Seat cushioning and chairs

Abstract

To provide a seat cushion material that facilitates standing-up motion by suppressing bottoming-out feeling in sitting forward, and to provide a chair.SOLUTION: A seat cushion material 60 is composed of a front side area 60A and a rear side area 60B that is rearward from the front side area 60A. At least a part of the front side area 60A and at least a part of the rear side area 60B are the seat cushion material 60 supported by a bearing material 42. The hardness of a rear part 62 of the front side area 60A adjoining the rear side area 60B in the front side area 60A is higher than the hardness of the rear side area 60B. The thickness h1, h2 of a part supported by the bearing member 42 in the front side area 60A is thinner than the thickness h3 of a part supported by the bearing member 42 of the rear side area 60B.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a seat cushion and a chair. [Background technology]

[0002] For example, a chair described in Patent Document 1 below has been known. In the seat of the vehicle chair described in Patent Document 1, the rear portion of the seat is made of an ionized gel material. When the control unit predicts a collision based on a signal from a collision prediction sensor, a voltage control unit electrically connected to the control unit applies a voltage to the ionized gel material. This makes the rear portion of the seat softer than the front portion. The rear portion of the seat is softened so that the buttocks of the seated person sink in, and the front portion of the seat, which is harder and thicker than the rear portion, restricts the forward movement of the seated person. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-156292 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the seat of the chair described in Patent Document 1 has a problem in that the rear part is soft and thin, so that the buttocks feel the hardness of the seat support member when sitting down, giving a feeling of hitting the bottom. Furthermore, when the sitting time is relatively short, such as in a hospital waiting room or an airport departure lobby, people stand up frequently. In particular, people with poor leg strength, such as the elderly, may move their lower legs backward and rub their buttocks forward when standing up, but if the front part of the seat is thick, it is difficult to move the lower legs backward and rub the buttocks forward, making it difficult to stand up.

[0005] Therefore, the present invention has been made in consideration of the above circumstances, and provides a seat cushion material and a chair that reduce the feeling of hitting the bottom when sitting forward, making it easier to stand up. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention employs the following means. That is, the seat cushion material according to the present invention is a seat cushion material including a front region and a rear region disposed adjacent to the rear side of the front region, and at least a part of the front region and at least a part of the rear region are supported by a support member, The front region includes a front region and an intermediate region that is adjacent to and rearward of the front region and includes a rear portion of the front region, and the intermediate region has a hardness higher than that of the rear region. The thickness of the portion supported by the support member in the rear region is thinner than the thickness of the portion supported by the support member in the rear region. The seat cushion material according to the present invention is A seat cushion material comprising a front region and a rear region disposed adjacent to the rear side of the front region, at least a part of the front region and at least a part of the rear region being supported by a support member, the front region comprising a front region and an intermediate region disposed adjacent to the rear side of the front region and including a rear part of the front region, the thickness of a part of the front region supported by the support member being thinner than the thickness of a part of the rear region supported by the support member, the hardness of the intermediate region being higher than the hardness of the rear region, The hardness of the front region is lower than the hardness of the middle region, the boundary surface between the middle region and the rear region slopes gradually downward as it moves forward, from the upper surface to the lower surface of the cushioning material, and the upper end is connected to the upper surface of the middle region and the upper surface of the rear region, and the boundary surface between the front region and the middle region slopes gradually downward as it moves forward, from the upper surface to the lower surface of the cushioning material, and the upper end is connected to the upper surface of the front region and the upper surface of the middle region.

[0007] In the seat cushion material configured in this manner, the thickness of the portion supported by the support member in the front region is thinner than the thickness of the portion supported by the support member in the rear region. With this configuration, the rear part of the front region with high hardness and the rear region with low hardness are adjacently arranged, so that the boundary between the front region and the rear region is clear. In other words, when sitting, the buttocks located in the rear region are in a state of being wrapped behind the boundary between the front region and the rear region. Therefore, when sitting, the buttocks are not likely to slip forward, and the person sits in a stable state. When standing up, the shins (parts below the knees) are easily bent backward relative to the thighs. With the feet on the ground, the shins are easily bent and the buttocks are easily pushed forward, and then the person can stand up. Therefore, before standing up, the shins are easily bent and the buttocks are easily pushed forward with the feet on the ground, making it easy to stand up. On the other hand, if the thickness of the portion supported by the support member in the front region is made thin, the occupant is more likely to feel the bottoming out when sitting forward. For this reason, the hardness of the rear part of the front region is made higher than that of the rear region. With this configuration, the rear part of the front region is harder than the rear region, so that the bottoming out feeling caused by the occupant's buttocks hitting the rear part of the front region when sitting forward and feeling the hardness of the support member is suppressed.

[0008] In the seat cushion material according to the present invention, the boundary surface between the front region and the rear region may be gradually inclined downward toward the front.

[0009] In the seat cushion material configured in this manner, the boundary surface between the front region and the rear region is gradually inclined downward as it approaches the front. With this configuration, when a load is applied from the buttocks of a seated person to the rear region, the rear part of the front region is likely to collapse backward due to the load. Therefore, the shape of the part from the rear part of the front region to the front part of the rear region changes smoothly without any steps, so that the buttocks can easily slide forward when the seated person stands up. Also, for example, if the boundary surface is along a vertical plane, the regions in front and behind the boundary surface will try to maintain an upright state. The rear part of the front region is harder than the rear region, and the seated person will clearly feel the hardness in front of the boundary surface. In the above-mentioned seat cushion material, the boundary surface gradually slopes downward toward the front, so that the seated person is less likely to feel the rear part of the front region, resulting in a good seating feeling.

[0010] In addition, in the seat cushion material of the present invention, the front region comprises a front region and an intermediate region arranged adjacent to and rearward of the front region and including a rear portion of the front region, and the hardness of the front region may be lower than the hardness of the intermediate region.

[0011] In the seat cushioning material configured in this manner, the hardness of the front region is lower than that of the middle region. With this configuration, the backs of the front thighs of the seated person are supported by the front region, which is softer than the middle region, and when the seated person stands up, the front of the thighs can sink downward and the shins can bend backward without applying a large load. Therefore, it is easy to bend the shins and push the buttocks forward with the feet on the ground before standing up, making it easier to stand up.

[0012] In addition, in the seat cushion material of the present invention, at least a portion of the front region and at least a portion of the middle region are supported by the support member, and the thickness of the portion in the front region supported by the support member may be thinner than the thickness of the portion in the middle region supported by the support member.

[0013] In the seat cushion material configured in this manner, the thickness of the portion supported by the support member in the front region is thinner than the thickness of the portion supported by the support member in the middle region. With this configuration, the backs of the front sides of the thighs of the seated person are supported by the front region, which is thinner than the middle region, and when the seated person stands up, the seated person can bend the shins backward without moving the front sides of the thighs significantly downward. Therefore, it is easy to bend the shins and push the buttocks forward with the feet on the ground before standing up, making it easier to stand up.

[0014] In the seat cushion material according to the present invention, the boundary surface between the front region and the middle region may be gradually inclined downward toward the front.

[0015] In the seat cushion material configured in this manner, the boundary surface between the front region and the middle region is gradually inclined downward as it approaches the front. With this configuration, when a load is applied from the thighs of a seated person, the rear part of the front region is likely to collapse backward due to the load. Therefore, the shape of the part from the rear part of the front region to the front part of the middle region changes smoothly without any steps, so that the thighs can easily slide forward when the seated person stands up.

[0016] Moreover, a chair according to the present invention includes any one of the seat cushion materials described above, and a support member that supports the seat cushion material from below.

[0017] In a chair configured in this manner, it is easy to stand up by bending the knees and pushing the buttocks forward with the feet on the ground before standing up, making it easy to stand up. In addition, since the rear part of the front region is harder than the rear region, when the occupant sits forward, the rear part of the front region hits the occupant's buttocks, reducing the feeling of bottoming out and feeling the hardness of the support member.

[0018] In the chair according to the present invention, the lower surface of the support member may be gradually inclined upward toward the front.

[0019] In a chair constructed in this way, the underside of the support member is gradually inclined upwards as it approaches the front. With this construction, a large vertical space is formed between the bottom of the front side of the support member and the surface on which the chair is placed, and the shins of the seated person are positioned in this space. This makes it possible to secure a large space in which the shins of the seated person can be positioned. Effect of the Invention

[0020] The seat cushion material and chair according to the present invention reduce the feeling of hitting the bottom when sitting forward, making it easier to stand up. [Brief description of the drawings]

[0021] [Figure 1] 1 is a perspective view of a chair according to an embodiment of the present invention, seen obliquely from the front. [Diagram 2] FIG. 2 is a perspective view showing a support structure of the chair shown in FIG. [Diagram 3] FIG. 2 is a cross-sectional view of the chair shown in FIG. [Figure 4] 2 is a bottom view of the support member of the chair shown in FIG. 1. FIG. [Diagram 5] 2 is a cross-sectional view of a portion of the seat of the chair shown in FIG. 1. [Figure 6] FIG. 2 is a plan view of the cushioning material for the seat of the chair shown in FIG. [Figure 7] FIG. 11 is a cross-sectional view of a portion of a chair seat according to a first modified example of an embodiment of the present invention. [Figure 8] FIG. 11 is a cross-sectional view of a portion of a chair seat according to a second modified example of an embodiment of the present invention. [Figure 9] FIG. 11 is a cross-sectional view of a cushioning material for a chair seat in accordance with a third modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, a chair according to one embodiment of the present invention will be described with reference to Figs. 1 to 6. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," and "center," do not only indicate such an arrangement strictly, but also indicate a state in which there is a relative displacement with an angle or distance to such an extent that a tolerance or the same function is obtained. In addition, in the following explanation, unless otherwise specified, the directions of front, back, up, down, left, right, etc. will be defined as the side in front of a person sitting in a normal posture on a chair placed on a horizontal floor surface being referred to as "front" and the opposite side as "rear", and the directions of up, down, left, and right will be the same as those seen from the person sitting on the chair.

[0023] As shown in Fig. 1, the chair unit 10 of this embodiment is used in waiting rooms in hospitals, airport lobbies, etc. The chair unit 10 is a so-called linked chair in which a plurality of chairs 40 are attached to one support structure 20 in a line in the left-right direction X.

[0024] The chair unit 10 includes a support structure 20 and a chair 40. The support structure 20 is placed on a floor surface. The support structure 20 supports the chair 40. As shown in FIG. 2, the support structure 20 includes a support rod 21, a leg 22, and a support bracket 23.

[0025] The support rod 21 extends in the left-right direction X. In this embodiment, the support rod 21 is parallel to the floor surface and extends linearly in the left-right direction X. The support rod 21 is made of a metal material with high rigidity in order to support the weight of the multiple chairs 40 and the seated person.

[0026] The legs 22 are placed on the floor surface. A plurality of the legs 22 are provided at intervals in the left-right direction X. The legs 22 are arranged offset in the left-right direction X with respect to the chair 40. The legs 22 are not arranged directly below the chair 40. In this embodiment, two legs 22 are provided, but three or more legs may be provided, and when three or more legs are provided, the legs 22 may be arranged directly below the chair 40. The two legs 22 are attached to both ends of the support rod 21, respectively. Since the two legs 22 have the same structure, only one leg 22 will be described below as a representative example.

[0027] The leg 22 has a connecting portion 28, a front ground rod 29, and a rear ground rod 30. The connecting portion 28 is connected to the end of the support rod 21 in the left-right direction X. The front ground rod 29 extends linearly downward and forward from the connecting portion 28. The rear ground rod 30 extends linearly downward and rearward from the connecting portion 28. The front ground rod 29 and the rear ground rod 30 extend in directions that move away from each other in the front-to-rear direction Y as they extend downward. The lower ends of the front ground rod 29 and the rear ground rod 30 are in contact with the floor surface.

[0028] The support bracket 23 is fixed to the support rod 21. The support bracket 23 is provided on an upper surface 21u of the support rod 21. The support bracket 23 supports the chair 40. The same number of support brackets 23 as the number of chairs 40 (three in the illustrated example) are provided. Since the multiple support brackets 23 have the same structure, only one support bracket 23 will be representatively described below.

[0029] The support bracket 23 has two brackets 31, 32 that are symmetrical in the left-right direction X. The two brackets 31, 32 are a first bracket 31 on the left side and a second bracket 32 ​​on the right side. The first bracket 31 and the second bracket 32 ​​are disposed at an interval in the left-right direction X. The first bracket 31 and the second bracket 32 ​​are symmetrical to each other in the left-right direction X. Each of these brackets 31, 32 is formed by bending a steel plate.

[0030] The first bracket 31 has a first side plate 31a and a first upper plate 31b. The first side plate 31a is a plate whose front and back surfaces face the left-right direction X. The first side plate 31a is longer in the front-rear direction Y than in the up-down direction Z. The first side plate 31a is provided with a notch 33 that opens downward. The notch 33 is disposed rearward of the center of the first side plate 31a in the front-rear direction Y. The support rod 21 is fitted into the notch 33. The periphery of the notch 33 is welded to the support rod 21, but may be fixed to the support rod 21 by a bolt or the like.

[0031] The first upper plate 31b is a plate whose front and back surfaces face the up-down direction Z. The first upper plate 31b is rectangular and longer in the front-rear direction Y than in the left-right direction X. Of both side edges of the first upper plate 31b in the left-right direction X, the side edge on the second bracket 32 ​​side (right side) is connected to the upper edge of the first side plate 31a via a bent portion. The first upper plate 31b extends from the upper edge of the first side plate 31a along the left-right direction X to the opposite side (left side) of the second bracket 32.

[0032] The first upper plate 31b is provided with a through hole 34. The through hole 34 passes through the first upper plate 31b in the up-down direction Z. Two through holes 34 are provided with an interval in the front-rear direction Y. The two through holes 34 are provided at positions sandwiching the notch 33 in the front-rear direction Y.

[0033] The second bracket 32 ​​has a second side plate 32a and a second upper plate 32b. The second side plate 32a has the same configuration as the first side plate 31a. The second side plate 32a is provided with the notch 33. The second upper plate 32b is also provided with the same configuration as the first upper plate 31b. The second upper plate 32b is provided with a through hole 34. However, the second upper plate 32b extends from the upper edge of the second side plate 32a along the left-right direction X to the opposite side (right side) of the first bracket 31.

[0034] As shown in Fig. 1, a plurality of chairs 40 are lined up in the left-right direction X. In the illustrated example, three chairs 40 are lined up in the left-right direction X. The end faces (small ends) of the chairs 40 adjacent to each other in the left-right direction X are in contact with each other. Since the three chairs 40 have the same structure, the following description will be given by representing only one chair 40.

[0035] The chair 40 has a symmetrical shape in the left-right direction X. The chair 40 includes a seat 41 and a backrest 71. The seat 41 is supported by the support structure 20. The seat 41 supports the buttocks of a seated person. The backrest 42 supports the back of the seated person.

[0036] As shown in Fig. 3 (the seat cover 69 and the back cover 79 are not shown), the seat 41 has a seat support member (support member) 42, a seat cushion material (seat cushion material) 60, and a seat cover 69 (see Fig. 1). An example of the seat support member 42 is a molded product obtained by stamping a resin base material.

[0037] As shown in Fig. 4, a first recess 44 is provided on the lower surface 42b of the seat support member 42. Two first recesses 44 are provided at an interval in the left-right direction X. The first recesses 44 are recessed upward from the lower surface 42b of the seat 41. The two first recesses 44 sandwich the center of the lower surface 42b of the seat 41 in the left-right direction X between them. The first upper plate 31b and the second upper plate 32b of the brackets 31, 32 of the support bracket 23 are respectively arranged on the bottom surfaces 44b of the two first recesses 44.

[0038] The first recess 44 is longer in the front-rear direction Y than in the left-right direction X. The first upper plate 31b and the second upper plate 32b of the bracket 31, 32 come into contact (surface contact) with the bottom surface 44b of the first recess 44. The bottom surface 44b of the first recess 44 is provided with a screw hole 46. Two screw holes 46 are provided at an interval in the front-rear direction Y. A bolt (not shown) is fitted into the screw hole 46. The bolt is fitted into the screw hole 46 through the through hole 34 of the first upper plate 31b and the second upper plate 32b. As a result, the head of the bolt sandwiches the first upper plate 31b and the second upper plate 32b between the lower surface of the seat 41 (the bottom surface 44b of the first recess 44). As a result, the seat 41 is fixed to the support bracket 23 via the bolt.

[0039] A second recess 47 is provided to connect the rear portions of the two first recesses 44. The second recess 47 is recessed upward from the lower surface 42b of the seat support member 42. The second recess 47 is longer in the left-right direction X than in the front-rear direction Y. An air hole 48 is provided in the bottom surface 47b of the second recess 47. Three air holes 48 are provided at intervals in the left-right direction X. The air holes 48 are holes that penetrate the seat support member 42 in the up-down direction Z. A support rod 21 is arranged vertically above the second recess 43.

[0040] A groove 50 is provided on the lower surface 42b of the seat support member 42. The groove 50 is recessed upward from the lower surface 42b of the seat support member 42. The groove 50 has two third recesses 51 and a fourth recess 53. A seat cover 69 (see FIG. 1) enclosing the seat support member 42 and the seat cushion material 60 is fixed to the outer walls of the third recesses 51 and the fourth recesses 53 by a tack or the like.

[0041] The third recess 51 is longer in the front-rear direction Y than in the left-right direction X. Air holes 52 are provided in a bottom surface 51b of the third recess 51. Two air holes 52 are provided with an interval in the front-rear direction Y. The air holes 52 are holes that penetrate the seat support member 42 in the up-down direction Z. The support rod 21 is arranged vertically above the rear air hole 52 (hereinafter referred to as "air hole 52a").

[0042] The fourth recess 53 is longer in the left-right direction X than in the front-rear direction Y. An air hole 54 is provided in a bottom surface 53b of the fourth recess 53. Two air holes 54 are provided with an interval in the left-right direction X. The air holes 54 are holes that penetrate the seat support member 42 in the up-down direction Z. The air hole 54 may be formed from the bottom surface 53b of the fourth recess 53 to the outer wall of the fourth recess 53.

[0043] When the seat cushion material 60, which will be described later, is compressed and deformed by the weight of a seated person, the air inside the seat cushion material 60 escapes to the outside through the air holes 48, 52, and 54, so that the seat cushion material 60 is easily compressed and deformed.

[0044] As shown in Fig. 5 (a cross-sectional view of the center of the seat 41 in the left-right direction X, with the seat cover 69 omitted), the upper surface 42u and the lower surface 42b of the seat support member 42 gradually slope upward as they move forward. A space s1 is formed between the front part 42f of the seat support member 42 and the installation surface of the chair 40. Because the lower surface 42b of the seat support member 42 gradually slopes upward as it moves forward, the height in the vertical direction Z of the space s1 is higher than the height in the vertical direction Z of a space s2 formed below the rear part 42e of the seat support member 42.

[0045] A downwardly protruding rib 49 is provided on the lower surface 42b of the seat support member 42. The rib 49 extends in the left-right direction X. Three ribs 49 are provided at intervals in the front-rear direction Y. The strength of the seat support member 42 is increased by the ribs 49.

[0046] The seat cushion material 60 is supported from below by the seat support member 42. For example, molded urethane is exemplified as the seat cushion material 60. By using molded urethane, a front region 61 and a middle region 62, which will be described later, are firmly joined together, and the middle region 62 and a rear region 63 are firmly joined together.

[0047] The seat cushion material 60 includes a front region 60A and a rear region 60B. The rear region 60B is disposed adjacent to the front region 60A on the rear side of the front region 60A. The front region 60A includes a front region 61 and a middle region 62. The middle region 62 is disposed adjacent to the front region 61 on the rear side of the front region 61. The middle region 62 covers the upper side of the front region 61. The rear region 60B includes a rear region 63. The rear region 63 is disposed adjacent to the middle region 62 on the rear side of the middle region 62.

[0048] The hardness of the rear portion of the front region 60A is higher than the hardness of the rear region 60B. In this embodiment, the hardness of the intermediate region 62 is higher than the hardness of the rear region 63.

[0049] The hardness of the front region 61 is the same as that of the rear region 63. The hardness of the intermediate region 62 is higher than that of the front region 61 and the rear region 63. In this embodiment, the hardness of the front region 61 and the rear region 63 is about 11 kg at 25% hardness according to the JIS K6400-2 D method. The hardness of the intermediate region 62 is about 16 kg at 25% hardness according to the JIS K6400-2 D method. Note that the hardness of the front region 61, the intermediate region 62, and the rear region 63 is an example, and the hardness of the intermediate region 62 can be appropriately set to be higher than that of the front region 61 and the rear region 63.

[0050] In the following description of the seat cushion material 60, the upper surface refers to the surface facing upward in the vertical direction Z, the lower surface refers to the surface facing downward in the vertical direction Z, the front surface refers to the surface facing forward in the front-to-back direction Y, and the rear surface refers to the surface facing backward in the front-to-back direction Y.

[0051] The upper surface 61u of the front region 61 has a horizontal surface portion 61a along a horizontal plane. In the upper surface 61u of the front region 61, a portion 61h (hereinafter referred to as a "first upper surface portion") in front of the horizontal surface portion 61a gradually slopes downward toward the front. A portion 61j (hereinafter referred to as a "second upper surface portion") behind the horizontal surface portion 61a gradually slopes upward toward the front.

[0052] A front surface 61f facing forward is formed at the front end of the front region 61. The boundary between the first upper surface portion 61h of the front region 61 and the front surface 61f is formed in a gentle curve.

[0053] A first lower surface 61c extending rearward is formed at the lower end of the front surface 61f of the front region 61. A first rear surface 61d extending upward is formed at the rear end of the first lower surface 61c. A second lower surface 61e extending rearward is formed at the upper end of the first rear surface 61d. A second rear surface 61g extending upward is formed at the rear end of the second lower surface 61e. A third lower surface 61k extending rearward is formed at the upper end of the second rear surface 61g.

[0054] A downward protrusion 61m is an area formed by the lower part of the front surface 61f of the front region 61, the first lower surface 61c, the first rear surface 61d, the second lower surface 61e, and the second rear surface 61g. The downward protrusion 61m protrudes downward from the front end portion of the front region 61.

[0055] The second rear surface 61g of the front region 61 abuts against the front end surface 42a (the front end surface facing forward) of the seat support member 42. The second rear surface 61g of the front region 61 is disposed in front of the front end surface 42a of the seat support member 42. The third lower surface 61k of the front region 61 abuts against and is supported by the front portion of the upper surface 42u of the seat support member 42.

[0056] The upper surface 62u of the middle region 62 gradually slopes upward toward the front. The upper surface 62u of the middle region 62 and the second upper surface portion 61j of the front region 61 are continuous with each other. No step is formed between the upper surface 62u of the middle region 62 and the second upper surface portion 61j of the front region 61.

[0057] A first boundary surface 64, which is a boundary surface between the middle region 62 and the front region 61, gradually slopes downward toward the front. An upper end of the first boundary surface 64 is connected to an upper surface 62u of the middle region 62 and a second upper surface portion 61j of the front region 61. A lower end of the first boundary surface 64 is connected to a third lower surface 61k of the front region 61 and a lower surface 62b of the middle region 62. As shown in FIG. 6, on an upper surface 60u of the seat cushion material 60, the first boundary surface 64 is aligned along the left-right direction X. An angle between the upper surface 62u of the middle region 62 and the first boundary surface 64 is an obtuse angle in a side cross-sectional view.

[0058] The third lower surface 61k may not be formed in the front region 61. The front region 61 may be configured not to abut on and be supported by the upper surface 21u of the seat support member 42, and the lower end of the first boundary surface 64 may be connected to the upper end of the second rear surface 61g of the front region 61.

[0059] As shown in FIG. 5, the lower surface 62b of the intermediate region 62 is in contact with and supported by the front portion of the upper surface 42u of the seat support member 42.

[0060] An upper surface 63u of the rear region 63 gradually slopes upward toward the front. The upper surface 63u of the rear region 63 and an upper surface 62u of the middle region 62 are continuous with each other. No step is formed between the upper surface 63u of the rear region 63 and the upper surface 62u of the middle region 62.

[0061] The second boundary surface 65, which is the boundary surface between the rear region 63 and the middle region 62, gradually inclines downward toward the front. The upper end of the second boundary surface 65 is connected to the upper surface 63u of the rear region 63 and the upper surface 62u of the middle region 62. The lower end of the second boundary surface 65 is connected to the lower surface 63b of the rear region 63 and the lower surface 62b of the middle region 62. The inclination angle of the second boundary surface 65 with respect to the horizontal plane is larger than the inclination angle of the first boundary surface 64 with respect to the horizontal plane. As shown in FIG. 6, on the upper surface 60u of the seat cushion material 60, the second boundary surface 65 is configured so that the center in the left-right direction X bulges forward. The angle between the upper surface 62u of the middle region 62 and the second boundary surface 65 is an obtuse angle in a side cross-sectional view.

[0062] The lower surface 63b of the rear region 63 abuts against and is supported by the upper surface 42u of the seat support member 42 from the middle in the front-rear direction to the rear end portion.

[0063] The rear surface 63c of the rear region 63 gradually slopes upward as it extends forward. An upper end of the rear surface 63c of the rear region 63 is connected to a rear end of the upper surface 63u of the rear region 63. A lower end of the rear surface 63c of the rear region 63 is connected to a rear end of the lower surface 63d of the rear region 63.

[0064] The center position in the front-to-rear direction Y of the upper surface 60u of the seat cushion material 60 is defined as the center position P. The distance from the front end 61p of the upper surface 61u of the front region 61 to the center position P is defined as the distance L1. The distance from the rear end 63p of the upper surface 63u of the rear region 63 to the center position P is defined as the distance L1. The upper surface 62u of the intermediate region 62 is located forward of the center position P in the front-to-rear direction Y of the upper surface 60u of the seat cushion material 60. The upper surface 62u of the intermediate region 62 is located rearward of the horizontal surface portion 61a of the front region 61, which is the portion of the seat cushion material 60 that is along the horizontal surface.

[0065] The seat cover 69 (see FIG. 1) forms the outer surface of the seat 41. The seat cover 69 covers the outer surfaces of the seat support member 42 and the seat cushion material 60. The seat cover 69 is made of a cloth material, a vinyl leather material, a natural leather material, or the like.

[0066] Next, the thickness of the front region 61, the middle region 62, and the rear region 63 will be described. Here, the thickness of each region refers to the maximum length of the portion where the lower surface of each region is supported by the seat support member 42 and the length in the up-down direction Z (direction along the vertical plane) connecting the upper surface and the lower surface of each region. Note that in the front region 61, the portion excluding the downward protrusion 61m is supported by the seat support member 42, and the length in the up-down direction Z of the portion rearward of the downward protrusion 61m is the thickness.

[0067] The thickness of the front region 61 is defined as h1. The thickness h1 is the length in the vertical direction Z connecting the first upper surface portion 61h and the third lower surface 61k of the front region 61. The thickness of the middle region 62 is defined as h2. The thickness of the rear region 63 is defined as h3.

[0068] The thickness h1 is thinner than the thickness h2. The thickness h2 is thinner than the thickness h3. The thicknesses h1 and h2 of the portion supported by the seat support member 42 in the front region 60A are thinner than the thickness h3 of the portion supported by the seat support member 42 in the rear region 60B. In addition, the thickness h1 of the portion supported by the seat support member 42 in the front region 61 is thinner than the thickness h2 of the portion supported by the seat support member 42 in the intermediate region 62.

[0069] As shown in FIG. 3, the backrest 71 extends upward from the rear end of the seat 41. The backrest 71 has a back support member 72, a back cushion 73, and a back skin 79 (see FIG. 1). The back support member 72 may be, for example, a molded product obtained by stamping a resin base material. The back support member 72 may be molded integrally with the seat support member 42, or may be molded separately from the seat support member 42 and connected to the seat support member 42. The back cushion 73 is supported from the rear by the back support member 72. The back cushion 73 may be, for example, molded urethane. The back cushion 73 is not disposed at the corners of the connection area between the back support member 72 and the seat support member 42. This allows the back support member 72 to bend backward with this part as a fulcrum. The back skin 79 forms the outer surface of the backrest 71. The back cover 79 covers the outer surfaces of the back support member 72 and the back cushion 73. The back cover 79 is made of a cloth material, a vinyl leather material, a natural leather material, or the like.

[0070] In the chair unit 10 thus configured, the thicknesses h1 and h2 of the portions supported by the seat support member 42 in the front region 60A are thinner than the thickness h3 of the portions supported by the seat support member 42 in the rear region 60B. With this configuration, the rear portion of the front region 60A (middle region 62 in this embodiment) having a high hardness and the rear region 60B having a low hardness are adjacently arranged, so that the boundary portion (second boundary surface 65 in this embodiment) between the front region 60A and the rear region 60B is clear. In other words, the buttocks located in the rear region 60B when seated are in a state of being wrapped behind the boundary portion between the front region 60A and the rear region 60B. Therefore, when seated, the buttocks are unlikely to slip forward, and the person sits in a stable state. When standing up, the shins (parts below the knees) are easily bent backward with respect to the thighs. With the feet on the ground, the shins are easily bent to push the buttocks forward, and then the person can stand up. Therefore, before standing up, the user can easily bend the shins and push the buttocks forward with the feet on the ground, making it easier to stand up. On the other hand, if the thicknesses h1, h2 of the portions of the front region 60A supported by the seat support member 42 are made thinner, the occupant is more likely to feel a bottoming out when sitting forward. For this reason, the hardness of the rear portion of the front region 60A is made higher than that of the rear region 60B (rear region 63 in this embodiment). With this configuration, the rear portion of the front region 60A is harder than the rear region 60B, so that the bottoming out feeling caused by the occupant's buttocks hitting the rear portion of the front region 60A when sitting forward and feeling the hardness of the seat support member 42 is suppressed. In addition, since the front region 61, which has a lower hardness than the intermediate region 62, covers the upper side of the intermediate region 62, resistance is less felt when bending the shin backward. In addition, the rear region 60B, which is softer than the rear portion of the front region 60A, sinks under the weight of the seated person and deforms to encase the buttocks of the seated person. The rear portion of the front region 60A, which is harder than the rear region 60B, prevents the buttocks of the seated person from shifting forward when seated.

[0071] In addition, the second boundary surface 65, which is the boundary between the front region 60A and the rear region 60B, gradually slopes downward as it approaches the front. With this configuration, when a load input from the buttocks of a seated person acts on the rear region 60B, the rear part of the front region 60A is likely to collapse backward due to the load. Therefore, since the shape of the part from the rear part of the front region 60A to the front part of the rear region 60B changes smoothly without any step or the like, when the seated person stands up, the buttocks can easily slide forward. Since the upper surface 62u of the intermediate region 62 and the second boundary surface 65 form an obtuse angle in a side cross-sectional view, the front region 60A is likely to collapse forward. Also, for example, if the boundary surface between the front region 60A and the rear region 60B is along a vertical plane, the regions before and after the boundary surface will tend to maintain an upright state. The rear part of the front region 60A is harder than the rear region 60B, and the seated person will clearly feel the hardness in front of the boundary surface. In this embodiment, the second boundary surface 65 is gradually inclined downward toward the front, so that the seated person is less likely to feel the rear part of the front region 60A, resulting in a good seating feeling.

[0072] Moreover, the hardness of the front region 61 is lower than that of the middle region 62. With this configuration, the backs of the front sides of the thighs of the seated person are supported by the front region 61, which is softer than the middle region 62, and when the seated person stands up, the front sides of the thighs can sink downward and the shins can bend backward without applying a large load. Therefore, before standing up, it is easy to bend the shins and push the buttocks forward with the feet on the ground, making it easy to stand up.

[0073] Furthermore, the thickness h1 of the portion of the front region 61 supported by the seat support member 42 is thinner than the thickness h2 of the portion of the intermediate region 62 supported by the seat support member 42. With this configuration, the backs of the front sides of the thighs of the seated person are supported by the front region 61, which is thinner than the intermediate region 62, and when the seated person stands up, the seated person can bend the shins backward without moving the front sides of the thighs downward significantly. Therefore, before standing up, the shins can be bent with the feet on the ground and the buttocks can be pushed forward, making it easier to stand up.

[0074] In addition, the first boundary surface 64, which is the boundary surface between the front region 61 and the middle region 62, gradually slopes downward toward the front. With this configuration, when a load is applied from the thighs of a seated person, the rear part of the front region 61 is likely to collapse backward due to the load. Therefore, since the shape of the part from the rear part of the front region 61 to the front part of the middle region 62 changes smoothly without any step or the like, the thighs can easily slide forward when the seated person stands up. Since the upper surface 62u of the middle region 62 and the first boundary surface 64 form an obtuse angle in a side cross-sectional view, the front region 61 is likely to collapse forward.

[0075] In addition, the underside 42d of the seat support member 42 gradually slopes upward as it approaches the front. With this configuration, a large vertical space s1 is formed between the bottom of the front part 42f of the seat support member 42 and the installation surface of the chair 40, and the shins of the seated person are positioned in the space s1. Therefore, a large space s1 for the shins of the seated person can be secured.

[0076] In addition, the air holes 48, 52a of the seat support member 42 are disposed vertically above the support rod 21. Therefore, when the chair unit 10 is viewed from below, the air holes 48, 52a of the seat support member 42 are hidden by the support rod 21 and are prevented from being seen.

[0077] (Variation 1) Next, a first modified example of the present invention will be described mainly with reference to FIG. Among the configurations of the following modified examples, the same configurations as those of the embodiment are given the same reference numerals and the description thereof will be omitted.

[0078] As shown in FIG. 7, in the seat cushion material 60X of the seat 41X of the chair unit 10 of this modified example, the front region 60A does not include the front region 61 of the embodiment shown above, but includes the middle region 62X. In this embodiment, the region of the front region 61 and the region of the middle region 62 of the embodiment shown above are combined to form the middle region 62X. The middle region 62X is a region from the front side of the second boundary surface 65 to the front end surface 60f of the seat cushion material 60X. The hardness of the middle region 62X is higher than that of the rear region 63. The thickness h2 of the middle region 62X is thinner than the thickness h3 of the rear region 63.

[0079] In the chair unit 10 thus configured, the thickness h2 of the portion supported by the seat support member 42 in the front region 60A is thinner than the thickness h3 of the portion supported by the seat support member 42 in the rear region 60B. With this configuration, the rear portion of the front region 60A with high hardness (the intermediate region 62X in this embodiment) and the rear region 60B with low hardness are adjacently arranged, so that the boundary portion between the front region 60A and the rear region 60B (the second boundary surface 65 in this embodiment) is clear. In other words, the buttocks located in the rear region 60B when seated are in a state of being wrapped behind the boundary portion between the front region 60A and the rear region 60B. Therefore, when seated, the buttocks are unlikely to slip forward, and the person sits in a stable state. When standing up, the shins (parts below the knees) are easily bent backward with respect to the thighs. With the feet on the ground, the shins are easily bent to push the buttocks forward, and then the person can stand up. Therefore, before standing up, the user can easily bend the shins and push the buttocks forward with the feet on the ground, making it easier to stand up. On the other hand, if the thickness h2 of the portion of the front region 60A supported by the seat support member 42 is made thinner, the occupant is more likely to feel a bottoming out when sitting forward. For this reason, the hardness of the rear portion of the front region 60A is made higher than that of the rear region 60B (rear region 63 in this embodiment). With this configuration, the rear portion of the front region 60A is harder than the rear region 60B, so that the bottoming out feeling caused by the occupant's buttocks hitting the rear portion of the front region 60A when sitting forward and feeling the hardness of the seat support member 42 is suppressed.

[0080] (Variation 2) Next, a second modified example of the present invention will be described mainly with reference to FIG. As shown in FIG. 8, in the seat cushion material 60Y of the seat 41Y of the chair unit 10 of this modified example, the front region 61Y is not in contact with or directly supported by the seat support member 42. The front end of the boundary surface 64X between the front region 61Y and the middle region 62Y of the front region 60A is connected to the middle of the front end surface 60f of the seat cushion material 60 in the up-down direction. The front end 62f of the middle region 62Y protrudes to the front end surface 60f of the seat cushion material 60. The hardness of the middle region 62Y is higher than the hardness of the front region 61Y and the rear region 63. The thickness h2 of the middle region 62X is thinner than the thickness h3 of the rear region 63.

[0081] In the chair unit 10 thus configured, the thickness h2 of the portion supported by the seat support member 42 in the front region 60A is thinner than the thickness h3 of the portion supported by the seat support member 42 in the rear region 60B. With this configuration, the rear portion of the front region 60A (middle region 62Y in this embodiment) having a high hardness and the rear region 60B having a low hardness are adjacently arranged, so that the boundary portion (second boundary surface 65 in this embodiment) between the front region 60A and the rear region 60B is clear. In other words, the buttocks located in the rear region 60B when seated are in a state of being wrapped behind the boundary portion between the front region 60A and the rear region 60B. Therefore, when seated, the buttocks are unlikely to slip forward, and the person sits in a stable state. When standing up, the shins (parts below the knees) are easily bent backward with respect to the thighs. With the feet on the ground, the shins are easily bent to push the buttocks forward, and then the person can stand up. Therefore, before standing up, the user can easily bend the shins and push the buttocks forward with the feet on the ground, making it easier to stand up. On the other hand, if the thickness h2 of the portion of the front region 60A supported by the seat support member 42 is made thinner, the occupant is more likely to feel a bottoming out when sitting forward. For this reason, the hardness of the rear portion of the front region 60A is made higher than that of the rear region 60B (rear region 63 in this embodiment). With this configuration, the rear portion of the front region 60A is harder than the rear region 60B, so that the bottoming out feeling caused by the occupant's buttocks hitting the rear portion of the front region 60A when sitting forward and feeling the hardness of the seat support member 42 is suppressed. In addition, since the front region 61Y, which has a lower hardness than the intermediate region 62Y, covers the upper side of the intermediate region 62Y, resistance is unlikely to be felt when bending the shin backward.

[0082] (Variation 3) Next, a third modified example of the present invention will be described mainly with reference to FIG. As shown in FIG. 9, in the seat cushion material 60Z of the seat 41Z of the chair unit 10 of this modified example, the seat support member 42Z supports the seat cushion material 60Z over substantially the entire length in the front-rear direction Y. The hardness of the middle region 62Z is ​​higher than the hardness of the front region 61Z and the rear region 63Z. The thickness h12 of the middle region 62Z is ​​thinner than the thickness h13 of the rear region 63. The thickness h11 of the front region 61Z is thicker than the thickness h12 of the middle region 62Z and thinner than the thickness h13 of the rear region 63. Note that even if the seat support member 42Z does not support the seat cushion material 60Z over substantially the entire length in the front-rear direction Y, it is sufficient that the thickness h11 of the front region 61Z is thicker than the thickness h12 of the middle region 62Z and thinner than the thickness h13 of the rear region 63.

[0083] In the chair unit 10 thus configured, the thicknesses h11 and h12 of the portions of the front region 60A supported by the seat support member 42Z are thinner than the thickness h13 of the portions of the rear region 60B supported by the seat support member 42Z. With this configuration, the rear portion of the front region 60A (middle region 62Z in this embodiment) having a high hardness and the rear region 60B having a low hardness are adjacently arranged, so that the boundary portion (second boundary surface 65 in this embodiment) between the front region 60A and the rear region 60B is clear. In other words, the buttocks located in the rear region 60B when seated are in a state of being wrapped behind the boundary portion between the front region 60A and the rear region 60B. Therefore, the buttocks are unlikely to slip forward when seated, and the person sits in a stable state. When standing up, the shins (parts below the knees) are easily bent backward with respect to the thighs. With the feet on the ground, it is easy to bend the shins and push the buttocks forward, and then stand up. Therefore, before standing up, it is easy to bend the shins and push the buttocks forward with the feet on the ground, making it easy to stand up. On the other hand, if the thicknesses h11, h12 of the portions of the front region 60A supported by the seat support member 42Z are made thinner, the occupant is more likely to feel a bottoming out when sitting forward. For this reason, the hardness of the rear portion of the front region 60A is made higher than that of the rear region 60B (the rear region 63Z in this embodiment). With this configuration, the rear portion of the front region 60A is harder than the rear region 60B, so that the bottoming out feeling caused by the occupant's buttocks hitting the rear portion of the front region 60A when sitting forward and feeling the hardness of the seat support member 42Z is ​​suppressed. In addition, since the front region 61Z, which has a lower hardness than the intermediate region 62Z, covers the upper side of the intermediate region 62Z, resistance is unlikely to be felt when bending the shin backward.

[0084] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0085] For example, the second boundary surface 65, which is the boundary between the front region 60A and the rear region 60B, does not have to be gradually inclined downward toward the front. The hardness of the front region 61 may be higher than the hardness of the middle region 62. The first boundary surface 64, which is the boundary surface between the front region 61 and the middle region 62, does not have to be gradually inclined downward toward the front. The lower surface 42d of the seat support member 42 does not have to be gradually inclined upward toward the front.

[0086] The rear region may be made of a plurality of members having different hardnesses, in which case the hardness of the rear portion of the front region only needs to be higher than the hardest member constituting the rear region.

[0087] Moreover, it is sufficient that at least a portion of each of the front region 60A and the rear region 60B is supported by the seat support member .

[0088] Furthermore, the air holes 48, 52a of the seat support member 42 do not have to be disposed vertically above the support rod 21.

[0089] Furthermore, the chairs 40 do not have to be linked together in such a way that multiple chairs 40 are attached to the support structure 20, but may be a single independent chair.

[0090] Also, the legs 22 may be disposed directly under the seat 41. The chair 40 does not have to include the backrest .

[0091] Furthermore, the seat cushion material 60 may be made of slab urethane instead of molded urethane.

[0092] In addition, within the scope of the invention, the components in the above-described embodiments may be replaced with well-known components, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0093] 10 Chair unit 40 Chair 42 Seat support member (support member) 60 Seat cushion material (seat cushion material) 60A Front Area 60B Posterior area 61 Anterior area 62 Intermediate area 63 Posterior area 64 First boundary surface (boundary surface) 65 Second boundary surface (boundary surface)

Claims

1. A seat cushion material comprising a front region and a rear region disposed adjacent to the rear side of the front region, wherein at least a part of the front region and at least a part of the rear region are supported by a support member, The front region is An anterior region; an intermediate region disposed adjacent to and rearward of the front region and including a rear portion of the front region; A seat cushion material in which the thickness of the portion supported by the support member in the intermediate region, which has a harder hardness than that of the rear region, is thinner than the thickness of the portion supported by the support member in the rear region.

2. 2. The seat cushion according to claim 1, wherein the boundary surface between the front region and the rear region is gradually inclined downward toward the front.

3. A seat cushioning material comprising a front region and a rear region disposed adjacent to the rear side of the front region, at least a portion of the front region and at least a portion of the rear region being supported by a support member, The front region is An anterior region; an intermediate region disposed adjacent to and rearward of the front region and including a rear portion of the front region; a thickness of a portion supported by the support member in the front region is thinner than a thickness of a portion supported by the support member in the rear region; the hardness of the intermediate region is greater than the hardness of the rear region; the hardness of the front region is less than the hardness of the middle region; The boundary surface between the intermediate region and the rear region is gradually inclined downward toward the front from the upper surface to the lower surface of the cushioning material, and an upper end portion is connected to the upper surface of the intermediate region and the upper surface of the rear region, The boundary surface between the front region and the intermediate region gradually slopes downward as it moves forward, from the upper surface of the cushion material to the lower surface, and the upper end portion is connected to the upper surface of the front region and the upper surface of the intermediate region.

4. At least a portion of the front region and at least a portion of the middle region are supported by the support member; 4. The seat cushion material according to claim 3, wherein a thickness of the portion supported by the support member in the front region is thinner than a thickness of the portion supported by the support member in the intermediate region.

5. A seat cushion material according to any one of claims 1 to 4, A support member that supports the cushion material of the seat from below.

6. 6. The chair according to claim 5, wherein the lower surface of the support member is gradually inclined upward toward the front.

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