JP2012010934A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair that solves the problem of a holding feeling and the problem of air permeability all at once without requiring advanced design techniques or experiences.SOLUTION: The chair is configured as follows. A backrest includes a back shell in which a plurality of vertically-extending strip members are arranged laterally side by side in an upper region and projections continuous to the strip members are formed in a lower region having a concavo shape wherein the lateral both sides protrude further forward than the lateral middle part.

Description

  The present invention relates to a chair suitably used in an office or the like.

  2. Description of the Related Art Conventionally, various types of chairs having a backrest using a back shell having an opening at an intermediate portion are known as one of this type of chair (see, for example, Patent Document 1).

  However, in this type of chair, when an opening is provided in the entire middle part of the back shell in order to soften the seating feeling, the feeling of holding the seated person around the waist tends to be impaired.

  On the other hand, in this type of chair, when an opening is provided only in the upper region of the back shell in order to secure a feeling of holding around the waist while maintaining a soft feeling of sitting, the air permeability of the lower region is likely to be impaired. .

  Advanced design technology and experience are required to design a seated back while eliminating these problems in a well-balanced manner.

JP 2010-63822 A

  The present invention has been made paying attention to the above circumstances, and can solve the above-mentioned problem of hold and air permeability at a time without requiring advanced design technology and experience. The purpose is to provide a chair that can be used.

  The present invention employs the following configuration in order to solve the above-described problems. That is, in the chair according to the present invention, the belt-like member is formed in a lower region in which a backrest is formed in a concave shape in which a plurality of belt-like members extending in the vertical direction in the upper region are arranged in the left and right directions, and both left and right sides protrude forward from the middle in the horizontal direction. And a back shell having a continuous ridge formed thereon.

  If it is such, while maintaining the softness of a seating feeling in the upper region of the back shell, it is possible to ensure a hold feeling with respect to the waist in the lower region of the back shell, and adjacent between adjacent belt-like members. Since the space between the ridges is continuous, air can pass through the portion, and air permeability can be secured.

  As a specific example, the upper region has a front portion that receives the back of the seated person, an upper curved portion that is provided continuously from the upper edge of the front portion and is curved until it is substantially horizontal at the top, and the upper curved portion. A back surface portion that is provided continuously to the rear edge of the portion and that curves downward and hangs downward, and the tip of the belt-shaped member is formed on the back surface portion, and the length dimension of each belt-shaped member is And those set so as to gradually decrease from the center of the back shell toward the left and right.

  A specific example of the lower ends of the plurality of strip-shaped members arranged on the left and right is located along a virtual curve line that gradually curves upward from the center of the back shell toward the left and right.

  It is preferable that the back shell has the widest width corresponding to the waist, and gradually becomes narrower upward from this width.

  If adjacent belt-like members are connected to each other at a position other than the top of the back shell, flexibility at the upper edge portion of the back shell can be secured.

  In the case where the back shell is supported by a back support member disposed facing the back surface of the back shell through a space, the back support member has a width dimension smaller than the width dimension of the upper region. What has is mentioned as a suitable one aspect | mode.

  A preferred example of the lower region of the back shell includes a waist corresponding portion corresponding to the waist of the seated person, and the upper region is formed continuously with the waist corresponding portion.

  In the upper region of the back shell, a slit-like opening is formed between the adjacent belt-like members, and the lower region of the back shell not having the slit-like opening is attached to the front surface of the back support arm The embodiment which is is mentioned as a preferable example.

  In the case where the back shell has a groove that opens outward on the periphery, the end of the stretch fabric attached to the outer surface of the back shell is pushed into the groove and fixed It is preferable that

  As described above, according to the present invention, it is possible to provide a chair that can solve the above-mentioned problem of holding and air permeability at once without requiring advanced design technology and experience.

The perspective view from the front which shows one Embodiment of this invention. The perspective view from the front which decomposes | disassembles and shows the tension ground of the embodiment. The front which abbreviate | omits and shows the tension | tensile_strength of the embodiment partially. The left view which decomposes | disassembles and shows the tension ground of the embodiment. The rear view which abbreviate | omits and shows the tension place of the embodiment partially. The perspective view from the back which abbreviate | omits and shows the leg of the embodiment. The disassembled perspective view which abbreviate | omits and shows a part of the whole embodiment. The perspective view from the front which expands and shows the principal part of the support base and back support arm of the embodiment. The disassembled perspective view which expands and shows the principal part of the support base of the same embodiment, and a back support arm. The perspective view from the back which abbreviate | omits and shows the support base part of the embodiment abbreviate | omitting. The front view which decomposes | disassembles and shows the support base part of the embodiment. The left view which shows the support base and seat of the embodiment. Explanatory drawing equivalent to FIG. 12 which shows the locking mechanism of the embodiment. The disassembled perspective view which shows the seat and seat receiver of the embodiment. Sectional view on the AA line which showed the principal part in FIG. BB sectional drawing which showed the principal part in FIG. CC sectional view which showed the principal part in FIG. The perspective view which showed the attachment structure of the backrest support body and back support member of the embodiment. The perspective view which decomposes | disassembles and shows the back shell and back support member of the embodiment. The front view of the back shell of the embodiment. The front view of the back support member of the embodiment. DD line sectional drawing which showed the principal part in FIG. EE sectional view which showed the principal part in FIG. The FF line expanded sectional view in FIG. The GG sectional view taken on the line in FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  In this embodiment, the present invention is applied to an office swivel chair.

  As shown in FIGS. 1 to 7, the chair includes a leg 1, a support base 3 supported by the leg 1, a seat receiver 5 disposed on the support base 3, and a support supported by the seat receiver 5. The seat 7, the back support 9 that is rotatably supported by the support base 3, the back 11 attached to the back support 9, and the back tilting operation of the back 11 are performed. And a rocking mechanism 13 for moving the seat receiver 5 and the seat 7 upward and downward, and an armrest 15 provided on the backrest support 9.

《Leg composition》
As shown in FIGS. 1 to 7, the leg 1 includes a leg base 17 and a leg support 19 provided at the center of the leg base 17.

  As shown in FIG. 1 to FIG. 5 and FIG. 7, the leg base 17 is provided with a plurality of leg blades 23 radially projecting from a hub 21 provided in the center portion. 25 are provided.

  As shown in FIGS. 1 to 5, 7, and 14, the leg support 19 is a gas spring type that is elastically expanded and contracted in the vertical direction so that it can be locked at a desired position. belongs to. That is, the leg support 19 includes a gas spring main body 27 fitted to the hub 21 of the leg base 17 and a rod 29 protruding from the upper end of the gas spring main body 27. An operation button 31 for unlocking is projected. The support base 3 is attached to the upper end of the rod 29. The unlocking operation button 31 is operated by an elevating operation lever 295 provided on an armrest 15 described later.

《Support base configuration》
As shown in FIGS. 7 to 13, the support base 3 includes a main frame 33 attached to the rod 29 of the leg support 19, and a front link shaft 35 and a support shaft 37 attached to the main frame 33. It will be. The front link shaft 35 is for supporting the front end portion of the seat receiver 5 through the front link 39. The support shaft 37 is for supporting the backrest support body 9 and supporting a substantially intermediate portion of the seat receiver 5 via the rear link 41.

  As shown in FIGS. 7 to 13, the main frame 33 has a boss portion 43 fitted to the upper end portion of the rod 29 in the leg support 19 and a semicircular arc shape in plan view surrounding the upper end side of the boss portion 43. The rear frame member 45, a pair of side frame members 47 extending forward from the left and right front ends of the rear frame member 45, and the front end portions of the side frame members 47 are coupled to each other and have a flat surface at the front end. A front frame member 49 is provided. The boss portion 43, the rear frame member 45, the side frame member 47, and the front frame member 49 are integrally formed by aluminum die casting or the like. A front bearing portion 51 that supports the front link shaft 35 is integrally provided on the upper surface portion of the front frame member 49, and the support shaft is located near the boundary between the rear frame member 45 and the side frame member 47. A rear bearing portion 53 that supports 37 is integrally provided. In addition, the height from the floor surface of the shaft center of the two bearing portions 51 and 53 is different, and the front bearing portion 51 is set at a higher position than the rear bearing portion 53.

  As shown in FIG. 12, the main frame 33 incorporates a tilt reaction force generation mechanism 55 that biases the backrest 11 forward.

  As shown in FIGS. 8 to 13, the tilt reaction force generating mechanism 55 includes a torque transmission bracket 57 having a base end portion supported by the support shaft 37 and a left and right torque transmission bracket 57. The movable shaft 59 is provided between the front end portions of the spring 57, and a spring 63 that elastically biases the movable shaft 59 backward as a scaffold by using a spring receiver 61 provided on the main frame 33 as a scaffold. Reference numeral 64 designates a lifting / lowering unlocking arm for pressing the unlocking operation button 31 provided on the rod 29 of the leg post 19, and as shown in FIGS. , A lifting wire for transmitting the operating force of the lifting control lever 295 provided on the armrest 15 to the lifting lock release arm 64. When the wire 297 is pulled by operating the operation lever 295, the base end boss portion 66 externally fitted to the support shaft 37 rotates and is provided integrally on the opposite side of the wire 297 across the base end boss portion 66. The unlocked arm 64 is rotated downward.

  The support base 3 is covered with an upper cover 65 and a lower cover 67 as shown in FIGS. 3 to 6, 10, and 11.

  As shown in FIGS. 10 and 11, the upper cover 65 covers the support base 3 from the upper surface side, and is provided with an upper locking claw 69 protruding downward to engage with the support base 3. The lower cover 67 covers the support base 3 from the lower surface side, and is provided with a lower locking claw 71 protruding upward to engage with the support base 3. Further, the upper cover 65 and the lower cover 67 are arranged so that the opening end edges 73 and 75 abut each other.

  On the outer peripheral surface of the front side of the main frame 33 of the support base 3, in other words, on the flat surface of the front end of the front frame member 49, as shown in FIGS. And a common upper / lower mounting portion 77 for mounting the upper and lower sides.

  More specifically, the main frame 33 of the support base 3 includes an upper locking claw 69 of the upper cover 65 and a lower locking claw 71 of the lower cover 67, as shown in FIGS. An upper and lower common mounting portion 77 for engaging is provided, and the upper and lower common mounting portion 77 is engaged with an engagement end surface 79 with which the upper locking claw 69 is engaged and with the lower locking claw 71. An end face 81, a locking end face 83 for preventing lateral shift for locking lateral shift of the upper locking claw 69, and a locking end face 85 for preventing lateral shift for locking lateral shift of the lower locking claw 71 are provided. Yes.

  As shown in FIGS. 8, 10, and 11, the upper and lower common mounting portion 77 is provided on the outer peripheral surface 87 of the front end of the front frame member 49 in the main frame 33, and the outer peripheral surface 87 of the front end is rectangular. It is recessed in the shape. In the upper and lower mounting part 77, the upper side is an engagement end surface 79 with which the upper locking claw 69 of the upper cover 65 is engaged, and the lower side is an engagement end surface 81 with which the lower locking claw 71 of the lower cover 67 is engaged. Further, in the upper and lower common mounting portion 77, the left and right sides are locking end surfaces 83 and 85 for preventing lateral displacement with respect to the upper locking claw 69 and the lower locking claw 71 of the upper cover 65 and the lower cover 67.

  Note that, in the vicinity of the middle in the front-rear direction on the outer periphery of the main frame 33, as shown in FIGS. 8 to 10, 12, and 13, an upper dedicated mounting portion 89 for mounting the upper cover 65 and a lower cover 67 are mounted. And a lower dedicated mounting portion 91. The upper cover 65 is provided with a claw 93 that engages with the upper dedicated mounting portion 89, and the lower cover 67 is provided with a claw 95 that engages with the lower dedicated mounting portion 91.

  Further, as shown in FIG. 10, an upper dedicated mounting portion 97 for mounting the upper cover 65 and a lower dedicated mounting portion 99 for mounting the lower cover 67 are provided at the rear end of the outer periphery of the main frame 33. Yes. The upper cover 65 is provided with a claw 101 that engages with the upper dedicated mounting portion 97, and the lower cover 67 is provided with a claw 103 that engages with the lower dedicated mounting portion 99. In other words, the rear frame member 45 of the main frame 33 includes a substantially horizontal central protrusion that is the lower dedicated mounting portion 99 and a pair of upper dedicated mounting portions 97 disposed on both sides of the lower dedicated mounting portion 99. Side ridges are provided. The upper dedicated mounting portion 97 is arranged with a height different from that of the lower dedicated mounting portion 99.

  In addition to the above, the opening edges 73 and 75 of the upper and lower covers 65 and 67 are provided with grooves, except for the vicinity of the rotating shaft, so that the outer peripheries of the upper cover 65 and the lower cover 67 are also brought into contact with each other. Specifically, one of the upper cover 65 and the lower cover 67 has a fitting recess exposed to the outside, and the other has an L-shaped groove that can be fitted to each other with the fitting recess exposed to the inside. . In this way, the upper and lower covers 65, 67 adapted to engage with the upper and lower dedicated mounting portions 89, 91 of the support base 3 are arranged so as to cover the claws 93, 95 at a certain distance from the support base 3. Even if it has comprised, upper and lower covers 65 and 67 can be reliably fitted.

  The left and right front links 39 are rotatably attached to the bearing portion 51 in front of the support base 3 described above via the front link shaft 35. The structure for attaching the front link 39 to the support base 3 is as follows. That is, as shown in FIGS. 8 to 13, the support base 3 includes a bearing portion 51 that supports the front link shaft 35 on the left and right sides, and a pair of opposed flat surfaces 105 that are perpendicular to the axial direction. The front link 39 is located between the planes 105 in the rotation range (U) when used so that the chair can perform its original function, and the front link 39 can be inserted into and removed from the support base 3 (not shown). In the rotation range at the time of insertion / removal, a plane corresponding portion 107 located outside the plane 105 is provided, and the front link 39 is rotatably supported by the support base 3 via the front link shaft 35.

  In other words, as shown in FIGS. 8 to 13, the support base portion 3 is positioned forward and upward at a bearing portion 51 that supports the front link shaft 35 and a position adjacent to the axial direction of the bearing portion 51. And an open link arm housing portion 109. The link arm housing portion 109 is formed between a pair of flat surfaces 105 orthogonal to the front link shaft 35. The front link 39 has a shaft hole 113 for holding the front coupling shaft 111 at the upper end portion and a boss portion 115 that is externally mounted on the front link shaft 35 at the base end portion. A link arm 117 is provided. The link arm 117 has a plane corresponding portion 107 corresponding to the link arm accommodating portion 109.

  In the in-use rotation range (U), the plane corresponding portion 107 of the link arm 117 is located between the opposing planes 105 of the link arm accommodating portion 109. Therefore, the left and right front links 39 are prohibited from being detached from the front link shaft 35 and the front connecting shaft 111. On the other hand, in the rotation range at the time of insertion / removal, the plane corresponding portion 107 of the link arm 117 is located outside the plane 105 facing the link arm housing portion 109. Therefore, the left and right front links 39 can be detached from the front link shaft 35 and the front connecting shaft 111. In the assembled state, the front link 39 is set so as not to rotate to the rotation range during insertion / removal. At the time of assembly, the front link 39 is laid back to the front link shaft 111 passed through the front link mounting portion 121 of the seat 5 and the front link shaft 35 passed through the front bearing portion 51 of the main frame 33 from the left and right. Fit. In this state, the front link 39 is tilted forward, and the link arm 117 of the front link 39 is fitted between the opposing flat surfaces 105 of the link arm housing portion 109. Thereafter, the rear link shafts 123 are fitted into the rear link mounting portions 127 located substantially in the middle of the seat receiver 5 and the back support arms 151 are attached from the left and right, whereby the assembly state described above is achieved. That is, the left and right front links 39 can be attached to the main frame 33 without using a retaining part such as a screw.

  The seat base 5 is supported on the support base 3 configured as described above via the front link 39 and the rear link 41.

《Composition of the seat》
As shown in FIG. 4 to FIG. 6, FIG. 12, FIG. 13, and FIG. On the lower surface of the seat 5, a front link mounting portion 121 for mounting the rotation end 119 of the front link 39 via the front connection shaft 111 and a rotation end 125 of the rear link 41 via the rear connection shaft 123 are provided. A rear link attachment portion 127 for attachment is provided. The front link mounting portion 121 and the rear link mounting portion 127 are provided integrally with the seat receiver 5.

  Ribs 126 are formed in a grid pattern in the vertical and horizontal directions on the upper surface of the seat 5, and two parallel parts of the ribs 126 extend so as to protrude below the seat 5, and the front link mounting portion 121. And the rear link attaching part 127 is comprised. The left and right sides of the front link mounting portion 121 and the rear link mounting portion 127 are closed by side walls 128 and 130 having through holes. These side walls 128 and 130 may also be formed by extending a part of the rib 126 downward. The other ribs 126 are formed so as to be connected to these ribs 126 at a plurality of locations, and are designed to contribute not only to the strength of the seat 5 itself but also to the strength of the front link mounting portion 121 and the rear link mounting portion 127. ing. That is, the front link mounting portion 121 and the rear link mounting portion 127 are hollow bodies having front walls 118 and 122, rear walls 120 and 124, and left and right side walls 128 and 130, respectively. , 122, the rear walls 120, 124, and the left and right side walls 128, 130 are formed by extending a part of the rib 126 downward.

《Composition of the seat》
As shown in FIGS. 7, 14, and 15, the seat 7 includes an inner shell 129 attached to the upper surface of the seat receiver 5, a cushion 131 disposed on the inner shell 129, and the cushion 131. And a tension fabric 133 stretched on the outer surface.

  As shown in FIG. 15, the inner shell 129 is integrally formed of synthetic resin, and is fixed to the seat receiver 5 with a claw or the like (not shown). The inner shell 129 is provided with a front end drooping portion 135 that gently hangs obliquely downward on the front side, and the intermediate portion 137 bulges below the peripheral portion 139 at the boundary between the intermediate portion 137 and the peripheral portion 139. An annular step 141 is formed.

  As shown in FIGS. 14 and 15, the cushion 131 is made of urethane foam or the like, and includes a cushion hanging portion 143 along the front end hanging portion 135 of the inner shell 129 on the front side. In addition, the upper surface of the cushion 131 which is the core material of the seat 7 is provided with a plurality of uneven portions arranged in one direction, in other words, a plurality of grooves 145 arranged in the front-rear direction in this embodiment.

  As shown in FIGS. 1 to 7, 14, and 15, the upholstery 133 is a bag that covers the cushion 131 and the peripheral edge 139 of the inner shell 129, and the upholstery that is wound around the lower surface of the inner shell 129. The edge 147 of 133 is arranged along the end surface of the step 141 of the inner shell 129. The step 141 and the edge 147 of the upholstery 133 are covered by the seat 5 so as to be hidden. The upholstery 133 has a visual feature portion associated with the groove 145 formed in the cushion 131. In this embodiment, the visual feature portion is a line 149 formed by embossing the stretch fabric 133. In this embodiment, a plurality of the filaments 149 exist so as to be arranged in the front-rear direction, and are present at positions where they overlap with the grooves 145 of the planar cushion 131 from above when the upholstery 133 is placed on the cushion 131. . However, it is important that the line 149 is recognized by the user's vision, and the groove 145 of the cushion 131 and the line 149 of the upholstery 133 do not necessarily overlap in plan view.

<< Configuration of back support body >>
As shown in FIGS. 7 to 9, 16, and 17, the backrest support 9 includes left and right back support arms 151 that extend rearward and upward from the support base 3, and the left and right back support arms 151. The upper connecting member 153 that connects the upper end portions 169 of each of the left and right sides, and the left and right sides that extend integrally from the base end of the torque transmission bracket 57 toward the rear upper side and that contact the inner side surface of the base end portion of the back support arm 151. A back support bracket 155 and a lower connecting member 157 for connecting the rear ends of the left and right back support brackets 155 are provided.

  As shown in FIGS. 1 to 9, 13, and 16 to 18, the left and right back support arms 151 are each made of resin and supported by the support base 3 so as to be rotatable. The front-rear direction extending part 159 and an upright part 161 extending continuously upward from the rear end of the front-rear direction extending part 159 are provided. In the example of illustration, the front-back direction extension part 159 and the standing part 161 have comprised the substantially U shape in the side view. Each back support arm 151 has a shaft mounting for fitting from the outside to the base end portion thereof, that is, the front end portion 163 of the longitudinally extending portion 159, to the end portion 165 of the support shaft 37 provided on the support base portion 3. Part 167 is provided. Each back support arm 151 is provided with an arm protrusion 171 for attaching the upper connecting member 153 to the tip, that is, the upper end 169 of the upright portion 161.

  As shown in FIGS. 3 to 9 and 16, the shaft mounting portion 167 of each back support arm 151 includes a shaft hole 173 that is opened only inward to fit the end portion 165 of the support shaft 37. ing. Specifically, the end 165 of the support shaft 37 is fitted into the shaft hole 173 via a bush 175 so as to be relatively rotatable. The bush 175 is inserted from the inner surface side of the back support bracket 155 before the support shaft 37 is mounted, and the support shaft 37 is fitted into the inner periphery of the bush 175 so as to be relatively rotatable. The flange portion 177 of the bush 175 is located between the back support bracket 155 and the main frame 33. The shaft mounting portion 167 is fitted on the outer periphery of the bush 175, and the end portion 165 of the support shaft 37 is covered by the shaft mounting portion 167. The shaft hole 173 has a tapered shape with a large diameter on the opening end side, and the support shaft 37 has a cylindrical shape. The bush 175 has a shape filling the space between the inner peripheral surface of the shaft hole 173 and the outer peripheral surface of the shaft 37. That is, the outer peripheral surface of the bush 175 has a tapered shape, and the inner peripheral surface has a cylindrical shape having the same cross-sectional shape in each part.

  The rear link 41 is integrally provided on the outer periphery of the shaft mounting portion 167 as shown in FIGS. 3 to 9, 16, and 17. Also, cover members 181 that cover the half 179 of the lower connecting member 157 are integrally projected on the inner side surface of each back support arm 151 in the vicinity of the shaft mounting portion 167. The cover member 181 is provided with a screw insertion hole 183. By screwing a screw 187 inserted into the screw insertion hole 183 into a screw hole 185 provided in the lower connecting member 157, the left and right back holes 183 are inserted. A support arm 151 is attached to the lower connecting member 157.

  In this state, the left and right back support arms 151 are coupled to each other via the lower connecting member 157, so that the shaft mounting portion 167 does not come out of the support shaft 37. That is, the left and right back support brackets 155 whose rear ends are connected by the lower connecting member 157 are supported by the support base 3 via the support shaft 37, and both ends of the support shaft 37 projecting outward from the back support bracket 155. Since the left and right back support arms 151 that rotate together with the back support bracket 155 are supported by the part 165, the left and right back support arms 151 are attached from the left and right outside of the back support bracket 155, so 37, the back support bracket 155 and the lower connecting member 157 can be covered. In this embodiment, the ends 189 of the cover member 181 of the left and right back support arms 151 are closely abutted in the assembled state.

  As shown in FIGS. 7 and 18, the arm projecting portion 171 of the back support arm 151 is for attaching the end of the upper connecting member 153, and is a screw insertion hole 191 and a screw hole continuous to the screw insertion hole 191. And a nut not shown.

  As shown in FIGS. 7 and 18, the upper connecting member 153 is a metal metal having a channel shape, and is installed between the arm projecting portions 171 of the left and right back support arms 151 and screwed to the nut. The screw 195 is attached to each back support arm 151. That is, the upper connecting member 153 has a shape that opens rearward, and is fitted between the upper end portion 169 of the back support arm 151 by being fitted to the arm projecting portion 171 from the front side.

  As shown in FIGS. 9, 12, 13, 16, and 17, the back support bracket 155 is made of metal and is integrally formed with the torque transmission bracket 57. Via the main frame 33 so as to be rotatable.

  As shown in FIGS. 9, 16 and 17, the lower connecting member 157 is made of metal, and both ends thereof are rigidly connected to the rear end of the back support bracket 155 by welding. The lower connecting member 157 has a skeletal function of the back support arm 151 made of synthetic resin in cooperation with the back support bracket 155. Moreover, it also has a function as a base for preventing the back support arm 151 fitted from the left and right from being detached from the left and right. Further, the lower connecting member 157 receives a backward tilting load acting on the backrest 11 via the back support arm 151, and transmits the load via the back support bracket 155 for torque transmission of the tilt reaction force generation mechanism 55. It also has a function of transmitting to the bracket 57.

  The backrest 11 is supported by the backrest support body 9 as described above.

《Composition of backrest》
As shown in FIGS. 1 to 7, the backrest 11 is made of a resin-made back shell 205 that is curved until it becomes substantially horizontal at the top 201 and has an opening 203 for promoting elastic deformation at an almost middle portion thereof. The back shell 205 includes a back support member 209 that supports a leading edge 207 located behind the top portion 201 of the back shell 205, and a tension fabric 206 attached to the surface side of the back shell 205.

  The back shell 205 is made of a resin supported by the backrest support 9 as shown in FIGS. 2 to 7, 19, 20, 22 to 24, and is substantially horizontal at the top 201. And has an opening 203 for promoting elastic deformation substantially in the middle. That is, in the back shell 205, a plurality of belt-like members 213 extending in the vertical direction are arranged in the upper region 211 on the left and right, and the opening 203 is formed between the belt-like members 213. Further, the back shell 205 has a shape corresponding to the waist of the seated person, that is, the waist-corresponding portion 215 having a wide left and right width and gradually becoming narrower as it goes upward in a front view.

  As shown in FIGS. 2 to 7, 19, 20, 22, and 24, the upper region 211 is provided continuously on the front portion 217 that receives the back of the seated person and the upper edge of the front portion 217. The top portion 201 includes an upper curved portion 219 that is curved until it is substantially horizontal, and a back portion 221 that is provided continuously from the rear edge of the upper curved portion 219 and curves downward and hangs down. A groove 223 that opens downward is formed at the leading edge 207 of the back surface portion 221.

  The groove 223 includes a main insertion portion 225 for fitting the back support member 209, and a sub-opening on the back side of the back support member 209 in a state where the back support member 209 is fitted to the main insertion portion 225. And a fitting portion 227. That is, the groove 223 provided in the distal end edge 207 of the back shell 205 is a stepped groove shape in which a main insertion portion 225 and a sub insertion portion 227 are continuously formed, and the main insertion portion 225 has a back support member. When an upper mounting portion 251 (described later) 209 is inserted, only the auxiliary insertion portion 227 is left open and left. The sub insertion portion 227 is continuous with a side edge groove 235 described later, and by attaching the tension fabric 206 using the sub insertion portion 227 and the side edge groove 235, the front shell 205 is moved from the front surface to the upper back surface side. It can be covered with a stretch fabric 206. It should be noted that a rib 228 for adjusting elastic deformation is formed on the belt-like member 213 of the back surface portion 221.

  Further, as shown in FIGS. 2 to 7, 19, 20, and 23, the lower region 229 of the back shell 205 has a concave shape in which the left and right sides protrude forward from the middle in the left-right direction. In the lower region 229, a protrusion 231 continuous with the strip member 213 is formed, and a thin portion 233 continuous with the opening 203 is formed between adjacent protrusions 231. A lower region 229 of the back shell 205 has a portion 215 corresponding to the waist of the seated person raised upward in a side view, and is curved so that the center in plan view is recessed.

  As shown in FIGS. 1, 2, 4, 6, 19, 22, and 23, the back shell 205 has side edge grooves 235 that are opened outward on the left and right side edges, respectively. The side edge grooves 235 and the sub-insertion portions 227 in the grooves 223 are continuous. In addition, a lower edge groove 237 that is continuous with the side edge groove 235 is provided at the lower end of the back shell 205.

  As shown in FIGS. 1 to 6, the lower portion 239 of the back shell 205 is attached to the front surface of the back support arm 151, and the upper portion 243 is supported by the back support member 209. The attachment of the lower part 239 of the back shell 205 will be described. A plurality of nut holes 204 are formed on the front side of the upright portion 161 of the left and right back support arms 151 so as to be spaced apart from each other. On the other hand, screw insertion holes respectively corresponding to the nut holes 204 are provided on the left and right sides of the lower portion 239 of the back shell 205. Accordingly, the mounting screws 241 are inserted through the screw insertion holes from the front and then screwed into the nut holes 204 to tighten the left and right sides of the lower portion 239 of the back shell 205 between the left and right back support arms 151. It can be fixed to the front surface of the upright portion 161. The screw 241 is concealed when the upholstery 206 is provided.

  As shown in FIGS. 1, 2, 4 to 7, 19, 21, 22, 22, 24 and 25, the back support member 209 is opened to the left and right and below the back surface of the back shell 205. It is a plate-like one disposed so as to form a space 245, and is supported by the backrest support 9 to control the deflection of the back shell 205 in the front-rear direction. The back support member 209 has a concave shape when viewed from the front in which the left and right sides protrude forward from the middle in the left-right direction. The width of the back support member 209 is smaller than the width of the front portion 217 and the lower region 229 of the upper region 211 of the back shell 205. A supporting member main body 247 having a lower mounting portion 249 provided at the lower end of the supporting member main body 247 and attached to the upper connecting member 153; and a main fitting portion 225 of the groove 223 provided at the upper end of the supporting member main body 247. And the rib 253 formed over the upper mounting portion 251, the support member main body 247 and the lower mounting portion 249. Note that the left and right end edges of the back support member are thicker than the middle part, and this functions as a peripheral reinforcing material.

  The support member main body 247 is plate-shaped as shown in FIGS. 4 to 7, 18, 19, 19, 21, 22, 24 and 25, and the left and right sides are more forward than the middle in the left-right direction. A protruding curved shape is formed, and a bent portion 255 is formed below the upper mounting portion 251. The bent portion 255 is shaped such that the upper side of the bent portion 255 is inclined forward with respect to the lower side. In other words, the bent portion 255 is bent in a square shape when viewed from the side.

  As shown in FIGS. 4 to 7, 19, 21, and 24, the upper mounting portion 251 has a thickness dimension that can be closely fitted to the main fitting portion 225, and is in a fitted state. And attached to the back shell 205 using screws 263. That is, the upper attachment portion 251 is a plate-like member extending upward from the upper end of the support member main body 247, and the upper end portion of the rib 253 is located on the front surface thereof. On the front surface of the upper mounting portion 251, the plate nut 257 is disposed between the adjacent ribs 253, and the upper end portion thereof is fitted into the main fitting portion 225 of the groove 223, thereby positioning and holding the plate nut 257. Be able to. The back support member 209 can be attached to the back shell 205 by screwing the screw 263 inserted from the back side through the screw hole 261 of the back shell 205 into the screw hole 259 of the plate nut 257. It has become. In this state, the plate nut 257 is hidden by the back shell 205 and the back support member 209.

  As shown in FIGS. 4 to 7, 19, 21, and 25, the lower mounting portion 249 includes a rear wall 265 that continuously extends downward from the lower end of the support member main body 247, and the rear wall 265. A top wall 267 that extends forward from the upper end of the wall and connects the ribs 253 located in the middle to each other, and a front wall 269 that hangs downward from the front edge of the top wall 267, and the upper connection The material 153 has a shape opened downward so that it can be fitted from above. A screw insertion hole 273 for inserting a screw 271 for attaching the back support member 209 to the upper connecting member 153 is formed in the front wall 269 of the lower attachment portion 249.

  As shown in FIGS. 7, 19, 21, 22, 24, and 25, the rib 253 extends in the vertical direction, and a plurality of ribs 253 are provided on the front surface of the back support member 209. These ribs 253 are shaped so that the projecting dimension gradually decreases toward the upper side. The ribs 253 are arranged on the left and right with a substantially constant interval. The ribs 275 located on both the left and right sides are cut off at the lower end of the support member main body 247 and do not extend to the lower mounting portion 249. The top wall 267 is located below the ribs 275 located on the left and right sides. And the front wall 269 is not provided. On the other hand, the rib 277 located in the middle extends to the front surface of the front wall 269 of the lower mounting portion 249. The protruding dimensions of the ribs 275 located on the left and right sides are set to be smaller than the protruding dimensions of the ribs 277 positioned in the middle. Further, below the back support member 209, the thickness dimension of the ribs 275 located on the left and right sides is larger than the thickness dimension of the ribs 277 located in the middle. Specifically, the ribs 275 located on the left and right sides, which are shorter in the vertical direction than the ribs 277 located in the middle, have a thickness dimension of about 6 millimeters below, while the ribs 277 located in the middle are located below. The thickness dimension is about 4 millimeters. Therefore, when the back support member 209 is viewed from the back side, it seems that there are frames extending in the vertical direction on both the left and right sides.

  As shown in FIGS. 1 to 7 and FIGS. 22 to 24, the tension fabric 206 is mainly composed of a breathable and translucent cloth material, and covers almost the entire area of the back shell 205. The end portion 279 is fixed to the outer peripheral edge of the back shell 205. More specifically, the lower end portion 281 of the upholstery 206 is pushed into the lower edge groove 237 of the back shell 205 and fixed, and the left and right end portions 283 are pushed into the side edge groove 235 of the back shell 205. It is fixed. Further, the upper portion 285 of the upholstery 206 is placed on the outer surface of the upper curved portion 219 and the rear portion 221 of the back shell 205, and the end portion 279 is pushed into the sub-insertion portion 227 of the groove 223 to be fixed. Specifically, a pushing material (not shown) is sewn on the entire periphery of the end portion of the upholstery fabric 206, and together with the pushing material, an end portion 279, a lower end portion 281 of the upholstery fabric 206, and left and right end portions. 283 is attached to the sub-insertion portion 227, the lower edge groove 237, and the side edge groove 235 of the groove 223 of the back shell 205, respectively. Note that the head of the screw 263 that connects the back shell 205 and the back support member 209 is covered with the tension fabric 206 attached to the back shell 205.

  The backrest 11 as described above is visible in a state in which both side edges of the back shell 205 protrude outward from both side edges of the back support member 209 in the rear view. In addition, the back side of the upholstery 206 can be visually recognized through the opening 203 of the back shell 205 when viewed obliquely from the rear, and the rib 253 of the back support member 209 can be visually recognized from the perspective viewed from diagonally forward. It is.

  The backrest 11 configured as described above and the seat 7 are interlocked by a locking mechanism 13.

《Configuration of locking mechanism》
As shown in FIGS. 4 to 13, the locking mechanism 13 is of a weight sensing type in which the seat 7 is moved upward while being tilted in accordance with the backward tilting motion of the backrest 11.

  Specifically, as shown in FIGS. 4 to 13, the locking mechanism 13 includes a support base portion 3 that holds a front link shaft 35 on the front side and a support shaft 37 on the rear side, and a lower end portion on the front side. After the front link 39 that is rotatably supported by the support base 3 via the link shaft 35 and the lower end portion are integrated with the shaft mounting portion 167 of the back support arm 151 supported by the support shaft 37. The link 41 and the front link attaching part 121 are connected to the turning end 119 of the front link 39 via the front connecting shaft 111 and the rear link attaching part 127 is connected to the turning end of the rear link 41 via the rear connecting shaft 123. The main body is composed of a seat 5 connected to 125.

  That is, as shown in FIGS. 4 to 13, the locking mechanism 13 supports the seat base 5 supporting the seat 7 on the support base 3 by the front link 39 and the rear link 41 inclined in the same direction. In accordance with the backward tilting operation of the back support arm 151 supported by the base 3, the front link 39 and the rear link 41 are rotated in the upright direction to lift the seat receiver 5 upward. When the backrest 11 is tilted backward, the front portion of the seat 7 is lifted more than the rear portion of the seat 7. That is, in the normal backrest and seat synchro-rocking mechanism, the seat is tilted only downward in accordance with the backward tilting motion of the backrest, but the weight sensing type locking mechanism as shown in this embodiment 13, unlike a normal locking mechanism, as shown by a two-dot chain line in FIG. 13, the seat 7 is tilted against the load of the seated person while the seat 7 is tilted in accordance with the backward tilting motion of the backrest 11. It is configured to lift.

  More specifically, as shown in FIG. 13, when the backrest 11 is not tilted backward, the forward link 39 has a forward inclination degree larger than the forward inclination degree of the rear link 41. Is set. In other words, the inclination angle α with respect to the horizontal line at the front link 39 is set smaller than the inclination angle β with respect to the horizontal line at the rear link 41 when the backrest 11 is not tilted backward. Further, the center of rotation of the front link 39 relative to the support base 3 is set at a position higher than the center of rotation of the rear link 41 relative to the support base 3. In other words, the axis of the front link shaft 35 is set at a position higher than the axis of the support shaft 37 by a distance h. The effective length dimension of the front link 39, that is, the inter-center distance L1 between the front link shaft 35 and the front connecting shaft 111, and the effective length dimension of the rear link 41, that is, the support shaft that is the rear link shaft. 37 and the rear connecting shaft 123 are set to be substantially the same distance L2. Further, the back support arm 151 is pivotally supported by a portion of the support base 3 that is in front of the leg column 19. In other words, the shaft mounting portion 167 of the back support arm 151 is supported by the support shaft 37 positioned in front of the leg support 19 in a side view.

  The point that the forward tilting degree of the front link 39 is larger than the forward tilting degree of the rear link 41 is intended to lift the front side of the seat 7 relatively larger than the rear side during the rearward tilting. By making the forward tilting degrees of the link 39 and the rear link 41 greatly different from each other, it is possible to set the lift of the front side of the seat 7 when tilting backward to a large value. That is, the front link 39 has many operations for lifting the front portion of the seat 7, that is, the front portion 7a1 of the seating surface 7a, and the rear link 41 is mainly for the operation of moving the seat 7 rearward. As a result, while the seat surface 7a lifts the front portion 7a1 much, the rear portion 7a2 of the seat surface 7a moves backward and moves backward so as to follow the backrest 11 tilting backward. As a result, the relative positional relationship between the rear end portion of the seat 7 and the lower end portion of the backrest 11 is effectively suppressed by tilting the seat surface 7a relatively rearward.

  The point of making the rotation center positions of the front link 39 and the rear link 41 different in the vertical direction is mainly for the purpose of adjusting the level of the seat 7 when standing upright. By combining with the forward tilt degree difference, the posture of the seat 7 when the backrest 11 stands and the posture of the seat 7 when the backrest 11 is tilted backward are both set to an optimum state. By making the effective length dimension L1 of the front link 39 and the effective length dimension L2 of the rear link 41 substantially the same, the setting can be made more appropriate.

  In general, in a chair in which the back support arm is pivotally supported at a position in front of the leg column in the support base, the backrest tends to sink downward when the backrest is tilted. When the normal weight-sensing locking mechanism that allows the entire seat to lift upward when tilting is used, a large sense of incongruity, more specifically, against the seated person's expectation, As a result of the entire seat including the seat being lifted up, there is a sense of incongruity caused by the simultaneous movement of the backrest sinking motion and the seat lifting motion opposite to the sinking motion in the vicinity of the seated person's waist. According to the configuration of the embodiment, the uncomfortable feeling is alleviated. That is, although the thing of this embodiment is a body weight sensing type, even when the backrest 11 is tilted backward, the rear side of the seat 7 is not lifted greatly, so that it is difficult to give a great sense of incongruity.

  In the present embodiment, the rear link 41 rotates integrally with the back support arm 151 and the torque transmission bracket 57 around the support shaft 37 that is the rotation center of the back support arm 151. Thereby, not only the interlocking operation of the seat 7 accompanying the back tilting operation of the backrest 11 but also the accurate positioning of the seat 7 by the support base 3 via the rear link 41 is realized. Further, in the present embodiment, the rotation range of the backrest 11 is set to 20 degrees, and the angle formed by the seat surface 7a in the state where the backrest 11 is tilted back as much as possible is compared to when the backrest 11 stands. It is set to tilt 4 degrees backward. That is, in the present embodiment, the backrest 11 by the front link 39 is larger than the dimension γ2 in which the rear portion 7a2 of the seating surface 7a is lifted mainly by lifting the substantially central portion of the seat 5 when the backrest 11 is tilted backward. As a result of setting the dimension γ1 at which the front portion 7a1 of the seat surface 7a is lifted when tilted backward to be larger, the angle of the seat surface 7a when the backrest 11 is fully tilted is tilted by 4 degrees than when the backrest 11 is upright. I have to. In addition, in the present embodiment, since the rear link 41 is connected to the substantially central portion in the front-rear direction of the seat receiver 5, both the front and rear links 39, 41 when the backrest 11 is tilted backward are lifted up. However, since the front link 39 lifts the seat receiver 5 more than the rear link 41, the rear end portion of the seat receiver 5 can be set relatively lower than the front end portion, and the front end portion of the seat receiver 5 is raised. At this time, the height position of the rear end portion of the seat receiver 5 is hardly changed between when the backrest 11 stands and when it tilts backward.

《Arrangement of armrest》
As shown in FIGS. 1 to 7 and 18, the armrest 15 includes an elbow support portion 287 that integrally projects forward from the front surface of the upper end portion of the back support arm 151 of the backrest support 9, and the elbow support portion. And an elbow rest 289 provided on 287.

  As shown in FIGS. 3 to 6 and 18, the elbow support portion 287 has a bottomed boat shape opened upward. One elbow support portion 287, in this embodiment, a bottom wall 291 at the front end portion of the right elbow support portion 287 when viewed from the seated person, is formed with a penetrating window 293, and the lower side through the window 293 The operation lever 295 is protruded. The operation lever 295 is for operating the operation button 31 for unlocking the leg column. The operation lever 295 and the operation button 31 are connected by a wire 297, and the operation force applied to the operation lever 295 is transmitted to the operation button 31 by the wire 297, so that the operation button 31 can be operated. The leg strut can be locked / unlocked. A proximal end portion of the operation lever 295 and one end portion of the wire 297 connected to the operation lever 295 are accommodated in the elbow support portion 287.

  The internal space of the elbow support portion 287 communicates with the wire guide space 298 formed in the standing portion 161 of the back support arm 151. The wire guide space 298 extends in the vertical direction, and a part or all of the wire guide space 298 opens forward. The lower end portion of the wire guide space 298 reaches just above the longitudinally extending portion 159, and is located slightly below the lower end of the back shell 205 in a state where the lower portion 239 of the back shell 205 is attached to the upright portion 161. Open to the front. Therefore, the wire 297 connected to the operation lever 295 is led from the inner space of the elbow support portion 287 to the lower end portion of the wire guide space 298, and then reaches the support base portion 3 along the longitudinally extending portion 159. The

  As shown in FIGS. 1 to 5, 7, and 18, the elbow rest 289 is detachable from the elbow support 287. As a result, any one of a plurality of types of elbow rests 289 that can be attached to the common elbow support 287 can be selected and used. In the elbow rest 289 shown in this embodiment, an attachment base 299 that is directly attached to the elbow support 287 and an elbow rest main body 301 that is supported by the attachment base 299 and on which a seated person's arm is placed are integrated. Is provided.

  The mounting base 299 includes a base 303 that is attached to the upper end 169 of the elbow support 287 and the back support arm 151, and a spacer 305 that extends substantially horizontally from the inner end of the base 303. The base 303 is hooked to the elbow support 287 by a locking mechanism (not shown) on the front side, and the rear side is attached to the front side of the back support arm 151 using screws 307. The spacer 305 of the elbow rest 289 is for filling a space where the top wall 267 directly below the rib 275 does not exist, and has a plate shape substantially continuous with the top wall 267 of the lower mounting portion 249 of the back support member 209. ing. The spacer 305 is closely interposed between the upper surface of the upper connecting member 153 and the lower end surfaces of the ribs 275 located on the left and right sides of the back support member 209.

  As described above, in the chair according to the present embodiment, the backrest 11 has a concave shape in which the plurality of belt-like members 213 extending in the vertical direction are arranged in the upper and lower directions in the upper region 211 and the left and right sides protrude forward from the middle in the horizontal direction. Since the lower region 229 includes the back shell 205 formed with the protrusion 231 continuous with the belt-like member 213, the flexibility of the backrest 11 can be increased in the upper region 211, and at the same time, In the region 229, the seating posture can be stabilized by increasing the holdability around the waist. Furthermore, an opening 203 is formed between adjacent belt-like members 213, and ridges 231 exist in the lower region 229 continuously to these belt-like members 213, and a seated person is placed between these ridges 231. Since the thin-walled portion 233 having a concave side is formed and the groove is directed in the vertical direction, the opening 203 and the thin-walled portion 233 form one continuous passage. Therefore, when air flows through this passage, air permeability is secured to some extent even when a seated person continues to sit for a long time, and a comfortable state can be maintained.

  A front portion 217 for receiving the back of the seated person; an upper curved portion 219 that is provided continuously from the upper edge of the front portion 217 and is curved until it is substantially horizontal at the top 201; and the upper curved portion 219 and a back surface portion 221 that is provided continuously from the rear edge and curves downward and hangs downward. A front end of the belt-shaped member 213 is formed on the back surface portion 221, and Since the length dimension is set so as to gradually decrease from the central part of the back shell 205 to the left and right, the belt-like member 213 at the central part of the back shell 205 extends to the upper edge of the backrest 11. Flexibility can be ensured. Furthermore, the holdability can be enhanced along the left-right direction of the backrest 11.

  Since the lower ends of the plurality of strip members 213 arranged in the left and right positions along the virtual curve line that gradually curves upward from the center portion of the back shell 205 toward the left and right, each strip member 213 is independently deformed. Can be controlled. That is, the belt-like member 213 at the center of the back shell 205 has a larger length than the belt-like members 213 at both the left and right ends, so that the belt-like member 213 deforms more greatly even though it has the same thickness. .

  It should be noted that a rib 228 for adjusting elastic deformation is provided on a part of the belt-like member 213 located at the back surface portion 221 in the upper region 211 of the back shell 205, and the belt-like member located at the front surface portion 217 or the upper curved portion 219. It is assumed that it is less elastically deformed than the other parts of 213. That is, since the back shell 205 is connected to the back support member 209 having rigidity at the lower side of the back surface portion 221, the thickness dimension of the belt-like member 213 in the back surface portion 221 is the same as that of the front surface portion 217 or the upper curved portion 219. If the thickness of the belt-like member 213 is the same as that of the belt-shaped member 213, the back surface portion 221 is actively bent and deformed when a load is applied to the seated person, and it may be difficult to support the front surface portion 217 side of the back shell 205. There is. However, the elastic deformation amount of the back surface portion 221 can be adjusted by the rib 228. Note that the elastic deformation amount may be adjusted by increasing the thickness of the belt-like member 213 regardless of the rib 228.

  The portion of the back shell 205 corresponding to the waist is the widest, and the width gradually decreases upward from this portion. Specifically, in the present embodiment, the width of the belt-like member 213 at both ends is gradually reduced toward the back shell 205, so that the width is gradually reduced upward. The strip members 213 at the left and right ends are set to have a larger thickness than the strip member 213 located at the other center. Therefore, the left and right ends of the waist corresponding portion 215 and the back shell 205 can be made relatively rigid, and a frame function for supporting a flexible upper portion can be given to these portions.

  Since the adjacent belt-like members 213 are connected to each other at a position other than the top portion 201 of the back shell 205, specifically, at a tip portion curved to the rear of the back shell 205, the flexible at the upper edge portion. Sex can be secured. That is, in the upper part 243 of the back shell 205, the belt-like members 213 are not connected to each other, so that each belt-like member 213 can be individually bent and deformed according to the load of the seated person.

  The back shell 205 is supported by a back support member 209 that is disposed facing the back surface of the back shell 205 via a space 245, and the back support member 209 is larger than the width dimension of the upper region 211. Since it has a small width dimension, air permeability and flexibility can be ensured by the space 245 opened in the left-right direction and the back direction. That is, since the space 245 is greatly opened in the back direction in addition to the left and right side direction, the effect of further improving the air permeability can be obtained. Moreover, since the width dimension of the back support member 209 is made smaller than the front surface side of the back shell 205, the back support member 209 is hardly visible in the front view, and the appearance from the front can be made clear.

  The lower region 229 of the back shell 205 is provided with a waist corresponding portion 215 corresponding to the waist of the seated person, and the upper region 211 is formed continuously with the waist corresponding portion 215, so that the highly rigid back shell is formed. The lower part 239 of 205 and the upper part 243 of the flexible back shell 205 can be smoothly continued.

  In the upper region 211 of the back shell 205, a slit-like opening 203 is formed between the adjacent band-like members 213, and the lower region 229 of the back shell 205 that does not have the slit-like opening 203 is formed in the back. Since it is attached to the front surface of the support arm 151, the back support arm 151 does not hinder the flexibility of the upper portion 243 of the back shell 205. That is, since the back shell 205 is attached to the back support arm 151 in a place where there is no slit-like opening 203, the strength of the back shell 205 can be maintained.

  The back shell 205 has a groove 223 that opens outward at the periphery, specifically, a side edge groove 235, a lower edge groove 237, and a sub-insertion portion 227 of the groove 223. Since the end portion 279 of the upholstery 206 attached to the outer surface is pushed into the groove 223 and fixed, the side edge groove 235, the lower edge groove 237, and the sub-insertion portion of the groove 223 The upholstery 206 can be easily attached to the back shell 205 using 227.

  Further, the backrest 11 faces through a resin-made back shell 205 having an opening 203 and supported by the backrest support 9, and a space 245 opened on the back surface of the back shell 205 vertically and horizontally. And a plate-like back support member 209 which is arranged, and this back support member 209 is supported by the backrest support body 9 and controls the deflection of the back shell 205 in the front-rear direction. The flexible back shell 205 having the opening 203 in the back shell 205 can be supported by the highly rigid back support member 209 having the rib 253. Therefore, the back shell 205 can be elastically deformed and bent toward the open space 245 according to the load of the seated person, and the back support member 209 has a plate shape having a width on the left and right sides. 205 can be supported in a balanced manner across the left and right. Each band-like member 213 has its upper end curved in the direction in which the seated person puts weight, and the space 245 between the back shell 205 and the back support member 209 matches the curve of each band-like member 213. And gradually increases upward. Therefore, corresponding to the upper portion 243 of the back shell 205 having a large amount of bending deformation, even if the back shell 205 is greatly deformed, the back support member 209 is not hit.

  Further, since the back shell 205 is separate from the back support member 209, it is easy to give different characteristics to the back shell 205 and the back support member 209. That is, in the chair of the present embodiment, the back shell 205 is given elasticity and the back support member 209 is given strength. Thus, the back shell 205 and the back support member 209 having different characteristics are respectively provided. It can be made by integral molding. Since the back shell 205 and the back support member 209 are each integrally formed of resin, mass production can be performed relatively easily.

  The backrest 11 is formed by connecting the leading edge 207 curved to the rear of the back shell 205 and the back support member 209 by a concave-convex fitting. Specifically, the backrest 205 has a groove 223 provided in the back shell 205. Since the upper mounting portion 251 that is the upper edge portion of the back support member 209 is fitted to the main insertion portion 225, the back shell 205 and the back support member 209 can be joined relatively easily.

  Further, the upper end edge of the back support member 209 is fitted into a groove 223 provided in the back shell 205, and a screw 263 passing through the back shell 205 is screwed into a plate nut 257 held by the back support member 209. By doing so, the back shell 205 and the back support member 209 are connected to each other, so that the plate nut 257 can be held between the ribs 253 of the back support member 209 in a non-rotatable manner. Therefore, in the conventional device, it is necessary to press the plate nut 257 from the back side with a hand, a tool, or the like when screwing the screw, but such trouble can be eliminated.

  In addition, when the back shell 205 as the other member is fitted to the back support member 209 as the one member, the back side of the attached plate nut 257 is covered. , And the plate nut 257 can be covered from the surface side of the back shell 205. Since the back shell 205 has a groove 223 that opens downward, and the upper edge of the rib 253 provided on the front surface side of the back support member 209 is fitted in the groove 223, We can fit well.

  Further, a plate nut 257 is disposed between the ribs 253 adjacent in the left-right direction, and the plate nut 257 is held between the ribs 253, and the upper mounting portion 251 that is the upper edge portion of the back support member 209 and the rib 253. Since the upper edge part and the said plate nut 257 are settled in the said groove | channel 223, an external appearance can be improved.

  Further, the screw 263 fitted from the back side of the back shell 205 is screwed to the plate nut 257, and the screw 263 is fitted directly to the surface exposed on the back side. There are no obstacles in the work, and the work is easy. Furthermore, since the head of the screw 263 is covered by the tension fabric 206, the head of the screw 263 is not directly visible, and the appearance can be improved. In other words, in this embodiment, the plate nut 257 is screwed from the back side of the back shell 205, and the back side of the back shell 205 is covered with the tension fabric 206, so that the screw is fixed. The head of the screw 263 at the time is also covered, and the appearance is improved.

  The groove 223 opens to the back side of the back support member 209 in a state where the main support portion 225 for fitting the back support member 209 and the back support member 209 is fitted to the main fit portion 225. Since the auxiliary insertion portion 227 is provided, the end portion 279 of the tension fabric 206 can be pushed in by using the auxiliary insertion portion 227. In other words, when the back shell 205 and the back support member 209 are fitted, the screw 263 is screwed so as to pass through the main insertion portion 225 of the back support member 209 from the back side of the back shell 205. Between the 205 and the back support member 209, a sub-insertion portion 227 of the groove 223 that opens outward is located. The end portion 279 of the upholstery fabric 206 can be pushed into the sub-insertion portion 227 to be fixed. Further, when the upholstery 206 is stretched on the back shell 205, the head of the screw 263 is positioned on the side of the back shell 205 where the upholstery 206 is stretched. Therefore, the back shell 205 and the back support member 209 can be separated according to the presence or absence of the tension fabric 206 while covering the head of the screw 263 used for connecting the back shell 205 and the back support member 209. .

  Further, the back shell 205 has side edge grooves 235 that are opened outward on the left and right side edges, respectively, and these side edge grooves 235 and the sub-insertion portions 227 of the grooves 223 are continuous. The side edges of the tension fabric 206 that is pushed into the sub-insertion portion 227 and fastened, that is, the left and right end portions 283 can be easily attached to the back shell 205. More specifically, side edges of the back shell 205 other than the front end edge 207, that is, the left and right side edges and the lower edge are gently connected to the sub-insertion part 227 and open outward. 235 and a lower edge groove 237 are formed in advance. Therefore, the sub-insertion portion 227, the side edge groove 235, and the lower edge groove 237 make a round around the back shell 205, and a tension fabric 206 attached to the outer surface of the back shell 205 is provided on one surface of the back shell 205. It is easy to install.

  The back shell 205 and the back support member 209 described above are each made of a translucent resin, and the presence of the ribs 253 and the color of the upholstery 206 can be seen from the back side of the back support member 209. Thus, the internal structure can also be part of the chair design. Further, on the back side of the backrest 11, the presence or absence of the ribs 253 appears from the back surface of the back support member 209 as shades of color, and shaded vertical stripes appear almost evenly in the left-right direction.

  On the other hand, in the lower region 229 of the backrest 11, the back support member 209 is not disposed on the back side of the lower region 229 of the back shell 205. That is, the back support member 209 is shorter in height than the back shell 205, and both are connected in the vicinity of the upper end, and there is a region where the back support member does not exist on the back of the back shell 205. . Therefore, in this portion, the back surface of the back shell 205 is exposed on the back side of the chair. When the chair is viewed from the back side, the ridges 231 and the thin portions 233 appear as shades of color from the back side of the back shell 205, and shaded vertical stripes appear almost evenly in the left-right direction.

  Further, the backrest support 9 includes left and right back support arms 151 extending rearward and upward from the support base 3 and an upper connecting member 153 that connects upper ends of the left and right back support arms 151. The back shell 205 has a lower portion 239 attached to the front surface of the back support arm 151, and the back support member 209 has a lower portion, that is, a lower attachment portion 249 attached to the upper connecting member 153. Therefore, the lower part 239 of the backrest 11 which is a part corresponding to the waist of the seated person can be firmly supported.

  Further, the backrest 11 is curved until it becomes substantially horizontal at the top 201, and has a resin-made back shell 205 having an opening 203 for promoting elastic deformation at an almost middle portion, and the top 201 of the back shell 205. Since the back shell 205 is elastically deformed including the curved portion, the degree of deformation at the upper edge can be increased. . Therefore, a certain degree of softness can be obtained in the vicinity corresponding to the neck of the seated person.

  In particular, the back shell 205 of the present embodiment has an upper curved portion 219 that is curved until it is substantially horizontal at the top portion 201, and a back surface portion 221 that is provided continuously from the rear edge of the upper curved portion 219 and curves downward and hangs down. Are curved until the leading edge 207 of the back shell 205 faces downward, so that the flexibility at the upper edge of the back shell 205 can be further increased.

  Moreover, since the front edge 207 of the back shell 205 is attached to the backrest support body 9 via the back support member 209, it can be softened while ensuring shape retention. More specifically, the lower portion 239 of the back shell 205 is attached to the front surface of the back support arm 151 of the back support 9 and the upper portion 243 of the back shell 205 is connected to the back support 9 via the upper connecting member 153. Since it is attached to the support arm 151, the upper part 243 and the lower part 239 of the back shell 205 can be attached to the back support arm 151 which is the same member, and the back shell 205 can be firmly supported while maintaining its shape retention. . Further, since the back shell 205 is attached to the back support arm 151 so as to form a part of a loop shape in a side view, the flexibility of the back shell 205 in the front-rear direction can be enhanced.

  The back shell 205 includes a front surface portion 217 that receives the back of the seated person, an upper curved portion 219 that is provided continuously from the upper edge of the front surface portion 217 and is curved until the top portion 201 is substantially horizontal, A back surface portion 221 that is provided continuously from the rear edge of the upper curved portion 219 and curves downward and hangs down. The opening 203 extends from the front surface portion 217 to the upper curved portion 219 and the back surface portion 221. Since it is formed in a vertically long shape, the elastic deformation amount of the upper edge portion of the back shell 205 can be further increased.

  The back shell 205 includes a plurality of band-like members 213 extending in the vertical direction and arranged side by side. The opening 203 is formed between the band-like members 213, so that the opening 203 has a vertically long shape. In combination with this, each band-like member 213 becomes an independent band-like hinge, and elastic deformation can be performed for each one. Therefore, different deformations occur for each belt-like member 213 depending on the load applied by the seated person, and the back shell 205 as a whole can respond finely to the movement of the seated person. That is, each belt-like member 213 is supported at both upper and lower ends, but is not linear, and is easily deformed elastically because it is curved in a direction in which the seated person puts weight. In particular, this elastic deformation is conspicuous in the end portion of the belt-like member 213 and the portion including the curvature of the top portion 201 in the horizontal direction. Since each of these belt-like members 213 is bent downward from the top portion 210, it can be hinge-deformed.

  In addition, as a specific aspect of the support at both ends that enables the elastic deformation of each belt-like member 209, there is a support connection structure by the back support member 209 of the present embodiment.

  The backrest support 9 includes left and right back support arms 151 that extend rearward and upward from the support base 3 and tilt backward with the backward tilting motion of the backrest 11, and the back shell 205 includes: Since the lower part 239 is attached to the back support arm 151, the backrest 11 can be tilted backward when a load is applied to the seating surface, and a comfortable seating feeling can be given.

  The backrest support 9 includes left and right back support arms 151 that extend rearward and upward from the support base 3 and an upper connection that connects the left and right back support arms 151 at a height corresponding to the waist of the seated person. The back support member 209 has a lower portion, that is, a lower mounting portion 249 attached to the back support arm 151 via the upper connecting member 153, so that the entire backrest 11 is provided. The mounting strength can be increased. That is, since the back shell 205 is attached to the back support arm 151 as a whole so as to form a part in a loop shape in a side view, the flexibility of the back shell 205 in the front-rear direction can be enhanced.

  The upper end of the back support arm 151 is located near the waist of the seated person, and the upper connecting member 153 connects the upper ends of the left and right back support arms 151. In addition to being able to support it, the portion above the waist can be softly supported with flexibility.

  The back shell 205 is a separate body from the back support member 209, and a distal end curved to the rear of the back shell 205 by fitting an upper end edge of the back support member 209 into a groove 223 provided in the back shell 205. Since the edge 207 and the back support member 209 are connected, the back shell 205 forming the seating surface is given elasticity, and the back support member 209 that firmly supports the back shell 205 is given rigidity. It is easy to give different characteristics to the shell 205 and the back support member 209.

  Further, an upper end edge of the back support member 209 is fitted into a groove 223 provided in the back shell 205, and a screw 263 that penetrates the back shell 205 is screwed to a nut held by the back support member 209. Thus, since the back shell 205 and the back support member 209 are connected to each other, the reliable connection between the back shell 205 and the back support member 209 can be easily performed.

  The backrest 11 includes a back shell 205 and a back support member 209 that are structural materials to which the tension fabric 206 is to be attached, and the back shell 205 and the back support member 209 push the end portion 279 of the tension fabric 206. And a guide surface that is continuous with one inner surface of the groove 223 and extends outward from the opening end of the groove 223. In other words, in the present embodiment, the structural material is a combination of the back shell 205 as the first member and the back support member 209 as the second member that supports the back shell 205, and the groove 223 is formed. The inner surface formed on the back shell 205 and the inner surface formed on the back support member 209 are provided, and the guide surface is formed on the back support member 209. Since the end portion 279 of the tension fabric 206 stretched on the outer surface of the back shell 205 is fixed to the groove 223, it is necessary to use a highly skilled and highly accurate assembly facility using this guide surface. Instead, the end 279 of the upholstery 206 can be pushed into the groove 223 to fix the upholstery 206 to the structural material. That is, since the end portion 279 of the tension fabric 206 is guided by the guide surface formed on the back support member 209 that is a part of the structural material, the tension fabric 206 is easily pushed into the sub-insertion portion 227 of the groove 223. .

  In other words, the chair according to the present embodiment has a stretched fabric mounting structure in which a groove 223 that is a recessed groove that opens outwardly to lock the stretched fabric 206 on the back shell 205 of the backrest 11 is provided. A groove 223 is provided in the surface of the bulge 11. Then, one opposing surface in the groove 223 is formed from the inside of the groove 223 to the outside to form an outer contour portion of the backrest 11.

  The upholstery 206 is attached so as to cover the surface of the back shell 205 which is a part of the structural material, and the open end of the groove 223 continuous with the surface is connected to the back which is a part of the structural material. Since the guide surface is formed between the outer end and the opening end of the groove 223, the guide surface is formed between the outer end of the back support member 209 that is continuous with the back surface of the shell 205, and therefore, the tension fabric 206. In spite of the fact that the outer peripheral edge provided with the tension is exposed to the outside, it is possible to suppress the possibility that the tension fabric 206 directly hits another member and is torn. That is, a step portion is provided at the opening end to create a height difference, and a groove 223 that opens outward is formed on the elevation surface of the step portion, so that the tip edge 207 of the back shell 205 on which the tension fabric 206 is stretched is formed. In addition, the lower end of the back support member 209 is located on the outer side, and the upholstery 206 can be separated vertically.

  Further, the back side of the back support member 209 is not provided with a rib 253 or the like and forms a smooth surface, and the guide surface is smoothly continuous with the inner surface of the groove 223. Therefore, even when the tension fabric 206 is pushed into the sub-insertion portion 227 of the groove 223 and fastened, the catch can be reduced as much as possible.

  Each of the back shell 205 and the back support member 209 of the present embodiment is a plate material constituting the backrest 11, and the opening end of the groove 223 crosses the middle of the plate material so as to connect the opposite sides of the plate material. In other words, since it is formed along the tip edge 207 of the back shell 205, the tension fabric 206 can be stretched separately at the boundary portion between the back shell 205 and the back support member 209.

  Further, the back shell 205, which is a part of the structural material, has side edge grooves 235 and lower edge grooves 237 that are opened outward on the left and right side edges and the lower edge, respectively. Since the edge groove 237 and the groove 223 are continuous, the back tension member 206 is attached to the backrest 11 so that the back support member 209 is not covered with the back tension member 206 while the entire back shell 205 is covered with the back tension member 206. be able to.

In the present embodiment, the structural material includes a back shell 205 and a back support member 209 connected to the tip edge 207 of the back shell 205, and the tip edge 207 of the back shell 205 and the back support The groove 223 is opened downward between the member 209 and the member 209. More specifically, the back shell 205 has a front portion 217 that receives the back of the seated person, and an upper curved portion 219 that is provided continuously with the upper edge of the front portion 217 and is curved until the top 201 is substantially horizontal. A rear portion 221 that is provided continuously to the rear edge of the upper curved portion 219 and curves downward and hangs downward, and the upper end edge of the back support member 209 is connected to the leading edge 207 of the rear portion 221. The groove 223 is formed by the above, and the end portion 279 of the tension fabric 206 that is in contact with the surface of the back shell 205 is pushed into the groove 223 so that the tension fabric 206 is attached only to the back shell 205. Can be stretched. That is, in the rear view, a sharp appearance can be obtained by dividing the range of the presence or absence of the upholstery 206 into the upper and lower parts.

  Further, the upholstery 206 is provided with a resin pushing material at an end thereof, and the end provided with the pushing material is pushed into the groove 223 and fixed, so that the pushing material is used. Thus, the tension fabric 206 can be easily attached to the groove 223.

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

  The shape of each belt-like member is not limited to the linear shape as shown in the above embodiment. Moreover, although the width dimension and thickness dimension of each strip | belt-shaped member were made substantially the same in the said embodiment, either one or both of the width dimension and thickness dimension of one strip | belt-shaped member are set with that of another strip | belt-shaped member. It may be set differently. If it is such, when it sees with the whole back shell, it becomes possible to control a deformation | transformation shape partially. As a specific example of changing the thickness dimension of the band-shaped member, a method is conceivable in which ribs are raised on the back surface side of the band-shaped member and the thickness dimension of the band-shaped member is partially changed.

  As a method of gradually narrowing the back shell upward, the width of the opening is made constant while the width of the belt is gradually reduced upward, while the width of the belt is kept constant. It is conceivable to gradually reduce the width dimension of the portion upward, or to gradually decrease the width dimension of the belt-like member and the width dimension of the opening portion upward. Further, as in the above-described embodiment, both the one that changes the width dimension of only a part of the adjacent band-shaped member and the opening and the one that changes the width dimension of at least one of the band-shaped member and the opening are considered. It is done. If it is such, it can become flexible so that it goes on a back shell, and a comfortable seating feeling can be given to a seated person.

  In the present embodiment, the back shell and the back support member are made of separate members and are connected to each other, but the back shell and the back support member may be integrally formed. Also, when the back shell and the back support member are made of different members, the material is not limited to synthetic resin, and the back support member may be made of metal such as aluminum.

  The groove provided at the tip edge of the back shell was a stepped groove shape in which a main insertion portion and a sub insertion portion were continuously formed, but is not limited thereto. That is, the main insertion portion and the sub insertion portion may be partitioned by a wall in the width direction. Moreover, the main insertion part and the sub insertion part are not restricted to what was provided continuously.

  In the above-described embodiment, the sub insertion portion is used to push in the end portion of the tension fabric. However, the sub insertion portion is not limited to such a utilization mode. For example, the base portion of the hanger is pushed in and the back side of the chair is used. A hanger may be attached to the hanger, and the hanger may be used as an attachment portion for various optional members other than the hanger.

  The stretch fabric provided on the back shell may be anything as long as it is for cosmetic use provided on the outer surface of the shell. If a highly translucent material is used as the upholstery, the belt-like member and the opening of the back shell will appear to rise. In addition, if a material with low translucency is used, the connection part on the back side of the back shell, that is, the head of the screw used to connect the back shell and the back support member can be obscured, and the appearance can be improved. Can be good.

  The opening provided in the back shell is not limited to that described above, and the position where the opening is provided, the shape and dimensions of the opening, and the like can be variously changed.

  The space provided on the back side of the back shell is not limited to the one opened in the left-right direction, and may be one opened in the up-down direction. In this case, the back shell and the back support member may be connected at, for example, a plurality of locations in the left-right direction.

  In this embodiment, the effective length dimension L1 of the front link 39 and the effective length dimension L2 of the rear link 41 are set to be substantially the same dimension, so that the seat posture when the backrest stands and the seat when the backrest tilts backward However, the above-mentioned setting may be performed by making the effective length dimension L1 of the front link 39 larger than the effective length dimension L2 of the rear link 41.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 11 ... Backrest 201 ... Top part 203 ... Opening part 205 ... Back shell 206 ... Tension ground 209 ... Back support member 211 ... Upper region 213 ... Band-shaped member 215 ... Waist part corresponding part 217 ... Front part 219 ... Upper curved part 221 ... Back part 223 ... groove 229 ... lower region 231 ... protrusion 245 ... space 279 ... end

Claims (9)

A plurality of strip-shaped members extending in the vertical direction in the upper region are lined up on the left and right sides, and a ridge continuous to the belt-shaped member is formed in a lower region that forms a concave shape in which the left and right sides protrude forward from the middle in the horizontal direction. A chair characterized by having a back shell. The upper region is continuous to the front portion that receives the seated person's back, the upper curved portion that is provided continuously to the upper edge of the front portion and is curved until it is substantially horizontal at the top, and the rear edge of the upper curved portion. And a back portion that curves downward and hangs down, and the tip of the strip member is formed on the back portion, and the length of each strip member is the center of the back shell The chair according to claim 1, which is set so as to gradually become smaller from left to right. The chair according to claim 1 or 2, wherein lower ends of a plurality of belt-like members arranged on the left and right are positioned along a virtual curve line that gradually curves upward from the center of the back shell toward the left and right. The chair according to claim 1, 2, or 3, wherein the back shell has the widest width corresponding to the waist and gradually narrows upward from this width. The chair according to claim 1, 2, 3, or 4, wherein the adjacent belt-like members are connected to each other at a position other than the top of the back shell. The back shell is supported by a back support member disposed facing the back surface of the back shell through a space, and the back support member has a width dimension smaller than the width dimension of the upper region. A chair according to claim 1, 2, 3, 4 or 5. The lower region of the back shell includes a waist-corresponding portion corresponding to the waist of the seated person, and the upper region is formed continuously with the waist-corresponding portion. 6. The chair according to 6. In the upper region of the back shell, a slit-shaped opening is formed between the adjacent band-shaped members, and the lower region of the back shell not having the slit-shaped opening is attached to the front surface of the back support arm. The chair according to claim 1, 2, 3, 4, 5, 6 or 7. The back shell has a groove that opens outward on the periphery, and an end of a tensioned fabric attached to the outer surface of the back shell is pushed into the groove to be fixed. The chair according to claim 1, 2, 3, 4, 5, 6, 7 or 8.

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