded to the first layer 21. In this case, the wave spring 30 can be easily removed from the installation space 23. For this reason, for example, if the cushion body 20 deteriorates, it is easy to replace only the cushion body 20 with a new one while reusing the wave spring 30.

[0040] The cushion 10 may have an asymmetrical shape and structure in the thickness direction. For example, the thicknesses of a pair of second layers 22 can be made different from each other.

[0041] For example, the hardness of a pair of second layers 22 can be made to differ from each other. • Instead of the through-hole 24 formed in the first layer 21, a recess opening towards the pressure-receiving surface 11 can be used. In this case, the second layer 22, which is located on the opposite side of the pressure-receiving surface 11, can be omitted. With this configuration, the initial load is absorbed by the second layer 22, while the larger load is received by the high-hardness first layer 21 and the wave spring 30. This synergistic effect further eliminates the feeling of bottoming out. Furthermore, the high-hardness first layer 21 serves as the base for the wave spring 30, concentrating the energy of the wave spring 30 vertically without loss, thereby generating a powerful resilient force.

[0042] The hardness of the elastic foam constituting the second layer 22 can also be set to be the same as the hardness of the elastic foam constituting the first layer 21. The hardness of the elastic foam constituting the second layer 22 can also be set lower than that of the elastic foam constituting the first layer 21. In this case, by making the second layer 22 on the pressure-receiving surface 11 side low hardness and the first layer 21 that holds the wave spring 30 high hardness, a multi-stage support characteristic that changes from "soft" to "rigid" in response to load is created. As a result, the sharp restoring force generated from the "circumferential apex" of the cylindrical wave spring 30 is diffused over the surface by the low-hardness second layer 22. This makes it possible to achieve a moist, comfortable fit on the surface without making the user feel the stiffness of the spring.

[0043] In this way, the hardness of the second layer 22 can be appropriately selected depending on the intended use of the cushion 10. The wave spring 30 is not limited to a cylindrical shape as illustrated in the above embodiment, but may also be an annular shape with a small thickness.

[0044] The cushion body 20 only needs to be formed of elastic foam in some parts, and may be partially formed of a material other than elastic foam. [Explanation of symbols]

[0045] 10…Cushion 11...Pressure-receiving surface 20…Cushion body 21…1st layer 22…Second layer 23…Installation space 24…Through hole 30... Wave Spring 31… Linear elastic body

Claims

1. A cushion body, in which at least a portion is formed of elastic foam and an internal space for arrangement is formed, The cushion body is provided with a wave spring, which is arranged within the aforementioned space and has elastic force in the thickness direction, The wave spring is formed as an annular or cylindrical shape overall, and is formed in a wave-like manner along its circumferential direction, thereby generating an elastic restoring force against the compressive load in the thickness direction, and is made of a linear elastic body. cushion.

2. The cushion body is A first layer made of elastic foam having recesses or through holes forming the aforementioned space, The first layer is laminated with a second layer made of elastic foam that covers the recess or the opening of the through hole, The wave spring is positioned between the first layer and the second layer. The cushion according to claim 1.

3. The second layer is positioned on the side of the load-receiving surface relative to the first layer. The hardness of the elastic foam constituting the second layer is set to be greater than or equal to the hardness of the elastic foam constituting the first layer. The cushion according to claim 2.

4. The second layer is positioned on the side of the load-receiving surface relative to the first layer. The hardness of the elastic foam constituting the second layer is set lower than the hardness of the elastic foam constituting the first layer. The cushion according to claim 2.

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