JP6312296B2 - Chair - Google Patents

Description

  The present invention relates to a chair having a backrest.

  As a chair used for office work or the like, there is a structure in which a back support for receiving a load on a back of a seated person is supported on the front side of a back support connected to a chair main body.

As this type of chair, there is known a chair in which a portion spaced downward from the upper end of a back support is supported by a back support so as to be swingable (see, for example, Patent Documents 1 and 2).
Since this chair has a free end at the upper end side of the back receiving body that receives the load on the back of the seated person, there is an advantage that the seated person can easily take a comfortable posture when the back is greatly bent backward. On the other hand, in this chair, when the seated person makes his / her back contact with the back support, the head tends to tilt backward, and it is difficult to assume a working posture with the head slightly tilted forward.

On the other hand, as a chair suitable for maintaining the office posture, a chair in which the upper end portion of the back support body is connected to the upper end portion of the back support body has been devised (see, for example, Patent Documents 3 and 4). ).
In this chair, the upper end portion of the back support is fixed to the back support, and the lower position is more easily displaced to the rear side than the upper end of the back support. For this reason, when the shoulder part of the seated person touches the position slightly below the upper end part of the back support, the part of the back contact that is in contact with the shoulder of the seated person is deformed rearward, and the head of the seated person It becomes easy to take a working posture that is pushed forward relatively.

  The chair described in Patent Document 3 is provided with an engaging claw that protrudes rearward at the upper end portion of the back plate that is the back support, and the engagement piece protrudes from the upper front surface of the back frame that is the back support. The engaging piece is provided with an engaging hole into which a protruding portion protruding from the lower surface of the engaging claw portion is inserted. The back plate of this chair slides and engages the engaging claw on the upper surface of the engaging piece on the back frame side, and in that state, inserts the projection of the engaging claw into the engaging hole on the engaging piece side. The other part of the upper end is fixed to the back frame by fastening means or the like.

  Moreover, the chair of patent document 4 attaches the standing piece which protrudes back to the upper edge part of the tension material which is a back support body, and attaches the front-end | tip part of the stand-up piece of the upper frame which is a back support body. Inserted into the receiving groove, the tip of the upright piece is screwed to the upper frame in this state.

Japanese Patent No. 5132919 JP 2010-063821 A JP 2011-092537 A Japanese Patent No. 4663220

  However, in the chair described in Patent Document 3, the protrusion of the engagement claw on the back support (back plate) side is fitted into the engagement hole on the engagement piece of the back support (back frame), and in this state. Since the upper end of the back support is fixed to the back support by fastening means, etc., the fastening means should be fastened when the back support is removed from the back support at the time of repair or parts replacement. After removing, the entire back support must be lifted upward and the projection of the engagement claw must be pulled out of the engagement hole on the engagement piece. For this reason, in the chair of patent document 3, the removal operation | work of a back support body is complicated and large-scale, and the improvement of removal work property is desired.

  In addition, the chair described in Patent Document 4 has an upright piece protruding from the upper edge of the back support (stretching material) inserted into the receiving groove of the back support (upper frame), and stands in that state. Since the structure is such that the piece is screwed to the back support from a part that is difficult to see from the outside, a narrow and limited space is required when removing the back support from the back support when repairing or replacing parts. The troublesome work of removing the screw must be done. For this reason, also in the case of the chair of patent document 3, improvement of the removal workability | operativity of a back support body is desired similarly.

  Therefore, the present invention is intended to provide a chair in which the back support and the back support are connected at the upper ends, but the back support can be easily removed as necessary.

The chair according to one aspect of the present application includes a back support that receives a load on the back of the seated person, and a back support that is disposed on the back side of the back support and supports the back support. In the chair having a backrest portion in which the upper end portion of the back support and the upper end portion of the back support are connected to each other, the back of the upper end of the back support is attached to the back support. An engagement protrusion that protrudes toward the protrusion is provided, and a protruding locking portion that protrudes in a direction substantially orthogonal to the protrusion direction of the engagement protrusion is provided at the tip of the engagement protrusion. An insertion hole into which the engagement protrusion is inserted from the front surface side, a disengagement restricting part that abuts on the overhanging engagement part protruding from the insertion hole and restricts the engagement protrusion from coming out, and protrudes from the insertion hole It is depressed toward the accommodation area of the overhanging locking portion, and is substantially orthogonal to the engaging direction of the engaging protrusion. An opening that is visible the projecting engaging portion from the direction, is provided, the engaging projection, along the width of the length and the horizontal direction of the protruding direction is formed in a large plate with respect to the vertical direction of the thickness, the A substantially rectangular plate-like insertion plate portion connected to the main body portion of the back support, and the overhanging member extending in the left-right direction from the distal end portion of the insertion plate portion and continuously formed with substantially the same thickness as the insertion plate portion A locking portion, and at least the protruding locking portion of the engaging protrusion includes the protruding locking portion at the time of a release operation for releasing the locking of the protruding locking portion locked to the pull-out restricting portion. A lightening hole that allows bending deformation in the direction of narrowing the overhang width is formed .
In the case of this invention, when removing the back support from the back support, an operator's fingertip or tool is inserted into the opening of the back support, and the accommodation region is inserted from the insertion hole of the back support by the fingertip or tool. The overhanging locking portion of the engaging protrusion protruding in the position is operated so as to be pushed back into the insertion hole. Thereby, the engagement between the overhanging locking portion of the engagement protrusion and the slip-out restricting portion on the back support body side is released, and the back support body can be detached from the back support body.

In this case, the engagement protrusion is shaped so as not to occupy a large space in the vertical direction inside the back support, and when the seat occupant is warped backward, the vertical direction from the back of the seat occupant to the back support is approximately When an in-line load is input, the insertion plate portion of the engagement protrusion is bent in the plate thickness direction, and a minute amount of displacement in the vertical direction of the back support is allowed. As a result, the back supporter flexibly follows the behavior of the back of the seated person and a good seating feeling can be obtained.

Further, in this case, when operating to push the overhanging locking portion of the engaging protrusion back into the insertion hole, the overhanging locking portion in the opening is pinched with a finger or a tool so that the overhanging locking portion is directed toward the lightening hole portion. The stop portion is easily bent, and the engagement between the overhanging locking portion and the drop-out restricting portion is easily released.

The chair according to one aspect of the present application includes a back support that receives a load on the back of the seated person, and a back support that is disposed on the back side of the back support and supports the back support. In the chair having a backrest portion in which the upper end portion of the back support and the upper end portion of the back support are connected to each other, the back of the upper end of the back support is attached to the back support. An engagement protrusion that protrudes toward the protrusion is provided, and a protruding locking portion that protrudes in a direction substantially orthogonal to the protrusion direction of the engagement protrusion is provided at the tip of the engagement protrusion. An insertion hole into which the engagement protrusion is inserted from the front surface side, a disengagement restricting part that abuts on the overhanging engagement part protruding from the insertion hole and restricts the engagement protrusion from coming out, and protrudes from the insertion hole It is depressed toward the accommodation area of the overhanging locking portion, and is substantially orthogonal to the engaging direction of the engaging protrusion. An opening that is visible the projecting engaging portion from the direction, is provided, the front surface of the upper portion of the the rear surface of the upper portion back receiving support the back receptacle is inclined toward the upper rear side cross It is as capable of abutting against opposite surfaces, and the engaging projection and said insertion hole, characterized in that with respect to the direction perpendicular to the facing surface is formed to be inclined toward the horizontal direction Is.
In this case, the extending length in the front-rear direction of the engagement protrusion on the back support side and the insertion hole on the back support side can be easily secured. For this reason, the contact part of an engagement protrusion and an insertion hole increases, and the support strength of a back support body increases. In addition, since the extending length of the engaging projection in the front-rear direction can be easily secured long, when a load in the direction intersecting the front-rear direction is input from the back of the seated person to the back support, It can be made easy to bend and deform along the load input direction.

It is desirable that the insertion hole is formed such that the side facing the main body portion of the back receiving body extends in a tapered shape.
In this case, when a load in a direction intersecting the back support is input from the back of the seated person to the back support, the base side of the engagement protrusion (the side facing the main body of the back support) is the insertion hole. It becomes easy to bend and deform in the part which expands in the taper shape.

  According to this invention, the back support body is provided with an opening that is recessed toward the housing area of the overhanging locking portion and that allows the overhanging locking portion to be visually recognized from a direction substantially orthogonal to the engaging direction of the engaging protrusion. Therefore, the back support and the back support are connected to each other at the upper ends so that the office posture can be easily taken. The stop can be released and the back support can be easily removed.

It is a side view of the chair of one Embodiment of this invention. It is a top view of the chair of one Embodiment of this invention. It is a rear view of the chair of one Embodiment of this invention. It is a back side perspective view of the chair of one embodiment of this invention. It is the perspective view which looked at the backrest part of the chair of one Embodiment of this invention from the rear lower part. It is the perspective view which looked at the backboard of the chair of one Embodiment of this invention from the rear lower part. It is the perspective view which looked at the back board support frame of the chair of one Embodiment of this invention from the front lower part. It is sectional drawing corresponding to the VIII-VIII cross section of FIG. 5 of the chair of one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described 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”.

1 and 2 are a side view and a plan view of the chair 1 of this embodiment, and FIGS. 3 and 4 are a rear view and a rear side perspective view of the chair 1 of this embodiment.
As shown in these drawings, a chair 1 according to this embodiment includes a leg 2 placed on a floor, a box-like support base 3 installed at the upper end of the leg 2, and a seated person. A seat 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, and a back that extends from the support base 3 to the rear upper side and seats on the seat body 4. And a drowning part 50. In this embodiment, the leg part 2, the support base 3, the seat receiving member 5, and the seat body 4 constitute a chair body part.

  The leg 2 includes a multi-leg 9 with casters 9a and a pedestal 10 that has a gas spring as a lifting mechanism that stands up from the center of the multi-leg 9 and has a support base 3 at the upper end of the pedestal 10. Is mounted so as 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 50.

  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 synthetic resin tension material 15 that is stretched on the seat frame and covers the upper side of the cushion material.

The backrest portion 50 has a front end connected to a tilt adjustment mechanism in the support base 3, a connection stay 17 extending from the rear end portion of the support base 3 toward the oblique rear upper side, and a rear end of the connection stay 17. A rectangular frame-shaped back support 7 connected to the support stay 17 and extending upward from the connection stay 17, and a back of a seated person seated on the seat 4 supported by the front side of the back support 7 And a back support 6 for supporting the. Since the back support 7 is a strength component for supporting the load of the back of the seated person input to the back support 6 on the chair main body side via the connecting stay 17, the rigidity and strength are sufficient. It is made of high synthetic resin.
In FIG. 1, reference numeral 11 is a pivot shaft of the backrest portion 50 on the support base 3, and reference numeral 12 is an operation knob of a tilt adjustment mechanism protruding from the side surface of the support base 3.

  The back support 6 of the backrest 50 includes a vertically long rectangular frame-shaped back plate frame 18 and a tension member 19 stretched on the back plate frame 18 so as to cover the opening 18d inside the back plate frame 18. And. The back plate frame 18 is integrally formed of a synthetic resin having elasticity, and the tension member 19 is formed by knitting a synthetic resin fiber having stretchability into a mesh shape. The tension member 19 is stretched on the back plate frame 18 with a relatively high tension, and comes into contact with the back of the seated person sitting on the seat body 4 so as to directly receive the load on the back of the seated person. Note that the outer peripheral end portion of the upholstery material 19 is locked and fixed by appropriate means in a holding groove (not shown) formed on the outer peripheral end surface of the back plate frame 18.

FIG. 5 is a view showing the upper half of the backrest portion 50, and FIG. 6 is a view showing the upper half of a single body of the back support 6. FIG. 7 is a view showing the upper half part of the back support 7 and FIG. 8 is a view showing a cross section corresponding to the VIII-VIII cross section of the backrest part 50 of FIG. 5, 6, and 8, the tension member 19 attached to the back plate frame 18 of the back support 6 is omitted for convenience of illustration.
As shown in these drawings, the back plate frame 18 of the back support 6 is formed in a substantially rectangular shape with rounded four corners when viewed from the front, and 3 minutes from the bottom in the height direction when viewed from the side. Is curved so that the height position of about 1 bulges most forward. The upper side 18a of the back plate frame 18 is greatly inclined so as to approach the horizontal direction toward the upper rear side. Further, as shown in FIG. 2, the back plate frame 18 is curved so that a central region in the left-right direction is slightly recessed rearward in plan view. The most bulging area on the front side of the back plate frame 18 is set to an area that supports the vicinity of the waist of the seated person sitting on the seat 4. Hereinafter, the most bulging portion on the front side of the back plate frame 18 is referred to as a “front bulging portion 20”.
Further, the front surface of almost the entire peripheral edge of the back plate frame 18 is smoothly inclined toward the rear side from the inside to the outside of the opening 18d.

  On the other hand, the back support 7 is formed in a vertically long, substantially rectangular frame shape with the lower side slightly narrowed in the rear view (front view). More precisely, as shown in FIG. 3, the upper half portions of the left and right side sides 7c (vertical beam portions) extend in the vertical direction so as to be substantially parallel to each other, and the left and right side sides 7c (vertical beam portions). The lower half is inclined so that the separation width gradually decreases downward. The upper ends of the left and right side sides 7c are connected by an upper side 7a extending substantially horizontally in the left-right direction, and the lower ends of the left and right side sides 7c are lower sides having a shorter extension length than the upper side 7a. 7b. The upper side 7a and the lower side 7b of the back support 7 are formed in a thick block shape, and the left and right side sides 7c are formed in a thin plate shape. As shown in FIG. 5 and FIG. 7, the left and right side sides 7 c extend such that the side body portion 7 c-1 is inclined forward from the inner side in the width direction toward the outer side. Reinforcing ribs 7c-2 projecting forward are provided on the part.

  The back plate frame 18 of the back support 6 is fixed to the back support 7 at three places spaced apart in the left-right direction of the upper side 18a and one place at the center of the lower side 18b. Specifically, as shown in FIG. 3, the upper side 18 a of the back plate frame 18 is fixed to the upper side 7 a of the back support 7 by locking with an engagement protrusion 22 described in detail later. The lower side 18 b is fixed to the lower side 7 b of the back support 7 by fastening with bolts 23.

  In the side view, the back support 7 is curved so that a height position of about one third from the bottom in the height direction of the side 7c bulges most forward. The front bulge portion 21 that bulges most forward is set at a position substantially corresponding to the front bulge portion 20 of the back plate frame 18. However, the bulging height of the front bulging portion 21 of the back support 7 is set lower than the bulging height of the front bulging portion 20 of the back plate frame 18.

  In addition, the bulge height of the front bulge portion 20 of the back plate frame 18 is between the front bulge portion 21 of the left and right sides 7 c of the back support 7 and the front bulge portion 20 of the back plate frame 18. A shape changing mechanism 24 that changes the curved shape of the side edge of the back support 6 by changing the shape of the back support 6 is interposed. Reference numeral 24 a in the figure is an operation lever of the shape changing mechanism 24.

Incidentally, on the rear surface 18a-1 of the upper side 18a of the back plate frame 18, as shown in FIG. As shown in FIG. 7, three insertion holes 25 into which the engagement protrusions 22 are inserted are formed at positions corresponding to the engagement protrusions 22 of the back plate frame 18 in the front surface 7a-1 of the upper side 7a. Has been.
As shown in FIG. 8, each of the engaging protrusions 22 protruding from the back plate frame 18 includes a rectangular plate-like insertion plate portion 22 a having a length in the protruding direction and a width in the horizontal direction with respect to the thickness in the vertical direction. And an overhanging locking portion 22b that is connected to the distal end portion of the insertion plate portion 22a and protrudes in the left-right direction. The overhanging locking portion 22b is formed in a plate shape having the same thickness as the insertion plate portion 22a. In the center position in the width direction of the overhanging locking portion 22b and the insertion plate portion 22a, a long hole-shaped lightening hole 30 is continuously formed. The lightening hole 30 constitutes a bending allowance portion for making the overhanging locking portion 22b bend easily inward in the width direction when an external force is applied to the overhanging locking portion 22b from the side. In order to make the overhanging locking portion 22b bend more easily on the inner side in the width direction, the lightening hole 30 is formed to be continuous with the overhanging locking portion 22b and the insertion plate portion 22a as in this embodiment. However, as long as it is formed at least in the range of the overhanging locking portion 22b, the overhanging locking portion 22b can be bent inward in the width direction. Moreover, the taper surface 22b-1 which inclines inward toward the front side is formed in the edge part of the right-and-left both sides of the protrusion latching | locking part 22b.

As shown in FIG. 8, the front surface 7 a-1 of the upper side 7 a of the back support 7 is formed to be inclined toward the upper rear side so as to follow the inclined shape of the upper side 18 a of the back plate frame 18. . The rear surface 18a-1 of the upper side 18a of the back plate frame 18 and the front surface 7a-1 of the upper side 7a of the back support 7 are opposed surfaces that come into contact with each other when a load is applied to the back plate frame 18 from the front side. Has been. The engagement protrusion 22 and the insertion hole 25 are formed so as to extend substantially horizontally in the front-rear direction. Therefore, the engagement protrusion 22 and the insertion hole 25 are inclined in the direction approaching the horizontal direction with respect to the direction orthogonal to the facing surface.
Further, each insertion hole 25 formed in the upper side 7a of the back support 7 is formed in a horizontally-long rectangular cross-sectional shape that is slightly larger than the cross-sectional shape of the insertion plate portion 22a of the engagement protrusion 22. However, the upper and lower surfaces in the insertion hole 25 are widened so that the front side (the side facing the rear surface 18a-1 of the upper side 18a of the back plate frame 18) expands in a tapered shape.

  On the lower surface of the upper side 7a of the back support 7, as shown in FIG. 5, three openings 31 that are recessed in a concave shape toward the upper side are provided. These openings 31 are provided corresponding to the respective insertion holes 25, and the corresponding insertion holes 25 communicate with each other in the bottoms. The bottom of the opening 31 is formed wider than the width of the insertion hole 25 in the left-right direction, and the engagement protrusion 22 protrudes when the engagement protrusion 22 is inserted into the insertion hole 25 from the front side of the back support 7. The locking part 22 b is accommodated in the bottom part of the opening part 31. The opening edge of the insertion hole 25 that opens to the front side of the bottom of the opening 31 constitutes a pull-out restricting portion 29 that engages with the overhanging locking portion 22 b protruding from the insertion hole 25 and restricts the engagement protrusion 22 from coming off. ing. Each opening 31 can visually recognize the overhanging locking portion 22b from a direction substantially orthogonal to the engaging direction of the engagement protrusion 22 and the removal restricting portion 29.

In addition, a substantially rectangular recess 32 that is long in the left-right direction is formed in the center region in the width direction of the lower surface of the upper side 7a of the back support 7. The recess 32 is formed in such a size that four fingers other than the thumb of the person to be gripped can be inserted when the central portion of the upper side 7a of the back support 7 is gripped as a handle from the rear. . Further, a stepped portion 33 that is recessed upward with respect to the opening edge of the recessed portion 32 is formed on the front side of the recessed portion 32 in the lower surface of the upper side 7 a of the back support 7. The step portion 33 is formed over a wider width in the left-right direction than the recess portion 32.
Here, of the three openings 31 formed on the lower surface of the upper side 7a of the back support 7, the two left and right openings 31 directly open on the lower surface of the upper side 7a. On the other hand, the central opening 31 opens at the center of the bottom in the recess 32 as shown in FIG. Note that a locking recess 35 (supporting portion) for locking and fixing an additional functional component such as a headrest is formed on the rear surface of the upper side 7a of the back support 7. A mounting hole and a nut (not shown) for screwing the additional functional parts are provided at positions corresponding to both ends in the locking recess 35. When the additional functional component is not attached, the locking recess 35 is closed by a closing cap 40 as shown in FIGS.

  Actually, when attaching the back support 6 to the back support 7, the three engaging protrusions 22 on the upper side 18 a of the back plate frame 18 of the back support 6 correspond to the upper side 7 a of the back support 7. Insert into the insertion hole 25. At this time, when the distal end side of the overhanging locking portion 22b of the engaging protrusion 22 is pushed into the insertion hole 25, the overhanging locking portion 22b receives a pressing force from the inner wall of the insertion hole 25 through the tapered surface 22b-1, and The stop 22b is compressed in the direction of the lightening hole 30. Thus, when the insertion of the engagement protrusion 22 proceeds and the overhanging locking portion 22b protrudes from the insertion hole 25 toward the bottom of the opening 31, the overhanging locking portion 22b is elastically restored in the opening 31 and opened. It comes into contact with the removal restricting portion 29 in the portion 31. As a result, the upper side portion of the back support 6 is connected to the upper side 7 a of the back support 7. Thereafter, the lower side 18 b of the back plate frame 18 of the back support 6 is fastened and fixed to the lower side 7 b of the back support 7 by bolts 23.

  On the other hand, when the back support 6 attached to the back support 7 in this way is removed from the back support 7 for repair or parts replacement, the upper side from the rear side of the back support 7 is used. An operator's fingertip or tool is inserted into each opening 31 on the lower surface of 7a, the overhanging locking portion 22b located on the bottom side of the opening 31 is pinched inward in the left-right direction, and the overhanging locking portion 22b is elastic. It is pushed back into the insertion hole 25 while being deformed. When the overhanging locking portion 22b is pushed back into the insertion hole 25 in this way, the engagement between the overhanging locking portion 22b and the removal restricting portion 29 is released. When the engagement of all the engagement protrusions 22 is released in this way, the bolt fastening between the lower sides of the back support 6 and the back support 7 is subsequently released, whereby the back support 6 from the back support 7. Is completely removed.

As described above, in the chair 1 of this embodiment, the opening 31 that allows the overhanging locking portion 22b to be visually recognized from the direction substantially orthogonal to the engagement direction of the engagement protrusion 22 is formed on the upper side 7a of the back support 7. Since the back support 6 and the back support 7 are connected to each other on the upper side so that the office posture is easily taken when sitting, the opening 31 is used when removing the back support 6. The locking of the overhanging locking part 22b and the slipping-out restricting part 29 can be easily released. Therefore, the back support 6 can be easily detached from the back support 7.
In particular, in the case of this embodiment, since the opening 31 is provided on the lower surface side of the upper side 7a of the back support 7, it is difficult to see the inside of the opening 31 during normal use, resulting in a decrease in appearance. There is nothing.

  Further, in the chair 1 of this embodiment, the engagement protrusion 22 is provided with the lightening hole 30 as a bending permission portion that allows bending deformation in the direction of narrowing the protrusion width of the protrusion locking portion 22b. When the overhanging locking portion 22b is pushed back into the insertion hole 25, the overhanging locking portion 22b can be easily engaged with the removal restricting portion 29 only by pinching the overhanging locking portion 22b from the side. It can be canceled. In this embodiment, the bendable portion is formed by forming the lightening hole 30 in the engagement protrusion 22. However, the bendable portion is, for example, concave in the central region in the width direction of the overhanging locking portion 22 b. It is good also as a structure notched in.

  Furthermore, in the case of this embodiment, the engagement protrusion 22 is a plate shape having a length in the protruding direction and a width in the left and right direction with respect to the thickness in the vertical direction, and is substantially rectangular connected to the main body side of the back plate frame 18. Since it has a structure including a plate-like insertion plate portion 22a and an overhanging locking portion 22b that is connected to the distal end portion of the insertion plate portion 22a and projects in the left-right direction from the insertion plate portion 22a, The occupied space in the vertical direction of the engagement protrusion 22 in the upper side 7a of the support 7 can be reduced. Further, since the engaging protrusion 22 has the above structure, when a load substantially along the vertical direction is input from the back of the seated person to the back support 6 when the seated person warps backward, the engaging protrusion 22 The insertion plate portion 22a of 22 bends up and down in the thickness direction, and allows a minute amount of displacement of the back support 6 in the vertical direction. For this reason, the back receiving body 6 can be made to flexibly follow the behavior of the back of the seated person, thereby obtaining a good seating feeling.

  Moreover, in the chair 1 of this embodiment, while the upper side 18a of the backplate frame 18 of the back support body 6 and the upper side 7a of the back support body 7 incline toward the rear upper side, these rear surface 18a-1 and front surface 7a. -1 is a contact surface that can contact each other, and the engagement protrusion 22 and the insertion hole 25 are formed so as to be inclined in a direction approaching the horizontal direction with respect to a direction orthogonal to the contact surface. Therefore, even if the upper side 7a of the back support 7 has a small cross-sectional shape, it is possible to easily ensure a long extension in the front-rear direction of the insertion hole 25 with the engagement protrusion 22. For this reason, the contact part length of the engagement protrusion 22 and the inner surface of the insertion hole 25 can be secured long, and the support strength of the back support 6 can be increased. In the case of this embodiment, since the extension length of the engagement protrusion 22 in the front-rear direction can be easily secured, a load in a direction intersecting the engagement protrusion 22 is input from the back of the seated person to the back support 6. When this occurs, the engagement protrusion 22 is easily bent and deformed along the load input direction. For this reason, the back receiving body 6 can be made to follow the behavior of the back of the seated person more flexibly. In particular, when the engagement protrusion 22 is a thin plate with a small thickness in the vertical direction as in this embodiment, this effect can be enjoyed more.

  In the case of the chair 1 of this embodiment, the insertion hole 25 on the back support 7 side is formed in a tapered shape so that the separation width of the upper and lower walls expands toward the front side. When the load in the direction along the vertical direction is input from the back portion to the back support 6, the base portion side of the engagement protrusion 22 is more easily bent and deformed at the portion where the insertion hole 25 is tapered. Therefore, with the above configuration, the back support 6 can follow the behavior of the back of the seated person more flexibly.

In addition, this invention is not limited to said embodiment, A various design change is possible in the range which does not deviate from the summary. For example, in the above-described embodiment, the back support 6 is configured by stretching the back material 19 on the back plate frame 18, but the back support is a cushioning material formed on a plate-like member having no large opening inside. A structure in which a tension member is attached or a structure of a single plate member having flexibility may be used.
In the above embodiment, the lower side 19b of the back plate frame 18 is fixed to the lower side 7b of the back plate support 7 by fastening with the bolts 23, but the lower side of the back plate frame (back support) is not necessarily There is no need to rigidly fix, and a regulating mechanism that regulates excessive displacement in the front-rear direction may be provided between the back support and the lower side of the back plate frame (back support). In such a case, it becomes easier to remove the back support.

1 Chair 6 Back Support 7 Back Support 7a-1 Front (opposite surface)
18a-1 Rear surface (opposite surface)
22 Engaging projection 22a Inserting plate part 22b Overhanging locking part 25 Inserting hole 29 Detachment restricting part 30 Meat removal hole (deflection allowable part)
31 Opening 50 Backrest

Claims (3)

A back support that receives the load on the back of the seated person,
A back support that is disposed on the back side of the back support and supports the back support,
In a chair provided with a backrest portion in which an upper end portion of the back support and an upper end portion of the back support are connected to each other,
On the back surface of the upper end portion of the back support, an engagement protrusion that protrudes toward the back support is provided,
At the tip of the engaging protrusion, a protruding locking part is provided that protrudes in a direction substantially perpendicular to the protruding direction of the engaging protrusion,
The back support body includes an insertion hole into which the engagement protrusion is inserted from the front surface side, and a disengagement restricting portion that abuts against the overhanging engagement portion protruding from the insertion hole and restricts the engagement protrusion from coming off. And an opening that is recessed toward the housing area of the overhanging locking portion protruding from the insertion hole and that allows the overhanging locking portion to be visually recognized from a direction substantially orthogonal to the engaging direction of the engaging protrusion. ,
The engagement protrusion is formed in a plate shape having a length in the protrusion direction and a width in the left-right direction with respect to the thickness in the vertical direction, and is a substantially rectangular plate-shaped insertion plate portion connected to the main body portion of the back support And the overhanging locking portion that extends in the left-right direction from the distal end portion of the insertion plate portion and is formed continuously in substantially the same thickness as the insertion plate portion,
At least the overhang locking portion of the engagement protrusion is arranged in a direction of narrowing the overhang width of the overhang locking portion during a release operation for releasing the lock of the overhang locking portion locked to the removal restriction portion. A chair formed with a lightening hole that allows bending deformation . A back support that receives the load on the back of the seated person,
A back support that is disposed on the back side of the back support and supports the back support
In a chair provided with a backrest portion in which an upper end portion of the back support and an upper end portion of the back support are connected to each other,
On the back surface of the upper end portion of the back support, an engagement protrusion that protrudes toward the back support is provided,
At the tip of the engaging protrusion, a protruding locking part is provided that protrudes in a direction substantially perpendicular to the protruding direction of the engaging protrusion,
The back support body includes an insertion hole into which the engagement protrusion is inserted from the front surface side, and a disengagement restricting portion that abuts against the overhanging engagement portion protruding from the insertion hole and restricts the engagement protrusion from coming off. And an opening that is recessed toward the housing area of the overhanging locking portion protruding from the insertion hole and that allows the overhanging locking portion to be visually recognized from a direction substantially orthogonal to the engaging direction of the engaging protrusion. ,
The rear surface of the upper end portion of the back support and the front surface of the upper end portion of the back support are inclined facing the upper rear side and are opposed surfaces that can contact each other .
The chair, wherein the engagement protrusion and the insertion hole are formed to be inclined in a direction approaching a horizontal direction with respect to a direction orthogonal to the facing surface. 3. The chair according to claim 1, wherein the insertion hole is formed such that a side facing the main body portion of the back receiving body extends in a tapered shape.

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