CN108853910B

CN108853910B - Seating device

Info

Publication number: CN108853910B
Application number: CN201710891776.0A
Authority: CN
Inventors: 松下刚
Original assignee: MTG Co Ltd
Current assignee: MTG Co Ltd
Priority date: 2017-05-08
Filing date: 2017-09-27
Publication date: 2022-03-22
Anticipated expiration: 2037-09-27
Also published as: JP2018187101A; JP6905855B2; CN108853910A

Abstract

The invention provides a sitting tool which can easily keep a state that a pelvis is erected for a long time. A seating device (S) for seating a user includes a hollow flexible main body (10), and the main body (10) includes a seating surface (14) inclined so as to rise backward and a protrusion (22) provided at the rear of the main body (10) and protruding upward. With this configuration, the pelvis can be easily kept standing for a long time.

Description

Seating device

Technical Field

The present invention relates to seating appliances.

Background

Conventionally, as one of seating devices on which a user sits, a soft and easily deformable hollow seat cushion is known. For example, a hollow seat cushion described in patent document 1 below includes a horizontal seat surface and a raised portion disposed so as to surround the seat surface. When the seat is seated on the hollow seat cushion, the buttocks of the user are received inside the raised portion, and the posture of the user is stabilized. Therefore, the seat cushion is suitable for performing, for example, a swinging motion of the waist, a twisting motion, and the like.

However, the seating device configured as described above is not suitable for a case where correction of pelvic distortion is desired, a case where seating is desired in a correct posture in which the spine is stretched, or the like. This is because, in a state where the seated person is seated on the horizontal seat surface in a correct posture (posture in which the pelvis is raised), the angle between the pelvis and the femur of the seated person is narrowed and the internal organs and nerves are pressed, so that the seated person is not easy, and if the seated person intends to take a relaxed posture, the pelvis tends to fall backward.

Thus, a hollow seat cushion described in non-patent document 1 below is known. Since the seating surface of the hollow seat cushion is inclined so as to rise rearward, the pelvis can be raised while maintaining an appropriate angle between the pelvis and the femur. That is, the hollow seat cushion is suitable for use in a case where it is desired to correct the distortion of the pelvis and a case where it is desired to sit in a correct posture with the spine stretched.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2014-124446

Non-patent document 1: ラッキーウェスト, [ feeding material ] スロープクッションエアー! オフィスにお family に! The load resistance is 100 kg! /bone disc front/low back pain/ダイエットクッション/lw-vg _351pk/bl/cg ((with) luckywest, [ free delivery ] inclined air cushion | office and home | load 100kg |/pelvic correction/low back pain/fat cushion/lw-vg _351pk/bl/cg), [ online ], [ search for 29 th year 4/26 th day ], internet < URL: http:// www.luckywest.co.jp/SH0P/lw _ vg351pk _ bl

Disclosure of Invention

Problems to be solved by the invention

However, in the seating device configured as described above, if seating is continued for a long time, the pelvis in the standing state may gradually fall backward.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a seating device that can be easily held in a state in which a pelvis is standing up for a long time.

Means for solving the problems

The seating device of the present invention is a seating device on which a user sits, and includes a hollow and flexible main body portion having a seating surface inclined so as to rise backward and a rising portion provided at a rear portion of the main body portion and rising upward.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the pelvis can be raised while maintaining an appropriate angle between the pelvis and the femur by the inclination of the seating surface. When the sitting surface is lowered by the sitting person sitting thereon, a portion on the rear side of the lowered portion is relatively raised, and therefore, the rear side of the pelvis is supported so as to be tilted forward by the raised portion provided at the rear portion of the main body. Therefore, the pelvis can be easily kept in the standing state for a long time.

Drawings

Fig. 1 is a perspective view showing a seating device in the present embodiment.

Figure 2 is a top view showing the seating device.

Figure 3 is a front view showing the seating device.

Figure 4 is a rear view showing the seating device.

Figure 5 is a side view showing the seating device.

Figure 6 is a cross-sectional view showing the seating device and is a cross-sectional view corresponding to the cross-section at position a-a of figure 2.

Figure 7 is a cross-sectional view of the seating device and is a cross-sectional view corresponding to the cross-section at position B-B of figure 2.

Figure 8 is a cross-sectional view of the seating device and is a cross-sectional view corresponding to the cross-section at position C-C of figure 2.

Fig. 9 is a sectional view showing the seating device in a state where the user is seated, and is a sectional view corresponding to a section at a D-D position in fig. 2.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described.

The seating device of the present invention may be configured such that the raised portion is hollow and fluid is sealed inside the body portion and the raised portion. According to such a configuration, when the front portion of the main body sinks by the seating of the user, the fluid inside moves rearward and flows into the inside of the swelling portion, and the swelling portion expands to press the pelvis forward, so that the state in which the pelvis is standing up can be more reliably maintained.

In the seating device according to the present invention, the main body may include a regulating member for regulating a relative positional displacement between the bottom surface and the seating surface.

In the seating device according to the present invention, the restricting member may have a peripheral surface that connects an outer peripheral edge of the seating surface and an outer peripheral edge of the bottom surface, and a connecting portion that connects the seating surface and the bottom surface differently from the peripheral surface. According to this configuration, since the relative positional displacement between the seating surface and the bottom surface is restricted by the restriction member, excessive rocking of the seating surface can be suppressed.

In the seating device according to the present invention, the main body may include a bottom surface having an area larger than the seating surface in a plan view. According to this configuration, since the body portion is formed in a stable state supporting the seating surface, stability can be increased.

< example >

Hereinafter, an embodiment embodying the present invention will be described in detail with reference to fig. 1 to 9.

The seating tool S in the present embodiment is a tool that is installed at any place such as a seat surface of a chair or a floor surface and is used by a user sitting thereon. Hereinafter, among the respective components, a side on which a user sits (upper side in fig. 1) is referred to as an upper side, and an opposite side thereof (lower side in fig. 1) is referred to as a lower side, and a front side (lower side in fig. 2) of the user in a state of sitting on the seating tool S is referred to as a front side, a rear side (upper side in fig. 2) is referred to as a rear side, a right side (left side in fig. 2) is referred to as a right side, and a left side (right side in fig. 2) is referred to as a left side.

The seating device S includes a hollow and flexible body portion 10. The body portion 10 as a whole is formed in a flat shape like a seat cushion. The main body 10 has a shape symmetrical with respect to the center in the width direction.

As shown in fig. 6, the main body 10 has a seat wall 11, a bottom wall 12, and a peripheral wall 13, and the internal space surrounded by these walls is hollow. A fluid (gas in this embodiment) is sealed in the internal space.

The main body 10 is made of a flexible synthetic resin (e.g., a soft polyvinyl chloride resin) or a material having rubber elasticity (an elastomer or the like). The body portion 10 is formed by rotational forming. The thickness dimensions of the seat wall 11, the bottom wall 12, and the peripheral wall 13 are set to be substantially constant (about 4mm to 5 mm). The weight of the main body 10 is set to 1600 g.

The seat surface wall 11 has a seating surface 14 on its upper surface (surface) on which a user sits. The seating surface 14 as a whole is gently curved so as to follow the contour of the buttocks of the user and is shallowly recessed. The outer edge 15 of the seating surface 14 protrudes upward along the recess of the seating surface 14 (see fig. 3). By making the circumferential wall 13 stand at an angle close to the vertical, the width of the outer edge portion 15 (the dimension of the seating surface 14 in the inward and outward directions) is gradually narrowed toward the tip. The tip of the outer edge 15 is shaped like an edge.

As shown in fig. 7, the seating surface 14 is inclined so as to rise rearward as a whole. That is, the front end side of the seating surface 14 is relatively low, and the rear end side is relatively high. The seating surface 14 is inclined at different angles at the front (hereinafter, referred to as a seating surface front portion 14F) and the rear (hereinafter, referred to as a seating surface rear portion 14R). The angle of inclination of the seating surface front portion 14F is relatively gentle, and the angle of inclination of the seating surface rear portion 14R is relatively steep. The boundary between the seating surface front portion 14F and the seating surface rear portion 14R is located at the rear end in the front-rear direction of the seating surface 14.

The seating surface 14 has a concave-convex shape. This prevents the buttocks of the seated user from becoming stuffy and prevents the buttocks from slipping. The bottom surface 28 is removed to provide a concave-convex shape over the entire body 10.

The seating device S of the present embodiment is formed with a plurality of stripe-shaped concavities and convexities (hereinafter, referred to as stripe-shaped concave-convex portions 16) as a concave-convex shape (see fig. 1). The bar-shaped uneven portion 16 is formed of a plurality of elongated ribs 17 and elongated grooves 18 formed between adjacent ribs 17, and extends radially from the center side of the seating surface 14 toward the outer edge side. The ridges 17 and grooves 18 of the stripe-shaped uneven portion 16 are thin at the center side and gradually widen toward the outer edge portion 15.

A bulging portion 19 bulging upward is formed in the front portion of the main body 10. As shown in fig. 3, the bulging portion 19 is provided at the center portion in the width direction of the seating surface 14, and is mountain-shaped when viewed from the front. As shown in fig. 7, the bulging portion 19 is formed on the seating surface front portion 14F. The top of the bulging portion 19 is substantially horizontal (parallel to the bottom surface 28) from the rear end (the boundary with the seating surface rear portion 14R) to the front end.

Thigh base thigh receiving portions 21 for receiving the thighs of the seated user are provided on both the left and right sides of the bulging portion 19. As shown in fig. 3, the thigh receiving portion 21 is a recess formed between the outer edge portion 15 of the seating surface 14 and the bulging portion 19, and is bent to follow the root of a thigh of a typical human thigh. Further, as shown in fig. 7, the thigh rest 21 is formed to be inclined downward toward the front with a substantially constant gradient. The protruding dimension of the bulging portion 19 is relatively increased from the rear end toward the front end by the thigh receiving portion 21 being inclined in a manner descending in the front direction. As shown in fig. 2, when the seating surface 14 is viewed in plan, the front ends of the left and right thigh receiving portions 21 are positioned further forward than the front end of the bulging portion 19, and the front edge center portion of the seating surface 14 is recessed shallowly.

The stripe-shaped uneven portion 16 extends substantially parallel to the front-rear direction on the top of the expanded portion 19, and extends obliquely with respect to the front-rear direction on the thigh receiving portion 21. The stripe-shaped uneven portion 16 gradually becomes lateral from the bulging portion 19 toward the rear end of the seating surface front portion 14F (the boundary with the seating surface rear portion 14R).

As shown in fig. 5, a raised portion 22 that rises upward is formed at the rear portion of the main body 10. The ridge portion 22 is provided in a protruding manner at the rear portion of the seating surface 14. The front surface of the bulge portion 22 constitutes the seating surface rear portion 14R. The rear surface of the ridge portion 22 stands at an angle substantially close to the vertical (at right angles to the bottom surface 28), and constitutes a part of the peripheral surface 23 (the outer peripheral surface of the peripheral surface wall 13). The front face of the ridge portion 22 is inclined as compared with the rear face, and the top of the ridge portion 22 is close to the outer edge side of the body portion 10.

As shown in fig. 3, the ridge portion 22 is divided into left and right portions by forming a recess portion 24 in the center portion in the width direction. As shown in fig. 2, the bulge portion 22 is formed to be separated from the front side portion by forming a narrow neck portion 25 at the front end portion.

As shown in fig. 3, a recessed portion 24 is provided by being shallowly recessed at the center in the width direction of the body portion 10. The recessed portion 24 has a recessed dimension that gradually increases from the left and right ends toward the center, and is disposed at the lowest position in the width direction. In other words, the left and right side edges of the recessed portion 24 are inclined so as to gradually decrease toward the center.

As shown in fig. 2, the narrowed neck portions 25 are provided on both the left and right sides of the main body portion 10 and are located at the boundary portion between the seating surface front portion 14F and the seating surface rear portion 14R. By providing the narrow neck portion 25, the bent portions having different sizes on the front side and the rear side of the narrow neck portion 25 are formed on both left and right side edge portions of the seating surface 14. In other words, the left and right side edge portions of the seating surface front portion 14F and the left and right side edge portions of the seating surface rear portion 14R are formed into curved shapes having different sizes in plan view.

The raised portion 22 includes a pair of independent raised portions 26 rising on both left and right sides of the recessed portion 24. The independent raised portions 26 are formed in a shape in which the outer edges thereof are independently curved in a plan view. A portion on the outer edge of the independent ridge portion 26 that is farthest from the center of the seating surface 14 (hereinafter, referred to as an outermost end portion 27) is close to the end in the width direction of the seating surface 14. Further, the outermost end portion 27 of the individual ridge portion 26 is close to the rear end in the front-rear direction of the seating surface 14.

The individual ridges 26 form a mountain shape whose protruding dimension gradually increases from the recessed portion 24 toward the outermost end 27 or from the thin neck portion 25 toward the outermost end 27. That is, the outermost end 27 is highest in the individual ridge 26. The front surface (seating surface rear portion 14R) of the independent ridge portion 26 is inclined so as to descend from each outermost end 27 toward a coupling portion 31 described later. The front faces of the pair of independent protrusions 26 are inclined to the center side (inside) in the width direction, in other words, to descend from both ends in the width direction of the main body 10 toward the center.

The stripe-shaped uneven portion 16 extends substantially in parallel with the front-rear direction from the center of the recessed portion 24 toward the coupling portion 31, and gradually becomes lateral toward the narrow neck portion 25.

The main body portion 10 includes a bottom surface 28 (lower surface of the bottom wall 12) having a larger area than the seating surface 14 in plan view. The outer peripheral edge of the bottom surface 28 is disposed outward of the outer peripheral edge of the seating surface 14 over the entire circumference. The bottom surface 28 is a horizontal and flat surface, and is provided at any installation place such as a seat surface of a chair or a floor surface. The bottom surface 28 is provided with holes (not shown) for injecting or discharging fluid into or from the internal space. The left and right side edges on the outer edge of the bottom surface 28 are bent without interruption as a whole. That is, no recess is formed at the portions corresponding to the recessed portion 24 and the thin neck portion 25 of the seating surface 14 on the outer edge of the bottom surface 28. In the front edge of the bottom surface 28, a gentle recess is formed, as in the seating surface 14.

As shown in fig. 7, the main body 10 includes a peripheral surface 23 (an outer peripheral surface of the peripheral surface wall 13) that connects an outer peripheral edge of the seating surface 14 and an outer peripheral edge of the bottom surface 28. Since the bottom surface 28 has a larger area than the seating surface 14, the upper end of the peripheral surface 23 is located slightly inward of the lower end of the peripheral surface 23 (on the center side of the seating surface 14). In particular, as shown in fig. 6 or 8, the peripheral surface 23 is recessed by the seating surface 14 at portions corresponding to the recessed portions 24 and the narrow neck portions 25 of the seating surface 14 (hereinafter, referred to as peripheral surface recessed portions 29), and the inclination of the peripheral surface 23 is increased as compared with other portions. The lower portion of the peripheral surface recess 29 stands at substantially the same angle as the other portions of the peripheral surface 23, and the upper portion is inclined more than the lower portion.

The circumferential surface 23 has stripe-like irregularities 16 over the entire circumference thereof. The stripe-shaped uneven portion 16 of the peripheral surface 23 extends in the up-down direction. The strip-like uneven portions 16 of the peripheral surface 23 continue from the seating surface 14.

As shown in fig. 6, the main body 10 includes a coupling portion 31 that couples the seating surface 14 and the bottom surface 28 to each other separately from the peripheral surface 23. The coupling portion 31 is provided at a position further to the rear side than the center of the main body portion 10 in the front-rear direction, and in the present embodiment, is provided at a boundary portion between the seating surface front portion 14F and the seating surface rear portion 14R.

As shown in fig. 2, the coupling portion 31 is disposed at the center in the width direction of the main body 10. The position of the coupling portion 31 in the left-right direction is aligned with the recessed portion 24, and the position in the front-rear direction is aligned with the thin neck portion 25. When the user sits at a correct position, the connection portion 31 is positioned directly below the pelvis of the user, and the lower end portions of the ilium are positioned on the left and right sides of the connection portion 31.

As shown in fig. 6, the coupling portion 31 is a vertically standing wall formed in a tubular shape, an upper end of the coupling portion 31 is connected to the seating surface 14 (seating surface wall 11) over the entire circumference, and a lower end of the coupling portion 31 is connected to the bottom surface 28 (bottom surface wall 12) over the entire circumference. The hole inside the coupling portion 31 is opened in the vertical direction and is a through hole 32 that penetrates the main body 10 in the vertical direction (from the seating surface 14 to the bottom surface 28). The through-hole 32 has a horizontally long shape in a plan view as shown in fig. 2.

The stripe-shaped uneven portion 16 extends from the seating surface 14 to the inner peripheral surface of the through hole 32. The stripe-shaped concave-convex portion 16 formed on the inner peripheral surface of the through hole 32 extends vertically.

Next, an example of a case where the seating device S of the present embodiment is used will be described.

First, the user carries the seating device S to an arbitrary place and sets it. At this time, the user can easily carry the seating tool S by putting his or her hand into the through hole 32 of the coupling portion 31.

Then, the user sits on the seating tool S. At this time, since the bulge portion 22 and the expanded portion 19 are provided on the seating surface 14, the proper seating position can be visually recognized easily. Further, when the user is seated at a position shifted to the rear side from the proper seating position, the top of the rising portion 22 locally collides with the hip, and thus the user feels that it is difficult to sit down. Thus, the user is encouraged to sit in the correct position.

When the user is seated in the correct position, the seating surface 14 is deformed to wrap around the buttocks of the user. This allows the user to obtain a soft body feeling, and the contact area between the buttocks and the seating surface 14 is increased, so that the contact pressure is reduced (body pressure is dispersed). Further, the sitting surface 14 is deformed to wrap the buttocks of the user, and the buttocks of the user are fixed, so that the posture is not easily impaired. Therefore, the user can continue to use the disposable diaper for a long time without difficulty.

In a state where the user is seated at the correct position, the base of the thigh of the user is placed on the thigh rest 21. By providing the bulging portions 19 between the thigh receiving portions 21, the user's thighs are fixed at the correct positions in the lateral direction, and can be seated in a natural posture with the right and left knees appropriately spread. Further, by providing the bulging portion 19, the buttocks of the user can be prevented from slipping forward and getting out of position. Since the thigh rest 21 (seating surface 14) is inclined so as to descend in the forward direction, the pelvis can be raised while maintaining an appropriate angle between the pelvis and the femur.

In a state where the user is seated at a correct position, the pelvis is located directly above the coupling portion 31. Therefore, the maximum force is applied around the coupling portion 31. When a large force is applied to the seating surface, the seating surface may be laterally moved to change the seating position of the user. However, since the seating device S of the present embodiment is provided with the coupling portion 31 at the portion where the maximum force is applied, the lateral movement of the seating surface 14 can be effectively prevented, and the change in the seating position of the user can be prevented. Further, the coupling portion 31 prevents a large (excessive) sinking of the seating surface 14, and the inclination of the seating surface 14 is maintained.

When the seating surface 14 sinks down by the seating of the user, the fluid inside moves, and the outer edge portion 15 of the seating surface 14 expands to be in close contact with the hip of the user. Since a load caused by the seating of the user is applied to the front portion relatively larger than the rear portion of the seating surface 14, the fluid inside moves from the front portion to the rear portion of the body portion 10. By moving the fluid to the rear of the main body 10, the bulge 22 is expanded on the back of the user's buttocks and brought into close contact with the buttocks, thereby supporting the pelvis from the rear. At this time, since the coupling portion 31 is provided at the center of the main body portion 10 in the width direction, the fluid inside is divided to the left and right sides of the coupling portion 31 and moves rearward. Further, since the bulge portion 22 is divided into the left and right independent bulge portions 26 by the recessed portion 24 and the narrow neck portion 25, the fluid flows intensively into the inside of the left and right independent bulge portions 26. Thus, the left and right independent swelling portions 26 expand to press the pelvis (lower part of the ilium) of the user from the rear side to the front side, and act on the pelvis of the user to raise the user. Further, since the front face of the independent ridge portion 26 faces the center side in the width direction, the independent ridge portion 26 presses the lower portions of the left and right ilia obliquely forward from obliquely rearward (rearward on both outer sides in the left-right direction). This restricts the ilium of the user from being deviated in the right-left direction or from falling backward, and the user keeps the pelvis from standing.

Further, if the posture of the user is deteriorated (the user becomes a hunched posture and the pelvis falls backward) during long-term use, the top of the rising portion 22 locally collides with the hip, and the user feels difficult to sit down. Therefore, the user is urged to sit in a good posture.

Next, the operation and effect of the embodiment configured as described above will be described.

The seating tool S of the present embodiment is a tool for seating a user, and includes a hollow and flexible main body portion 10, the main body portion 10 includes a seating surface 14 inclined so as to rise backward, and a rising portion 22 rising upward is provided at a rear portion of the main body portion 10. According to this configuration, the pelvis can be raised while maintaining an appropriate angle between the pelvis and the femur by the inclination of the seating surface 14. When the seating surface 14 is lowered by the seated person sitting on the seat, a portion on the rear side of the lowered portion is relatively raised, and therefore, the rear side of the pelvis is supported so as to tilt forward by the raised portion 22 provided at the rear portion of the main body portion 10. Therefore, the pelvis can be easily kept in the standing state for a long time.

The bulge portion 22 is hollow, and a fluid is sealed inside the main body portion 10 and the bulge portion 22. According to this configuration, when the front portion of the main body 10 sinks by the seating of the user, the fluid inside moves backward and flows into the inside of the swelling portion 22, and the swelling portion 22 expands to press the pelvis forward, so that the state in which the pelvis is standing up can be more reliably maintained.

The main body 10 includes a bottom surface 28, a peripheral surface 23 that couples the outer periphery of the seating surface 14 and the outer periphery of the bottom surface 28, and a coupling portion 31 that couples the seating surface 14 and the bottom surface 28 to each other separately from the peripheral surface 23. According to this configuration, since the relative positional displacement of the seating surface 14 and the bottom surface 28 is suppressed at the connecting portion 31, excessive rocking of the seating surface 14 can be suppressed.

The main body 10 further includes a bottom surface 28 having a larger area than the seating surface 14 in a plan view. According to this configuration, since the main body 10 is stably supported by the seating surface 14, stability can be increased.

< other embodiments >

The present invention is not limited to the embodiments described above and illustrated in the drawings, and for example, the following embodiments are also included in the technical scope of the present invention.

(1) In the above embodiment, the main body 10 includes the bottom surface 28, but the present invention is not limited thereto, and the bottom surface of the main body may be open.

(2) In the above embodiment, the coupling portion 31 is formed in a cylindrical shape, but is not limited thereto, and may be formed in any shape as long as the coupling portion couples the seating surface and the bottom surface, and may be, for example, a columnar shape.

(3) In the above embodiment, the through hole 32 is formed in the coupling portion 31, but the present invention is not limited thereto, and the through hole may be closed. In this case, the through-hole may be closed by a core member made of a material harder (less likely to be elastically deformed) than the main body portion.

(4) In the above embodiment, the thickness dimension of the main body 10 is set to be substantially constant, but the present invention is not limited to this, and the body feeling of the user may be changed, for example, by changing the thickness dimension of the main body.

(5) In the above embodiment, the main body 10 is entirely hollow, but the present invention is not limited to this, and a part of the main body may be solid, and for example, the inside of the raised portion may be solid.

(6) In the above embodiment, the raised portion 22 is formed to have the pair of independent raised portions 26 with the recessed portion 24 provided therebetween, but is not limited thereto, and may be a member having a substantially constant projecting height along the rear end portion of the main body portion.

(7) In the above embodiments, the concave-convex shape of the seating surface is specifically exemplified, but the present invention is not limited thereto, and the concave-convex shape of the seating surface may be arbitrarily changed, and the concave-convex shape may not be necessarily provided.

(8) In the above embodiment, the case where the coupling portion 31 is provided in the main body 10 is shown as an example of the restricting member, but the restricting member is not limited to this, and may be formed of a portion of the peripheral wall, for example, a portion formed of a harder material than the other portion from the outer peripheral edge of the seating surface to the peripheral wall or the bottom surface wall, or may be provided in place of or in addition to the coupling portion.

(9) In the above-described embodiment, the entire body portion 10 including the coupling portion 31 is formed of the same material, but is not limited thereto, and the coupling portion may be formed of a material that is less elastically deformable than other portions, for example.

[ notation ] to show

S … seating tool

10 … body part

14 … seating surface

22 … bump

23 … peripheral surface

28 … bottom surface

31 ….

Claims

1. A seating device for a user to sit on,

the seating device includes a hollow and flexible body portion,

the main body includes: a seating surface inclined in a rearward rising manner;

a raised part which is arranged at the rear part of the main body part and is raised upwards;

a recessed portion at a central portion in the left-right direction of the raised portion; and

thin neck parts at the left and right sides of the body part,

the raised part is provided with independent raised parts at two sides of the depressed part and at the rear side of the thin neck part, fluid is sealed in the main body part and the independent raised parts,

when a seated person sits, the fluid inside moves, and the independent bulging portion deforms so as to support the pelvis of the seated person from the rear side.

2. The seating device of claim 1 wherein,

the top of the independent ridge is disposed at the highest position in the body portion.

3. The seating device of claim 1 wherein,

the main body has a regulating member for regulating a relative positional displacement between the bottom surface and the seating surface.

4. The seating device of claim 3 wherein,

the restricting member has:

a peripheral surface connecting an outer peripheral edge of the seating surface and an outer peripheral edge of the bottom surface; and

and a connecting portion that connects the seating surface and the bottom surface differently from the peripheral surface.

5. A seating device as claimed in any one of claims 1-4,

the main body portion includes a bottom surface having an area larger than the seating surface in a plan view.