JP2010094311A - Chair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a failure of giving a bottom reaching feeling to a sitting person when receiving a large load on a sitting surface, in a chair adopting the configuration of incorporating a fluid bag into at least one of a seat and a backrest and making it possible to lead a fluid in and out of the fluid bag. <P>SOLUTION: A thigh part supporting fluid bag 31 and a buttocks part supporting fluid bag 33 having variable capacity fluid chambers 31b1 and 33b1 capable of leading fluid in and out of the inside and fixed capacity fluid chambers 31b2 and 33b2 enclosing the fluid inside respectively, are incorporated in the seat 4 of the chair, and a sitting feeling is changed by the expansion and contraction of the fluid bags 31 and 33 accompanying the leading of the fluid in and out of the variable capacity fluid chambers 31b1 and 33b1. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a chair in which a fluid bag is built in at least one of a seat and a backrest.

Conventionally, a chair having a fluid bag in which at least one of the seat or the backrest is filled with fluid is known in order to provide the seat or the backrest with a cushion function (see, for example, Patent Document 1). . In such a chair, it is conceivable that the fluid bag is inflated and contracted, the surface shape of the fluid bag is deformed, and the fluid bag supports at least one of the thigh, the buttocks, the waist, and the back. Further, it is also considered that the fluid can be led into and out of the fluid bag and the cushioning property can be changed.
JP 2002-45261 A

  However, if the fluid bag having the configuration described in Patent Document 1 adopts a configuration that allows the fluid to be introduced and removed as it is, the fluid bag has a small amount of fluid, and when a large load is applied to the seating surface, The site | part which the outer wall of the seating surface side of a bag and the outer wall on the opposite side to a seating surface generate | occur | produce directly occurs. At that time, at the part where the outer wall on the seating surface side of the fluid bag and the outer wall on the opposite side of the seating surface are in direct contact, the seated person is given a feeling of bottoming that can be felt that he has directly contacted the outer shell of the fluid bag. This can cause problems.

  The present invention aims to solve such problems.

  That is, in order to solve the above-described problem, the chair according to the present embodiment has a variable capacity fluid chamber in which fluid can be introduced and introduced into at least one of a seat and a backrest, and a constant capacity in which fluid is enclosed. A fluid bag having a fluid chamber is built in, and the seating feeling can be changed by expansion and contraction of the fluid bag as the fluid flows into and out of the variable capacity fluid chamber.

  In such a case, even when all the fluid is derived from the variable capacity fluid chamber, the fluid is sealed in the constant capacity fluid chamber, so that the fluid in the constant capacity fluid chamber is It plays the role of a cushion and can prevent the seated person from feeling a bottom.

  As a configuration for easily forming a fluid bag having a constant volume fluid chamber, there is a configuration in which the constant volume fluid chamber is provided outside the variable capacity fluid chamber. This is because such a fluid bag can be formed by bonding a fluid bag having a constant volume fluid chamber to a fluid bag having a variable volume fluid chamber.

  On the other hand, as a mode for more reliably suppressing the leakage of fluid from the above-described constant volume fluid chamber, there is one in which the constant volume fluid chamber is provided inside the variable volume fluid chamber. In such a case, at least a part of the outer wall of the constant volume fluid chamber is disposed inside the variable capacity fluid chamber that cannot be accessed from the outside, so that the outer wall of the constant volume fluid chamber is This is because the occurrence of damages that are damaged is reduced.

  Further, as a configuration capable of effectively suppressing the leakage of fluid from the constant volume fluid chamber, the fluid to be introduced into and introduced into the variable capacity fluid chamber is different from the fluid sealed in the constant volume fluid chamber. Are listed. If it is such, even if the outer wall of the variable capacity fluid chamber and the outer wall of the constant capacity fluid chamber are formed to the same thickness with the same material, the constant capacity from the wall body made of the material This is because if the permeability of the fluid sealed in the fluid chamber is low, fluid leakage from the constant volume fluid chamber can be suppressed.

  As an example of a specific configuration of the fluid bag described in the previous stage, the fluid to be led out to and from the variable capacity fluid chamber is air, and the fluid sealed in the constant capacity fluid chamber is a size that does not pass through the fluid bag, such as nitrogen. In other words, the gas is composed of only the other molecules.

  According to the configuration of the chair according to the present invention, even when all the fluid is led out from the variable capacity fluid chamber, the fluid is sealed in the constant capacity fluid chamber. It is possible to prevent the fluid from acting as a cushion and giving a seated person a feeling of bottoming.

  Hereinafter, an embodiment in which the present invention is applied to a synchro tilt type office swivel chair will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, this chair has a seat 4 disposed on a support base 2 supported by a leg 1 via a seat receiver 3, and a backrest 5 is tilted backward on the support base 2. It is operably attached. The backrest 5 is provided with a lumbar support 6, a headrest 7 and an armrest 8. Hereinafter, the configuration of each unit will be described.

  <Configuration of Leg Part 1> As shown in FIGS. 1 to 3, the leg part 1 includes a leg blade type leg base 11 having casters 11a and a leg support 13 erected at the center of the leg base 11. It comprises. The leg support 13 is a normal one mainly composed of a gas spring, and the support base 2 is attached to the upper end of the leg support 13.

  <Structure of Support Base 2> As shown in FIGS. 2 and 3, the support base 2 is supported by the leg 1 so as to be horizontally pivotable, and includes a housing 15 attached to the leg support 13 and the housing 15. A support shaft 17 for supporting the backrest that penetrates the housing 15, and a tilting reaction force (not shown) that generates an elastic repulsive force against the backward tilting operation of the backrest 5 by applying a force to the support shaft 17. And a mechanism. The tilt reaction force generation mechanism is configured to be able to apply an elastic repulsion force in the rotational direction to the support shaft 17 by using a coil spring, a gas spring or the like (not shown), but is a normal one. Description is omitted.

  <Structure of Seat Receiver 3> As shown in FIGS. 3 and 4, the seat receiver 3 is attached to the upper surface of the seat main body 19 and the seat main body 19 with screws or the like so that the seat 4 can be moved back and forth. And a guide member 21. The seat main body 19 is a thick plate reinforced by a large number of ribs. The front end side 19a is supported by the support base 2 so as to be movable back and forth, and the rear end side 19b is described later. The backrest 5 is supported so as to be relatively rotatable. With this configuration, the seat 4 disposed on the seat receiver 3 sinks at a constant angle ratio with respect to the back tilting operation of the backrest 5, in other words, a synchro tilting operation is realized. It has become.

  <Structure of Seat 4> As shown in FIGS. 1 to 9, the seat 4 has a thigh support region 4b, a buttocks support region 4c, and left and right side support regions 4d and 4e. As a specific structure, a seat unit 25 is mounted on a seat outer shell 23.

  The seat outer shell 23 includes a shell main body 23a that is slidably slidable in the front-rear direction on the seat main body 19, and side support forming portions 23b and 23c provided on both the left and right sides of the shell main body 23a. It is integrally formed of synthetic resin. As shown in FIG. 4, a slit 23d extending in the front-rear direction is formed in the shell body 23a. These slits 23d have an inverted L-shaped transverse cross-sectional shape whose bottom surface side is narrower than the upper surface side, and the guide member 21 slidably engaged with these slits 23d is screwed into the seat receiving body 19. The seat outer shell 23 is attached to the seat receiving body 19 so as to be movable back and forth and so as not to be detached. A lock mechanism (not shown) for adjusting the fixing position of the seat 4 in the front-rear direction is provided between the seat outer shell 23 and the seat receiving body 19. This locking mechanism can always release the locked state by locking the seat outer shell 23 to the seat receiving body 19 and operating one of the non-fluid bag operating bodies 4y described later. As usual. One side support forming portion 23b of the seat outer shell 23 is provided with a notch window 23e for exposing a fluid bag operation body 4x, that is, an opening / closing operation body 35c and a release operation body 37c described later, The other side support forming portion 23c is provided with an operating body mounting portion 23f for mounting the non-fluid bag operating body 4y. The seat unit 25 is mounted on the seat outer shell 23 thus formed.

  As shown in FIG. 4, the seat unit 25 includes a seat inner shell 27 and an exterior material 29 that covers the surface side of the seat inner shell 27, and the seat inner shell 27 and the exterior material 29 are provided. The thigh support fluid bag 31 which expands and contracts by the introduction and introduction of air, which is a fluid, and the buttocks support fluid bag 33 are interposed therebetween. These fluid bags 31 and 33 are connected so as to be able to communicate with each other through a communication channel 39 opened and closed by an on-off valve 35, as shown in FIGS. The air can be opened to the atmosphere as an external fluid existence environment via a release flow path 41 opened and closed by a release valve 37. These valves 35 and 37 that are fluid control devices are attached to the seat inner shell 27 by a lower surface cover 43 that is a holding member.

  As shown in FIGS. 4 and 9, the seat inner shell 27 is for receiving a load acting on the seating surface 4a of the seat 4, and includes a shell body 27a and side supports provided on both left and right sides of the shell body 27a. And a forming portion 27b. The shell main body 27a and the side support forming portion 27b are integrally formed of synthetic resin or the like, and the side support forming portion 27b has a recessed shape on the back side. As shown in FIGS. 4 and 7, both the fluid bags 31 and 33 are attached to the surface side of the shell body 27 a, and the on-off valve 35 and the release valve 37, which are fluid control devices, are provided on the side support. It is positioned and arranged on the back side of the forming portion 27b by ribs 27f. Then, by attaching the lower surface cover 43 to the side support forming portion 27b with screws or the like, the both valves 35 and 37 are held by the seat inner shell 27. A pair of passages 27c are formed at the boundary between the shell body 27a and the side support forming portion 27b, and the fluid bags 31, 33 and the valves 35, 37 are connected to the passages 27c. The pipes 39a and 39b are inserted. As shown in FIGS. 4 and 9, each of the passages 27 c includes a tunnel portion 27 d formed by recessing the back side of the seat inner shell 27 in a groove shape, and the inside of the tunnel portion 27 d within the seat inner shell 27. And a hole 27e communicating with the surface side. The width and depth of the tunnel portion 27d are set to dimensions that allow the pipes 39a and 39b to be fitted therein. The peripheral portion of the exterior material 29 is fixed to the lower surface side of the peripheral portion of the seat inner shell 27 thus formed using a tacker or the like (not shown).

  As shown in FIGS. 3 to 6, the exterior material 29 includes an external cushion 29a made of molded urethane or the like, and a tension fabric 29b that covers the surface side of the external cushion 29a. The exterior material 29 is drawn toward the seat inner shell 27 at a middle position in the front-rear direction of the seat 4, thereby forming a boundary k1 that partitions the thigh support region 4b and the buttocks support region 4c. Yes. The thigh support fluid bag 31 is built in the thigh support region 4b, and the heel support fluid bag 33 is built in the heel support region 4c. In other words, these fluid bags 31 and 33 are arranged adjacent to each other with the boundary k1 interposed therebetween. The configuration of the retracted portion of the exterior material 29 will be specifically described as follows. As shown in an enlarged view in FIG. 6, a region defining groove k1m is formed in a portion corresponding to the boundary k1 on the surface side of the external cushion 29a. Then, by pulling the lead-in wire k1s attached to the surface side of the upholstery 29b in the direction of the seat inner shell 27, the draw-in wire k1s is immersed together with the upholstery 29b into the region defining groove k1m. k1 is formed. A string k1h or the like penetrated through the outer cushion 29a and the seat inner shell 27 is used for drawing in the lead-in wire k1s.

  As shown in FIG. 5, a wall k1k including the region defining groove k1m is formed at a portion corresponding to the boundary k1 on the bottom surface side of the external cushion 29a, and the wall k1k defines the boundary k1k. A substantial thickness is given to k1. In other words, the wall k1k positions the adjacent fluid bags 31 and 33 so as not to approach each other below a certain distance. In this seat 4, as shown in FIG. 1, boundaries k2, k3 are also formed between the thigh support region 4b and the left and right side support regions 4d, 4e, and the buttocks support region Boundaries k4 and k5 are also formed between 4c and the left and right side support regions 4d and 4e. And the positioning of the fluid bag 31 for supporting the thigh in the left-right direction is performed by the walls k2k, k3k formed in the portions corresponding to the boundaries k2, k3 on the back side of the external cushion 29a, and the boundary Positioning in the left-right direction of the fluid bag 33 for supporting the heel portion is performed by walls k4k, k5k formed at portions corresponding to k4, k5.

  As shown in FIGS. 4, 7 and 8, the thigh support fluid bag 31 is made of a synthetic resin film or the like, and is capable of inflating and contracting the air as the first fluid. A bag body 31a that forms a capacity fluid chamber 31b1 and an internal cushion 31c that is an elastic body for self-recovery accommodated in the variable capacity fluid chamber 31b1 are provided at one end of the variable capacity fluid. A fluid outlet 31d communicating with the chamber 31b1 is provided. Inside the variable capacity fluid chamber 31b1 of the bag body 31a, a constant capacity fluid chamber 31b2 filled with nitrogen as the second fluid is provided. In the present embodiment, the constant capacity fluid chamber 31b2 is formed between the part of the bag 31a and the partition wall 31b3 by providing a partition wall 31b3 inside the bag body 31a. In the present embodiment, the constant volume fluid chamber 31b2 is provided on the side opposite to the seating surface 4a. That is, the variable capacity fluid chamber 31b1 is disposed on the seating surface 4a side. The internal cushion 31c is made of slab urethane or the like, and has a notch 31f for forming a cavity in a portion corresponding to the fluid outlet 31d and is fluid on the surface on the seating surface 4a side. A flow groove 31g is provided as a flow control means for smoothing the air flow. For example, a plurality of the flow grooves 31g are formed in parallel. The fluid bag 31 has a thickness having an upright wall portion 31e at the periphery thereof, and has a smaller thickness change rate than a coplanar fluid bag having no upright wall portion.

  Here, the “thickness change rate” refers to the fluid bag 31 for supporting the thigh, the fluid bag 33 for supporting the buttocks, the fluid bag 59 for supporting the back, which will be described later, It means a change value of the thickness dimension per unit flow rate in the case where air as a fluid is led into and out of a fluid bag 61 for supporting a lower back, which will be described later. In addition, the said thickness dimension is a dimension of the direction orthogonal to the seating surfaces 4a and 5a, Comprising: The value of a site | part with the largest change is said. In other words, the thickness dimension is a dimension in a direction perpendicular to the seating surfaces 4a and 5a, and is a value of a part that most affects the seating surfaces 4a and 5a. In order to set the seating feeling, the seating surface 4a, how much the fluid bag 31, 33, 59, 61 is more than how the total volume of the fluid bag 31, 33, 59, 61 changes. This is because it is necessary to pay attention to whether it expands or contracts in the 5a direction.

  The rate of change in thickness of the fluid bags 31, 33, 59, 61 is such that the fluid bags 31, 33, 59, 61 incorporated in the seat 4 or the backrest 5 are placed on the seating surfaces 4 a, 5 a of the seat 4 or the backrest 5. This is a characteristic value that represents the magnitude of the effect. The fact that the rate of change in thickness indicates a large value means that the thickness of the fluid bag 31, 33, 59, 61 is more easily changed with respect to the introduction and introduction of air as the same amount of fluid. The fact that the rate of change shows a small value means the opposite.

  The rate of change in thickness can be basically adjusted by making the substantial capacity of the fluid bags 31, 33, 59, 61 different. However, in the fluid bag 31, 33, 59, 61 applied to the chair, depending on the overall shape of the seat 4 or the backrest 5, or the shape or width of the region in which the fluid bag 31, 33, 59, 61 is incorporated, The projection area and shape from the seating surface side are subject to certain restrictions. Therefore, in order to adjust the rate of change in thickness of the fluid bags 31, 33, 59, 61 under such restrictions, the peripheral shape of the fluid bags 31, 33, 59, 61, that is, the presence or absence of the standing wall portions 31e, 33e, The deformation characteristics of the portions 31e and 33e are an important factor.

  As shown in FIGS. 4, 7, and 8, the heel support fluid bag 33 is a variable capacity fluid that is made of a synthetic resin film or the like and in which air as a first fluid can be led in and out. A bag 33a that forms a chamber 33b1, and an internal cushion 33c that is an elastic body for self-recovery accommodated in the variable capacity fluid chamber 33b1, and at one end thereof, the variable capacity fluid chamber A fluid outlet 33d communicating with 33b1 is provided. Inside the variable capacity fluid chamber 33b1 of the bag 33a, a constant capacity fluid chamber 33b2 in which nitrogen as a second fluid is sealed is provided. In this embodiment, the constant capacity fluid chamber 33b2 is formed between the part of the bag 33a and the partition 33b3 by providing a partition 33b3 inside the bag 33a. In the present embodiment, the constant volume fluid chamber 33b2 is provided on the side opposite to the seating surface 4a. That is, the variable capacity fluid chamber 33b1 is arranged on the seating surface 4a side. The inner cushion 33c is made of slab urethane or the like, and has a notch 33f for forming a cavity at a portion corresponding to the fluid outlet port 33d, and is fluid on the surface on the seating surface 4a side. A flow groove 33g is provided as a flow control means for smoothing the air flow. For example, a plurality of the flow grooves 33g are formed in parallel. The fluid bag 33 has a thickness having a standing wall portion 33e at the periphery thereof, and the rate of change in thickness is set smaller than that of a fluid bag having the same plane shape without the standing wall portion. The fluid outlet 33 d of the fluid bag 33 is connected to the fluid outlet 31 d of the fluid bag 31 via the communication channel 39, and the communication channel 39 can be intermittently connected by the opening / closing valve 35. ing.

  As shown in FIGS. 4 and 7, the opening / closing valve 35 has a first port 35a at one end and a second port 35b at the other end, in order to intermittently connect the ports 35a and 35b. It is a normal thing provided with the valve element which is not illustrated. As shown in FIG. 7, the open / close valve 35 allows the first port 35a and the second port 35b to communicate with each other when an open / close operating body 35c having a lever shape is operated to an open position o shown by a solid line. The communication between the ports 35a and 35b is cut off when operated to the closed position c shown in FIG. The first port 35a of the open / close valve 35 is connected to the fluid outlet 31d of the thigh support fluid bag 31 via a pipe 39a that constitutes a part of the communication channel 39, and the second port 35b is In addition, it is connected to a fluid outlet 33 d of the flange supporting fluid bag 33 through a pipe 39 b constituting a part of the communication channel 39. The release valve 37 is adjacent to the opening / closing valve 35.

  As shown in FIGS. 4 and 7, the release valve 37 has a first port 37a at one end and a second port 37b at the other end, in order to intermittently connect the ports 37a and 37b. It is a normal thing provided with the valve element which is not illustrated. The release valve 37 includes a release operation body 37c having a push button shape. When the release operation body 37c is pressed to the release position, the first port 37a and the second port 37b communicate with each other. When the operation is stopped, the communication between the ports 37a and 37b is blocked. The first port 37a of the release valve 37 is open to the atmosphere as an external fluid existence environment, and the second port 37b is connected to the thigh via a pipe 41a constituting a part of the release channel 41. It is connected to the fluid outlet 31 d of the part support fluid bag 31. As described above, the release valve 37 and the opening / closing valve 35 are attached to the lower surface side of one side support region 4d of the seat 4 using the lower surface cover 43 serving as a holding member.

  As shown in FIGS. 4 and 9, the lower surface cover 43 has a hole 43a for attaching the opening / closing operation body 35c of the opening / closing valve 35 and a window for exposing the release operation body 37c of the release valve 37 to the outside. It is a plate having 43b and is attached to the side support forming portion 27b of the seat inner shell 27 using screws or the like. In a state where the lower surface cover 43 is attached, both valves 35 and 37 positioned by the ribs 27f are held in a sandwiched state between the lower surface cover 43 and the side support forming portion 27b. As shown in FIG. 2, the opening / closing operation body 35 c disposed on the outer surface side of the lower surface cover 43 is mechanically attached to the opening / closing valve 35 through the hole 43 a, and the release operation body 37 c of the release valve 37. Is exposed to the outside through the window 43b. In the state in which the seat unit 25 configured as described above is mounted on the seat outer shell 23, the lower surface cover 43 fits into the notch window 23e of the seat outer shell 23, and in appearance, the lower surface cover. The outer surface of 43 is formed so as to form a part of the outer surface of the seat outer shell 23. Since the coupling structure between the seat inner shell 27 of the seat unit 25 and the seat outer shell 23 is a normal one, illustration and description thereof are omitted. According to the above configuration, the operation portions 35c and 37c of both valves 35 and 37 are also components of the seat unit 25, so that the seat unit 25 including the operation portions 35c and 37c can be attached and detached as a unit. , Can be moved. Further, when the seat unit 25 is mounted on the seat outer shell 23, the seat unit 25 can be directly operated from outside the chair.

  <Configuration of Backrest 5> As shown in FIGS. 1 to 3 and FIGS. 10 to 16, the backrest 5 includes a back support region 5b, a waist support region 5c, and left and right side support regions 5d and 5e. As a specific structure, the back unit 53 is mounted on the surface of the back outer shell 51.

  As shown in FIGS. 2 and 3, the back outer shell 51 is a continuous shell body 51a, a lower end portion 51b positioned below the seat 4, and the shell body 51a smoothly connected to the lower end portion 51b. And an intermediate bent portion 51c. In other words, the back outer shell 51 is formed by extending the lower end 51b to the support base 2 and attaching the extended end 51b1 to the support shaft 17 for supporting the backrest of the support base 2. Yes. The back outer shell 51 is, for example, an integrally formed product made of aluminum die cast, and has a strength comparable to a back support rod in a normal chair. The back outer shell 51 can tilt backward as the support shaft 17 rotates in the same manner as the back support rod. On the upper surface side of the lower end portion 51b of the back outer shell 51, a seat receiving mounting portion 51d for supporting the rear end side 19b of the seat receiving body 19 so as to be relatively rotatable is provided. Further, an armrest mounting portion 51e for mounting the armrest 8 is integrally provided on the surface side of the intermediate bent portion 51c. The back unit 53 is attached to the surface of the back outer shell 51 thus formed.

  As shown in FIGS. 10, 12 and 16, the back unit 53 includes a back inner shell 55 and an exterior material 57 covering the surface side of the back inner shell 55. Between 55 and the exterior member 57, a back support fluid bag 59 that expands and contracts by the introduction and introduction of fluid air and a waist support fluid bag 61 are interposed. As shown in FIGS. 10 and 13, both the fluid bags 59 and 61 are connected to each other through a communication channel 69 that is opened and closed by an opening / closing valve 65, and one of the fluid bags 61 is a release valve. It can be opened to the atmosphere, which is the environment where the external fluid exists, via a release flow path 71 opened and closed by 67. These valves 65 and 67 that are fluid control devices are attached to the back inner shell 55 by a back cover 73 that is a holding member.

  As shown in FIGS. 10 and 15, the back inner shell 55 is for receiving a load acting on the seating surface 5a of the backrest 5, and is provided on the shell main body 55a and both the left and right sides of the shell main body 55a. And a side support forming portion 55b. The shell main body 55a and the side support forming portion 55b are integrally formed of synthetic resin or the like, and the side support forming portion 55b has a recessed shape on the back side as shown in FIG. ing. The fluid bags 59 and 61 are attached to the surface side of the shell body 55a, and the opening / closing valve 65 and the release valve 67, which are fluid control devices, are provided by ribs 55f on the back side of the side support forming portion 55b. Positioned and arranged. The back cover 73 is attached to the side support forming portion 55b with screws, elastic claws or the like, so that the valves 65 and 67 are held by the back inner shell 55. As shown in FIGS. 10 and 15, a pair of passages 55c are formed at the boundary between the shell body 55a and the side support forming portion 55b, and the fluid bags 59, 61 and the passages 55c are formed in these passages 55c. Pipings 69a and 69b for connecting the valves 65 and 67 are inserted. Each of the passages 55c includes a tunnel portion 55d formed by recessing the back side of the back inner shell 55 into a groove shape, and a hole 55e communicating the inside of the tunnel portion 55d with the surface side of the back inner shell 55. It becomes. The width and depth of the tunnel portion 55d are set to dimensions that allow the pipes 69a and 69b to be fitted therein. The peripheral portion of the exterior material 57 is fixed to the back surface side of the peripheral portion of the back inner shell 55 formed in this manner using a tacker or the like (not shown).

  As shown in FIGS. 10 to 12 and 16, the exterior member 57 includes an external cushion 57a made of molded urethane or the like, and a tension fabric 57b that covers the surface side of the external cushion 57a. The exterior material 57 is drawn to the back inner shell 55 side at an intermediate position in the vertical direction of the backrest 5, thereby forming a boundary k11 that partitions the back support region 5b and the waist support region 5c. ing. The back support fluid bag 59 is built in the back support region 5b, and the waist support fluid bag 61 is built in the waist support region 5c. In other words, these two fluid bags 59 and 61 are arranged adjacent to each other with the boundary k11 interposed therebetween. The configuration of the retracted portion of the exterior material 57 will be specifically described as follows. As shown in an enlarged view in FIG. 12, a region defining groove k11m is formed in a portion corresponding to the boundary k11 on the surface side of the external cushion 57a. Then, by pulling the lead-in wire k11s attached to the surface side of the upholstery 57b in the direction of the back inner shell 55, the draw-in wire k11s is immersed in the region defining groove k11m together with the upholstery 57b. k11 is formed. A string k11h or the like penetrated through the external cushion 57a and the back inner shell 55 is used for drawing the lead-in wire k11s.

  As shown in FIG. 11, a wall k11k including the region defining groove k11m is formed at a portion corresponding to the boundary k11 on the back side of the external cushion 57a, and the wall k11k defines the boundary k11k. A substantial thickness is given to k11. In other words, the wall k11k positions the adjacent fluid bags 59 and 61 so as not to approach each other below a certain distance. In this backrest 5, as shown in FIG. 1, boundaries k12 and k13 are also formed between the back support region 5b and the left and right side support regions 5d and 5e, and the waist support region 5c. Boundaries k14 and k15 are also formed between the left and right side support regions 5d and 5e. The back support fluid bag 59 is positioned in the left-right direction by the walls k12k, k13k formed at the portions corresponding to the boundaries k12, k13 on the back side of the external cushion 57a, and the boundary k14, Positioning of the waist bag supporting fluid bag 61 in the left-right direction is performed by walls k14k and k15k formed at a portion corresponding to k15.

  As shown in FIGS. 13 and 14, the back support fluid bag 59 has a variable capacity fluid chamber 59b1 that is made of a synthetic resin film or the like and into which air as a first fluid can be led in and out. A bag body 59a to be formed and an internal cushion 59c, which is an elastic body for self-recovery accommodated in the variable capacity fluid chamber 59b1, are connected to the variable capacity fluid chamber 59b1 at one end thereof. It has a fluid outlet 59d. Inside the variable capacity fluid chamber 59b1 of the bag body 59a, a constant capacity fluid chamber 59b2 filled with nitrogen as a second fluid is provided. In this embodiment, the constant capacity fluid chamber 59b2 is provided between the bag body 59a and a partition wall 59b3 provided with a partition wall 59b3 inside the bag body 59a. In the present embodiment, the constant capacity fluid chamber 59b2 is provided on the side opposite to the seating surface 5a. That is, the variable capacity fluid chamber 59b1 is arranged on the seating surface 5a side. The internal cushion 59c is made of slab urethane or the like, and has a notch 59f for forming a cavity in a portion corresponding to the fluid outlet port 59d and is fluid on the surface on the seating surface 4a side. A flow groove 59g is provided as a flow control means for smoothing the air flow. For example, a plurality of the flow grooves 59g are formed in parallel. The fluid bag 59 does not have a standing wall portion at the periphery thereof, and has a larger thickness change rate than the fluid bag having the same front shape having the standing wall portion.

  As shown in FIGS. 13 and 14, the waist supporting fluid bag 61 has a variable capacity fluid chamber 61b1 that is made of a synthetic resin film or the like and into which air as a first fluid can be led in and out. A bag body 61a to be formed and an internal cushion 61c, which is an elastic body for self-recovery accommodated in the variable capacity fluid chamber 61b1, are provided at one end thereof in communication with the variable capacity fluid chamber 61b1. A fluid outlet 61d is provided. Inside the variable capacity fluid chamber 61b1 of the bag body 61a, a constant capacity fluid chamber 61b2 filled with nitrogen as the second fluid is provided. In this embodiment, the constant capacity fluid chamber 61b2 is provided between the bag body 61a and a partition wall 61b3 provided with a partition wall 61b3 inside the bag body 61a. In the present embodiment, the constant volume fluid chamber 61b2 is provided on the side opposite to the seating surface 5a. That is, the variable capacity fluid chamber 61b1 is disposed on the seating surface 5a side. The internal cushion 61c is made of slab urethane or the like, and has a notch 61f for forming a cavity in a portion corresponding to the fluid outlet port 61d and is fluid on the surface on the seating surface 5a side. A flow groove 61g is provided as a flow control means for smoothing the air flow. For example, a plurality of the flow grooves 61g are formed in parallel. The fluid bag 61 is a thin bag that does not have a standing wall portion on its periphery, and has a thickness change rate larger than that of a fluid bag that has the standing wall portion and has the same front shape. The fluid bag 61 has a smaller area than the back supporting fluid bag 59 in a front view, and the volume of the variable capacity fluid chamber 61b1 is the variable capacity of the back supporting fluid bag 59. It is set smaller than the volume of the fluid chamber 59b1. That is, the thickness change rate of the waist support fluid bag 61 is set to be larger than the thickness change rate of the back support fluid bag 59. The fluid outlet 61 d of the fluid bag 61 is connected to the fluid outlet 59 d of the fluid bag 59 via a communication channel 69, and the communication channel 69 can be intermittently connected by the opening / closing valve 65. ing.

  As shown in FIGS. 10 and 13, the open / close valve 65 has a first port 65 a at one end and a second port 65 b at the other end, in order to intermittently connect the ports 65 a and 65 b. It is a normal thing provided with the valve element which is not illustrated. As shown in FIG. 13, the opening / closing valve 65 allows the first port 65a and the second port 65b to communicate with each other when the lever-shaped opening / closing operation body 65c is operated to the open position o shown by the solid line. The communication between the ports 65a and 65b is cut off when operated to the closed position c shown in FIG. The first port 65a of the on-off valve 65 is connected to the fluid outlet 61d of the waist supporting fluid bag 61 via a pipe 69a that constitutes a part of the communication channel 69, and the second port 65b is It is connected to a fluid outlet 59 d of the back support fluid bag 59 through a pipe 69 b that constitutes a part of the communication channel 69. The release valve 67 is adjacent to the opening / closing valve 65.

  As shown in FIGS. 10 and 13, the release valve 67 has a first port 67a at one end and a second port 67b at the other end, in order to intermittently connect the ports 67a and 67b. It is a normal thing provided with the valve element which is not illustrated. The release valve 67 has a release operation body 67c having a push button shape. When the release operation body 67c is pressed to the release position, the first port 67a and the second port 67b communicate with each other. When the operation is stopped, the communication between the ports 67a and 67b is blocked. The first port 67a of the release valve 67 is open to the atmosphere as an external fluid existence environment, and the second port 67b is supported by the waist portion via a pipe 71a constituting a part of the release flow path 71. The fluid bag 61 is connected to the fluid outlet 61d. The release valve 67 and the opening / closing valve 65 are attached to the back side of one side support region 5d of the backrest 5 using the back cover 73 as a holding member as described above.

  As shown in FIGS. 2 and 15, the back cover 73 has a hole 73 a for attaching the opening / closing operation body 65 c of the opening / closing valve 65 and a window for exposing the release operation body 67 c of the release valve 67 to the outside. It is a plate-shaped member having 73b and is attached to the side support forming portion 55b of the back inner shell 55 using screws, elastic claws or the like. When the back cover 73 is attached, both valves 65 and 67 positioned by the rib 55f are held in a sandwiched state between the back cover 73 and the side support forming portion 55b. The opening / closing operation body 65c arranged on the outer surface side of the back cover 73 is mechanically attached to the opening / closing valve 65 through the hole 73a, and the release operation body 67c of the release valve 67 is connected through the window 73b. To be exposed to the outside. When the back unit 53 configured as described above is mounted on the surface of the back outer shell 51, the outer surface of the back cover 73 is formed so as to be continuous with the back surface of the back outer shell 51. Since the coupling structure between the back inner shell 55 and the back outer shell 51 of the back unit 53 is a normal one, illustration and description thereof are omitted. According to the above configuration, since the operation parts 65c and 67c of both valves 65 and 67 are also components of the back unit 53, the back unit 53 including the operation parts 65c and 67c can be attached and detached as a unit. , Can be moved. Further, when the back unit 53 is attached to the back outer shell 51, the back unit 53 is configured to be directly operable from the outside of the chair. The lumbar support 6 is provided on the backrest 5 formed as described above.

  <Structure of Lumber Support 6> As shown in FIGS. 3 and 16, the lumbar support 6 is a lumbar disposed on the surface side of the back inner shell 55 so as to bite into the back surface of the waist supporting fluid bag 61. A support member 75 and a position adjusting mechanism 77 for moving the lumbar support member 75 in the vertical direction are provided. The lumbar support member 75 has a curved surface 75a for sliding while pressing the back surface of the fluid bag 61. Specifically, the lumbar support member 75 has, for example, a bowl shape. On the back surface of the lumbar support member 75, a pair of protrusions 75b are provided. The position adjusting mechanism 77 includes a vertically extending pair of slits 77a provided on the back inner shell 55 for guiding the protrusions 75b, and an upper end 77c disposed on the back side of the back inner shell 55. An elevating operation lever 77b joined to the projection 75b facing the back side through 77a using a screw 75c. The gripping portions 77d of the elevating operation lever 77b protrude outward from both side edges of the spine unit 53. By applying an operating force in the vertical direction to the gripping portions 77d, the upper and lower portions of the lumbar support member 75 are The direction position can be changed.

  <Configuration of Other Options> As shown in FIGS. 1 to 3, the headrest 7 includes a headrest body 79, a headrest frame 81 that supports the headrest body 79, and an attachment portion 83 that holds the headrest frame 81 so as to be movable up and down. The attachment portion 83 is attached to the surface of the upper end portion of the back outer shell 51 using a screw or the like. Since the mounting structure is a normal one, illustration and description are omitted.

  As shown in FIGS. 1 to 3, the armrest 8 is provided on each side of the backrest 5, and an elbow strut 87 having a base end attached to the armrest attaching portion 51 e of the back outer shell 51, And an elbow rest 89 supported by the elbow support 87.

  Next, the operation of the embodiment described above will be described.

  When this chair leans on the backrest 5, the backrest 5 performs a backward tilting operation with an elastic repulsive force. When the backrest 5 is tilted backward, the seat support 3 having the rear end supported on the lower end of the back outer shell 51 of the backrest 5 performs a synchro operation and tilts in a direction in which the rear end sinks while moving backward. By selectively operating the non-fluid bag operating body 4y provided on the lower surface side of the side support region 4e on the right side of the seat 4, the backrest 5 can be locked at a desired rearward tilt position, or the column 13 of the leg 1 can be locked. The height position of the seat surface can be changed by changing the expansion / contraction position of the seat 4, or the front-rear direction fixing position of the seat 4 with respect to the seat receiver 3 can be changed. The above operation is realized by a known technique employed in a normal office swivel chair or a technique based thereon, and detailed description thereof is omitted. Hereinafter, the operation relating to the fluid bag will be described in detail.

  <Operation related to the seat> The fluid bag operation body 4x disposed on the lower surface side of the left side support portion 4d of the seat 4, that is, the opening / closing operation body 35c and the release operation body 37c are operated to be built in the seat 4. The holding state for the seated person can be adjusted by reciprocally expanding and contracting the fluid bag 31 for supporting the thigh and the fluid bag 33 for supporting the buttocks.

  First, as shown by a solid line in FIG. 7, when the opening / closing operation body 35 c is operated to the open position o, the variable capacity fluid chamber 31 b 1 of the thigh support fluid bag 31 and the variable capacity fluid chamber 33 b 1 of the buttocks support fluid bag 33. Are in communication with each other through the communication channel 39. In this state, when the seated person moves the weight forward and presses the seating surface 4 a of the seat 4 with the thigh, the load in the compression direction on the thigh support fluid bag 31 is greater than the load on the buttocks support fluid bag 33. Also grows. As a result, the air in the thigh support fluid bag 31 flows into the buttocks support fluid bag 33 through the communication channel 39, the thigh support fluid bag 31 is reduced, and the thigh support fluid is reduced. The bag 33 is inflated. Conversely, when the seated person shifts his / her weight rearward and presses the seating surface 4a of the seat 4 with the buttocks, the load on the buttocks support fluid bag 33 becomes larger than the load on the thigh support fluid bag 31. As a result, the air in the buttocks support fluid bag 33 flows into the thigh support fluid bag 31 through the communication channel 39, and the buttocks support fluid bag 33 is reduced and the thigh support fluid bag 33 is reduced. The fluid bag 31 is inflated.

  As described above, when the opening / closing operation body 35c is operated to the open position o, both the fluid bags 31, 33 are inflated and contracted in accordance with the load acting on the seating surface 4a of the seat 4. The seat 4 exhibits the function of changing the support state following the change in the posture of the seated person. On the other hand, as shown by an imaginary line in FIG. 7, when the opening / closing operation body 35c is operated to the closed position c and the opening / closing valve 35 is switched to the shut-off state, both the fluid bags 31, 33 are locked in a desired deformation state. Will be. That is, when the thigh support fluid bag 31 is contracted and the buttocks support fluid bag 33 is locked in an inflated state, the seating surface 4a of the seat 4 holds the seated person in a forward tilted posture, which is suitable for work. It is possible to maintain a proper posture. On the other hand, when the buttocks support fluid bag 33 is contracted and the thigh support fluid bag 31 is locked in an inflated state, the seating surface 4a of the seat 4 is in a state of holding the seated person in a tilted posture, and a relaxed posture Is acceptable. Of course, both fluid bags 31 and 33 can be locked at an intermediate desired position between the forward tilt posture and the rear tilt posture described above. Even in the locked state, air flow and volume changes in the fluid bags 31 and 33 can occur, so that the fluid bags 31 and 33 can individually exhibit a cushion function.

  Even when the opening / closing operation body 35c is operated to the open position o, the air to the constant capacity fluid chamber 31b2 of the thigh support fluid bag 31 and the constant capacity fluid chamber 33b2 of the buttocks support fluid bag 33 is prevented. There is no derivation. That is, even when the air inside one of the variable capacity fluid chambers 31b1 and 33b1 all flows into the other, the constant capacity fluid chamber 31b2 inside the variable capacity fluid chambers 31b1 and 33b1 on the side from which the air has flowed out. 33b2 is maintained in a state in which nitrogen is sealed. Therefore, the cushion function of each fluid bag 31, 33 is maintained at a minimum by the nitrogen in the constant volume fluid chambers 31b2, 33b2.

  The air in the variable capacity fluid chambers 31b1 and 33b1 of the fluid bags 31 and 33 may gradually leak to the outside through a synthetic resin sheet or the like constituting the bag body. Appropriate bulges 31 and 33 cannot be obtained. In this case, the opening / closing valve 35 is opened and a state where no load is applied to the seating surface 4a of the seat 4 is maintained, and then the release operation body 37c is pressed to the release position to open the release valve 37. . As a result, the variable capacity fluid chambers 31b1 and 33b1 of the fluid bags 31 and 33 are opened to the atmosphere via the release flow path 41. As a result, both the fluid bags 31 and 33 are inflated while sucking outside air by the elastic repulsive force of the internal cushions 31c and 33c accommodated therein, and self-reset to the normal reference state. When the fluid bags 31 and 33 have completely returned to the reference position, if the pressing operation to the release operation body 37c is stopped and the release flow path 41 is closed, the above-described operation is performed again. It becomes possible.

  <Backrest Operation> A back support built in the backrest 5 by operating an opening / closing operation body 65c and a release operation body 67c disposed on the back side of the side support portion 5d formed on the left side of the backrest 5. The holding state for the seated person can be adjusted by reciprocally expanding and contracting the fluid bag 59 for supporting and the fluid bag 61 for supporting the waist.

  First, as shown by a solid line in FIG. 13, when the opening / closing operation body 65 c is operated to the open position o, the fluid chamber 59 b of the back support fluid bag 59 and the fluid chamber 61 b of the waist support fluid bag 61 communicate with each other. It becomes a communication state via. In this state, when the seated person presses the seating surface 5a of the backrest 5 with his back in accordance with a backward tilting operation or the like, the load in the compression direction on the back support fluid bag 59 is larger than the load on the waist support fluid bag 61. Become. As a result, the air in the back support fluid bag 59 flows into the waist support fluid bag 61 through the communication channel 69, the back support fluid bag 59 shrinks, and the waist support fluid bag 61 inflates. . On the contrary, when the seated person presses the seating surface 5a of the backrest 5 at the waist with a forward tilting operation or the like, the load on the waist support fluid bag 61 becomes larger than the load on the back support fluid bag 59. As a result, the air in the waist support fluid bag 61 flows into the back support fluid bag 59 through the communication channel 69, the waist support fluid bag 61 shrinks, and the back support fluid bag 59 inflates. .

  As described above, when the opening / closing operation body 65c is operated to the open position o, both the fluid bags 59 and 61 expand and contract in a reciprocal manner according to the load acting on the seating surface 5a of the backrest 5. Yes, the backrest 5 exhibits the function of changing the support state following the change in the posture of the seated person. On the other hand, as shown by an imaginary line in FIG. 13, when the opening / closing operation body 65c is operated to the closed position c and the opening / closing valve 65 is switched to the shut-off state, both the fluid bags 59, 61 are locked in a desired deformation state. Will be. That is, when the back support fluid bag 59 is reduced and the waist support fluid bag 61 is locked in a swelled state, the seating surface 5a of the backrest 5 holds the seated person in a tilted posture, and a relaxed posture or It is possible to maintain a posture suitable for stretching and the like. On the other hand, when the waist supporting fluid bag 61 is contracted and the back supporting fluid bag 59 is inflated and locked, the seating surface 5a of the backrest 5 holds the posture of pushing the seated person's back forward. It becomes possible to maintain a posture suitable for work. Of course, both the fluid bags 59 and 61 can be locked at the intermediate desired position between the two positions described above. Even in the locked state, air flow and volume changes in the fluid bags 59 and 61 can occur, so that the fluid bags 59 and 61 can individually exhibit a cushion function.

  As in the case of the seat 4 described above, the constant capacity fluid chamber 59b2 of the back support fluid bag 59 and the waist support fluid bag 61 are fixed even when the opening / closing operation body 65c is operated to the open position o. Air is not led into and out of the capacitive fluid chamber 61b2. That is, even when all the air inside one of the variable capacity fluid chambers 59b1 and 61b1 flows into the other, the constant capacity fluid chamber 59b2 inside the variable capacity fluid chambers 59b1 and 61b1 on the side from which the air has flowed out. 61b2 is maintained in a state in which nitrogen is enclosed. Therefore, the cushion function of each fluid bag 59, 61 is maintained at a minimum by the nitrogen in the constant capacity fluid chambers 59b2, 61b2.

  Further, the air in the variable capacity fluid chambers 59b1 and 61b1 of the fluid bags 59 and 61 may gradually leak to the outside in the same manner as the seat 4 described above, and the fluid bags 59 and 61 when used for a long period of time. The proper bulge is not obtained. In that case, the opening / closing valve 65 is opened and a state in which no load is applied to the seating surface 5a of the backrest 5 is maintained, and then the release operation body 67c is pressed to the release position to open the release valve 67. To do. As a result, the variable capacity fluid chambers 59b1 and 61b1 of the fluid bags 59 and 61 are opened to the atmosphere via the release flow path 71. As a result, both the fluid bags 59 and 61 are inflated while sucking outside air by the elastic repulsive force of the internal cushion 61c accommodated therein, and self-reset to the normal reference state. When the fluid bags 59 and 61 have completely returned to the reference state, if the pressing operation to the release operation body 67c is stopped and the release flow path 71 is closed, the above-described operation is performed again. It becomes possible.

  In this embodiment, a lumbar support member 75 is interposed between the waist support fluid bag 61 and the back inner shell 55, and the vertical position of the lumbar support member 75 is changed by operating the lifting lever 77b. It is possible to adjust the sense of support of the lower back more precisely. That is, since the lumbar support member 75 is in sliding contact with the back surface of the waist supporting fluid bag 61, the lumbar support member 75 is conspicuous in appearance on the seating surface 5a of the backrest 5 even if the position of the lumbar support member 75 is changed. No change will occur. However, the feeling of repulsion given to the seated person from the waist supporting fluid bag 61 increases in the vicinity of the position where the lumbar support member 75 exists, and the hold feeling of the waist is adjusted by adjusting the position of the lumbar support member 75. It becomes possible.

  As described above, if the configuration according to the present embodiment is adopted, the fluid bags 31, 33, 59, 61 receive a large load when seated, and the variable capacity fluid chambers 31b1, 33b1, 59b1, 61b1 are received. Even when all the air is derived from the air, the constant capacity fluid chambers 31b2, 33b2, 59b2, 61b2 are maintained in a state in which nitrogen is sealed, so that the constant capacity fluid chambers 31b2, 33b2, 59b2, 61b2 are maintained. The cushion function of each fluid bag 31, 33, 59, 61 is maintained by the nitrogen inside, and it is possible to prevent the seated person from feeling a bottom.

  Further, by providing partition walls 31b3, 33b3, 59b3, 61b3 inside the variable capacity fluid chambers 31b1, 33b1, 59b1, 61b1, respectively, constant capacity is provided inside the variable capacity fluid chambers 31b1, 33b1, 59b1, 61b1. Since the fluid chambers 31b2, 33b2, 59b2, 61b2 are formed, the partition walls 31b3, 33b3, 59b3, 61b3 are difficult to access from the outside, and the partition walls 31b3, 33b3, 59b3, 61b3 are damaged by the action from the outside. It is hard to happen. Accordingly, it is possible to more reliably suppress fluid leakage from the constant capacity fluid chambers 31b2, 33b2, 59b2, and 61b2.

  In addition, the variable capacity fluid chambers 31b1, 33b1, 59b1, 61b1 of the fluid bags 31, 33, 59, 61 are disposed on the seating surface 4a side, and the constant capacity fluid chambers 31b2, 33b2, 59b2, 61b2 are disposed on the seating surface 4a. Since the variable capacity fluid chambers 31 b 1, 33 b 1, 59 b 1, 61 b 1 are located on the side directly receiving the load from the seated person, the shape of each fluid bag 31, 33, 59, 61 is seated. It is possible to flexibly respond to changes in posture.

  Further, since the variable capacity fluid chambers 31b1, 33b1, 59b1, 61b1 are led in and out, while the constant capacity fluid chambers 31b2, 33b2, 59b2, 61b2 are filled with nitrogen, the bag Even if the bodies 31a, 33a, 59a, 61a and the partition walls 31b3, 33b3, 59b3, 61b3 are formed with the same thickness by the same material, nitrogen has a larger molecule than oxygen in the air, and the bag body 31a , 33a, 59a, 61a and the partition walls 31b3, 33b3, 59b3, 61b3, and it is possible to effectively suppress the leakage of fluid from the constant capacity fluid chambers 31b2, 33b2, 59b2, 61b2.

  The present invention is not limited to the embodiment described above.

  For example, as schematically shown in a cross section in FIG. 17, the partition wall A31c is not only in the whole area of the variable capacity fluid chamber A31b1 formed in the bag A31a but in a part of the variable capacity fluid chamber A31b1, for example, only in the center. The fluid bag A31 in which the constant volume fluid chamber A31b2 is formed inside the partition wall A31c may be used instead of each fluid bag in the above-described embodiment. In this embodiment, the variable capacity fluid chamber A31b1 is disposed on the seating surface side and the constant capacity fluid chamber A31b2 is disposed on the opposite side of the seating surface. Therefore, the shape of each fluid bag can be flexibly accommodated by the change in the seating posture. In addition, in this aspect, since the variable capacity fluid chamber A31b1 extends over the entire seating surface of the fluid bag A31, it is possible to receive a change in load distribution corresponding to a change in the seating posture of the seated person over a wider area. .

  Further, as schematically shown in a cross section in FIG. 18, a first bag body B31a having a variable capacity fluid chamber B31b1 inside, and a constant capacity fluid chamber B31b2 circumscribing the first bag body B31a inside. The fluid bag B31 including the second bag body B31h may be used instead of each fluid bag in the above-described embodiment. In such a case, the second bag body B31h having the constant capacity fluid chamber B31b2 is bonded to the first bag body B31a having the variable capacity fluid chamber B31b1 inside, thereby the variable capacity fluid chamber. A fluid bag B31 having B31b1 and a constant volume fluid chamber B31b2 can be easily formed.

  Furthermore, as schematically shown in FIG. 19, a second bag body C31h having a constant capacity fluid chamber C31b2 is intermittently provided outside the first bag body C31a having a variable capacity fluid chamber C31b1 inside. A plurality of fluid bags C31 may be employed instead of the fluid bags in the above-described embodiment.

  On the other hand, in the above-described embodiment, the fluid bags 31, 33, 59, 61 and the outer cushions 29a, 57a of the exterior materials 29, 57 are arranged without a substantial gap. However, as shown in FIG. More preferably, gaps 31 s and 33 s are provided between the thigh support fluid bag 31 and the heel support fluid bag 33 and the outer cushion 29 a of the exterior material 29.

  If comprised in this way, the expansion allowance of the said fluid bags 31 and 33 is securable. That is, since the fluid bags 31 and 33 can be deformed using the gaps 31s and 33s when the fluid bags 31 and 33 receive a load at the time of sitting, the cushioning properties of the fluid bags 31 and 33 are improved. It can be secured to improve sitting comfort. 20 shows an example of the thigh support fluid bag 31 and the buttock support fluid bag 33. However, the back support fluid bag 59 and the waist support fluid bag 61 and the exterior material 57 of the backrest 5 are not shown. Of course, a clearance may be similarly provided between the external cushion 57a. In addition, a gap may be provided between some of the fluid bags and the external cushion, instead of providing a gap between all the fluid bags and the external cushion.

  Further, the fluid led out to and from the variable capacity fluid chamber does not need to be air, and may be other gas such as nitrogen or a liquid such as water.

  In addition, the same effect can be obtained if the fluid sealed in the constant volume fluid chamber is not limited to nitrogen but is a gas composed only of molecules having a size that does not pass through the fluid bag. Further, the same effect can be obtained even if the liquid sealed in the constant volume fluid chamber is a liquid composed only of molecules having a size that does not pass through the fluid bag. Furthermore, even if the fluid sealed in the constant volume fluid chamber is the same as the fluid led out to the variable volume fluid chamber, such as air, the outer wall of the constant volume fluid chamber is formed of a material having low gas molecule permeability, Alternatively, the same effect can be obtained by a configuration in which the outer wall of the constant volume fluid chamber is a double wall. In addition, even if a fluid introduction means for introducing fluid into the constant volume fluid chamber is connected and a check valve for suppressing fluid leakage from the constant volume fluid chamber is provided, the same applies. The effect is obtained. As a specific example of such a configuration, an elastic body for self-recovery is arranged inside the constant volume fluid chamber, and the constant volume fluid chamber communicates with the outside so that air can be introduced into the constant volume fluid chamber. And a non-return valve for permitting the introduction of air from outside and restricting the outflow of air to the outside.

  In the above embodiments, a plurality of fluid bags having different capacities are connected, or even if there is no large difference in capacity, for example, by changing the shape depending on the presence or absence of a standing wall, etc. Although the case where the thickness change rate is varied between the fluid bags is described, the present invention is not limited to such a configuration. However, if the thickness change rate is made different between the fluid bags as in this embodiment, for example, it is better to make the change in expansion / contraction of the fluid bag stronger like the lumbar support part. A thing with a large thickness change rate can be placed, and a part with a small thickness change rate can be placed in the part where the change in expansion and contraction of the fluid bag does not need to be felt so much, and a comfortable holding feeling can be obtained as a whole chair. It becomes possible.

  In addition, various changes may be made without departing from the spirit of the present invention.

1 is an overall perspective view showing an embodiment of the present invention. The whole perspective view which shows the back side of the embodiment. The exploded perspective view of the embodiment. The disassembled perspective view which shows the seat of the embodiment. The perspective view which shows the external cushion of the seat in the embodiment from the lower surface side. The partial expanded sectional view of the seat in the embodiment. The bottom view which shows the fluid bag of the seat in the embodiment. XX sectional drawing in FIG. The disassembled perspective view which shows the inner shell of the seat in the embodiment from the lower surface side. The disassembled perspective view which shows the backrest of the embodiment. The perspective view which shows the external cushion of the backrest in the embodiment from the back side. The partial expanded sectional view of the backrest in the embodiment. The rear view which shows the backrest fluid bag in the same embodiment. The YY sectional view taken on the line in FIG. The partial expansion perspective view which shows the inner shell of the backrest in the embodiment from the back side. The fragmentary sectional view which shows the lumbar support part of the backrest of the embodiment. The cross-sectional view which shows schematically the fluid bag in the 1st modification of this invention. The cross-sectional view which shows schematically the fluid bag in the 2nd modification of this invention. The cross-sectional view which shows schematically the fluid bag in the 3rd modification of this invention. The partial expanded sectional view of the seat in the 4th modification of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 4 ... Seat 5 ... Backrest 31 ... Fluid bag for thigh support 33 ... Fluid bag for hip support 59 ... Fluid bag for back support 61 ... Fluid bag for waist support 31b1, 33b1, 59b1, 61b1 ... Variable Capacity fluid chamber 31b2, 33b2, 59b2, 61b2 ... Constant capacity fluid chamber

Claims (6)

  A fluid bag having a variable capacity fluid chamber into which fluid can be introduced and introduced into at least one of a seat and a backrest and a constant capacity fluid chamber in which the fluid is enclosed is incorporated, and the variable capacity fluid chamber is provided. A seating feeling can be changed by expansion and contraction of the fluid bag accompanying the flow of fluid into and out of the chair.   The chair according to claim 1, wherein the constant volume fluid chamber is provided outside the variable volume fluid chamber.   The chair according to claim 1, wherein the constant volume fluid chamber is provided inside the variable volume fluid chamber.   The variable-capacity fluid chamber of the fluid bag is disposed on the seating surface side of the seat or the backrest, and the constant-capacity fluid chamber is disposed on the opposite side of the seating surface of the seat or the backrest. Chair.   The chair according to claim 1, 2, 3, or 4, wherein the fluid to be introduced into and introduced into the variable capacity fluid chamber is different from the fluid sealed in the constant capacity fluid chamber. 6. The fluid to be led into and out of the variable capacity fluid chamber is air, and the fluid sealed in the constant capacity fluid chamber is a gas composed of only molecules having a size that does not pass through the fluid bag, such as nitrogen. Chairs.

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