JP2020054431A - Spring support structure for chair - Google Patents

Abstract

To simplify a spring support structure to reduce the number of components.SOLUTION: A spring mechanism composed of a first spring mount 45, second spring mount 46, and compression coil spring 47 disposed therebetween is bridged across respective spring mount receiving parts 48, 49 of two members coupled using a single shaft so as to be mutually oscillated, such as a synchro-frame 3 and back frame 5, to apply spring force between the two members. At least one set of the spring mounts and spring mount receiving parts is a set of a first mount receiving part 48 having a surface 57 orthogonal to a direction in which the spring force acts and two flat surfaces 57a along the direction of the spring force acting and the first spring mount 45 that has a pair of flanges 72 for clamping the flat surfaces 57a of the first mount receiving part 48 and a pressure receiving surface 74 for abutting the surface 57 of the first mount receiving part 48 between the flanges 72 to receive force applied to the spring and comprises a slit 73 having a gap between the pair of flanges 72 wider than a gap between the flat surfaces.SELECTED DRAWING: Figure 14

Description

  The present invention relates to a spring support structure for a chair. More specifically, the present invention relates to a support structure of a spring mechanism, such as a reaction force mechanism of a chair or a locking mechanism, which is bridged between two members that are swingably connected to each other by one axis.

  2. Description of the Related Art There is a spring mechanism, such as a chair reaction force mechanism or a rocking mechanism, that is applied between two members that are swingably connected to each other by a single shaft and applies a spring force between the two members. Conventionally, this spring mechanism is generally rotatably connected to the two members via a spring mount in case the included angle between the two members changes. For example, in the case of a reaction mechanism or a locking mechanism of a chair, a spring mount is arranged at both ends of a spring, and the spring mounts at both ends are connected via a connecting shaft between two members, for example, a main frame and a synchro frame or another frame. It is mounted (see Patent Document 1).

  The spring mounts at both ends are rotatably supported with respect to the two members, respectively, so that the spring follows the movement in which the included angle of the two members is widened or narrowed. For this reason, since a force that induces buckling acts on the spring, a sliding shaft for preventing the buckling of the spring by arranging the spring mounts on one axis is provided between the spring mounts. ing. The sliding shaft is made to be able to move in and out of the shaft hole of at least one of the spring mounts, so that the sliding shaft is arranged on one axis while substantially changing the distance between the two spring mounts.

JP 09-238768 A

  However, a connecting shaft that rotatably supports the spring mount with respect to the two members, and a pin and a sliding shaft that slide between the spring mounts at both ends to prevent buckling of the spring are required, so that the component cost increases. There's a problem.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a chair spring support structure having a simple structure with a small number of parts.

  To achieve the above object, a chair spring supporting structure according to claim 1 comprises a first spring mount, a second spring mount, and a compression coil spring disposed between the first and second spring mounts. A spring mechanism that spans between the respective spring mount receivers of the two members swingably connected to each other and applies a spring force between the two members, at least one of the spring mount and the spring mount receiver is A first spring mount receiving portion having a surface orthogonal to the direction in which the spring force acts, two planes along the direction in which the spring force acts, and a pair of flanges sandwiching the plane of the first spring mount receiving portion. A pressure receiving surface that abuts the first spring mount receiving portion between the flanges to receive a force applied to the spring, and a slit in which the interval between the pair of flanges is wider than the interval between the planes. 1 spring So that there is in the count.

  In the spring support structure for a chair according to the first aspect, the first spring mount receiving portion is a flat plate portion having an end surface orthogonal to the direction in which the spring force acts, and the first spring mount is a pair of flat members sandwiching the flat plate portion. And a pressure receiving surface that abuts against the end face of the flat plate portion between the flanges to receive the force applied to the spring, and that a slit between the pair of flanges is wider than the plate thickness of the flat plate portion. Is preferred.

  Here, the spring support structure applies a load in a direction orthogonal to the thickness of the flat plate portion.

  In the spring support structure, the first spring mount receiving portion is a flat plate portion having a surface directly facing the direction in which the spring force is applied and two side surfaces orthogonal to the surface, and the first spring mounts are orthogonal to each other. At the same time.

  Further, in the spring support structure, it is preferable that one of the spring mount receiving portions is configured using a flat plate portion of the frame material.

  In the spring support structure, the other of the spring mount and the spring mount receiving portion includes a second spring mount receiving portion formed of a semicircular or hemispherical convex or concave portion, and a second spring mount receiving portion. It is preferable that the second spring mount has a semicircular or hemispherical concave portion or protrusion which is fitted to the semicircular or hemispherical protrusion or concave portion and is swingably supported.

  Furthermore, a chair according to the present invention is characterized in that the chair spring supporting structure according to any one of the above-described aspects is incorporated.

  In the chair spring supporting structure according to claim 1, one of the spring mounts is provided with a slit sandwiching the two planes, and the rotation of the spring mount is suppressed within the range of rattling of the slit, thereby preventing the spring from rotating. Even if there is no sliding shaft for preventing buckling, the arc movement of the spring can be absorbed to some extent while preventing buckling of the spring. In addition, since parts supporting the spring do not use independent parts but utilize a part of the mating part on which the spring mount is mounted, the structure can be simplified and the cost can be reduced by further reducing the number of parts. .

  Furthermore, by fitting the other spring mount receiving portion and the spring mount into a semicircular or hemispherical convex or concave portion, the two flat surfaces and the slit can be fitted together with play and play. In combination with one of the spring mounts, the parts supporting the spring do not use independent parts, but use the mating parts on which the spring mounts are mounted, that is, a part of the two members, so that only two points of the spring mounts at both ends are used. Therefore, by further reducing the number of parts, the structure can be greatly simplified and the cost can be reduced.

  In addition, the flatness of the frame material is used to fix the spring mount so that a force is applied in the direction perpendicular to the plate thickness direction (vertically in the width direction longer than the plate thickness), so the section modulus increases. , In terms of strength.

It is a perspective view showing one embodiment of a chair to which the present invention is applied. It is a perspective view showing one embodiment of a slide structure of a movable elbow, (A) is a state where an elbow pad is moved to a front end position and an upper surface angle is kept horizontal, and (B) is an elbow pad moved to a rear end position. This shows a state in which the upper surface angle is tilted backward. It is a center longitudinal section of the slide structure of the movable elbow in the state which moved the elbow pad to the front end position, and maintained the horizontal posture. FIG. 4 is a perspective view showing a relationship between a first guide groove of an upper slider part and a fixed shaft with an armrest pad of the armrest of FIG. 3 removed; It is the perspective view seen from the bottom which shows the spherical sliding surface of an upper slider part. FIG. 4 is a perspective view showing a relationship between a second guide groove of a lower slider part, a fixed shaft, and a movable shaft, with an upper slider part of an armrest of the armrest of FIG. 3 removed; FIG. 4 is an exploded perspective view of a lower slider part and an elbow rest receiving portion. It is a perspective view showing other embodiments of a lower slider part and an armrest receiving part. It is a top view which shows the movement locus of the armrest of the armrest of FIG. It is a perspective view which shows the embodiment which applied the spring support structure of the chair to the tilt spring mechanism, and expands and shows the connection part of a synchro frame and a back frame. It is a perspective view showing one embodiment of a main frame and a synchro frame. It is a perspective view showing one embodiment of a main frame. It is a perspective view which expands and shows the lower end arm part attached to the synchro frame of a back frame. FIG. 4 is an enlarged longitudinal sectional view showing a tilt spring mechanism and a mechanism around the tilt spring mechanism. It is a perspective view showing one embodiment of a tilt spring mechanism seen from the other spring mount side. It is a perspective view showing one embodiment of a tilt spring mechanism seen from one spring mount side. It is an exploded perspective view showing one embodiment of a backrest attachment structure seen from the back side. It is an expansion disassembled perspective view of the upper connection part of a backrest and a back frame. It is a top view of a back frame. It is a cross-sectional view which shows the fitting state of the pocket part of the backrest and the T-shaped locking member of the back frame. It is a perspective view of a resin spring. It is explanatory drawing of the mounting state of the resin spring with respect to a pocket part. It is a left front upper perspective view showing a state where an inner shell and an outer shell of a backrest of the chair of the embodiment are disassembled. It is a right rear lower perspective view of the inner shell of the backrest of the embodiment. It is sectional drawing which follows the front-back direction vertical surface of the peripheral part of the bending locking piece in the state in which the inner shell of the backrest of embodiment was attached to the outer shell. It is sectional drawing which follows the front-back direction vertical surface of the periphery part of the curved locking piece in the state where the inner shell of the backrest of embodiment was attached to the outer shell. It is sectional drawing which follows the front-back direction vertical surface of the surrounding part of the engagement convex part, the engagement recessed part, and the rotation suppression part in the state in which the inner shell of the backrest of embodiment was attached to the outer shell. Explaining the coupling force between the engaging protrusion and the engaging recess in the embodiment when pulled in a direction perpendicular to the elastic deformation direction, the engaging protrusion, the engaging recess, and the front-rear vertical direction of the periphery of the rotation suppressing portion. It is sectional drawing which follows a surface. Explaining the coupling force between the engaging convex portion and the engaging concave portion of the embodiment when rolled along the elastic deformation direction, the front and rear vertical surfaces of the engaging convex portion and the engaging concave portion and the peripheral portion of the rotation suppressing portion It is sectional drawing which follows. It is a left front perspective view explaining the relationship between the outer shell of the backrest according to the embodiment, the operating section and the pushing section constituting the pushing member. It is a left front upper perspective view of the operation unit of the pushing member of the embodiment. FIG. 4 is a right rear upper perspective view showing a state in which an operating section and a pushing section of the pushing member of the embodiment are disassembled. It is a right side view showing the state where the operation part and the extrusion part which constitute the extrusion member of the embodiment were combined and attached to the outer shell of the backrest (the outer shell is shown as a schematic section). It is a figure explaining how to attach to the outer shell the operation part which comprises the extrusion member of embodiment.

  Hereinafter, the configuration of the present invention will be described in detail based on an embodiment shown in the drawings. In this specification, the front, rear, left, and right directions are defined with the occupant as the center, and "front or front" refers to the chair in each of the armrest, the seat, and the backrest, and the occupant sitting on the chair. Forward or backward, and "rear or backward" is similarly backward or backward for the chair and occupant. The direction orthogonal to the front-rear direction and the horizontal plane is the left-right direction for the occupant in each of the armrest, the seat, and the backrest, and is the width direction of the chair. Further, "up" and "down" are up and down for the chair and occupant, respectively, in the armrests, seat and backrest, and up and down in the vertical plane.

  FIG. 1 shows an embodiment of a chair to which the present invention is applied. This chair includes, for example, a leg 1 having casters, a main frame (see FIG. 11) supported by the leg 1, and a synchro frame (see FIG. 11) 3 which is swingably connected to the main frame. A seat 4 supported between the main frame 2 and the synchro frame 3, a back frame 5 (see FIG. 10) supported by the synchro frame 3, and a backrest supported by the back frame 5 and the synchro frame 3. 6 and a movable elbow 7 attached to the seat 4.

  For example, as shown in FIG. 11, the locking mechanism of the chair includes a main frame 2 attached to an upper end of a leg 1, a front-rear movement and a tilt movement with respect to the main frame 2 which are disposed above the main frame 2. (Mainly indicates the outer shell of the seat) 4 attached to the main frame 1 so as to be swingably connected to the main frame 1 and rotatably connected to the rear end of the seat 4. A synchro frame 3 to which a lower end of the backrest 6 is connected, a synchro gas spring with a lock mechanism (hereinafter simply referred to as a synchro gas spring) 8 interposed between the main frame 2 and the synchro frame 3, and a synchro The backrest 5 is swingably connected to and supported by the frame 3 and the upper part of the backrest 6 is hooked thereon. A reaction force mechanism (not shown) such as a compression coil spring is provided between the main frame and the front end of the synchro frame.

  In the case of the present embodiment, the back frame 5 is connected to the rear end of the synchro frame 3 so as to be swingable in the front-rear direction, and a compression coil spring (not shown) is provided between the main frame and the front end of the synchro frame. A synchro gas spring 8 is attached between the rear end of the main frame and the middle of the synchro frame, while a reaction force mechanism is provided between the shaft of the front end of the main frame 2 and the shaft of the synchro frame 3. The front end and the rear end of the seat 4 are rotatably supported respectively, and the back frame 5 is fixed to the rear end of the synchro frame 3 so as to be tiltable in the front-rear direction. The backrest 6 and the seat 4 can be synchronized with each other. In addition, it is supported so as to be fixable at an arbitrary position, and a force for giving a repulsive force to the tilting and returning to the initial position is constantly urged. Further, in the case of the present embodiment, a tilt spring mechanism 9 is incorporated between the synchro frame 3 and the lower end of the back frame 5, and a tilt function is provided in which only the backrest 6 is inclined together with the back frame 5. Although not shown in the present embodiment, the seat 4 has an inner shell having a spring property as a structural member for uniformly supporting the weight of the seated person, and a cushion material such as urethane foam placed on the inner shell. And an outer shell (corresponding to a seat support) that receives them and is attached to the main frame, and armrests 7 are fixed to the outer shell by, for example, screws. .

  In the present embodiment, the optional member of the chair includes a support member attached to a part of the chair such as the back and the seat of the chair, and a movable member slidable with respect to the support member and having a use surface on the upper surface. Have The support member and the movable member are provided such that the movable member is slidable with respect to the support member, and at least one of the sliding surfaces between the support member and the movable member is formed of a spherical surface or a curved surface. Alternatively, a sliding mechanism is provided that slidably supports the movable member so that the other sliding surface moves on the curved surface, and forms a spherical slide that changes the inclination of the upper surface of the movable member according to the sliding operation of the movable member, The movable member is provided so as to change the inclination of the use surface of the movable member by sliding with respect to the support member.

(Option member mounting structure and chair movable elbow sliding structure)
2 to 9 show an example in which the optional member of the chair according to the present invention is applied to a sliding structure of a movable elbow as an example.

  The armrest of the present embodiment has a slide structure in which an armrest 13 as a movable member can slide on an elbow rest receiving portion 12 on an elbow support 11 as a support member fixed to the chair body. That is, a slide mechanism 14 that forms a spherical slide between the elbow rest receiving part 12 and the elbow rest 13 so as to slidably support the elbow rest 13 so as to move on a spherical surface or a curved surface with respect to the elbow rest receiving part 12. The vertical angle (hereinafter, referred to as the upper surface angle θ of the armrest) of the used surface of the armrest 13 (hereinafter referred to as the upper surface 24 or simply the upper surface 24) of the armrest 13 is changed according to the sliding operation of the armrest 13. It was made. In the present specification, the inclination of the use surface of the optional member (so-called vertical angle of the upper surface) is based on the upper surface of the optional member (a surface on which a part of the body of the occupant, such as an arm or an elbow, hits). An angle measured up and down with reference to a tangent plane (horizontal plane) passing through a plane, for example, a vertical axis passing through the center of curvature of a spherical surface or a curved surface that forms a sliding portion and a spherical or curved surface, and has the same meaning as an elevation angle There is an elevation angle above and a depression angle below.

  The movable elbow of the present embodiment is an example having a height adjusting function, and has, for example, a column structure in which the height of an elbow rest receiving portion 12 that supports an elbow rest 13 can be adjusted. That is, the elbow support 11 includes a support main body 21 fixed to the chair main body side and an elevating frame 22 housed in the support main body 21 so as to be able to move up and down. The support body 21 and the elevating frame 22 can be switched between an engaged state (fixed state) in which the column main body 21 and the elevating frame 22 are connected to each other and a state in which the column body 21 and the elevating frame 22 can be moved up and down (disengaged state). It has a structure. At the upper end of the elevating frame 22, an elbow rest receiving part 12 including a pedestal part (for example, an elliptical pedestal part 22a as shown in FIGS. 7 and 8) expanded to have an area large enough to support the elbow rest 13 is provided. Provided. Of course, the mechanism that the elbow support 11 expands and contracts, that is, the mechanism that allows the height of the armrest to be adjusted, allows the height position of the armrest 13 to be adjusted according to the physique and preference of the seated person. Is preferred, but not always necessary. Therefore, the elbow rest receiving portion 12 may have a structure integrally formed with the support body 21 in some cases.

  The armrest 7 of the present embodiment is mainly configured to be fixed to the back side of the seat 4, for example, a seat back shell or a seat plate shell constituting the seat or a seat receiving member (not shown) for attaching the seat to the leg. And an elevating frame 22 which is housed in the rising portion 21a of the supporting column body 21 so as to be able to move up and down, and an elbow rest receiving portion 12 formed at the upper end of the elevating frame 22. And an elbow pad 13 forming a sliding portion (spherical sliding) between them. The support body 21 has a base end 21b fixed to a not-shown seat plate shell or the like with a fastener such as a bolt, and the elbow rest receiving portion 12 serving as an upper end is positioned near the seated person's elbow, for example. The elbow rest receiver 12 is arranged substantially parallel to the side edge of the seat and assembled to the chair body. In the present embodiment, the elbow support 11 is attached to the bottom surface of the seat, so that the elbow support 11 is installed as a fixed frame that does not rotate with the locking operation of the back. However, depending on the case, it may be attached to a back (not shown) or attached to a member that tilts with a rocking operation of the back.

  In the case of the present embodiment, for example, as shown in FIG. 3, the slide mechanism 14 slides between the upper surface of the armrest receiving portion 12, that is, the sliding surface 40 d of the lower slider part 15, and the lower surface of the armrest 13, that is, the upper slider part 16. It comprises a moving surface 40u and a connecting means for slidably connecting them. In the case of the present embodiment, as the connecting means, for example, guide grooves 19 and 20 that define a movement trajectory, and an axis that slidably connects the lower slider part 15 and the upper slider part 16 through the guide grooves 19 and 20, for example, One of the shafts (hereinafter, referred to as a movable shaft 17) is formed by a combination with screws 17, 18, for example, penetrating a guide groove (hereinafter, referred to as a second guide groove 20) of the lower slider part 15. The other shaft (hereinafter, referred to as a fixed shaft 18) is fixed to the elbow pad 13, passes through a guide groove (hereinafter, referred to as a first guide groove 19) of the upper slider part 16, and the tapping of the elbow pad receiving portion 12 is performed. It is fixed by being screwed into the screw boss 22c. Here, it is preferable that the fastening direction of the movable shaft 17 and the fixed shaft 18 be fastened toward the center of curvature of the spherical or curved surface of the slide mechanism 14. In this case, the occurrence of twisting during sliding is unlikely to occur.

  In the case of the present embodiment, the guide groove is divided into a lower surface of the armrest 13, that is, the upper slider part 16, and an upper surface of the armrest receiving portion 12, that is, the lower slider part 15, as shown in FIGS. It is formed. The second guide groove 20 of the lower slider part 15 guides, for example, the front half of the armrest 13, and is formed in an arc shape displaced inward in the width direction of the chair as shown in FIG. As a result, the front half of the armrest 13 is displaced toward the widthwise outside of the chair again while being displaced toward the inside in the widthwise direction of the chair in the middle of the track, so that the front end is slightly inward from the rear end position. Guide to the position. On the other hand, the first guide groove 19 of the upper slider part 16 guides, for example, the rear half of the elbow pad 13, and in the case of the present embodiment, similarly to the second guide groove 20, the inside of the chair in the width direction. Is formed in the shape of an arc displaced toward the chair, so that the rear half of the armrest 13 is displaced inward in the width direction of the chair again while being displaced inward in the width direction of the chair in the middle of the track, so that the front end Then, the guide is guided to a position slightly inside the rear end position. Therefore, as shown in FIG. 9, the armrest 13 moves back and forth in a meandering manner by the cooperation of the first guide groove 19 and the second guide groove 20.

  Here, the guide mechanism of the present embodiment is configured such that one guide groove 19 is formed on the upper slider part 16 and the other guide groove 20 is formed on the lower slider part 15, while the upper slider part 16 is formed on the side of the elbow rest receiving part 12. A movable shaft 17 that moves in the guide groove 20 of the lower slider part 15 (moves with the armrest) toward the elbow rest 13 which is a movable member is provided with a fixed shaft 18 that relatively moves within the guide groove 19 of the slider part 16. The armrest 13 is configured to be moved by the relative movement of the two shafts 17 and 18 in the two guide grooves 19 and 20. By providing a plurality of guide grooves 19 and 20 separately in two parts 15 and 16 which are vertically overlapped, the upper surface of the elbow rest receiving portion and the elbow support portion has a limited space as long as the space for disposing the guide groove and the shaft is not large. However, by providing the plurality of grooves, it is possible to prevent the structural strength of each of the parts 15 and 16 from being reduced and to combine the plurality of guide grooves 19 and 20 so as to overlap (interfere). Therefore, the restriction on the movement of the armrest 13 is reduced (in other words, there is no monotony and a complicated trajectory can be drawn), and a characteristic trajectory can be drawn. In the present embodiment, an example is described in which two guide grooves are employed as the plurality of guide grooves. However, the present invention is not particularly limited to this, and three or more guide grooves may be used as necessary. May be divided into three or more parts.

  The structure in which the plurality of guide grooves 19 and 20 are dispersed is not particularly limited to the above-described armrest structure that moves on a spherical surface. For example, it goes without saying that the present invention can be applied to an armrest structure that moves on a flat slide surface. Furthermore, in the present embodiment, the first guide groove 19 and the second guide groove 20 are both arc-shaped, but the present invention is not limited to this combination of groove shapes, and one or both guide grooves, for example, the first guide groove 19 may be in a linear form, or various non-linear forms such as a hyperbolic form, a polygonal line form, a S-shaped form, an L-form, a T-form, a Y-form, a V-form, a J-form, etc. A combination of non-curved shapes may be used.

  The plurality of guide grooves 19 and 20 provided separately for the upper slider part 16 and the lower slider part 15 support at least the front side and the rear side in the sliding direction, and are arranged at the front. It is preferable that the guide groove 19 disposed on the lower slider part 15 be disposed on the upper slider part 16. In this case, the second guide groove 20 of the lower slider part 15 is accommodated in the space inside the elbow pad receiving part 12, and is covered with the upper slider part 16 and is not exposed to the outside. On the other hand, since the first guide groove 19 of the upper slider part 16 is provided behind the elbow rest receiving portion 12, when the occupant grasps the front part of the elbow rest 13 and lowers the elbow rest 13, Since a part of the groove is not exposed in front of the elbow rest receiving portion 12, even if it is exposed, it is rarely present in a range where a fingertip can reach. Therefore, even if the elbow rest 13 is moved so as to protrude in front of the elbow rest receiving portion 12, even if the posture in which the finger is put on the front part of the elbow rest 13 causes an accident such as finger pinching. There is no.

  The armrest 13 includes, for example, the upper slider part 16, a pad 25 covering the upper slider part 16, and an inner shell 27 fixed to the pad 25. Here, the inner shell 27 is provided with, for example, an L-shaped claw having a vertical cross-sectional shape, and a structure for fixing the pad 25 and the upper slider part 16 by engaging with an engagement hole of the upper slider part 16. However, it may be omitted in some cases. Reference numeral 43 in the drawing denotes a hole for passing a fastening screw for connecting the upper slider part 16 and the inner shell 27 attached to the pad 25 covering the upper slider part 16, and reference numeral 44 denotes a screw part of the movable shaft 17. Is a hole through which

  Here, the upper surface 24 of the armrest 13 is not limited to a specific shape or angle, but is a flat surface (including a horizontal surface as well as an inclined surface) or a spherical surface having a large radius of curvature approximating a flat surface. Alternatively, an appropriate form such as a curved surface or a curved surface in which two sides of a horizontal surface and an inclined surface that form a superior arc with an included angle can be used as necessary, but in the case of this embodiment, Is formed by a spherical surface having the same center of curvature as the spherical surface of the sliding portion (for example, illustrated in FIG. 3). In this case, since the upper surface 24 of the elbow pad 13 can be supported so as to fit the forearm shape of the seated person, the concentration of the surface pressure hardly occurs.

  In the case of the present embodiment, the lower slider part 15 includes a guide member 35 forming the second guide groove 20 and an upper slider surrounding the second guide groove 20, as shown in FIGS. It is composed of two members, a sliding member 36 forming a sliding surface that comes into sliding contact with the part 16. The guide member 35 includes the second guide groove 20 and a plurality of fool holes 33, and the edge 30 of the second guide groove 20 is formed in the shape of a jetty and defines a fool hole 33 disposed around the same. Are connected to each other by a rib 29 to form one plate. On the other hand, the sliding member 36 becomes the same height or slightly higher than the edge (pier portion) 30 of the second guide groove 20 of the guide member 35, and surrounds the periphery of the second guide groove 20 and the fool hole 33. Then, it comes into sliding contact with the upper slider part 16. That is, the sliding surface 40 d of the lower slider part 15 is mainly formed by the sliding member 36. The guide member 35 and the slide member 36 are moved from the side opening so that the hole 42 of the slide member 36 penetrates the ridge-shaped edge 30 of the second guide groove 20 of the guide member 35. The guide member 35 is inserted into the space above the locking lever restraining spring portion 32 of the combination 36 and is housed in the pedestal portion 22a of the elbow rest receiving portion 12 and fixed by screws. The combined guide member 35 and sliding member 36 are fitted and fixed in the step 22b formed by the rib 29 inside the pedestal portion 22a, and are integrated with the top of the elevating frame 22 to form an elbow pad. The receiving part 12 is constituted. The guide member 35 and the sliding member 36 constitute a sliding surface 40d of the lower slider part 15 having a spherical or curved surface. Reference numeral 41 in the drawing is a hole through which a boss 22C for screwing the fixed shaft 18 at the rear end of the elevating frame pedestal portion 22a passes, and a part of the sliding member 36 surrounds the boss 22C supporting the fixed shaft 18. It is provided as follows. Reference numeral 42 denotes a hole that penetrates the ridge-shaped edge 30 that defines the second guide groove 20 of the guide member. Reference numeral 32 denotes a locking lever restraining spring portion that restrains the rotation axis of the locking lever 23 rotatably supported on the pedestal portion 22a.

  In addition, the lower slider part 15 is not limited to the embodiment configured by dividing into two members, and may be configured by a single member including a so-called spherical crown that forms a gentle spherical surface that is upwardly convex as shown in FIG. 8, for example. good. The elbow rest part 12 is integrated with the step part 22b of the pedestal part 22a of the elbow rest part 12 and fixed by screwing. Of course, the elbow rest receiving portion 12 may be configured by being integrally formed with the pedestal portion 22a in advance. In addition, the slide mechanism according to the present embodiment is composed of the upper slider part and the lower slider part, which are independent parts that form part of the elbow rest receiving part and the elbow rest, but are not particularly limited to this. For example, although not shown, the upper surface of the elbow pad receiving portion and the lower surface of the elbow pad may be constituted.

  As a material constituting the sliding portion, a material for smoothing relative sliding of the armrest 13 or the armrest receiving portion 12, for example, PTFE (Teflon (registered trademark)), MC nylon, POM, ultra high molecular weight polyethylene, It is preferable to use PET, PEEK, PPS, POM-HL (sliding grade) or a metal plate coated with these resin materials. For example, in the case of the elbow rest receiving portion 12 shown in FIG. 8, the lower slider part 15 made of a plate made of a material having excellent slidability is attached to the step portion (recessed portion) of the pedestal portion 22a at the top of the lifting frame 22. ) A sliding surface is formed by fitting and fastening to 22b. For example, a tapping screw (not shown) is threaded through the lower slider part 15 into a tapping screw boss 22c provided inside the pedestal portion 22a of the elevating frame 22, so that a stepped portion of the pedestal portion 22a is formed. The lower slider part 15 to be fitted into 22b is fixed to form the elbow rest receiving portion 12.

  In the case of the present embodiment, the slide mechanism 14 is configured such that the upper slider part 16 and the lower slider part 15 are formed of a spherical surface having the same curvature, that is, an upper slider part 16 having a concave surface and a lower slider part 15 having a convex surface. By combining the sliding surfaces and the guides so that the sliding surfaces and the guides are in close contact with each other, a spherical sliding structure is obtained in which the armrest 13 slides on the spherical surface and moves. In this case, since the interval between the screws for fastening the upper and lower parts 15 and 16 does not change, there is an advantage that rattling does not occur when the armrest 13 slides.

  In addition, the slide mechanism 14 of the present embodiment is configured such that both the upper surface of the armrest receiving portion 12, that is, the surface of the lower slider part 15, and the lower surface of the armrest 13, that is, the surface of the upper slider part 16, have the same radius of curvature (so-called spherical surface). However, the present invention is not limited to this, and may be spherical surfaces having different curvatures. In some cases, if at least one of the sliding surfaces constituting the slide mechanism 14 is a spherical surface or a curved surface, for example, an elbow rest is used. If the upper surface of the portion 12 is a spherical surface, the lower surface of the armrest 13 may be a flat surface and slidably contact as a tangent plane. Of course, in some cases, the sliding surface on the movable member side may be a spherical surface or a curved surface, and the sliding surface on the support member side may be an aspheric surface, for example, a flat surface. That is, the upper slider part 16 which is the lower surface of the armrest 13 does not need to be always in close contact with the entire surface of the lower slider part 15 which is the upper surface of the armrest receiving portion 12, and partially contacts the upper surface of the elbow rest receiving portion 12. You may make it comprise the sliding part which contacts. For example, the radius of curvature of the lower surface of the armrest 13 may be smaller than the radius of curvature of the upper surface of the armrest receiving portion 12. Also in this case, the position of the elbow pad 13 can be shifted by sliding in the front-rear direction on the lower slider part 15 of the elbow pad receiving portion 12, and the upper surface angle of the elbow pad 13 can be changed.

  In the case of the present embodiment in which the lower slider part 15 which is the upper surface of the elbow rest receiving portion 12 is spherical, the sliding direction of the movable elbow is not limited to a specific direction, but may be in the front-back, left-right, and diagonal directions. Although all directions (ie, 360 °) can be set, in the present embodiment, the directions are set in the front-back direction. The sliding mechanism of the movable elbow always changes the direction of inclination, that is, the angle θ of the upper surface of the elbow, simultaneously with the movement of the elbow rest. Specifically, that the elbow rest upper surface angle θ changes before and after the sliding with the elbow rest means that the upper surface angle θ at one stroke end is larger than the upper surface angle θ at the other stroke end. Is reduced to about 0 ° in one embodiment, but is not particularly limited to this, and the upper surface angle θ at one stroke end is greatly inclined. The smaller upper surface angle θ at the other stroke end is used as a general meaning. For example, in the present embodiment, when the armrest 13 is located at the forefront, the elbowrest upper surface angle θ is substantially 0 ° (strictly, not limited to the horizontal state of a flat surface, but a vertical line passing through the center of curvature of a spherical surface or a virtual spherical surface). The state in which the axis and the horizontal plane are orthogonal to each other (including the state of FIG. 2A), and the degree of the depression angle of the upper surface angle θ of the armrest 13 increases as the arm slides toward the rear side, and the structure tilts backward. (See FIGS. 2A and 2B). In other words, when the elbow pad 13 which is a movable member is at the front end position, the state becomes a horizontal state, and as it slides backward, it becomes a backward inclined state. Of course, the slide structure of the slide mechanism 14 is not particularly limited to the above-described one. For example, when the elbow pad 13 is at the rearmost part, the upper surface angle θ of the elbow pad 13 is horizontal, and the elbow pad 13 faces the front side. The upper surface angle θ of the elbow pad 13 may be inclined forward (becomes a depression angle) as it slides, and the upper surface angle of the elbow pad 13 may be changed when the elbow pad 13 is located at the center of the sliding range in the front-rear direction. The upper surface angle of the armrest 13 may be inclined forward or backward as the armrest 13 slides forward or backward, being horizontal or almost horizontal (the state of FIG. 2A).

  The sliding direction of the movable elbow is not limited to the above-described front-back direction of the chair, and can be set to any direction. For example, the elbow rest receiving part 12 is provided on the support body 21 so as to be arranged in a direction intersecting with the side edge of the seat, and the sliding direction is set to an oblique direction (direction between the front-rear direction and the left-right direction), and the elbow rest 13 is inclined forward. It can also be provided so that it tilts forward as it slides in the direction, or tilts backward as it slides in the oblique direction. Further, the elbow rest receiving portion 12 is provided on the support body 21 so as to be disposed substantially parallel to the front edge of the seat, the sliding direction is the left-right direction, and the upper surface angle θ when the elbow rest 13 is at one moving end is set. The upper surface angle θ at the other moving end becomes smaller with respect to the size, or conversely, the inclination of the elbow rest changes from a small upper surface angle θ to a larger upper surface angle θ. For example, the upper surface angle θ of the elbow pad 13 is horizontal at the center position of the sliding range, and the elbow pad upper surface angle is tilted to the left or right as the elbow pad 13 slides to the other of the left and right moving ends. You may do it. In addition, when the armrest 13 is slid in the oblique direction or the left / right direction, the upper surface angle θ of the armrest 13 is inclined forward or backward or left or right when the armrest 13 is at the center position of the sliding range. Alternatively, the upper surface angle θ may be made horizontal as the user slides to the left or right.

  In other words, the movable elbow is inclined obliquely back and forth or left or right. When one of the various posture changes and the angle of the elbow rest surface is changed, the movable elbow rests on the backrest of the chair described above. There is also an embodiment of the armrest in which the armrest is inclined backward (inclined so that the rear end side is lowered) by sliding the armrest rearward. Regardless of the sliding direction of the movable elbow, it is sufficient if the upper surface angle θ of the elbow pad 13 changes in the process of sliding the elbow pad. Of course, in the case of a curved surface, it can be set not only in the front-back direction (the circumferential direction of the curved surface) but also in an oblique direction. That is, in the sliding mechanism of the movable elbow of the chair of the present invention, the direction of inclination always changes simultaneously with the movement of the elbow rest.

  Further, in the case of the present embodiment, the position of the intersection of the vertical axis V passing through the center of curvature of the spherical surface or the curved surface and the spherical surface or the curved surface (referred to as the pole 26 or the apex) is set to the support member, ie, the elbow support 11. Is located on the vertical axis passing through the center of the support body 21, but is not particularly limited thereto. For example, the position of the elbow rest receiving portion 12 near the frontmost portion or the rearmost portion, or between them And may be set outside the elbow rest receiving portion 12 in some cases. That is, the pole of the spherical surface or the vertex of the curved surface does not necessarily need to be the center of the elbow rest.

  The first and second guide grooves 19 and 20 may be any as long as the movement of the armrest 13 can be restricted to a desired movement direction and movement trajectory, and is not particularly limited to the illustrated embodiment. Absent. For example, two linear guide grooves are provided side by side in the front and rear direction, and the elbow rest 13 can be slid with respect to the elbow rest receiving portion 12 by the movable shaft 17 and the fixed shaft 18 passing through each guide groove 19, 20. May be connected. In this case, the elbow rest 13 moves linearly in the front-back direction.

  A pair of guide grooves 19 and 20 for moving the armrest 13 in an arbitrary direction are provided on one or both of opposing surfaces (sliding surfaces) of the armrest receiving portion 12 and the armrest 13, respectively. Are provided with shafts 17 and 18 as slides that slidably connect the opposing surfaces through the guide grooves 19 and 20 and that are relatively movable. In the present embodiment, the guide grooves 19 and 20 and the shafts 17 and 18 serving as sliders to be fitted into the guide grooves 19 and 20 are separately arranged on two members constituting two opposing sliding surfaces. However, the present invention is not particularly limited to this, and a pair of guide grooves 19 and 20 may be arranged on one side, and a pair of slider shafts 17 and 18 may be arranged on the other side. Alternatively, at least two sliders may be arranged so as to slide apart from each other in the sliding direction. In the present embodiment, the pair of guide grooves 19 and 20 are slightly shifted, for example, about 10 mm inward in the width direction at the end (front side) than at the start end (rear side). As a result, when the elbow rest moves in the front-rear direction, the position of the elbow rest also shifts in the width direction between when the movement starts and when the movement ends.

  In the case of the present embodiment, the movable shaft 17 is a screw with a flange having a flange 17a on its head, and is screwed into a nut 34 fitted in a hexagonal hole 31 of a boss 28 formed substantially at the center of the upper slider part 16. The upper and lower slider parts 15 and 16 are slidably connected without tightening. The flange 17a of the movable shaft 17 is slidably connected to the second guide groove 20 by engaging with an edge portion on the back surface side (that is, the step portion 20a). On the other hand, the fixed shaft 18 is provided with, for example, an O-ring 38 on the head side via a roller wheel 37, and the portion of the O-ring 38 is hooked on an edge portion of the first guide groove 19 (that is, a step portion 19a). By being applied, the O-ring 38 including the roller wheel 37 rolls, so that the first guide groove 19 and thus the upper slider part 16 are supported so as to slide. The fixed shaft 18 passes the tapping screw portion at the distal end through the first guide groove 19 of the upper slider part 16 and the hole 41 of the sliding member of the lower slider part 15 so that the tapping screw boss 22c of the elbow rest receiving portion 12 is formed. It is fixed by screwing in. In the case of the present embodiment, rail-shaped steps 19a and 20a for accommodating the O-ring 38 including the roller wheel 37 or the flange 17a are formed at the edges of the first guide groove 19 and the second guide groove 20. . Therefore, the shafts 17 and 18 slidably connect the upper and lower slider parts 15 and 16 to each other by the O-ring 38 or the flange 17a being hooked on the stepped portions 19a and 20a while penetrating the guide grooves 19 and 20. An appropriate friction is generated between the armrest receiving portion 12 and the armrest 13 so that the armrest 13 can be moved only when a certain force is applied to the armrest 13. Although the O-ring 38 including the roller wheel 37 on the head of the fixed shaft 18 enables smooth movement, a flange structure may be used instead.

The sliding structure of the movable elbow of the chair configured as described above is assembled, for example, as follows.
First, the lower slider part (sliding member 36, guide member 35) 15 is fixed to the lifting frame base 22a by screwing. In the case of the present embodiment, the lower slider part 15 including the sliding member 36 and the guide member 35 has an internal space (step S 22 b) formed inside the pedestal part 22 a of the elbow rest receiving part 12 in a state of being combined in advance. After being placed in the recess, it is fixed, for example, by screwing.

  Next, the screw portion of the movable shaft 17 is inserted from the hole 44 of the upper slider part 16 and screwed into the nut 34 housed in the hexagon hole 31 of the boss portion 38, and the movable shaft 17 is screwed to the upper slider part 16. A position where the flange 17a at the lower end of the movable shaft 17 protruding from the upper slider part 16 passes through the guide groove 20 through the penetration hole 39 at the rear end of the guide groove 20 of the lower slider part 15 (that is, the end on the fixed shaft 18 side). That is, after passing it under the guide member 35, it is slid forward. As a result, the portion of the flange 17a at the lower end of the movable shaft 17 is hooked by the edge / step portion 20a of the guide groove 20 below the guide groove 20 and is engaged in the axial direction. Since the flange 17a of the movable shaft 17 is wider than the width of the guide groove 20, it does not come off.

  Thereafter, the upper slider part 16 is placed at a position where the guide groove 19 and the tapping screw boss 22c (at the rear end of the elevating frame base 22a) are aligned. Then, a wheel (the O-ring 38 is provided around) 37 is placed on the guide groove 19, and the fixed shaft 18 is passed through the wheel 37 and the guide groove 19 through the fixed shaft 18 and screwed to the tapping screw boss 22c. I do. Lastly, the pad 25 including the inner shell 27 is put on the upper slider part 16 from above and screwed in the hole 43.

  As described above, after the lower slider part 15 and the upper slider part 16 are combined, the movable shaft 17 can move to the penetration hole 39 even if the elbow pad 13 slides from the front end position to the rear end position. Since it cannot be made, it does not fall out of the guide groove 20. That is, since the armrest can be formed by a method of placing various parts from above, the assembly is simplified.

  According to the movable elbow configured as described above, the elbow pad 13 is slid in the front-rear direction so as to slide on the upper surface of the elbow pad receiving portion 12, that is, on the lower slider part 15, so that the upper surface angle of the elbow pad 13 is adjusted. θ is changed simultaneously. In other words, the movable elbow of the present embodiment always changes the direction of inclination at the same time as the movement of the elbow rest 13, and changes the position of the elbow rest 13 by one operation of sliding the elbow rest 13 in the front-rear direction. And the change of the upper surface angle θ are simultaneously realized. Then, for example, in the case of the embodiment of FIG. 2, the amount of change is minimized when one stroke end is reached, and maximized when the other stroke end is reached. That is, when the elbow pad 13 is pushed to the front end position (for example, in the state of FIG. 2A), the elbow pad 13 extends vertically through the center of curvature of the spherical surface of the elbow pad receiving portion 12 (that is, the lower slider part 15). A state in which the elbow rest 13 is arranged equally at the front and the rear with the pole 16 where the line V intersects with the upper surface 24 of the elbow rest 13 as a boundary, and a very gentle spherical surface approximating a plane is uniformly developed forward and backward. As a result, the overall posture is kept almost horizontal. On the other hand, when the elbow pad 13 is retracted to the rear end position (the state shown in FIG. 2B), the elbow pad 13 passes through the vertical line V passing through the center of curvature of the spherical surface of the elbow pad receiving portion 12 and the upper surface 24 of the elbow pad 13. Most of the elbow rest 13 is disposed rearward in the direction away from the pole 16 with the pole 16 where the crossing of the arm 16 intersects. Posture). That is, the elbow pad 13 is tilted in the process of sliding on the spherical surface of the lower slider part 15, and the upper surface angle is tilted backward while moving.

  Therefore, in the state of FIG. 2A in which the elbow pad 13 is pushed out to the front end position, for example, the upper surface of the elbow pad 13 that forms a surface that is gently curved with the same inclination in the front-rear direction at the center of the elbow support 11 At 24, the forearm of the occupant in the working position is fully supported, and the weight of the arm on the shoulder is reduced. Therefore, by keeping most of the forearm almost horizontal with the hands and wrists slightly raised, the occupant's forearm was maintained in a posture suitable for keyboard operations and mouse operations. It is. On the other hand, even when the seated person leans on the backrest and the backrest tilts backward, when the armrest 13 is retracted to the rear end position (the state of FIG. 2B), the position of the armrest 13 slides rearward. At the same time, the degree of backward inclination increases (most of the upper surface of the elbow rest 13 is inclined backward) and follows the occupant who shifts to the reclining posture, so that the elbow rest 13 keeps supporting without leaving the occupant's forearm. You can take a comfortable posture.

  As described above, the upper surface angle θ of the armrest gradually changes by moving on the spherical surface by moving the armrest 13 intentionally or by following the movement of the arm. Regardless of whether you are working or resting, you can maintain a comfortable posture.

  The form of the optional member of the chair described above is a preferred example, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the present invention has been described mainly with reference to an example of an elbow rest that slides in the front-rear direction. However, the present invention is not particularly limited to this, and is applicable to other optional members such as a memo table. It goes without saying that you can do it.

  Even in the case where the optional member is a memo table of a chair, it is possible to set the sliding direction not only in the front-back direction but also in the left-right direction and the oblique direction similarly to the case of the armrest. Also in this case, the position and posture, that is, the angle of the upper surface (use surface) of the memo table can be simultaneously changed by sliding the memo table in each sliding direction. For example, as shown in FIG. 1, when a memo table member incorporating the memo table 10 is mounted instead of a part of the support structure of the armrest, for example, the pad 25 covering the upper slider part 16, the memo table can be moved in the front-rear direction. At the same time, the top surface of the memo pad, which is the working surface of the memo pad, tilts forward as the memo pad slides forward or backward as it slides backward, or vice versa. Can be awakened.

  In addition, when a support member is attached to the left side of the chair seat and a portion having a sliding surface that forms a spherical slide is arranged in the left and right direction of the chair so that the memo table can slide in the left and right direction, the memo table as a movable member The upper surface of the memo pad, which is the use surface of, tilts to the right as the memo pad slides to the right (that is, the memo pad surface tilts inward when moved inward in the left-right direction) or tilts to the left as it slides to the left (ie, (The memo table surface tilts outward when it is moved outward in the left-right direction), or conversely, it can be raised horizontally from the left tilt or right tilt state.

  Of course, the support member attached to a part of the chair such as the seat or back of the chair and slidably supporting the memo table, corresponds to the armrest receiving portion in the above-described embodiment of the armrest, that is, forms a spherical slide. By disposing the portion having the sliding surface to be inclined, it is possible to slide in an oblique direction (a direction between the front-back direction and the left-right direction). Also in the case of this embodiment of the memo table, the upper surface of the memo table is not necessarily limited to changing the posture from the horizontal state to the inclined state or vice versa with the sliding, and the magnitude of the upper surface angle θ, that is, the range of gradual change of the inclination. It may be changed within.

  In addition, the change in the posture of the memo table is not limited to that at both ends of the slide. When the memo table is at the center position of the slide range, the upper surface angle θ is kept horizontal or small, and the memo table is left or right, The memo table may be inclined as it slides in either direction. That is, regardless of the sliding direction of the memo table, when the memo table is slid, the magnitude of the inclination of the upper surface of the memo table changes simultaneously with the movement of the memo table. Of course, in the case of a curved surface, it can be set not only in the front-back direction (the circumferential direction of the curved surface) but also in an oblique direction.

  Further, in the above-described embodiment, the lower slider part 15 of the elbow rest receiving part 12 and the upper slider part 16 of the elbow rest 13 are slid by the first and second guide grooves 19, 20 and the pair of shafts 17, 18. The guide means and the connecting means which are movably mechanically connected and supported are also used, but the present invention is not particularly limited to this, and the connecting means and the guide means may be separated and made independent. In some cases, the two members may be movably connected to each other by a non-mechanical connecting means such as a samarium-cobalt magnet or a neodymium magnet with an attractive force of a magnet having a high holding force. In this case, there is no need for a guide groove, and the guide groove is fixed at a position where it is attracted by the magnet.

  Further, in the above-described embodiment, an example of the movable member that reciprocates substantially along a horizontal plane has been mainly described. However, the present invention is not particularly limited to this, and in some cases, an arbitrary angle, for example, along a slope or a vertical plane. It is also possible to apply the present invention to an optional member of a chair in which a movable member slides.

   Further, in the above-described embodiment, the sliding surface between the lower slider part 15 and the upper slider part 16 constituting the sliding part is spherical, and can be slid in any direction, that is, in the front-back and left-right directions. The shape is not limited, and may be a so-called curved surface such as an arch in the front-back direction or an arch in the left-right direction. It goes without saying that this also applies to other optional components of the chair, such as a memorandum.

(Spring support structure)
10 to 16 show an embodiment of the spring support structure. This spring support structure is applied to a tilt mechanism, is incorporated between the synchro frame 3 and the back frame 5, and is provided with a spring force so as to constantly bias the back frame 5 forward. I have. The back frame 5 is swingably connected to a back frame mounting seat 54 at the rear end of the synchro frame 3 by a connecting shaft 65, and is supported so as to be swingable within a certain range.

  Here, in the case of the present embodiment, as shown in FIGS. 11 and 12, the synchro frame 3 increases the mechanical rigidity as a structure, particularly the torsional rigidity, and accommodates the synchro gas spring 8 inside. By connecting the rear ends of the pair of left and right plates 50 with a bent plate material 53, the front ends are connected with a swing shaft 65 and a connection pin 64, and the middle is connected with a rotation shaft 63, so that there is no bottom. It is formed in a box-like frame shape. For example, a pair of right and left back frame mounting seats 54 is formed at a rising portion of a rear end portion developed in a T shape. Between the back frame mounting seats 54, a back seat 51 for mounting the synchro frame mounting seat 130 at the lower end of the backrest 6 is formed as a part of the bent plate material 53. The back seat 51 is formed in a seat surface having an angle and shape compatible with the synchro frame mounting seat 130 of the back outer shell 90, for example, a flat surface, and has a hole for passing a fastening bolt opened in the synchro frame mounting seat 130. Screw holes 61 are provided at positions and intervals corresponding to 144. In the case of the present embodiment, a screw hole 61 is formed by fixing a nut to the back surface of the back support seat 51 by welding or the like.

  Further, the synchro frame 3 of the present embodiment is provided with a flat plate portion 52 developed in a plane orthogonal to the back support seat 51 in front of the back support seat 51 for reinforcement. The flat plate portion 52 is provided with a space 59 for accommodating the operation mechanism 67 of the synchro gas spring 8 so as not to interfere with the operation mechanism 67 of the synchro gas spring 8 with the lock mechanism. Further, a space 60 for mounting the tilt spring mechanism 9 is provided. The left and right plates 50 are connected by a band-shaped bridge portion 56 remaining between a space 59 in which the synchro gas spring 8 is mounted and a mounting space 60 of the tilt spring mechanism 9. The bridge portion 56 is used as one spring mount receiving portion (hereinafter, referred to as a first spring mount receiving portion 46) for supporting one spring mount of the tilt spring mechanism 9, that is, the first spring mount 45. There is a flat plate portion having an end face 57 orthogonal to the direction in which the spring force acts and two flat surfaces 57a along the direction in which the spring force acts. Reference numeral 66 in the figure is a shaft on which the operating mechanism 67 of the synchro gas spring 8 is mounted.

  On the other hand, the back frame 5 is provided with a spring mount receiving portion 49 at a central portion of the lower end arm portion 68. The spring mount receiving portion 49 is, for example, a semicircular convex portion or a convex portion, and is formed on a wall surface 133 that abuts the concave portion 132. In addition, the lower end arm portion 68 of the back frame 5 is provided with a claw portion 69 projecting forward and protruding outward across the bottom of the synchro frame 3. The claw portion 69 is hooked on the claw portion 55 at the lower end of the back frame mounting seat 54 of the synchro frame 3 when the back frame 5 leans forward, and the frame near the back frame mounting seat 54 of the synchro frame 3 when tilting backward. It is hooked on the lower edge of 50 to regulate the backward tilt position. That is, the range of the tilting operation of the back frame 5 is restricted by the engagement between the claw 55 at the lower end of the back frame mounting seat 54 and the synchro frame 3.

  In the case of the present embodiment, the tilt spring mechanism 9 includes one compression coil spring 47 and a pair of spring mounts 45 and 46 disposed at both ends thereof, with the spring mounts 45 and 46 at both ends interposed. It is mounted between the rear part of the synchro frame 3 and the lower end arm 68 of the back frame 5.

  One of the spring mounts (hereinafter, referred to as a first spring mount 45) has a slit groove 73 that fits into a part of the plate material of the synchro frame 3, for example, the bridge portion 56, as shown in FIGS. On the opposite side, there is provided a shaft portion 70 into which the spring 47 is fitted. The first spring mount 45 has a seat 71 for supporting the spring 47 and an arc-shaped peripheral wall 76 around the shaft 45, and supports the spring 47. In the case of the present embodiment, the shaft portion 70 is a hollow shaft with a hollow inside in order to reduce the weight and thickness of the components and prevent the occurrence of sink marks. The first spring mount 45 is fixed by using the bridge portion 56 of the synchro frame 3, that is, the bridge portion 56 is used as the first spring mount receiving portion 48, and the first spring mount 45 is It has a slit groove 73 slightly wider than the wall thickness. By fitting the slit groove 73 into the bridge portion 56, the force applied to the spring acts in a direction orthogonal to the plate thickness of the bridge portion 56, so that the secondary section modulus increases. In the present embodiment, the bridge portion 56 is used for fixing. However, the present invention is not limited to this. The end surface 57 orthogonal to the direction in which the spring force acts and the two The flat plate portion having the flat surface 57a is not limited to the above-described bridge portion 56, and the flat plate portion may be used as a mount receiving portion even at another portion of the synchro frame 3 or the main frame 2. Is possible.

  In the case of the present embodiment, the slit groove 73 of the first spring mount 45 is formed by a pair of flanges 72 sandwiching the flat plate / bridge section 56 and the end face 57 of the bridge section 56 between the flanges 72 to form a spring. It is preferable to have a pressure receiving surface 74 that receives such a force, and that the gap between the pair of flanges 72 is slightly wider than the plate thickness of the bridge portion 56 and that rattling occurs. Thereby, even if there is no sliding shaft between the first and second spring mounts 45 and 46, it is possible to adopt a structure in which the buckling of the spring 47 is prevented while absorbing the arc movement of the spring 47 to some extent. Further, the first spring mount 45 has three surfaces including a pressure receiving surface 74 and two side surfaces 75 orthogonal to the pressure receiving surface 74, as shown in FIG. Is preferred. Similarly, the bridge portion 56 (that is, the first spring mount receiving portion 48) also has a total of 3 including the end surface 57 facing the pressure receiving surface 74 of the first spring mount 45 and the two side surfaces 58 orthogonal to each other at both ends. It preferably has a surface. As a result, the first spring mount 45 and the bridge portion 56 are simultaneously abutted on three sides of the direction in which the spring force is applied and two sides orthogonal to the direction, and are sandwiched by three surfaces. In addition, since the movement can be restricted with a certain amount of play in the left-right direction as well, even if there is no sliding shaft between the first and second spring mounts 45 and 46, the spring 47 can be further improved. It is possible to adopt a structure in which the buckling of the spring is prevented while absorbing the arc movement to some extent. Note that a rib for reinforcement is provided between the flange 72 and the seat 71.

  The other spring mount (hereinafter, referred to as a second spring mount 46) is, for example, as shown in FIGS. 15 and 16, a spring mount receiving portion (hereinafter, referred to as a second spring mount) provided on a lower end arm 68 of the back frame 5. (Referred to as a second spring mount receiving portion 49) is provided on the rear surface side with a semicircular concave portion 77, and has a shaft portion 78 on the front surface side into which a spring is fitted. In the case of the present embodiment, the second spring mount 46 has a shaft portion 78, a concave portion 77, and a rectangular seat portion 79 that supports the spring at the boundary between these. It is sufficient that the second spring mount receiving portion 49 has at least a convex portion that fits into the concave portion 77 of the second spring mount 46. In the case of the present embodiment, as shown in FIG. A semicircular convex portion 49 is formed on the wall surface 133 where the concave portion 132 of the lower arm portion 68 of the back frame 5 abuts, so as to be arranged right and left. The spring mount 46 is provided so as to restrict the lateral displacement of the spring mount 46. Therefore, by fitting the convex portion of the second spring mount receiving portion 49 of the lower end arm portion 68 of the back frame 5 with the concave portion 77 on the rear side of the second spring mount 46, the movement in the left-right direction is restricted. And swingably supported in the vertical direction.

  Further, the second spring mount 46 and the second spring mount receiving portion 49 are not limited to the above-described combination of the concave and convex portions. For example, the combination of the concave and convex portions may be reversed, or the combination of the hemispherical convex portion and the concave portion. And a shaft part (not shown) depending on the case. Further, in some cases, a hook may be used instead of the concave portion of the second spring mount. In any case, if at least one of the combination of the first spring mount 45 and the first spring mount receiving portion 48 is provided, the arc movement of the spring 47 is suppressed to some extent. The buckling of the spring 47 is suppressed even if there is no sliding shaft / pin between the pins 46.

  According to the spring support structure according to the above-described embodiment, the first spring is held by loosely holding the flat plate portion, for example, the bridge portion 56 in the slit groove 73 between the pair of flanges 72 of the first spring mount 45. Since the substantial rotation of the mount 45 itself can be prevented, the sliding shaft / pin for preventing the buckling of the spring 47 can also be omitted. In other words, the number of parts supporting the spring 47 can be reduced to two, only the spring mounts 45 and 46 at both ends, so that the number of parts can be reduced. Moreover, since the force is applied (vertically in the width direction) so that a force is applied in a direction perpendicular to the thickness direction of the flat plate portion of the synchro frame 3, for example, the bridge portion 56, the section modulus is increased and the strength is also increased.

  The form of the above-described spring support structure is an example of a preferred form of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the example in which the spring support structure is applied to the tilt mechanism has been mainly described. However, the present invention is not particularly limited thereto. It goes without saying that the present invention can be applied to any other spring supporting structure, for example, a spring supporting structure of a reaction force mechanism, as long as it is a spring mechanism that is stretched between two members and applies a spring force between the two members. Also in this case, if one of the spring mounts of the spring mechanism disposed between the main frame 2 and the synchro frame 3 is a block that fits with the flat plate portion, the spring buckles while allowing some rotation. Therefore, the sliding shaft and the pin between the spring mounts can be omitted. In addition, since one spring mount receiving portion can be configured by using a part of the flat plate member, a connecting shaft for receiving the spring mount can be omitted. This also enables cost reduction. Further, by forming the other spring mount as a block having a concave portion or a convex portion to be fitted with a spherical or curved convex portion or a concave portion, the structure is further simplified.

 Further, in the above-described embodiment, the first spring mount 45 is configured to simultaneously restrain the three surfaces 57 and 58 of the first spring mount receiving portion 48. However, the present invention is not limited thereto. In some cases, the structure may be such that it comes into contact only with the front facing the direction in which the compression force of the spring is applied. In this case, it is preferable to prevent the first spring mount 45 from being displaced in the left-right direction by other means.

  Further, in the above-described embodiment, the bridge portion 56, which is a part of the flat plate portion 53 of the synchro frame 3, is used as the first spring mount receiving portion 48. However, the present invention is not limited to this. It is also possible to use a part of a simple cylindrical member. The pipe may be formed with two planes, more preferably two planes parallel to each other, and sandwiched by the slit groove 73 between the pair of flanges 72 of the first spring mount. In other words, at least one of the spring mount and the spring mount receiving portion has a first mount receiving portion having a surface orthogonal to the direction in which the spring force acts and two planes along the direction in which the spring force acts, A pair of flanges sandwiching the plane of the first spring mount receiving portion, and a pressure receiving surface that abuts the first mount receiving portion between the flanges to receive a force applied to the spring; And a first spring mount provided with a slit having a larger interval than the interval between the planes.

(Backrest tilt mechanism)
17 to 21 show an example of the embodiment of the backrest tilt mechanism. In the backrest tilt mechanism according to this embodiment, a lower end portion and an upper portion of a backrest 6 are supported by a synchro frame 3 and a back frame 5 swingably attached to the synchro frame 3. More specifically, for example, the synchro frame mounting seat 130 at the lower end of the backrest 6 is fixed to the back support seat 51 of the synchro frame 3, while the pocket 135 provided at the upper back of the backrest is connected to the front of the back frame 5. Are supported so as to be hooked on the locking member 134. For this reason, when the backrest 6 is tilted, a part of the engagement member 134 is located between the pocket portion 135 above the backrest 6 and the locking member 134 of the back frame 5 when the back frame 5 is tilted. Tilt is allowed in order to allow relative movement by sliding before contact with the part. In this embodiment, a so-called back support rod is formed by the synchro frame 3 and the back frame 5, and the synchro frame 3 corresponds to a lower back support rod, and the back frame 5 corresponds to an upper back support rod.

  The back frame 5 is made of, for example, a resin molded product of glass fiber-containing polypropylene or the like, and a lower portion thereof is swingably connected by a connection shaft 65 passing through a hole 62 of a back frame mounting seat 54 at the rear end of the synchro frame 3. At the same time, it is urged by a spring 47 of a tilting mechanism interposed between the synchro frame 3 in a direction of tilting forward, that is, in a direction of pushing back the backrest 6 against a seated person.

  At the upper part of the front surface of the back frame 5 (that is, the surface facing the back outer shell 90), a T-shaped claw (hereinafter referred to as a T-shaped claw) having a shaft portion 134a protruding forward and a protruding portion 134b projecting in the left-right direction is provided. A stop member 134 is provided. The T-shaped locking member 134 is fitted into the pocket portion 135 on the back surface of the back outer shell 90, and functions so as not to be able to be detached in the front-rear direction after being fitted. The T-shaped locking member 134 does not catch on the pocket 135 in the vertical direction (pull-out direction), but extends the bottom 137 or the peripheral edge 136 of the pocket 135 in the front-rear direction (direction orthogonal to the pull-out direction). The backrest 6 is provided so as not to be detached from the back frame 5 by engaging with the portion. In addition, the T-shaped locking member 134 is formed by intentionally forming a concave portion 134c in the center shaft portion 134a, that is, by so-called lightening (also referred to as "thiefing") so that the thickness is formed to be constant. That is, care is taken not to cause sink marks on the back side of the back frame 5 during injection molding. Moreover, the backrest tilt mechanism described in Patent Literature 1 has a large number of parts and therefore has a thick structure, and it is difficult to obtain a clean appearance. However, according to the present embodiment, the number of parts is small and thin. Because it can be shaped, a neat appearance is obtained.

  On the other hand, the backrest 6 is not limited to a specific structure and shape. In the case of the present embodiment, for example, a back outer shell 90 made of a synthetic resin supported by the back frame 5 and a back outer shell 90 A back inner shell 80 made of synthetic resin attached to the shell 90. The back inner shell 80 is covered with upholstery after arranging a cushion material such as urethane foam on the front side, for example, and the edges of the upholstery turned to the back side are fixed by stapling or the like, and the back inner shell 80 is put together. It is configured as one part. The back outer shell 90 is made of a resin material having a certain degree of flexibility and rigidity as a structure supporting the back. By attaching the back inner shell 80, the back outer shell 90 forms a backrest surface and a body support surface. It is provided in. The back inner shell 80 and the back outer shell 90 are integrated by being removably joined with claws and clips.

  A downward pocket 135 for fitting a T-shaped locking member 134 protruding to the front side of the back frame 5 from below is integrally formed on the back outer shell 90 by injection molding using a slide mold. Have been. The pocket portion 135, for example, has an inverted U-shaped peripheral portion 136 that supports the back side of the T-shaped locking member 134, and occupies the inside of the peripheral portion 136 to support the front side of the T-shaped locking member 134. A space for fitting the T-shaped engaging member 134 is formed between the I-shaped bottom 137 and the I-shaped bottom 137. In the case of the back outer shell 90 of the present embodiment, since a space for removing a slide die for injection molding the pocket portion 135 is required, the bottom portion 137 has an I shape surrounded by a hole. That is, the pocket portion 135 is provided with a step in the front-rear direction between the inverted U-shaped peripheral edge portion 136 and the I-shaped bottom portion 137 therebetween during the injection molding of the back outer shell, so that the T-shaped locking member is formed. A space is formed for fitting 134. In order to smooth the movement of the T-shaped locking member 134, a rail-shaped projection 138 slightly higher than the peripheral surface is formed at the bottom of the pocket 135 to reduce the contact area. I have.

  In the vicinity of the entrance of the pocket 135, a locking claw 139 is formed to be hooked for preventing the T-shaped locking member 134 from coming off. The locking claw 139 is bent in the front-rear direction, has a return portion (reverse hook) 140 protruding rearward, and is an entrance of an internal space for accommodating the T-shaped locking member 134 of the pocket portion 135. Narrow. When the T-shaped locking member 134 is inserted, the tapered surface 141 abuts and is not pushed into the front space, so that it is not caught. The abutment of the T-shaped locking member 134 functions as a stopper.

  The backrest 6 in the present embodiment is formed, for example, in a shape protruding forward in a side view (i.e., a U-shape), and is curved so as to protrude rearward in a plan view. Has made. Then, the synchro frame attachment seat 130 at the lower end of the back outer shell 90 is fixed to the synchro frame 3 with the screw 131, and the upper pocket portion 135 is hooked on the T-shaped locking member 134 of the back frame 5, so that The portion between the two connection portions is supported so as to be separated from the backrest in a side view. Further, in this embodiment, the synchro frame mounting seat 130 at the lower portion of the back outer shell 90 is screwed into the screw hole 61 of the back seat 51 at the rear end of the synchro frame 3, while the upper pocket portion 135 is attached to the back frame. 5, the back frame 5 is tilted (tilted) with respect to the synchro frame 3 so that the T-shaped locking member 134 of the back frame 5 and the pocket portion of the backrest. In this case, slippage and slippage occur with respect to 135. Therefore, a resin spring 142 is provided at the back of the pocket portion 135, that is, at the portion where the upper end surface of the T-shaped locking member 134 of the back frame 5 abuts, so as to reduce the impact force and the collision sound at the time of abutting. Have been. As shown in FIG. 21, for example, the resin spring 142 has a shape in which a wheel is crushed, and has a mounting claw 143 having a turn on the upper surface side. As shown in FIG. 22, the resin spring 142 forms a part of the pocket 135 where the part of the engagement member 134 which rises relatively at the depth of the pocket 135, that is, at the time of the tilting operation of the back frame, comes into contact. It is fixed to the back frame 5 by fitting the mounting claws 143 into the concave portions 145 (the upper side serving as the ceiling). The resin spring 142 is provided so that the hook of the mounting claw 143 is caught in the concave portion 145 and does not fall off unless it is intentionally removed.

  Further, grease may be applied between the inner surface of the pocket 135 and the T-shaped locking member 134 so that dust is not generated inside the pocket 135 due to rubbing between them. Also in this case, since the resin spring 142 is hooked on the back outer shell 90 at the return portion of the mounting claw 143, it does not fall off due to the influence of grease application.

  The back outer shell 90 is fixed by screwing the synchro frame mounting seat 130 to the synchro frame 3, inserting the upper pocket portion 135 into the T-shaped locking member 134 of the back frame 5 and hooking the same. Therefore, when the backrest 6 is pulled forward to be pulled out (or when a force for unconsciously removing the backrest 6 is applied), the backrest 6 is in a direction of being hooked on the T-shaped locking member 134, so that the backrest 6 is separated from the back frame 5. It is not possible. On the other hand, if the backrest 6 is pulled straight upward according to the procedure and pulled out (when a force for intentionally removing the backrest 6 is applied), the back outer shell 90 does not catch on the T-shaped locking member 134 of the back frame 5. The backrest 6 can be separated from the back frame 5.

  The above-described backrest tilt mechanism is an example of a preferred embodiment of the present invention, but is not limited thereto, and can be variously modified without departing from the gist of the present invention. For example, in the backrest tilt mechanism of the above-described embodiment, the T-shaped locking member 134 is formed on the front surface of the back frame 5 and the pocket portion 135 is formed on the back side of the backrest 6. A pocket 135 may be formed on the front surface, and a T-shaped locking member 134 may be formed on the back side of the backrest 6. In addition, the backrest has been described with an example of a structure in which a cushion is wrapped with upholstery, but the invention is not particularly limited to this. It may be a so-called resin mesh type having a backrest surface at a portion formed at the bottom. Furthermore, the support of the backrest may be of various shapes and structures, and is not limited to the shell-like support shown in the present embodiment. For example, the support may be mainly composed of a frame.

(Shell engagement structure)
The backrest 6 has an outer shell 90 formed of a resin, and an inner shell 80 formed of a resin and disposed on the front side of the outer shell 90 (FIG. 24). Although not shown, a back cushion is mounted on the front surface of the inner shell 80 and is covered with a skin material.

  The outer shell 90 is a resin member having a size large enough to support the back of a seated person. In the example shown in the drawing, the outer shell 90 has a shape that is convex forward in a side view (that is, a rectangular shape). ) And in a plan view, it is formed in a curved shape so as to protrude backward.

  The inner shell 80 is a member made of resin, and is formed into a concave / convex / curved shape similar to the outer shell 90.

  The outer shell 90 has a structure for attaching the inner shell 80 to the outer shell 90, and includes a plurality of locking pieces 92 at a position near the upper end and a plurality of engagement recesses 93 at a position near the lower end. Is done.

  The inner shell 80 has a structure for attaching the inner shell 80 to the outer shell 90, and a locking hole 83 into which a locking piece 92 of the outer shell 90 is inserted and engaged has the locking at a position near the upper end. The engaging protrusions 85 formed at positions facing the respective pieces 92 and inserted into and engaged with the engaging recesses 93 of the outer shell 90 face the respective engaging recesses 93 at positions closer to the lower end. Prepare for position.

  The locking piece 92 of the outer shell 90 has a hook shape, and is formed to protrude forward from the front surface of the outer shell 90.

  The locking piece 92 has a joining portion 92a that projects forward from the front surface of the outer shell 90, and a locking claw portion 92b that extends upward from the front end of the joining portion 92a.

  In the example shown in the figure, four locking pieces 92 are provided at a position near the upper end of the outer shell 90 so as to be spaced apart from each other in the left-right direction.

  Of the four locking pieces 92 that are spaced apart from each other in the left-right direction, two of the two left and right ends are particularly enhanced in the function of retaining after being inserted into and engaged with the locking holes 83 on the inner shell 80 side. The bent locking pieces 92X, 92X are formed and provided, and two sandwiched between the bent locking pieces 92X, 92X are formed and provided as curved locking pieces 92Y, 92Y.

  The bent locking piece 92X is formed such that the connecting portion between the lower surface of the joining portion 92a and the front surface of the locking claw portion 92b forms a corner portion 92c, that is, the tip of the lower surface of the joining portion 92a is curved. Instead, it is formed in a bent shape (FIG. 25).

  On the upper side of the inner shell 80, while the portion near the upper end of the inner shell 80 is lowered from above the locking piece 92 of the outer shell 90, the locking piece 92 enters the locking hole 83, and then the outer shell 90. And the locking claw portion 92b of the locking piece 92 is exposed to the front side of the inner shell 80, and the joint portion 92a of the locking piece 92 is positioned in the locking hole 83. Attached to shell 90.

  In a state where the locking piece 92 is inserted into the locking hole 83 and the locking claw portion 92b is exposed on the front side of the inner shell 80, the locking hole of the inner shell 80 is formed by the rear surface of the locking claw portion 92b. The locking portion 87 that forms the upper edge of the 83 (in other words, above the locking hole 83) is held so as to be pressed down.

  At this time, the bent locking piece 92X has a shape in which the connecting portion between the lower surface of the joining portion 92a and the front surface of the locking claw portion 92b forms a corner portion 92c, and the tip of the lower surface of the joining portion 92a is bent. By doing so, the forward extension of the lower surface of the joint portion 92a is sufficiently ensured and the lower surface of the engagement hole 83 is engaged with the lower edge 83a in the front-rear direction, so that the upper portion of the inner shell 80 (particularly, Even if the lower edge 83a of the locking hole 83 is slightly displaced forward, the lower edge 83a of the locking hole 83 is joined to the bent locking piece 92X. It is difficult to cross the corner 92c at the front end of the portion 92a. This makes it difficult for the locking hole 83 to come off from the bending locking piece 92X (in other words, it becomes difficult for the bending locking piece 92X to come off from the locking hole 83), and thus the upper part of the inner shell 80 is extended to the outer shell 90. It is hard to come off.

  In particular, it is conceivable that the inner shell 80 is designed and formed so that the upper edge of the inner shell 80 is higher than the upper edge of the outer shell 90. In such a case, the upper end portion of the inner shell 80 is considered. It is also conceivable that only the upper end portion of the inner shell 80 is gripped (that is, the upper edge of the outer shell 90 is not gripped) and pulled forward (or pushed forward). On the other hand, the structure of the bent locking piece 92 </ b> X that can exert the effect of being difficult to be detached / removed from the locking hole 83 is useful.

  In addition, the locking hole 83 of the inner shell 80 does not easily come off from the bent locking piece 92X of the outer shell 90, but it comes off when pulled by a suitable force.

  When the peripheral portion of the locking hole 83 into which the bending locking piece 92X is inserted and engaged is pulled, the lower edge 83a of the locking hole 83 slides against the lower surface of the joint 92a of the bending locking piece 92X. The lower edge 83a rides over the corner 92c when it moves and is further pulled by a corresponding force, and the locking hole 83 comes off the bent locking piece 92X.

  On the other hand, the curved locking piece 92Y is formed such that the connecting portion between the lower surface of the joining portion 92a and the front surface of the locking claw portion 92b forms a curved portion 92d, that is, the distal end of the lower surface of the joining portion 92a is bent. It is formed not in a curved shape but in a curved shape (FIG. 26). The curved locking piece 92Y is formed such that a connecting portion between the lower surface of the joining portion 92a and the front surface of the locking claw portion 92b forms a slope, that is, the tip of the lower surface of the joining portion 92a has a slope shape. It may be done.

  In the curved locking piece 92Y, the connecting portion between the lower surface of the joining portion 92a and the front surface of the locking claw portion 92b forms a curved portion 92d so that the tip of the lower surface of the joining portion 92a is curved. Accordingly, when the upper portion of the inner shell 80 (particularly, the peripheral portion of the locking hole 83) is pulled forward and the lower edge 83a of the locking hole 83 shifts forward, the lower end of the locking hole 83 The edge 83a can easily cross the curved portion 92d at the front end of the joint 92a of the curved locking piece 92Y. As a result, the locking holes 83 are easily detached from the curved locking pieces 92Y (in other words, the curved locking pieces 92Y are easily removed from the locking holes 83), and the upper part of the inner shell 80 is extended to the outer shell 90. It is easy to come off.

  In the example shown in the figure, four locking pieces 92 are provided as a whole, two of the left and right ends are bent locking pieces 92X and the remaining two are curved locking pieces 92Y. The number and arrangement of the bending locking pieces 92X and the bending locking pieces 92Y as a whole are not limited to the examples shown in the drawings. For example, the number of the inner shell 80 and the outer shell 90 may be different. An appropriate number and an arrangement method are appropriately set in consideration of the fact that the engagement force can be secured.

  By appropriately arranging the bending locking pieces 92X and the bending locking pieces 92Y, the coupling force between the inner shell 80 and the outer shell 90 is appropriately secured, and the replacement and maintenance of parts are performed. When the inner shell 80 is detached from the outer shell 90, labor is saved and efficiency is reduced by avoiding extra work, and parts are damaged when detached. It is possible to avoid the problem that replacement or repair is required. That is, engagement / connection that is detachable and hard to be easily detached is realized.

  The engaging structure of the chair component according to the present embodiment is configured such that the outer shell 90 is provided with an engaging recess 93, and the inner shell 80 is detachably and elastically deformably engaged with the engaging recess 93. A rotation suppressing portion that reduces or suppresses the rotation of the engaging convex portion with respect to the engaging concave portion in a state where the engaging convex portion and the engaging concave portion are engaged with the inner shell; Is provided.

  The engagement convex portion 85 of the inner shell 80 is formed integrally with the inner shell 80 (accordingly, formed of resin) and protrudes rearward from the rear surface of the inner shell 80.

  The engagement convex portion 85 includes a pair of joining support portions 85a, 85a projecting from the rear surface of the inner shell 80, and a pair of hook portions 85b, 85b connected to the rear ends of the pair of joining support portions 85a, 85a, respectively. And a pair of inclined portions 85c, 85c connected to the rear ends of the pair of hook portions 85b, 85b (FIG. 27).

  The pair of joining support portions 85a, 85a are formed in a manner of projecting from the rear surface of the inner shell 80 so as to be opposed to each other while being separated from each other backward.

  The pair of hook portions 85b, 85b are formed in such a manner as to be inclined from the rear ends of the pair of joining support portions 85a, 85a so as to be away from the other joining support portion 85a, and to extend rearward. .

  The pair of inclined portions 85c, 85c respectively extend rearward from the rear ends of the pair of hook portions 85b, 85b so as to approach the other hook portion 85b. 85c, 85c are formed in such a manner that the rear ends thereof are joined to each other.

  The engaging projection 85 in the example shown in the figure is formed as a house shape or an arrow shape in a sectional view by the above-described configuration.

  In the example shown in the figure, three engagement projections 85 are provided at a position near the lower end of the inner shell 80 so as to be spaced apart from each other in the left-right direction. Note that the number of the engagement convex portions 85 is not limited to the example shown in the drawing, and may be appropriately determined in consideration of, for example, securing an engagement force between the inner shell 80 and the outer shell 90. The number is appropriately set.

  In the example shown in the drawing, regarding the three engaging projections 85 that are spaced apart from each other in the left-right direction, the forming directions are different between the engagement projections 85 at the left and right ends and the middle engagement projection 85. Specifically, the direction in which the pair of joining support portions 85a, 85a, the hook portions 85b, 85b, and the inclined portions 85c, 85c face each other and are elastically deformed as the engagement convex portions 85 are the left and right ends. Are in the up-down direction, while the middle engagement protrusion 85 is in the left-right direction.

  The direction in which the engaging protrusions 85 are formed is adjusted such that the plurality of engaging protrusions 85 can firmly cope with the external force applied to the inner shell 80 as a whole, or is provided by the portion of the inner shell 80. The direction of the external force may be assumed and adjusted in consideration of the direction. Note that all of the plurality of engaging projections 85 may be formed in the same direction.

  The engaging concave portion 93 of the outer shell 90 is formed on the front side of the outer shell 90 as an integral part of the outer shell 90 (accordingly, formed of resin).

  The engaging concave portion 93 is configured such that the engaging convex portion 85 of the inner shell 80 is inserted, and the hook portion 85b is hooked and engaged.

  The engagement recess 93 has a pair of overhangs 93a, 93a projecting from the front surface of the outer shell 90, and a pair of claws 93b, 93b provided at the front end of each of the pair of overhangs 93a, 93a. (FIG. 27).

  The pair of projecting portions 93a, 93a are formed so as to project from the front surface of the outer shell 90 so as to face each other while being separated from each other in a forward direction.

  The pair of claws 93b, 93b are formed to bend from the front ends of the pair of overhangs 93a, 93a, respectively, to the other overhang 93a.

  The pair of claw portions 93b, 93b are separated from each other, and the space between the pair of claw portions 93b, 93b is an opening as an engagement recess 93. The engagement recess 93 is directed forward, that is, toward the inner shell 80. It is formed to have all the openings.

  On the lower side of the inner shell 80, the engaging convex portion 85 enters the engaging concave portion 93 while the portion near the lower end of the inner shell 80 is pushed from the front of the engaging concave portion 93 of the outer shell 90. The pair of inclined portions 85c, 85c of the convex portion 85 are located between the pair of overhang portions 93a, 93a of the engaging concave portion 93, and the pair of joining support portions 85a, 85a of the engaging convex portion 85 are engaged with the engaging concave portion. 93 and a pair of hooks 85b, 85b of the engaging projection 85 are moved toward the inner edge of each of the pair of claws 93b, 93b of the engaging recess 93. Each of them is attached to the outer shell 90 while being hooked and engaged.

  When the engagement convex portion 85 enters the engagement concave portion 93, the pair of inclined portions 85c, 85c of the engagement convex portion 85 are connected to the pair of claw portions 93b, 93b forming the opening of the engagement concave portion 93, respectively. A pair of joint support portions 85a, 85a, hook portions 85b, 85b, and inclined portions 85c, 85c, which are opposed to each other while being separated from each other while being slid with respect to the inner edge, are engaged with each other in the direction in which each of them faces each other. By elastically deforming the portion 85, the hook portion 85b goes over the claw portion 93b together with the inclined portion 85c, and enters between the pair of overhang portions 93a, 93a.

  Here, the engagement convex portion 85 is orthogonal to the direction in which the pair of joining support portions 85a, 85a, the hook portions 85b, 85b, and the inclined portions 85c, 85c face each other (referred to as “elastic deformation direction”). When it is pulled along the direction, it can exert a strong engaging force on the engaging concave portion 93 (FIG. 28), while the inner shell 80 around the engaging convex portion 85 is rolled / turned. When an external force acts on the engaging concave portion 93 to cause the inner concave portion 93 to rotate, the inner shell 80 around the engaging convex portion 85 is easily rolled / turned along the elastic deformation direction. 29 (in FIG. 29, it is rolled / turned along the paper surface of FIG. 29), and easily rolls off the engagement recess 93 when the external force acts on the engagement recess 93.

  That is, with respect to the engagement / connection between the engagement convex portion 85 and the engagement concave portion 93, a portion on the lower end side of the inner shell 80 (particularly, a peripheral portion of the engagement convex portion 85) is pulled forward along the front-rear direction. In this case, the engaging projection 85 does not easily come off from the engaging recess 93 by exerting a strong engaging force.

  On the other hand, when the lower end portion of the inner shell 80 (particularly, the peripheral portions of the engagement projections 85 at the left and right ends) is pulled upward or downward from the front so as to be rolled up along the vertical plane in the front-rear direction. In this case, the engaging projections 85 (FIG. 24) at the left and right ends whose elastic deformation direction is the vertical direction are easily detached from the engaging recess 93.

  Also, when the lower end portion of the inner shell 80 (particularly, the peripheral portion of the middle engagement projection 85) is pulled from the front to the left or right so as to be turned along the horizontal plane in the front-rear direction, it is elastically deformed. The middle engaging projection 85 (FIG. 24) whose direction is the left-right direction is easily detached from the engaging recess 93.

  Therefore, in order to reduce or suppress the turning of the engaging convex portion 85 with respect to the engaging concave portion 93 in a state where the engaging convex portion 85 and the engaging concave portion 93 are engaged, each engagement of the rear surface of the inner shell 80 is performed. A turn suppressing portion 86 is formed at a position adjacent to / in the vicinity of the convex portion 85.

  The rotation suppressing portion 86 can reduce or suppress the rotation of the engaging convex portion 85 with respect to the engaging concave portion 93 in a state where the engaging convex portion 85 and the engaging concave portion 93 are engaged. However, the present invention is not limited to a specific mode. For example, it may hinder the displacement of the inner shell 80 with respect to the outer shell 90, and particularly, the engagement convex portion 85 of the inner shell 80 and the vicinity of the engagement convex portion 85 There is a mode in which deformation of a portion is suppressed.

  The rotation suppressing portion 86 contacts the front surface of the outer shell 90 when the engagement protrusion 85 of the inner shell 80 and the peripheral portion of the engagement protrusion 85 are displaced or deformed. The contact portion may be provided so as to prevent the engagement convex portion 85 of the inner shell 80 and its peripheral portion from being displaced or deformed.

  The rotation suppressing portion 86 prevents the deformation of the engagement convex portion 85 and the inner shell 80 in the peripheral portion thereof by increasing the rigidity of the inner shell 80 by providing the rotation suppressing portion 86. It may be provided intentionally.

  More specifically, for example, a wall-shaped protrusion protruding toward the front surface of the outer shell 90 is provided at a position around the engagement protrusion 85 on the rear surface of the inner shell 80 as in the example shown in the drawing. Alternatively, the thickness of the inner shell 80 around the engaging projection 85 may be increased, or a reinforcing member may be attached to a position around the engaging projection 85.

  Even if an external force is applied to the inner shell 80 from any direction, in order to effectively suppress the turning of the engaging convex portion 85, when the turning suppressing portion 86 is provided as a wall-shaped protrusion, It is preferable that the wall-shaped protrusion serving as the rotation suppressing portion 86 is formed and provided as a square (specifically, a square in a rear view) surrounding the engagement protrusion 85. In the case where the rotation suppressing portion 86 is formed by making the thickness 80 large, the range of the square shape (specifically, the square shape in rear view / front view) including the position where the engagement convex portion 85 is formed is thickened. Preferably, when a reinforcing member is attached as the rotation suppressing portion 86, the reinforcing member as the rotation suppressing portion 86 has a square shape (specifically, a square shape in rear view) surrounding the engagement convex portion 85. Preferably attached to.

  However, the wall-shaped protrusion serving as the rotation suppressing portion 86 does not have to be formed as a complete square protrusion without interruption of all sides, that is, may be formed as a protrusion that is partially cut off. good. Further, the range in which the inner shell 80 is thickened as the rotation suppressing portion 86 does not have to be thickened without leakage over the entire surface of the square shape, that is, may include a portion that is not thickened. Further, the reinforcing member serving as the rotation suppressing portion 86 may not be attached so that all sides form a perfect square shape without interruption, that is, may be attached intermittently.

  As described above, the engagement protrusion 85 is particularly wound / turned along the elastic deformation direction of the inner shell 80 around the engagement protrusion 85 (in the drawing, along the paper surface of FIG. 29). When an external force (such as being rolled up / turned) acts to rotate with respect to the engagement recess 93, the engagement recess 93 is easily detached. For this reason, in order to reduce or suppress the turning of the engagement protrusion 85 along the elastic deformation direction, the peripheral portion of the engagement protrusion 85 of the inner shell 80 is moved in the elastic deformation direction of the engagement protrusion 85. It is effective to reduce or suppress the displacement and deformation along.

  Therefore, when the rotation suppressing portion 86 is provided as a wall-shaped protrusion, it is formed and provided as a wall-shaped protrusion along the elastic deformation direction of the engagement protrusion 85, or the inner shell 80 is provided in the elastic deformation direction. It is preferable that the outer shell 90 be formed and provided in such a manner that it can come into contact with the front surface of the outer shell 90 when being rolled / turned along.

  In the example shown in the drawing, of the rotation suppressing portions 86 provided as the wall-shaped projections with respect to the engagement projections 85 at the left and right ends, the elastic deformation directions of the engagement projections 85 at the left and right ends (that is, up and down) Direction), the wall-shaped protrusion 86a provided along the direction (ie, the left-right direction) is in contact with the front surface of the outer shell 90 when the inner shell 80 is to be rolled up in the elastic deformation direction. This suppresses the turning of the engaging projections 85, and the wall-shaped projections 86b provided along the elastic deformation directions (that is, the up and down directions) of the engaging projections 85 at both the left and right sides make the inner shell 80 elastic. When it is attempted to be rolled up along the deformation direction, the inner shell 80 exerts its rigidity and abuts against the front surface of the outer shell 90 to suppress the turning of the engagement projection 85.

  In the example shown in the drawing, among the rotation suppressing portions 86 provided as wall-shaped protrusions with respect to the middle engagement protrusion 85, the elastic deformation direction of the middle engagement protrusion 85 (that is, left and right) The wall-shaped protrusion 86c provided along the direction) enhances the rigidity of the inner shell 80 when the inner shell 80 is turned up along the elastic deformation direction, and contacts the front surface of the outer shell 90. The rotation of the engagement projection 85 is suppressed by the above, and a wall-shaped projection provided along a direction (ie, up-down direction) orthogonal to the elastic deformation direction (ie, left-right direction) of the middle engagement projection 85. The portion 86d contacts the front surface of the outer shell 90 when the inner shell 80 is turned up along the elastic deformation direction, thereby suppressing the turning of the engagement projection 85.

  It is also preferable that the rotation suppressing portion 86 be provided on a line connecting a position where an external force for rolling / turning the inner shell 80 is applied and a position where the engaging convex portion 85 and the engaging concave portion 93 are engaged. I can say. For example, in the example shown in the drawing, when an external force that is to be rolled up from the lower end of the inner shell 80 is applied below the engagement position between the engagement protrusions 85 and the engagement recesses 93 at the left and right ends, the left and right ends The wall-shaped protrusion 86a provided above the engagement convex portion 85 and the engagement concave portion 93 corresponds to this. When the wall-shaped projection 86a is provided on a line connecting the point of action of the force for rolling / turning the inner shell 80 and the engagement position of the inner shell 80, when the inner shell 80 is rolled / turned. The wall-shaped projection 86d abuts against the front surface of the outer shell 90 to prevent the engagement projection 85 from turning, and effectively prevents the engagement projection 85 from coming off the engagement recess 93 and coming off. You.

  When the inner shell 80 is made thicker to form the rotation suppressing portion 86, it is preferable that the inner shell 80 be formed in a belt-like shape along the elastic deformation direction of the engagement convex portion 85.

  When a reinforcing member is attached as the rotation suppressing portion 86, it is preferable that the reinforcing member be attached along the elastic deformation direction of the engaging projection 85.

  In addition, the formation of the wall-shaped protrusion, the increase in the thickness of the member, and the attachment of the reinforcing member, which are cited as examples of the mode of the rotation suppressing portion 86, may be such that any one of these may be used. Alternatively, a plurality of these may be used in combination.

  Further, in the example shown in the figure, the engagement convex portion 85 is provided on the inner shell 80 side, the engagement concave portion 93 is provided on the outer shell 90 side, and the rotation suppressing portion 86 is provided only on the inner shell 80 side. Although they are provided, the manner in which the engagement convex portions 85 and the engagement concave portions 93 and the rotation suppressing portions 86 are arranged is not limited to the example shown in the drawing. In addition, the arrangement is not limited to the arrangement in which the rotation suppressing portion 86 is provided only on the side where the engagement convex portion 85 is provided as in the example shown in the drawing.

  More specifically, for example, only as an example, after the engagement convex portion 85 is provided on the inner shell 80 and the engagement concave portion 93 is provided on the outer shell 90, the rotation suppressing portion (86) is provided with the outer shell 90. May be provided. In addition, as a mode of the rotation suppressing portion (86) provided in the outer shell 90 to reduce and suppress the rotation of the engaging convex portion 85 with respect to the engaging concave portion 93 due to the rolling / turning of the inner shell 80, the inner When the shell 80 is displaced or deformed, the rotation suppressing portion (86) abuts on the rear surface of the inner shell 80 to prevent the inner shell 80 from being displaced or deformed.

  In addition, after the engaging convex portion (85) is provided on the outer shell 90 and the engaging concave portion (93) is provided on the inner shell 80, the rotation suppressing portion (86) is provided between the outer shell 90 and the inner shell 80. It may be provided in at least one of them. Also in this case, when the inner shell 80 is rolled / turned, the engagement concave portion (93) moves with respect to the engagement convex portion (85), so that the engagement concave portion (93) engages with the engagement convex portion (93). 85) turns around. For this reason, a rotation suppressing portion 86 is provided in the inner shell 80, and a rotation suppressing portion (86) is provided in the outer shell 90. In addition, the inner shell 80 is rolled / turned and the engagement concave portion (93) moves with respect to the engagement convex portion (85), so that the rotation of the engagement convex portion (85) with respect to the engagement concave portion (93) is reduced. As a mode of the rotation suppressing portion (86) provided on the outer shell 90 for suppressing, the rotation suppressing portion (86) is provided on the rear surface of the inner shell 80 when the inner shell 80 is displaced or deformed. One that prevents the inner shell 80 from being displaced or deformed due to the contact.

  In addition, after the engaging convex portion (85) and the engaging concave portion (93) are provided on the outer shell 90 and the engaging convex portion (85) and the engaging concave portion (93) are provided on the inner shell 80, the turning operation is performed. The suppressing portion 86 may be provided on at least one of the outer shell 90 and the inner shell 80.

  The engagement projection 85 of the inner shell 80 does not easily come off the engagement recess 93 of the outer shell 90, but does come off when pulled by an appropriate force.

  When the engaging projection 85 that has been inserted into and engaged with the engaging recess 93 is pulled out, the pair of hooks 85b, 85b of the engaging projection 85 form the opening of the engaging recess 93. A pair of joining support parts 85a, 85a, hook parts 85b, 85b, and slant parts 85c, 85c that are opposed to each other while being separated from each other while sliding with respect to the inner edges of the pair of claw parts 93b, 93b. The engaging portion 85b is elastically deformed as the engaging convex portion 85 in the opposite direction (that is, the elastic deformation direction), so that the hook portion 85b gets over the claw portion 93b and is pulled out of the engaging concave portion 93 together with the inclined portion 85c.

  With the engagement convex portion 85, the engagement concave portion 93, and the rotation suppressing portion 86, the coupling force between the inner shell 80 and the outer shell 90 is appropriately ensured. The inner shell 80 can be detached from the connector 90, and the problem that parts are damaged at the time of removal and replacement or repair with a substitute is required can be avoided. That is, engagement / connection that is detachable and hard to be easily detached is realized.

  According to the chair engaging structure and chair configured as described above, the engaging projection 85 of the inner shell 80 is elastically deformed to engage with the engaging recess 93 of the outer shell 90. Therefore, it can be configured as a detachable structure, and a rotation suppressing portion 86 that reduces or suppresses the rotation of the engaging convex portion 85 engaged with the engaging concave portion 93 is provided. Therefore, the engagement protrusion 85 is displaced or deformed in the state of being engaged with the engagement recess 93, and is not suitable for engagement between the engagement protrusion 85 and the engagement recess 93. Displacement and deformation of the portion 85 can be suppressed. For this reason, it is possible to prevent the engagement convex portion 85 from being displaced or deformed and the engagement with the engagement concave portion 93 from being unexpectedly disengaged. In addition, the backrest to which the engagement structure is applied, and thus the safety and comfort of use of the chair can be improved.

  In addition, although the above-mentioned embodiment regarding the engaging structure of the parts of the chair is an example of a preferred embodiment when carrying out the present invention, the embodiment of the present invention is not limited to the above-described embodiment, and the present invention The present invention can be variously modified without departing from the scope of the invention.

  For example, in the above-described embodiment, the example in which the embodiment of the engagement structure of the chair parts is applied to the assembly of the backrest 6 of the chair whose overall structure is illustrated in FIG. The backrest and the chair to which the above-described points of the engagement structure can be applied are not limited to the backrest 6 and the chair shown in the drawings as the embodiment. The backrest (specifically, the engagement / connection between the inner shell 80 and the outer shell 90) is not limited to the backrest (specifically, the inner shell 80 and the outer shell 90 constituting the backrest). The essential points of the above-described engagement structure can be applied to engagement, attachment, and fitting of various other components and members. Furthermore, the subject of application of the above-mentioned engagement structure is not limited to the chair, and the above-described engagement structure is used for engagement, attachment, and fitting of various parts and members constituting various furniture. The gist of can be applied.

  Based on the above, the main points of the engagement structure of the above-mentioned chair components are arranged as follows. First, the outer shell 90 is a first component, the inner shell 80 is a second component, the engaging concave portion of the outer shell 90 is a concave portion, the engaging convex portion 85 of the inner shell 80 is a convex portion, and turning of the inner shell 80 is suppressed. The parts 86 are each generalized as a turning suppressing part. In the above, the “first part” and “second part” include not only a part that is positioned as a part in the configuration of the whole chair and a part corresponding to the part of the counterpart, but also the whole chair. It also includes components that can be positioned as members in the configuration and components that can correspond to members in relation to the counterpart parts / members.

  The key point of the above-described engagement structure of the chair components is the engagement structure between the first component and the second component. The first component has a concave portion, and the second component has the concave portion. A protrusion that elastically deforms and engages is provided, and the protrusion rotates with respect to the recess in a state where the protrusion and the recess are engaged with at least one of the first component and the second component; It is arranged that a rotation suppressing unit that reduces or suppresses the rotation is provided. In the configuration described above, the first component and the second component may be made of resin, and in particular, the convex portion of the second component may be made of resin.

(Lumbar support mounting structure)
The backrest 6 is provided on a pair of left and right pushing members 100L, 100R attached to the outer shell 90 so as to be relatively movable, and is disposed in front of the pair of left and right pushing members 100L, 100R to support the waist of a seated person. The lumbar supporter 81 includes a connecting member 82 provided between the inner shell 80 and the lumbar supporter 81 to support the lumbar supporter 81 (FIG. 24).

  The pair of left and right pushing members 100L and 100R (that is, the left pushing member 100L and the right pushing member 100R) are slidable in the left-right direction between the center position P1 and the left / right end position P2, respectively. It is configured as a simple mechanism.

  The outer shell 90 constitutes an extrusion member support that supports the back of the occupant and movably supports the pair of left and right extrusion members 100L and 100R (in other words, functions as a support for the extrusion members).

  The inner shell 80 constitutes a lumbar supporter holder that holds the lumbar supporter 81 (in other words, functions as a lumbar supporter holder).

  The lumbar supporter 81 is formed in a substantially plate shape by a resin, and is held by the inner shell 80 via a connecting member 82.

  The lumbar supporter 81 is configured such that substantially the entire body, that is, a part directly extruded and its surrounding part can be moved in the front-rear direction by being pushed out from the rear by the pushing members 100L and 100R that can slide in the left-right direction. Is done.

  The connecting member 82 is interposed between the inner shell 80 and the lumbar supporter 81 to connect the lumbar supporter 81 to the inner shell 80 so that the lumbar supporter 81 can move back and forth.

  In the example shown in the figure, a total of four connecting members 82 are provided between the inner shell 80 and the lumbar supporter 81 on the left and right sides at the upper end and the lower end of the lumbar supporter 81, respectively.

  In the example shown in the figure, the inner shell 80, the lumbar supporter 81, and the connecting member 82 are integrally formed of resin.

  The pair of left and right extrusion members 100L, 100R are slidably attached to the outer shell 90, which is a support for supporting the pair of left and right extrusion members 100L, 100R, in the left-right direction.

  The pair of left and right pushing members 100L, 100R directly presses the lumbar supporter 81 provided on the front side of the pair of left and right pushing members 100L, 100R from the rear. As a result, a lumbar support portion capable of extruding and supporting the waist of a seated person is constituted mainly by the pair of left and right push members 100L and 100R and the lumbar supporter 81.

  The position of the pair of left and right push members 100L and 100R in the left-right direction can be changed with respect to the degree of lumbar support by the lumbar support portion, that is, the degree of pushing of the occupant against the waist (in other words, pressing against the occupant's waist). Can be adjusted arbitrarily.

  In the outer shell 90, as a structure related to the lumbar support portion, a portion that is bent forward in a side view (that is, a rectangular shape) is spaced apart in a vertical direction in a front view and a rear view and extends along a horizontal direction. A pair of upper and lower (ie, two) slits 91U and 91L (that is, an upper slit 91U and a lower slit 91L) provided in parallel with each other are formed.

  The outer shell 90 and the pair of left and right extruded members 100L and 100R are guided by a pair of upper and lower slits 91U and 91L formed in the outer shell 90, and the pair of left and right extruded members 100L and 100R are independent of each other in the left and right direction. It is configured to be able to move along.

  The pair of left and right extrusion members 100L, 100R are engaged with a pair of upper and lower slits 91U, 91L, and are attached so as to straddle a band-shaped portion 94 between the slits 91U, 91L.

  A substantially rectangular opening 84 is formed in the inner shell 80 at a position corresponding to the waist of a seated person as a structure related to the lumbar support portion.

  The opening 84 has an opening length in the left-right direction of a size that allows a pair of left and right pushing members 100L, 100R located at the left and right end positions P2, P2 to be included in the opening 84 in front view / rear view. No matter where the pair of left and right pushing members 100L and 100R that move between the center position P1 and the left and right end position P2 are located in the opening 84, the position is always included. It is formed as having an opening height in the vertical direction of the dimensions.

  A lumbar supporter 81 is provided in the opening 84 via a connecting member 82. As a result, the lumbar supporter 81 on the inner shell 80 side is disposed at a portion that can abut on the pair of left and right pushing members 100L, 100R attached to the outer shell 90 side in the front-rear direction.

  The mounting structure of the components of the chair according to the present embodiment is a structure in which the pushing members 100L and 100R are mounted on the outer shell 90, and the outer shell 90 has a band-shaped portion 94 sandwiched between the pair of slits 91U and 91L. Each of the pushing members 100L and 100R includes an operating unit 110 disposed on the rear side of the outer shell 90 and an extruding unit 120 disposed on the front side of the outer shell 90. It has a pair of connecting portions 113U and 113L for connecting to the pushing portion 120, and each of the pair of connecting portions 113U and 113L of the operation portion 110 projects toward the pushing portion 120 and slides through the slits 91U and 91L. A vertical portion that extends from the moving portion 114 and the sliding portion 114 with the horizontal fitting portion 115 interposed therebetween and is larger than the width of the slits 91U and 91L. A pair of edges 91a and 94a, which form the slit 91U, which are opposed to each other in the longitudinal direction of the slits 91U and 91L, and the edge 94a is displaced stepwise and forms the slit 91L. The edge portion 94b is shifted stepwise so that the horizontal fitting portion 115 and the vertical fitting portion 116 can pass between the steps between the edges 91a and 94a and between the steps between the edges 91b and 94b, respectively. Portion 94 is adapted to flex.

  Further, the method of mounting the components of the chair according to the present embodiment is a method of mounting the extruded members 100L and 100R to the outer shell 90. The outer shell 90 has a band-shaped portion 94 sandwiched between a pair of slits 91U and 91L. Each of the pushing members 100L and 100R includes an operating unit 110 disposed on the rear side of the outer shell 90 and an extruding unit 120 disposed on the front side of the outer shell 90. It has a pair of connecting portions 113U and 113L for connecting to the pushing portion 120, and each of the pair of connecting portions 113U and 113L of the operation portion 110 projects toward the pushing portion 120 and slides through the slits 91U and 91L. A vertical fitting that extends from the moving part 114 and the sliding part 114 with the horizontal fitting part 115 interposed therebetween and is larger than the width of the slits 91U and 91L. A pair of edges 91a and 94a, which are opposed to each other in the longitudinal direction of the slits 91U and 91L to form the slit 91U by bending the band-shaped portion 94, so that the slit 91L is shifted. The pair of edges 91b and 94b to be formed are shifted in steps, and the horizontal fitting portion 115 and the vertical fitting portion 116 are formed between the steps of the edges 91a and 94a and between the steps of the edges 91b and 94b, respectively. I let it pass.

  The left pushing member 100L and the right pushing member 100R are members made of resin, and function to slide along the slits 91U and 91L along the left-right direction and to press the lumbar supporter 81 from behind.

  Each of the left and right pushing members 100L and 100R has an operating portion 110 located on the rear side of the outer shell 90 and a pushing portion 120 located on the front side of the outer shell 90 (FIG. 30).

  The operating portion 110 includes a handle portion 111 that projects rearward along the up-down direction, a contact portion 112 that extends from the front end of the handle portion 111 in both left and right directions, and a vertical portion provided on the front surface of the contact portion 112. It has a pair of connecting portions 113U and 113L (FIG. 31).

  The handle portion 111, the contact portion 112, and the pair of upper and lower connecting portions 113U and 113L are integrally formed of resin.

  The contact portion 112 is formed substantially in a D-shape in rear view / front view, and is disposed along the rear surface of the outer shell 90.

  The handle portion 111 protrudes rearward from the rear surface of the contact portion 112, and is formed in a substantially semi-elliptical shape whose left and right plate surfaces are substantially along the vertical direction.

  The operation unit 110 is configured to be able to perform a function as a grip unit that is gripped when the occupant operates the left and right push members 100L and 100R. The occupant can arbitrarily change the position of the push-out unit 120 in the left-right direction by gripping the operation unit 110 (specifically, the grip unit 111) and performing a slide operation.

  The pair of upper and lower connecting portions 113U and 113L (that is, the upper connecting portion 113U and the lower connecting portion 113L) is a structure for connecting the operating portion 110 and the pushing portion 120, and is a front side of the contact portion 112. In addition, as a pair of upper and lower members which are separated from each other in the up-down direction, they are provided so as to protrude forward (that is, toward the outer shell 90 and the extruded portion 120).

  The pair of upper and lower connecting portions 113U and 113L respectively include a sliding portion 114 connected to the front surface of the contact portion 112, a horizontal fitting portion 115 connected to the front end of the sliding portion 114, and a horizontal fitting portion 115. And a pair of left and right vertical fitting portions 116, 116 that are connected to the left and right ends. However, the shapes of the connecting portions 113U and 113L are not limited to the examples shown in the drawings, and may have various forms.

  The sliding portion 114 projects forward from the front surface of the contact portion 112, and is formed in a plate shape with upper and lower plate surfaces extending along the horizontal direction.

  The sliding portion 114 of each of the pair of upper and lower connecting portions 113U and 113L has a degree / size in which the upper and lower sliding portions 114 and 114 are vertically separated from each other in a vertical direction. It is adjusted so as to have the same degree / dimension in the direction, and is formed at a position penetrating each of the pair of upper and lower slits 91U and 91L.

  The horizontal fitting portion 115 extends in the left-right direction from the front end of the sliding portion 114, and is formed in a plate shape having upper and lower plate surfaces extending in the horizontal direction. The code of the horizontal fitting portion of the upper connecting portion 113U is 115u, and the code of the horizontal fitting portion of the lower connecting portion 113L is 115l.

  The pair of left and right vertical fitting portions 116u and 116u of the upper connecting portion 113U project from each of the right and left ends of the upper surface of the horizontal fitting portion 115u so as to face each other while being upwardly separated from each other. Are provided as a pair of left and right projecting pieces.

  The pair of left and right vertical fitting portions 116l, 116l of the lower connecting portion 113L project from each of the left and right ends of the lower surface of the horizontal fitting portion 115l so as to face each other while being separated from each other downward, and the left and right plate surfaces are vertical. It is provided as a pair of left and right protruding pieces along the direction.

  The pushing portion 120 has a pair of upper and lower fitting recesses 121U and 121L that open rearward, and a pair of upper and lower locking claws 126U and 126L that project rearward (FIG. 32).

  The pushing portion 120 is formed in a substantially rectangular shape in front view / back view, and is disposed along the front surface of the outer shell 90.

  The pair of upper and lower fitting recesses 121U and 121L (that is, the upper fitting recess 121U and the lower fitting recess 121L) is a structure for connecting the operating unit 110 and the pushing unit 120. It is formed on the rear surface side as a pair of upper and lower parts which are separated from each other in the vertical direction, and is opened in a rearward direction (that is, toward the outer shell 90 and the operation unit 110).

  The upper fitting recess 121U is formed along the left-right direction, and includes a horizontal recess 122u into which the horizontal fitting portion 115u of the upper connecting portion 113U of the operation unit 110 enters, and a left and right end of the horizontal recess 122u. It has a pair of left and right vertical recesses 123u, 123u that are formed facing each other upward and separated from each other and into which a pair of left and right vertical fitting portions 116u, 116u of the upper connection portion 113U of the operation portion 110 enter.

  The lower fitting concave portion 121L is formed along the left-right direction and includes a horizontal concave portion 122l into which the horizontal fitting portion 115l of the lower connecting portion 113L is inserted, and a left and right end portion of the horizontal concave portion 122l. It has a pair of left and right vertical recesses 123l, 123l formed to face each other downward and spaced apart from each other and into which a pair of left and right vertical fitting portions 116l, 116l of the lower connecting portion 113L of the operation portion 110 enter. .

  The pair of upper and lower locking claws 126U and 126L (that is, the upper locking claw 126U and the lower locking claw 126L) have a structure for maintaining the connection state between the operation unit 110 and the pushing unit 120, It is formed on the rear surface side of the part 120 as a pair of upper and lower parts which are separated from each other in the up-down direction, and extends backward (that is, toward the outer shell 90 and the operation unit 110).

  The upper locking claw 126U is provided at a position adjacent to the upper side of the upper lateral recess 122u so as to project backward.

  The upper locking claw 126U has a claw portion 126a protruding downward at the rear end.

  The lower locking claw 126L is provided at a position adjacent to the lower side of the lower lateral recess 122l in such a manner as to project rearward.

  The lower locking claw 126L has a claw portion 126b protruding upward at the rear end.

  The operating portion 110 disposed on the rear side of the outer shell 90 and the pushing portion 120 disposed on the front side of the outer shell 90 are formed by a pair of upper and lower connecting portions 113U and 113L of the operating portion 110, each sliding portion 114, 114 penetrates a pair of upper and lower slits 91U and 91L formed in the outer shell 90 (in other words, is located in the pair of upper and lower slits 91U and 91L so as to straddle the front side and the rear side of the outer shell 90). ), The horizontal fitting portion 115 and the left and right pair of vertical fitting portions 116 and 116 of the pair of upper and lower connecting portions 113U and 113L of the operating portion 110 respectively form the pair of upper and lower fitting concave portions 121U and 121L of the pushing portion 120. It is assembled and attached to the outer shell 90 in the fitted state.

  When the horizontal fitting portion 115u and the pair of right and left vertical fitting portions 116u and 116u of the upper connecting portion 113U are fitted into the horizontal recess 122u and the pair of left and right vertical recesses 123u and 123u of the upper fitting recess 121U, The upper locking claw 126U (particularly, a downwardly protruding claw portion 126a) of the pushing portion 120 is locked to a locking recess 117u formed at the upper rear end of the upper horizontal fitting portion 115u of the operating portion 110. Then, the fitting state between the upper connecting portion 113U and the upper fitting recess 121U is maintained (FIG. 32).

  Further, the horizontal fitting portion 115l of the lower connecting portion 113L and the pair of left and right vertical fitting portions 116l, 116l are turned into a horizontal recess 122l of the lower fitting recess 121L and a pair of left and right vertical recesses 123l, 123l. When the fitting portion is fitted, a lower engaging claw 126L (particularly, a claw portion 126b projecting upward) on the lower side of the push-out portion 120 is formed at the lower rear end of the lower horizontal fitting portion 115l of the operating portion 110. Locked to the stop recess 117l, the fitting state between the lower connecting portion 113L and the lower fitting recess 121L is maintained (FIG. 32).

  As a result, the state in which the operation unit 110 and the pushing unit 120 are combined and connected to each other and attached to the outer shell 90 is maintained. Therefore, according to the above-described configuration, the operating unit 110 and the pushing unit 120 are combined and attached without using other additional members such as screws.

  In the example shown in the figure, the pair of upper and lower locking recesses 117u and 117l are both provided on the operation unit 110, and the pair of upper and lower locking claws 126U and 126L are both provided on the pushing unit 120. At least one of the structures corresponding to the pair of upper and lower locking recesses 117u and 117l is provided in the pusher 120, and at least one of the structures corresponding to the pair of upper and lower locking claws 126U and 126L is the operating unit 110. May be provided.

  When the operating unit 110 and the pushing unit 120 are combined and connected to each other and attached to the outer shell 90, the sliding unit 114 of the upper connecting unit 113U and the sliding unit 114 of the lower connecting unit 113L are connected. The band portion 94 of the outer shell 90 is located between the operation unit 110 and the pushing unit 120 in the front-rear direction.

  Then, in a state where the operating portion 110 and the pushing portion 120 are combined and attached to the outer shell 90, the upper and lower sliding portions 114, 114 are guided by a pair of upper and lower slits 91U, 91L, respectively, and the band portion 94 is provided. The right and left push members 100L, 100R slide along the left / right direction while the right and left push members 100L and 100R are sandwiched between the operation unit 110 (specifically, the contact portion 112) and the push unit 120 in the front / rear direction (FIG. 33).

  Here, when the dimensions of the connecting portions 113U, 113L (particularly, a pair of left and right vertical fitting portions 116, 116 in the example shown in the figure) are larger than the width of the slits 91U, 91L in the vertical direction, Cannot be respectively passed through the upper and lower slits 91U and 91L.

  Therefore, by bending the band portion 94 sandwiched between the pair of upper and lower slits 91U and 91L forward, the upper edge 94a of the band portion 94 and the upper edge 91a on the outer shell 90 side forming the upper edge of the upper slit 91U are formed. A gap G1 is formed between the lower edge 94b of the band-shaped portion 94 and the lower edge 91b of the outer shell 90 that forms the lower edge of the lower slit 91L (FIG. 34). ).

  By bending the band-shaped portion 94 as described above, a pair of edges 91a (upper edge 91a) and an edge 94a (upper edge 94a) opposing in the longitudinal direction of the upper and lower slits 91U and 91L to form the slit 91U. And a pair of edges 91b (lower edge 91b) and an edge 94b (lower edge 94b) which form the slit 91L are shifted stepwise, and between the steps of the edges 91a, 94a and the edge 91b. , 94b are formed as upper and lower gaps Gu and Gl (that is, upper gap Gu and lower gap Gl).

  If the pair of edges forming the upper and lower slits 91U and 91L is bent and the upper and lower gaps Gu and Gl are formed so as to be shifted in steps, the upper and lower connecting portions 113U and 113L of the operation unit 110 (FIG. In particular, in the example shown in (1), a pair of left and right vertical fitting portions 116, 116) can be passed.

  For example, in a state in which the band-shaped portion 94 is bent forward, the upper and lower connecting portions 113U and 113L of the operation portion 110 are directed toward the band-shaped portion 94 and the upper and lower connecting portions 113U and 113L are aligned (that is, the operation The upper and lower connecting portions 113U and 113L are brought into contact with the rear surface of the band-shaped portion 94 in such a manner that the upper and lower connecting portions 113U and 113L are oriented along the longitudinal direction of the band-shaped portion 94 (in other words, the direction along the upper and lower slits 91U and 91L). From this position, the belt-shaped portion 94 is arranged such that the direction in which the upper and lower connecting portions 113U and 113L are arranged (vertical direction for the operation portion 110) is orthogonal to the longitudinal direction of the band-shaped portion 94 (the direction along the upper and lower slits 91U and 91L). The operation unit 110 is rotated while the upper and lower connecting parts 113U and 113L are in contact with the rear surface of the part 94. This allows the pair of left and right vertical fitting portions 116, 116 to pass through the upper and lower gaps Gu, Gl, respectively. Thereafter, when the bending of the band portion 94 is released, the sliding portions 114, 114 of the pair of upper and lower connecting portions 113U, 113L respectively pass through the pair of upper and lower slits 91U, 91L, and the pair of left and right vertical fitting portions 116 are provided. , 116 are exposed to the front side of the outer shell 90, and the operation unit 110 engages with the outer shell 90 (in other words, the operation unit 110 is attached to the outer shell 90).

  According to the above-described configuration, a pair of structures having dimensions larger than the width of the slits and projecting outward with respect to the space / structure between the pair of slits (the band-shaped portion 94 in the example shown in the drawing). Can be attached / engaged through the slit.

  In the example shown in the drawing, the outer shell 90 has a shape curved so as to project rearward in a plan view, in other words, it curves along a direction in which a pair of upper and lower slits 91U and 91L are formed. It is formed in a shape. For this reason, the gaps Gu and Gl are easily created by bending the belt portion 94 forward. However, it is not essential that the member in which the gap is created has a curved shape, and the main member (the outer shell) in which a slit is formed between the member and the elastically deformable portion corresponding to the band portion 94 in the example shown in the drawing. A pair of edges forming a slit by bending of the elastically deforming portion with respect to the main body portion of the elastic member 90 are stepwise shifted to form gaps Gu, Gl (that is, a gap between the edge of the main member and the edge of the elastically deforming portion). Gap) may be created.

  In the above description based on the example shown in the drawings, the pushing members 100L and 100R are attached to the slits 91U and 91L formed along the left and right direction. The direction is not limited to the left-right direction, but may be the up-down direction, or may be any direction.

  Further, in the example shown in the drawing, a pair of vertical fitting portions 116, 116 are provided on each of the pair of upper and lower connecting portions 113U, 113L of the operation unit 110, which are separated from each other in the left-right direction and are arranged along the left-right direction. Like that. The upper and lower pairs of left and right vertical fitting portions 116 and 116 are arranged in a direction orthogonal to the slits 91U and 91L after passing through the pair of upper and lower slits 91U and 91L. Therefore, the operation unit 110 can be engaged with the slits 91U, 91L by a pair of upper and lower right and left vertical fitting portions 116, 116 arranged in a direction orthogonal to the pair of upper and lower slits 91U, 91L. It is possible to slide left and right in a state of being engaged with the slits 91U, 91L in a stable posture by a pair of left and right vertical fitting portions 116, 116 which are separated from each other. Therefore, in the example shown in the drawing, in order to extrude the lumbar supporter 81, in addition to the operating unit 110, the extruding unit 120 is combined with the extruding members 100L and 100R, but is engaged with the slits 91U and 91L. In order to slide or slide, a component corresponding to the push-out unit 120 is not always necessary, and it is possible to use only the operation unit 110 as a configuration that engages with the slits 91U and 91L.

  According to the mounting structure, the mounting method and the chair of the components of the chair configured as described above, the pair of upper and lower slits 91U and 91L are respectively formed by the elastic deformation of the band-shaped portion 94 of the outer shell 90. The upper and lower connecting portions 113U and 113L (particularly, in the example shown in the figure, a pair of right and left vertical fitting portions 116 and 116) pass through the operating portion 110 so that the operating portion 110 and the pushing portion 120 Connecting portions 113U, 113L (particularly, in the example shown in the figure, the width of the slits 91U, 91L is smaller than the dimensions of the pair of right and left vertical fitting portions 116, 116). In particular, in the example shown in (1), a pair of left and right vertical fitting portions 116, 116) can be passed. For this reason, the usefulness and versatility of the mounting structure and the mounting method can be improved.

  In particular, according to the operating unit 110 and the pushing unit 120 having the above-described configuration, since the operating unit 110 and the pushing unit 120 are combined and attached, there is no need to use a screw that is passed over them. There is no need to make the vertical width of the 91U, 91L large enough to allow screws to penetrate. For this reason, it is possible to reduce the thickness of the sliding portion 114 in the vertical direction as long as the strength as the sliding portion 114 can be ensured, and the slits 91U and 91L are made corresponding to the thinning of the sliding portion 114. Each of them can be made thin (in other words, the widths of the slits 91U and 91L in the vertical direction are made narrower). Thereby, for example, it is possible to prevent a situation in which a finger or clothing is caught, or to improve the appearance.

  In addition, although the above-described embodiment regarding the mounting structure and the mounting method of the components of the chair is an example of a preferred embodiment when implementing the present invention, the embodiment of the present invention is not limited to the above-described embodiment. The present invention can be variously modified without departing from the scope of the present invention.

  For example, in the above-described embodiment, an example of the embodiment of the mounting structure and the mounting method of the components of the chair has a whole structure shown in FIG. 1 and the like. A pair of left and right push members 100L and 100R of a lumbar support portion provided in the backrest 6 of the chair. Although the description has been given by taking as an example the case where the present invention is applied to the attachment to the outer shell 90, the backrest and the chair to which the above-described points of the attachment structure and the attachment method can be applied are the backrest 6 shown in the drawings as an embodiment. It is not limited to chairs and chairs.Moreover, the application of the above-mentioned points of the mounting structure and the mounting method is not limited to the mounting of the extruded member to the outer shell constituting the backrest, but constitutes the backrest. The above-described points of the mounting structure and the mounting method can be applied to mounting of various components and members to various components and members other than mounting of the extruded member to the outer shell. Furthermore, the application of the essential points of the above-described mounting structure and mounting method is not limited to chairs, and the above-described mounting method is used for mounting various parts and members constituting various furniture to various parts and members. The points of structure and mounting method can be applied.

  Based on the above, the main points of the mounting structure and mounting method of the above-mentioned chair parts are arranged as follows. First, the outer shell 90 is a second component, the strip portion 94 of the outer shell 90 is an elastically deformable portion, the extruded members 100L / 100R are the first component, the operating portion 110 of the extruded member 100L / 100R is the first component, and the extruded member. The 100L / 100R extruded portion 120 is a second part, the upper and lower connecting portions 113U and 113L are a pair of connecting portions, the sliding portions 114 of the connecting portions 113U and 113L are penetrating portions, and the fitting portions 113U and 113L are vertically fitted. The parts 116u and 116l are each generalized as a protrusion or a single part. In the above, the “first part” and “second part” include not only a part that is positioned as a part in the configuration of the whole chair and a part corresponding to the part of the counterpart, but also the whole chair. It also includes components that can be positioned as members in the configuration and components that can correspond to members in relation to the counterpart parts / members.

  The essential point of the above-mentioned chair component mounting structure is a structure in which the first component is mounted on the second component, and the second component has an elastic deformation portion sandwiched between a pair of slits. Is composed of a first component disposed on one side of the second component and a second component disposed on the other side of the second component, wherein the first component is the first component. And a pair of connecting portions for coupling the first component and the second component, wherein each of the pair of connecting portions of the first component extends toward the second component and extends through the slit and extends from the through portion. And a pair of edges that form a slit that are opposed to each other in the longitudinal direction of the slit and that are offset from each other in a stepwise manner. It is arranged that the elastically deformable portion bends so that the portion can pass.

  In addition, the point of the above-mentioned method of attaching the parts of the chair is a method of attaching the first part to the second part, wherein the second part has an elastically deformable portion sandwiched between a pair of slits, Is composed of a first component disposed on one side of the second component and a second component disposed on the other side of the second component, and the first component is the first component. A pair of connecting portions for coupling the component and the second component, wherein each of the pair of connecting portions of the first component extends toward the second component and extends through the slit and extends from the through portion; And a pair of edges that form the slit and that are opposed to each other in the longitudinal direction of the slit by bending the elastically deformable portion to form the slit. Are arranged so as to pass through the projecting portion or one portion of the step.

  Further, as described above, only the components corresponding to the operation unit 110 in the above-described embodiment are used, and the vertical fitting portions 116u and 116l of the upper and lower coupling portions 113U and 113L engage with the edges forming the slit. You may do it.

  In this case, the main point of the above-mentioned chair component mounting structure is a structure in which the first component is mounted on the second component, and the second component has an elastically deformable portion sandwiched between a pair of slits. The first component has a pair of penetrating portions penetrating each of the pair of slits, and a protrusion or a piece extending from each of the penetrating portions and having a width larger than the width of the slit, and opposed in the longitudinal direction of the slit. Then, the pair of edges forming the slit is displaced stepwise, and the elastically deforming portion is bent so that the protrusion or the one part can pass between the steps of these edges, and has passed between the steps of the edges. It can be arranged that the protruding portion or the one engages with the edge forming the slit after the elastic deformation portion is released from the deflection.

  In addition, the point of the above-mentioned method of attaching the parts of the chair is a method of attaching the first part to the second part, wherein the second part has an elastically deformable portion sandwiched between a pair of slits, , A pair of penetrating portions penetrating each of the pair of slits, and a protruding portion or a piece extending from each of the penetrating portions and having a width larger than the width of the slit. In this case, a pair of edges forming the slit are opposed to each other so as to be shifted in a stepwise manner so that a protruding part or a part is passed between the steps of the edges.

  In the above configuration, the first component and the second component may be made of resin, and in particular, the second component may be made of resin (that is, the first component is made of resin). It does not matter).

3. One of two members (synchronous frame) connected to each other so as to be swingable by one shaft
5. The other of the two members (back frame) connected to each other so as to be swingable by one shaft
45 First spring mount 46 Second spring mount 47 Spring (compression coil spring)
48 First spring mount receiving portion 49 Second spring mount receiving portion 56 Flat plate portion (for example, a bridge portion) having an end surface orthogonal to the direction in which the spring force acts and two planes along the acting direction
57 End face orthogonal to the direction in which the spring force of the first spring mount receiver acts 57a Two planes along the direction in which the spring force of the first spring mount receiver acts 58 On the end face of the first spring mount receiver Two orthogonal side surfaces 72 A pair of flanges of the first spring mount that sandwich the flat plate portion 73 A slit of the first spring mount 74 A pressure receiving surface of the first spring mount 75 A second surface that abuts against a side surface of the first spring mount receiving portion. Side of spring mount 1

Claims (7)

A first spring mount, a second spring mount, and a compression coil spring disposed therebetween, between two spring mount receivers of two members which are swingably connected to each other by one axis; A spring mechanism that spans the two members to apply a spring force between the two members,
At least one of the spring mount and the spring mount receiving portion,
A first spring mount receiving portion having a surface orthogonal to a direction in which the spring force acts and two planes along the direction in which the spring force acts;
A pair of flanges sandwiching the flat surface of the first spring mount receiving portion, and a pressure receiving surface that abuts the first spring mount receiving portion between the flanges to receive a force applied to a spring; A first spring mount having a slit in which a gap between the pair of flanges is wider than a gap between the planes,
A spring supporting structure for a chair. The first spring mount receiving portion is a flat plate portion having an end surface orthogonal to a direction in which a spring force acts. The first spring mount includes a pair of flanges sandwiching the flat plate portion, and the flat plate portion interposed between the flanges. 2. A pressure receiving surface which abuts against an end surface of the flat plate to receive a force applied to a spring, and wherein a slit between the pair of flanges is wider than a plate thickness of the flat plate portion. Chair spring support structure. 3. The spring supporting structure for a chair according to claim 2, wherein a load is applied in a direction orthogonal to a thickness of the flat plate portion. The first spring mount receiving portion is a flat plate portion having a surface facing the direction in which the spring force is applied and two side surfaces orthogonal to the direction, and the first spring mount is provided on the three surfaces orthogonal to each other. The spring support structure for a chair according to any one of claims 1 to 3, wherein the chair is in contact with the chair at the same time. The spring support structure according to any one of claims 1 to 4, wherein one of the spring mount receiving portions is configured using a flat plate portion of the frame material. The other of the spring mount and the spring mount receiving part is a second spring mount receiving part comprising a semicircular or hemispherical convex or concave part, and a semicircular or hemispherical part of the second spring mounting receiving part. 6. A second spring mount having a semicircular or hemispherical concave or projecting portion which fits with the projecting portion or the concave portion and is swingably supported. A spring support structure for the chair according to any one of the above. A chair incorporating the chair spring support structure according to any one of claims 1 to 6.