JP2015084866A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair capable of changing a curved shape of a backrest greatly and suppressing a decrease in the ability to support a seated person.SOLUTION: A chair comprises: a backrest 6 with a receiving surface component part 20 for contacting with a seated person and receiving a load; a backrest support member 7 for supporting the backrest 6 from behind; and curved shape changing means 8 for relatively moving a central part 24 and both end parts 25 in a width direction of the backrest 6 forward and backward and changing a curved shape of the receiving surface component part 20.

Description

  The present invention relates to a chair having a backrest.

  As a chair provided with a backrest related to the above technical field, for example, chairs described in Patent Documents 1 and 2 below are known. These chairs are configured such that the shape of the backrest in contact with the seated person can be changed.

  The chair described in Patent Literature 1 has a movable / locking mechanism that changes the shape of the backrest by flexibly deforming a part of the backrest shell of the backrest. This movable / locking mechanism has an attachment part attached to the center part in the width direction of the backrest shell, and a movable part that can rotate with respect to the attachment part and bends both ends (auxiliary support parts) in the width direction of the backrest shell. And have.

  The chair described in Patent Document 2 has a bending adjustment mechanism that changes the shape of the backrest by moving both end portions in the width direction of the annular frame on which resin fibers are stretched close to and from the left and right. . This bending adjustment mechanism has a tightening bolt that adjusts the tightening amount in the width direction between the annular frame and a pair of leg portions formed perpendicular to the back surface thereof.

Japanese Patent No. 4185992 Japanese Utility Model Publication No. 46-3518

However, the above prior art has the following problems.
The chair described in Patent Document 1 is a single component of a backrest shell that ensures the strength of the backrest. The central portion in the width direction of the backrest shell is provided with a movable / locking mechanism mounting portion and receives a load from the seated person, so that the rigidity is high. Therefore, the portion deformed by the movable / lock mechanism is a slight range of both end portions (auxiliary support portions) in the width direction of the backrest shell with reduced rigidity. Moreover, it takes time and effort to form the back shell in the width direction so that the central portion and the both end portions have different rigidity.
Further, the chair described in Patent Document 2 is stretched around the annular frame because the bending adjustment mechanism moves the tightening bolt to the left and right to change the distance between both ends in the width direction of the annular frame. The tension | tensile_strength of resin fiber falls and the force which supports a seated person will fall.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a chair that can greatly change the curved shape of the backrest and can suppress a decrease in force that supports a seated person.

The chair according to the present invention employs the following configuration in order to solve the above problems.
The chair according to the present invention includes a backrest having a receiving surface component that receives a load in contact with a seated person, a backrest support member that supports the backrest from behind, a center portion and both end portions in the width direction of the backrest And a curved shape changing means for changing the curved shape of the receiving surface constituting part by moving the relative position back and forth.
According to this configuration, since the back of the backrest is supported by the backrest support member, it is possible to receive a seated person's load even if the rigidity of the entire backrest is lowered. Therefore, sufficient elasticity can be given to the backrest, and the curved shape of the receiving surface constituting portion can be greatly changed. In addition, since the backrest relatively moves the center portion and both end portions in the width direction back and forth, the distance between the both end portions in the width direction is not greatly changed when the curved shape is changed, and the force of supporting the seated person is reduced. Reduction can be suppressed.

Further, in the chair according to the present invention, the curved shape changing means is provided at a fixed portion that fixes the central portion to the backrest support member, and at both ends, and moves back and forth with respect to the backrest support member. And a possible moving end.
According to this configuration, since the center portion in the width direction of the backrest is fixed to the backrest support member, both ends in the width direction of the backrest are moved back and forth with respect to the backrest support member. The curved shape of the curved receiving surface constituent part can be changed.

In the chair according to the present invention, the backrest has a protruding portion that bends forward, and the moving end portion is provided at a position corresponding to the protruding portion. Is.
According to this configuration, since the protruding portion that bends forward of the backrest is a portion that affects the sitting comfort that supports the waist of the seated person, by moving the position corresponding to the protruding portion back and forth, The seated feeling of the seated person can be easily changed. For example, the lateral displacement of the seated person can be prevented by changing the curved shape of the backrest so as to hold the seated person's waist.

Moreover, the chair which concerns on this invention WHEREIN: The said receiving surface structure part has a boundary part which forms the area | region which deform | transforms by the said relative movement, and the area | region which does not deform | transform relatively rather than this area | region, It is characterized by the above-mentioned. Is.
According to this configuration, the region that deforms due to the boundary portion can be distinguished from the region that does not deform relatively, and the curved shape of the receiving surface component can be controlled to some extent. It can suppress that a feeling changes greatly.

Further, in the chair according to the present invention, the curved shape changing means is supported by one of the backrest and the backrest support member so as to be movable, and the center portion and the both end portions are relatively moved back and forth. It has an operating member for making it operate | move.
According to this configuration, by operating the operation member, the center portion and both end portions in the backrest width direction can be relatively moved back and forth, and the operability is improved.

Moreover, the chair which concerns on this invention WHEREIN: The said operation member is a base end part rotatably supported by either one side of the mutually opposing surface of the said backrest and the said backrest support member, and the said base end part And a distal end portion that presses the other side of the opposing surface of the backrest and the backrest support member.
According to this configuration, the operation member is operated, the distal end portion thereof is rotated around the base end portion, the backrest or the opposite surface of the backrest support member is pressed, and the operation member is stretched between the opposite surfaces. By making it, the curved shape of a receiving surface structure part can be changed.

Further, in the chair according to the present invention, an engagement groove that can be engaged with the distal end portion along the rotation trajectory of the distal end portion is provided on the other side of the opposite surface of the backrest and the backrest supporting member. It is characterized by being formed.
According to this configuration, since the distal end portion of the operating member is engaged with the engaging groove while the distal end portion rotates, the distal end portion is prevented from being released from the backrest or the backrest support member and being released from being pressed. it can.

Moreover, the chair which concerns on this invention WHEREIN: The said front-end | tip part is formed in the ball shape, It is characterized by the above-mentioned.
According to this configuration, the distal end portion of the operation member rotates around the proximal end portion, but since the distal end portion is ball-shaped, it is possible to maintain a constant contact with the backrest or the backrest support member it can.

  According to the present invention, it is possible to obtain a chair that can greatly change the curved shape of the backrest and can suppress a decrease in the force for supporting the seated person.

It is a side view of the chair of 1st Embodiment of this invention. It is a top view of the chair of 1st Embodiment of this invention. It is a rear view of the chair of 1st Embodiment of this invention. It is a back side perspective view of the chair of a 1st embodiment of this invention. It is a block diagram of the curve shape change means of 1st Embodiment of this invention. It is a back view of the backrest provided with the engagement groove | channel of the curved shape change means of 1st Embodiment of this invention. It is arrow AA sectional drawing in FIG. It is a front view of the backrest board of the backrest of 2nd Embodiment of this invention. It is a top view of the backrest board of the backrest of 3rd Embodiment of this invention. It is a front view of the fixing | fixed part of the backrest and backrest support member of 4th Embodiment of this invention. It is arrow BB sectional drawing in FIG. It is a front view explaining how to combine the backrest and backrest support member of the fourth embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the direction indicated by the arrow FR in the figure facing the front of the person seated in the chair in a regular posture is referred to as “front”, and the opposite direction is referred to as “rear”. For “upper”, “lower”, “left”, and “right”, the direction indicated by the arrow UP in the figure above the person sitting on the chair in a regular posture is “up” and the opposite direction is “ The direction indicated by the arrow LH on the left side of the person seated in a normal posture on the chair is called “left”, and the direction opposite to that is called “right”.

First, the first embodiment shown in FIGS. 1 to 7 will be described.
FIG. 1 is a side view of a chair 1 according to a first embodiment of the present invention.
As shown in FIG. 1, a chair 1 according to this embodiment includes a leg 2 placed on a floor, a box-shaped support base 3 installed at the upper end of the leg 2, and a seat on which a seated person sits. A body 4, a seat receiving member 5 that is attached to the upper surface of the support base 3 and supports the seat body 4 so as to be slidable back and forth, a backrest 6 that supports the back of a seated person seated on the seat body 4, and a backrest 6. The backrest supporting member 7 supported from behind and the curved shape changing means 8 for changing the curved shape of the receiving surface constituting portion 20 of the backrest 6 are provided.

The leg 2 has a diverging leg 9 with casters 9 a and a pedestal 10 that stands up from the center of the diverging leg 9 and incorporates a gas spring as an elevating mechanism. 3 is attached to be rotatable in the horizontal direction. The support base 3 incorporates an elevation adjustment mechanism for the pedestal column 10 and a tilt adjustment mechanism for the backrest support member 7. The back support member 7 has a substantially L shape in a side view, and a front lower end thereof is connected to a tilt adjustment mechanism in the support base 3.
In FIG. 1, reference numeral 11 denotes a pivot shaft of the backrest support member 7 on the support base 3, and reference numeral 12 denotes an operation knob of a tilt adjustment mechanism protruding from the side surface of the support base 3.

  The seat body 4 includes a seat plate 13 that forms a skeleton portion, and a seat body 14 that is attached to the upper portion of the seat plate 13. The seat body 14 is not shown in detail, but a seat frame (not shown) attached to the outer peripheral edge of the seat plate 13 and a cushion material (not shown) made of urethane or the like installed on the upper surface of the seat plate 13. And a seat skin material 15 which is stretched on the seat frame and covers the upper side of the cushion material.

FIG. 2 is a plan view of the chair 1 according to the first embodiment of the present invention. FIG. 3 is a rear view of the chair 1 according to the first embodiment of the present invention. FIG. 4 is a rear perspective view of the chair 1 according to the first embodiment of the present invention.
As shown in FIG. 2, the backrest 6 has a receiving surface constituting portion 20 that receives a load in contact with a seated person. The receiving surface constituent part 20 has a curved shape that protrudes backward in the plan view shown in FIG. The receiving surface component 20 of the present embodiment includes a resin-backed backrest 21 (see FIG. 4), a cushion material (not shown) installed on the front surface of the backrest 21, and a tension on the backrest 21. And a seat skin material 22 that covers the cushion material.

  The backrest 6 has a substantially rectangular shape with rounded four corners in the rear view shown in FIG. Moreover, the backrest 6 has the protrusion part 23 bent forward, as shown in FIG. The backrest 6 of the present embodiment has a convexly bent shape in front as viewed from the side shown in FIG. The apex of the protrusion 23 is formed at a position corresponding to the seated person's waist. That is, the protruding portion 23 has a shape bent at an appropriate position so that a portion slightly above the lower end portion of the backrest 6 protrudes forward in a side view shown in FIG.

  As shown in FIG. 1, the backrest support member 7 supports the backrest 6 from behind. The backrest support member 7 is a strength member that has higher rigidity than the backrest 6 and supports the load of the seated person received by the backrest 6. The backrest support member 7 is resin-molded, and is configured to have higher rigidity than the backrest 6 due to the thickness, the arrangement of reinforcing ribs, and the like. The backrest support member 7 has a frame portion 30 having an outer shape substantially the same as the outer shape of the backrest 6 in the rear view shown in FIG. The frame part 30 has an opening part 31 that opens greatly on the back side.

  As shown in FIG. 1, the backrest support member 7 has a protrusion 32 that bends forward at a position corresponding to the protrusion 23 of the backrest 6. That is, the protrusion 32 has a shape bent at an appropriate position so that a portion slightly above the lower end of the frame 30 protrudes forward in a side view shown in FIG. An operation member 50 of the curved shape changing means 8 described later is arranged on the protruding portion 32. The backrest support member 7 includes a connecting portion 33 that extends forward from the lower end portion of the frame portion 30. The connecting portion 33 is connected to a tilt adjustment mechanism in the support base 3.

FIG. 5 is a configuration diagram of the curved shape changing means 8 according to the first embodiment of the present invention. FIG. 6 is a rear view of the backrest 6 provided with the engagement groove 60 of the curved shape changing means 8 according to the first embodiment of the present invention. FIG. 7 is a cross-sectional view taken along the line AA in FIG. In these drawings, the cushion material and the seat skin material 22 forming the receiving surface constituting portion 20 are not shown.
As shown in FIG. 5, the curved shape changing means 8 changes the curved shape of the receiving surface constituting portion 20 by relatively moving the central portion 24 and both end portions 25 in the width direction (left-right direction) of the backrest 6 in the front-rear direction. To do.

  As shown in FIG. 3, the curved shape changing means 8 includes a fixing portion 40 that fixes the central portion 24 of the backrest 6 to the backrest support member 7, and both ends of the backrest 6 as shown in FIGS. 2 and 5. And a moving end 41 that is provided in the portion 25 and is movable back and forth with respect to the back support member 7. As shown in FIG. 3, the fixing portion 40 is configured to fix the central portion 24 of the backrest 6 to the backrest support member 7 with a plurality of fixing screws 42.

  The fixing screw 42 fixes the upper end portion of the center portion 24 of the backrest 6 to the upper end portion of the frame portion 30 of the backrest support member 7 and fixes the lower end portion of the center portion 24 of the backrest 6 to the backrest support member. 7 is fixed to the lower end of the frame 30. The upper end portion of the central portion 24 of the backrest 6 is fixed by the fixing screw 42 at a center in the width direction of the backrest 6 and at three places on both sides thereof. Further, the fixing of the lower end portion of the central portion 24 of the backrest 6 with the fixing screw 42 is performed at one place in the center of the backrest 6 in the width direction.

  The moving end 41 is a free end of the backrest 6 that is not fixed to the backrest support member 7, and is configured to be movable back and forth with respect to the backrest support member 7. That is, the moving end 41 moves back and forth by elastic deformation of the backrest 6 (backrest plate 21) with the fixed portion 40 as a fulcrum. The moving end portion 41 is provided at a position corresponding to the protruding portion 23 of the backrest 6. The operation member 50 is disposed at a position corresponding to the protruding portion 23 of the backrest 6, and the moving end portion 41 is configured to move back and forth when the operation member 50 is pressed.

  As shown in FIG. 1, the operation member 50 is movably supported by one of the backrest 6 and the backrest support member 7 (in this embodiment, the backrest support member 7). The operation member 50 is for moving the central portion 24 and both end portions 25 of the backrest 6 back and forth, and has a grip portion 51 that can be gripped by a seated person. The grip 51 improves the operability of the seated person. As shown in FIG. 3, the gripping part 51 has a substantially L shape and protrudes to the side of the backrest 6 so that the seated person sits on the seat 4. It can be gripped with.

  As shown in FIGS. 4 and 5, the operation member 50 rotates to either one of the opposing surfaces 26 and 34 of the backrest 6 and the backrest support member 7 facing each other (in the present embodiment, the opposing surface 34 side). A base end portion 52 that is supported, and the other end of the backrest 6 and the opposing surfaces 26 and 34 of the backrest support member 7 that rotate about the base end portion 52 (in this embodiment, the opposing surface 26 side). And a tip portion 53 that presses. Further, on the other side of the opposing surfaces 26, 34 of the backrest 6 and the backrest support member 7 (on the opposing surface 26 side in this embodiment), as shown in FIGS. An engagement groove 60 that can be engaged with the distal end portion 53 is formed along the.

  The engagement groove 60 is provided behind the backrest 6. As shown in FIG. 6, the engaging groove 60 is provided along the outer shape of both end portions 25 of the backrest 6. That is, the engagement groove 60 extends in the height direction (vertical direction). The engaging groove 60 extends so as to straddle the position corresponding to the protruding portion 23 of the backrest 6 in the vertical direction, and the width direction along the inclined shape below the protruding portion 23 of the backrest 6 ( (Left and right direction) It is formed to bend inward.

  As shown in FIG. 7, the engagement groove 60 is formed by a liner 61 having a predetermined slidability and a holding portion 64 in the liner support member 63. The liner 61 is in sliding contact with the distal end portion 53 of the operation member 50 and has a shape corresponding to the shape of the distal end portion 53. The distal end portion 53 of the operation member 50 of the present embodiment is formed in a ball shape (spherical shape), and the liner 61 is formed in an arc shape in a cross-sectional view. The liner 61 is configured to be divided into a first liner member 61a and a second liner member 61b. The 1st liner member 61a and the 2nd liner member 61b are comprised so that a combination with the uneven | corrugated fitting part 62 is possible.

  The liner 61 is fixed behind the backrest 6 (backrest plate 21) by a liner support member 63. The liner support member 63 includes a holding portion 64 that holds the liner 61 and an engagement protrusion 65 that can be engaged with the backrest plate 21. The holding portions 64 are provided as a pair at intervals smaller than the outer diameter of the liner 61. The engagement protrusion 65 is provided so as to protrude in the width direction (left-right direction) inside the liner support member 63. Note that a plurality of engagement protrusions 65 are provided at appropriate positions on the left and right sides of the liner support member 63 (not shown). The liner 61 and the liner support member 63 may be integrally formed by means such as two-color molding.

  The backrest plate 21 has an attachment groove 66 to which the liner support member 63 can be attached. A plurality of ribs 67 are erected in the mounting groove 66. The liner 61 is sandwiched and fixed between the liner support member 63 and the plurality of ribs 67. The rib 67 is provided with an engagement hole 68 that engages with the engagement protrusion 65 of the liner support member 63. The engagement hole 68 is provided through the rib 67 in the width direction (left-right direction). The liner support member 63 is fixed to the backrest plate 21 by the engagement protrusion 65 and the engagement hole 68 engaging with each other.

  The operation member 50 has a distal end 53 that engages with the engagement groove 60, and a proximal end 52 that is rotatably supported by the rotation shaft 69. The rotation shaft 69 extends in the width direction and is provided on the back support member 7. The base end portion 52 has a bearing hole 70 through which the rotation shaft 69 is inserted. The diameter of the bearing hole 70 is designed to be larger than the diameter of the rotating shaft 69. That is, the base end portion 52 has a backlash in a direction orthogonal to the axis of the rotation shaft 69. The operation member 50 of this embodiment can move the front-end | tip part 53 to the width direction (left-right direction) along the engagement groove | channel 60 shown in FIG.

  Next, an operation for changing the shape of the backrest 6 using the curved shape changing means 8 having the above-described configuration and its operation will be described.

  While sitting on the seat body 4, the seated person grips the grip portion 51 of the operation member 50 that protrudes to the left and right of the backrest 6 shown in FIG. In the operation member 50, the base end portion 52 is rotatably supported by the backrest support member 7, and the distal end portion 53 is rotated upward about the base end portion 52 (see FIG. 1). When the distal end portion 53 rotates upward, the operation member 50 pushes between the opposing surfaces 26 and 34 of the backrest 6 and the backrest support member 7 and pushes the distance between the opposing surfaces 26 and 34. The backrest support member 7 has higher rigidity than the backrest 6, and the backrest 6 side is elastically deformed.

  As shown in FIG. 3, the backrest 6 has a central portion 24 fixed to the backrest support member 7 by a fixing portion 40, and both end portions 25 are movable with respect to the backrest support member 7. For this reason, the both ends 25 of the backrest 6 move forward by the pressing of the operating member 50 (see FIG. 5). When both end portions 25 of the backrest 6 move forward, the curvature of the receiving surface constituting portion 20 of the backrest 6 increases, and the curved shape of the receiving surface constituting portion 20 changes from the shape C1 to the shape C2 as shown in FIG. Will be changed.

  In the present embodiment, since the back of the backrest 6 is supported by the backrest support member 7, the load on the seated person can be increased even if the rigidity of the backrest 6 is lowered as much as the strength can be secured by the backrest support member 7. Can receive. Therefore, sufficient elasticity can be given to the backrest 6, and the curved shape of the receiving surface constituting portion 20 can be greatly changed as shown in FIGS. 2 and 5. Further, since the backrest 6 relatively moves the central portion 24 and both end portions 25 in the width direction back and forth, the distance between the both end portions 25 in the width direction is not greatly changed when the curved shape is changed.

  That is, in the conventional form in which the central portion 24 and both end portions 25 of the backrest 6 in the width direction are relatively moved to the left and right, when the receiving surface constituting portion 20 is made of a tension material or the like, Although the supporting force may be reduced, in the present embodiment, the central portion 24 and both end portions 25 in the width direction of the backrest 6 are moved relative to each other in the front-rear direction, so that a decrease in the force that supports the seated person is suppressed. can do.

  Further, in the present embodiment, the central portion 24 in the width direction of the backrest 6 is fixed to the backrest support member 7, and the moving end portions 41 provided at both end portions 25 in the width direction of the backrest 6 are operated by the operation member 50. Press and move back and forth. The moving end portion 41 is provided at a position corresponding to the protruding portion 23 that bends forward of the backrest 6. Since the protrusion 23 is a part that affects the sitting comfort that supports the waist of the seated person, the seating feeling of the seated person can be easily changed by moving the position corresponding to the protrusion 23 back and forth. For example, the lateral displacement of the seated person can be prevented by changing the curved shape of the backrest 6 so as to hold the waist of the seated person.

  Further, in this embodiment, the operation member 50 is operated, the distal end portion 53 is rotated around the base end portion 52, the opposite surface 26 side of the backrest 6 is pressed, and the operation member 50 is moved to the opposite surface. The curved shape of the receiving surface constituting part 20 is changed by stretching between 26 and 34. As shown in FIG. 7, the backrest 6 is provided with an engaging groove 60 along the turning locus of the tip portion 53. For this reason, the front-end | tip part 53 is engaged with the engagement groove | channel 60, while rotating, and it does not remove | deviate from the backrest 6, and pressure is not cancelled | released. Further, the distal end portion 53 is formed in a ball shape so that the manner of hitting the backrest 6 can be kept constant, and even if the operation member 50 is rotated, the feeling of operation does not change.

  Thus, according to the above-described embodiment, the backrest 6 having the receiving surface component 20 that receives the load in contact with the seated person, the backrest support member 7 that supports the backrest 6 from the back, and the backrest 6 By adopting a configuration in which the center portion 24 and the both end portions 25 in the width direction of the base plate are moved back and forth to change the curved shape of the receiving surface constituting portion 20, the backrest is adopted. Thus, the chair 1 that can greatly change the curved shape 6 and can suppress a decrease in the force to support the seated person is obtained.

Subsequently, a second embodiment of the present invention will be described with reference to FIG. 8 with reference to FIGS. In each embodiment described below, the same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted.
FIG. 8 is a front view of the backrest plate 80 of the backrest 6 according to the second embodiment of the present invention. The chair of this embodiment is different from the first embodiment only in the structure of the backrest 6, and the other parts are the same as those of the first embodiment.

  The back surface receiving portion 20 of the backrest 6 of this embodiment is installed on the backrest plate 80 in which a plurality of openings are formed in the height direction and the width direction by a large number of wire portions 82, and on the front surface of the backrest plate 80. A cushion material (not shown), a seat covering material (not shown) that is stretched over the backrest plate 80 and covers the cushion material, and a backrest cover (not shown) that covers the back of the backrest plate 80 Is formed. The backrest plate 80 is formed by a frame 81 that forms an outer edge portion thereof, and a plurality of wire portions 82 that are arranged vertically and horizontally inside the frame 81.

  The receiving surface forming unit 20 forms a region T1 that is deformed by the relative movement of the central portion 24 and the both end portions 25 by the curved shape changing means 8 described above and a region T2 that is relatively undeformed than the region T1. The boundary portion 83 is provided. The boundary portion 83 of this embodiment is formed on the backrest plate 80. The boundary portion 83 has a slit 84 formed in the wire portion 82 of the backrest plate 80. The slits 84 are provided at appropriate positions of the wire portion 82 and are arranged side by side in the height direction (vertical direction).

  The boundary portion 83 is formed with a slit 84 formed in the wire portion 82 to reduce the rigidity at an appropriate place to form a deformation boundary. According to the second embodiment, the presence of the boundary portion 83 makes it possible to distinguish between the deformed region T1 and the relatively undeformed region T2, and the curved shape of the receiving surface constituting unit 20 can be controlled to some extent. That is, since the deformation of the receiving surface constituting part 20 can be directed to the left and right to some extent, the operational effects of the first embodiment can be more reliably exhibited, the curved shape of the backrest 6 can be greatly changed, and the curved shape It can suppress that a seated person's seating feeling changes greatly in the case of a shape change.

Subsequently, a third embodiment of the present invention will be described with reference to FIG. In each embodiment described below, the same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted.
FIG. 9 is a plan view of the backrest plate 21 of the backrest 6 according to the third embodiment of the present invention. The chair of this embodiment is different from the first embodiment only in the structure of the backrest plate 21, and the other parts are the same as those of the first embodiment.

  The boundary 83 in this embodiment is formed on the backrest plate 21. The boundary portion 83 has a groove 85 formed in the backrest plate 21. The groove 85 is provided at an appropriate position on the backrest plate 21 and extends in the height direction (vertical direction). The boundary portion 83 forms a boundary of deformation by reducing the thickness (rigidity) at an appropriate position by the groove 85 formed in the backrest plate 21. According to the third embodiment, since there is the boundary portion 83, the region T1 that is deformed and the region T2 that is not relatively deformed can be distinguished, and the curved shape of the receiving surface constituting unit 20 can be controlled. The same effects as those of the second embodiment can be exhibited.

Subsequently, a fourth embodiment of the present invention will be described with reference to FIGS. 10 to 12 with reference to FIGS. In each embodiment described below, the same parts as those in the above embodiment are denoted by the same reference numerals, and redundant description is omitted.
FIG. 10 is a front view of the fixing portion 40 between the backrest 6 and the backrest support member 7 according to the fourth embodiment of the present invention. 11 is a cross-sectional view taken along the line BB in FIG. FIG. 11 is a front view for explaining how to combine the backrest 6 and the backrest support member 7 according to the fourth embodiment of the present invention. The chair of this embodiment is different from the first embodiment only in the structure of the backrest 6, the backrest support member 7, and the fixing portion 40, and other parts are the same as those of the first embodiment.

  As shown in FIG. 10, the receiving surface constituting portion 20 of the backrest 6 of this embodiment includes a backrest plate 80 in which a plurality of openings are formed in the height direction and the width direction by a number of wire portions 82, and the backrest plate 80. Cushion material (not shown) installed on the front surface of the back plate 80, sheet skin material (not shown) stretched on the back plate 80 and covering the cushion material, and a back cover covering the back surface of the back plate 80 (Not shown). The backrest plate 80 is formed by a frame 81 that forms an outer edge portion thereof, and a plurality of wire portions 82 that are arranged vertically and horizontally inside the frame 81.

The frame 81 has a slit 86 that divides the center of its lower end. The space formed by the slit 86 communicates with the opening 87 at the center of the lower end formed by the wire portion 82. For this reason, the backrest plate 80 is divided into two forks at the center of the lower end.
As shown in FIG. 12, the backrest support member 7 is provided with a plurality of ribs 90 vertically and horizontally for ensuring rigidity inside the frame portion 30. The rib 90 is formed on the lower end portion of the frame portion 30 and the connecting portion 33.

  As shown in FIG. 10, the curved shape changing means 8 includes a fixing portion 40 that fixes the central portion 24 of the backrest 6 to the backrest support member 7. The fixing portion 40 includes a fixing screw 42 that fixes the upper end portion of the center portion 24 of the backrest 6 to the upper end portion of the frame portion 30 of the backrest support member 7, and a backrest support for the lower end portion of the center portion 24 of the backrest 6. And an engaging portion 43 that engages with the lower end portion of the member 7. As shown in FIG. 12, the engaging portion 43 is formed by an engaging protrusion 44 provided on the backrest 6 and an engaging groove 45 provided on the backrest support member 7. The engaging portion 43 restricts the forward movement (detachment) of the lower end portion of the backrest 6 while allowing the deformation of the backrest 6 in the direction of opening the lower end portion of the backrest plate 80.

The engagement protrusion 44 is formed integrally with the backrest plate 80. The engagement protrusions 44 are rods extending downward from the lower end of the backrest plate 80, and are provided as a pair on both sides of the slit 86. The engagement protrusion 44 has a front end portion 44a that swells forward.
On the other hand, the engagement groove 45 is formed integrally with the back support member 7. The engagement grooves 45 are grooves formed between the ribs 90 at the lower end of the frame portion 30, and are provided as a pair corresponding to the engagement protrusions 44. The engagement groove 45 is formed extending in the left-right direction.

  As shown in the sectional view of FIG. 11, the engagement groove 45 is opened obliquely upward and forward, and the engagement protrusion 44 is inserted into the opening. The engagement groove 45 has an opening 46 formed on the side surface of the rib 90 forming the front wall. The front end portion 44a of the engagement protrusion 44 is engaged with the opening portion 46, so that the front protrusion 44a is prevented from coming off obliquely upward. As shown in FIG. 10, the opening 46 is formed extending in the left-right direction. For this reason, the engagement protrusion 44 is configured to be movable to the left and right in a state where the tip end portion 44 a is engaged with the opening 46.

  According to the fourth embodiment having the above-described configuration, the lower end portion of the central portion 24 of the backrest 6 is not completely fixed, and a semi-fixed state that restricts forward movement is allowed while allowing lateral deformation. Can do. As described above, the backrest 6 fixes the central portion 24 in the width direction of the backrest 6 to the backrest support member 7 and operates the moving end portions 41 provided at both end portions 25 in the width direction of the backrest 6. The member 50 is pressed and moved back and forth. According to this 4th Embodiment, since the lower end part of the center part 24 of the backrest 6 is not completely fixed, following the front-back movement of the movement end part 41, it can deform | transform flexibly in the left-right direction. Thereby, the force required for operation of the operation member 50 becomes smaller than in the first embodiment, and the operability of the operation member 50 can be improved.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above-described embodiment, the configuration in which the distal end portion of the operation member presses the opposite surface side of the backrest has been described. However, the present invention provides a configuration in which the distal end portion of the operation member presses the opposite surface side of the backrest support member. It may be. In this case, it is preferable to employ a configuration in which an engagement groove is formed on the opposite surface side of the backrest.

  Further, for example, in the above-described embodiment, the configuration in which the base end portion of the operation member is supported by inserting the rotation shaft through the bearing hole has been described. However, in the present invention, the base end portion of the operation member is supported by the ball joint. It may be configured. However, in the case of a ball joint, it moves in response to loads in all directions, so if the load from the seated person is excessive, the bearing hole is designed to be large as in the above embodiment, and the axis of the rotating shaft It is preferable to adopt a robust configuration in which a play is intentionally given in a direction orthogonal to the direction.

  Further, for example, in the above-described embodiment, the configuration in which the receiving surface constituent portion is formed by the backrest plate and the cushion material disposed on the front surface thereof has been described. However, in the present invention, the receiving surface constituent portion is stretched on the frame member. The structure formed with tension materials, such as the made mesh, may be sufficient. In this case, it is preferable to adopt a configuration in which the frame member is configured to be elastically deformable and pressed in the front-rear direction by the operation member.

  Further, for example, in the above-described embodiment, the configuration in which the center portion in the width direction of the backrest is fixed and both end portions in the width direction of the backrest are moved back and forth has been described. The structure which fixes both ends and moves the center part in the width direction of a backrest back and forth may be sufficient. In this case, it is preferable to employ a configuration in which the backrest support member is disposed behind the center portion in the width direction of the backrest and the center portion is pressed by the operation member.

  Further, for example, in the above-described embodiment, the configuration in which the center portion and the both end portions in the backrest width direction are relatively moved back and forth by the operation member has been described, but the present invention does not use the operation member but directly by hand. The center part and both ends in the width direction of the backrest may be relatively moved back and forth. However, if the operation member is used, it is possible to change the curved shape of the backrest with less force than moving it directly by hand.

  Also, for example, in the above-described embodiment, as the fixing portion, the lower end portion of the center portion of the backrest is not completely fixed, and the semi-fixed state that restricts the forward movement is allowed while allowing the deformation in the left-right direction. Although the configuration employing the joint portion has been described, the present invention is not limited to this configuration. For example, a protrusion-like locking part that restricts the forward movement (disengagement) of the lower end of the center part of the backrest is provided, and the lower end part of the center part of the backrest is fixed only by the locking part. You may employ | adopt the structure made into a semi-fixed state.

  Further, for example, in the above-described embodiment, the configuration in which the fixing screw for fixing the upper end portion of the center portion of the backrest to the upper end portion of the frame portion of the backrest support member is employed as the fixing portion has been described. It is not limited to this configuration. For example, a plurality of engagement protrusions are formed behind the upper end of the center part of the backrest, and these engagement protrusions engage with an engagement recess formed in the backrest support body, so that the center part of the backrest A configuration may be adopted in which the upper end portion of the backrest is fixed to the upper end portion of the frame portion of the back support member. In addition, by providing a slight play in the size of the engaging recess, the upper end of the center part of the backrest is also semi-fixed so that the backrest can be easily moved with respect to the backrest support member, and the operation is thereby performed. The operability of the member can be further reduced.

DESCRIPTION OF SYMBOLS 1 Chair 6 Backrest 7 Backrest support member 8 Curved shape change means 20 Reception surface structure part 23 Protrusion part 24 Center part 25 Both ends part 26 Opposing surface 34 Opposing surface 40 Fixed part 41 Moving end part 50 Operating member 52 Base end part 53 Tip portion 60 Engaging groove 83 Boundary portion T1 region T2 region

Claims (8)

A backrest having a receiving surface component that receives a load in contact with a seated person;
A back support member that supports the back from behind;
A chair comprising: a curved shape changing means for changing the curved shape of the receiving surface constituting portion by relatively moving a central portion and both end portions in the width direction of the backrest back and forth. The curved shape changing means includes
A fixing portion for fixing the center portion to the back support member;
The chair according to claim 1, further comprising: a moving end portion provided at each of the both end portions and movable back and forth with respect to the backrest support member. The backrest has a protrusion that bends forward;
The chair according to claim 2, wherein the moving end portion is provided at a position corresponding to the protruding portion.   The said receiving surface structure part has a boundary part which forms the area | region which deform | transforms by the said relative movement, and the area | region which does not deform | transform relatively rather than this area | region, The any one of Claims 1-3 characterized by the above-mentioned. The chair according to item.   The curved shape changing means includes an operation member that is movably supported by one of the backrest and the backrest support member and relatively moves the central portion and the both end portions back and forth. The chair as described in any one of Claims 1-4 characterized by these. The operating member is
A base end portion rotatably supported on one side of the backrest and the opposed surfaces of the backrest support member;
The chair according to claim 5, further comprising: a distal end portion that rotates around the base end portion and presses the other side of the opposing surface of the backrest and the backrest support member.   An engagement groove is formed on the other side of the backrest and the opposing surface of the backrest support member, the engagement groove being engageable with the tip portion along the rotation trajectory of the tip portion. The chair according to claim 6.   The chair according to claim 6 or 7, wherein the tip portion is formed in a ball shape.

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