JP2014090996A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair in which an assembly operation of a cover covering a back board supported by a back support rod and the back support rod is easily performed.SOLUTION: A chair C possesses: a back support rod 4; a back board supported by the back support rod 4; a bag-shaped surface skin material put on outside of the back board; and a lower back support rod cover 61 covering the back support rod 4 from the bottom. The back board has a housing unit throwing open downward and containing at least a bottom end opening edge part of the surface skin material at the bottom edge. The lower back support rod cover 61 comprises a cover main body 611 covering the bottom of the back support rod 4, and a back board blocking unit 612 provided integrally to the cover main body 611, blocking up the housing unit of the back board and holding the bottom end opening edge of the surface skin material in the housing unit.

Description

  The present invention relates to a chair having a back plate that is supported by a back support rod and to which a bag-like skin material is attached on the outside, and a cover that covers the back support rod from the lower side.

  Conventionally, as this type of chair, there is known a chair in which a back plate is attached to a distal end portion of a back support rod and the back support rod is covered with a synthetic resin cover (see, for example, Patent Document 1). ).

  However, in the conventional one, the back plate is attached so that the upper end of the upper and lower covers that cover the back support rod is sandwiched from the front and rear. Therefore, it is necessary to assemble while paying attention to the fitting of the four parts of the upper and lower covers that cover the back support rod and the front and rear covers that constitute the back plate.

JP 2010-099222 A

  An object of this invention is to provide the chair which can perform the assembly operation | work of the cover which covers the back board supported by a back support rod and this back support rod easily.

  The present invention employs the following configuration in order to solve the above-described problems. That is, the chair according to the present invention includes a back support rod, a back plate supported by the back support rod, a bag-like skin material that is attached to the outside of the back plate, and the back support rod on the lower side. A lower back support cover that covers from the bottom plate, the back plate having a receiving portion that opens downward at the lower end thereof and accommodates at least the lower end opening edge of the skin material. The lower back support cover covers the lower side of the back support, and the cover body is provided integrally with the cover main body so as to close the lower plate opening edge of the skin material. It is characterized by comprising a back plate closing portion held in the housing portion.

  If it is such, compared with the conventional thing, the assembly operation | work of the cover which covers the back board supported by a back support rod and this back support rod can be performed easily. Furthermore, since the lower back support cover can cover not only the lower side of the back support but also the lower end receiving portion of the back plate, the back support cover, the back plate and the skin material can be easily structured. The lower end opening edge can be hidden from the lower side.

  The back support rod has an upward mounting surface at a tip portion, and the back plate has a mounting arm portion extending forward at a lower end, and the mounting arm portion is attached to the mounting portion of the back support rod. What was attached with the volt | bolt with which the surface was mounted | worn from the upper side is mentioned as a suitable one aspect | mode.

  A specific example of the back plate includes a back shell and a back joint attached to the back shell and having the attachment arm portion at the lower end.

  In a preferred embodiment, the first upper support rod is provided with first and second upper back support covers that cover the back support rod from above and can be attached and detached independently of each other. The cover covers a portion corresponding to the mounting surface of the back support rod, and the second upper back support cover covers an exposed portion other than the mounting surface of the back support rod.

  Since this invention is the structure as mentioned above, the chair which can perform the assembly operation | work of the back board supported by a back support rod and the cover which covers this back support rod easily can be provided.

The external view of the chair which concerns on one Embodiment of this invention. The rear view of the chair which concerns on the embodiment. The center side sectional view of the chair concerning the embodiment. The expanded sectional view of the principal part of FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. The disassembled perspective view of the chair which concerns on the same embodiment. The disassembled perspective view of the outer shell and inner shell of the seat of the embodiment. The exploded perspective view from the upper part of the seat of the embodiment. The exploded perspective view from the lower part centering on the seat of the embodiment. The bottom view which abbreviate | omits and shows the seat of the embodiment partially. BB sectional drawing of FIG. Action explanatory drawing shown in the same cross section as FIG. The disassembled rear view which abbreviate | omits and shows the seat which concerns on the embodiment partially. The disassembled perspective view from the front which abbreviate | omits and shows the backrest and cover aggregate | assembly of the embodiment partially. The disassembled perspective view from the back centering on the backrest of the embodiment. The disassembled perspective view from the back centering on the backrest of the embodiment. The front view which shows the back shell and back back cover of the embodiment. The disassembled perspective view of the back shell and lumbar support device of the embodiment. The rear view which shows the principal part of the lumbar support apparatus of the embodiment. The disassembled perspective view which shows the upper back support rod cover which concerns on the modification of this invention.

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

  As shown in FIGS. 1 to 19, the chair C includes a leg body 1, a support base 2 that is supported on the upper part of the leg body 1 and can be turned horizontally, and a seat 3 disposed on the support base 2. And a back support rod 4 provided on the support base 2 so as to be able to tilt backward, and a backrest 5 attached to the back support rod 4.

<Legs>
As shown in FIGS. 1 to 6, the leg 1 includes a leg blade type leg base 11 having casters 13, and a leg column 12 erected at the center of the leg base 11. The leg strut 12 is a normal one mainly composed of a gas spring, and the support base 2 is attached to the upper end of the leg strut 12.

<Support base>
As shown in FIGS. 1 to 6, 9, and 15, the support base 2 is supported by the legs 1 so as to be horizontally turnable and vertically movable, and is attached to the leg support 12. A housing 20, a main shaft 21 for supporting the backrest that penetrates the housing 20, and a tilt (not shown) that applies a force to the main shaft 21 to generate an elastic repulsive force with respect to the backward tilting operation of the backrest 5. And a reaction force generation mechanism. The tilt reaction force generation mechanism is configured to be able to apply an elastic repulsion force in the rotational direction to the main shaft 21 using a coil spring, a gas spring, or the like (not shown). Is omitted.

<Za>
As shown in FIGS. 1 to 13, the seat 3 includes an outer shell 31, an inner shell 32 disposed on the outer shell 31 through a slide guide mechanism 33 so as to be slidable in the front-rear direction, A slide positioning mechanism 34 for moving and locking the inner shell 32 to a desired slide position, a cushion 35 disposed on the inner shell 32, and a lower surface 326 c of the peripheral edge 326 of the cushion 35 and the inner shell 32. A covered seat skin material 36 is provided.

  As shown in FIGS. 2 to 9 and FIGS. 11 to 13, the outer shell 31 has a load receiving surface P <b> 3 that receives a load from a seated person on the upper surface 31 c side. The outer shell 31 is different in the form of the upper surface 31c between the first half area 31a and the second half area 31b. The outer shell 31 includes an outer shell main body 311, the vertical ribs 312, horizontal ribs 313, and oblique ribs 314 projecting from the upper surface 311 a of the outer shell main body 311, and the rear half region of the lower surface 311 b of the outer shell main body 311. A rear half central portion 315 having a surrounding wall 315a that protrudes toward the upper surface 311a of the outer shell main body 311 and a ceiling wall 315c that closes the protruding end 315b of the surrounding wall 315a. It is provided and is integrally molded using a hard synthetic resin. Downward vertical ribs 315f and downward horizontal ribs 315g protrude from the lower surface 315e of the top wall 315c of the rear half central portion 315. The protruding end surfaces 312a, 313a, and 314a of the vertical rib 312, the horizontal rib 313, and the diagonal rib 314, and the upper surface 315d of the top wall 315c of the rear half center portion 315 are configured to belong to one virtual common curved surface P2. Yes. The portion of the virtual common curved surface P2 belonging to the front half region 31a is curved so that each portion maintains a substantially constant height in the front-rear direction and gradually rises from the center portion toward the left and right side edges in the left-right direction. is there. The portion belonging to the latter half region 31b of the virtual common curved surface P2 is curved so that the front side gradually rises forward in the front-rear direction, and the other portions are maintained at a substantially constant height. In the left-right direction, it is curved so as to gradually rise from the center toward the left and right side edges. The load receiving surface P3 is set in a region excluding the peripheral edge of the latter half region 31b, and is set to belong to the virtual common curved surface P2. Specifically, the load receiving surface P3 is defined by the upper surface 315d of the top wall 315c and the protruding end surfaces 312a, 313a, and 314a of the vertical rib 312, the horizontal rib 313, and the diagonal rib 314 disposed on the left and right sides of the upper surface 315d. It is configured. The load receiving surface P3 is formed around the sitting reference point S1 set in the latter half region 31b, and includes an inclined portion P31 that gradually rises forward from the sitting reference point S1 to the front side. ing. By providing the inclined portion P31, it is possible to suppress the forward displacement of the seated person and to improve the fit at the time of sitting. The first lever 23 provided under the outer shell 31 is for adjusting the reaction force so as to adjust the spring preload of the tilt reaction force generation mechanism provided in the support base 2. It has become. The second lever 24 is for adjusting the height position of the seat 3, and a wire (not shown) connected to the lever 24 is formed by a recess 312 b formed in the vertical rib 312 and a hole in the outer shell main body 311. It is led to the vicinity of the upper end of the leg column 12 of the leg 1 through 311c. Since the third lever 25 is used to adjust the angle of the backrest 5, a wire (not shown) connected to the lever 25 is formed on the concave portion 312 c formed on the vertical rib 312 and the ceiling wall 315 c of the rear central portion 315. Through the formed groove 315h, the gas is guided to a gas spring for adjusting a backrest angle (not shown) disposed below the outer shell 31. Since the connection structure of these wires is normal, description is abbreviate | omitted.

  As shown in FIGS. 3 to 12, the inner shell 32 includes a load transmission portion 327d for supporting a load from a seated person on the load receiving surface P3 at a portion corresponding to the load receiving surface P3. Thus, an inner shell main body 321 having a shell shape including a step 325 whose peripheral edge 326 side is increased in the vicinity of the peripheral edge, and a rib 326b protruding from the upper surface 326a of the peripheral edge 326 of the inner shell main body 321 are provided. It is integrally formed of an elastically deformable synthetic resin. The peripheral edge portion 326 is wrapped by the outer edge 364 of the seat covering material 36, and has an upward wall 326d extending upward at the outermost edge. A region 327 surrounded by the step portion 325 of the inner shell main body 321 is slidable on the protruding end surfaces 312 a, 313 a, and 314 a of the vertical rib 312, the horizontal rib 313, and the diagonal rib 314 in the front half region 31 a of the outer shell 31. Slidable on the first half shell portion 327a that can be in close contact with, the projecting end faces 312a, 313a, and 314a of the rear rib 311, the lateral rib 313, and the oblique rib 314 and the upper surface 315d of the top wall 315c. A rear end shell portion 327b that can be in close contact with the rear end shell portion 327b, and an intermediate shell portion 327c that smoothly connects the front edge of the rear end shell portion 327b to the rear edge of the front half shell portion 327a. The intermediate shell portion 327c is provided with the load transmission portion 327d. The load transmitting portion 327d is formed by forming a plurality of slits 327g extending in the front-rear direction in the intermediate shell portion 327c with a space in the left-right direction. In the no-load state, the lower surface of the load transmitting portion 327d is formed. A space 327f is formed between 327e and the load receiving surface P3. The load transmitting portion 327d can be elastically deformed relatively easily in the thickness direction due to the presence of the slit 327g. When the load from the seated person is received, the load transmitting portion 327d is elastically deformed downward and the outer shell 31 is elastically deformed. It is comprised so that it may contact | abut to the load receiving surface P3. That is, the load from the seated person is finally received by the load receiving surface P3 of the outer shell 31 through the load transmitting portion 327d.

  The inner shell 32 is disposed on the outer shell 31 via the slide guide mechanism 33 so as to be slidable in the front-rear direction within a predetermined range, and is not accompanied by an interlocking transition of the load receiving surface P3. The seating depth dimension of the seat 3 can be changed. That is, by sliding the inner shell 32 with respect to the outer shell 31, the seating depth dimension of the seat 3 can be changed. However, since the load receiving surface P3 is provided on the outer shell 31, It does not move in conjunction with the sliding movement of the inner shell 32.

  As shown in FIGS. 6 to 13, the slide guide mechanism 33 is formed at a plurality of locations on the inner shell 32 and extends in the front-rear direction, and is slidably inserted into each of the guide slits 322 and has an upper end. A plurality of sliders 331 having retaining heads 332 slidably contacting the upper surface 32a of the inner shell 32, and a plurality of slider mounting portions 31e provided on the outer shell 31 to fix the lower end portions 333 of the sliders 331. It is equipped with. More specifically, the guide slits 322 are formed in the vicinity of the four corners of the inner shell 32, and a head that surrounds the retaining head 332 of the slider 331 around each guide slit 322. Protective ribs 323 are provided in a protruding manner. The protruding end surface 323a of each head protecting rib 323 is set to belong to the virtual common curved surface P2. Further, the upper surface 332 a of the retaining head 332 of each slider 331 is inclined so as to be accommodated in the head protecting rib 323. Each of the sliders 331 has a prismatic shape that can slide along the corresponding guide slit 322, and has a screw hole (not shown) on the lower end surface 334. Each of the slider attachment portions 31e is formed in the vicinity of the four corners of the outer shell 31, and has a bottomed rectangular tube shape with which the lower end portion 333 of the slider 331 can be fitted from above. . A screw insertion hole (not shown) through which a screw 31g can be inserted from the lower surface 31d side of the outer shell 31 is formed at the bottom 31f of each slider mounting portion 31e. The screw 31g is inserted into the screw hole 311c. Each slider 331 is fixed to the outer shell 31 by being screwed to the outer shell 31. 11 and 12, the slider 331 is indicated by a two-dot chain line.

  The inner shell 32 that is guided by the slide guide mechanism 33 having the above configuration and slides in the front-rear direction can be positioned and locked at a desired slide position by the slide positioning mechanism 34.

  As shown in FIGS. 6 to 13, the slide positioning mechanism 34 includes an operation member 341 that can move up and down between the lower lock position (D) and the upper lock release position (U), and the sliding movement of the inner shell 32. Accordingly, a plurality of positioning engaging portions 31r selectively corresponding to the operation member 341 are provided. In the slide positioning mechanism 34, the inner shell 32 is prohibited from sliding while the operation member 341 is lowered to the lower lock position (D) and engaged with the corresponding engagement portion 31 r, and the operation member 341 is moved. In this state, the engagement with the engaging portion 31r is released while the upper shell is released to the upper unlocking position (U), and the sliding movement of the inner shell 32 is allowed. An operation end 349 of the operation member 341 protrudes toward the lower surface 31d side of the outer shell 31, and a contact surface that locks the operation member 341 on the outer shell 31 at the upper lock release position (U). 31m is provided. The operating member 341 is an independent part that is separate from both the outer shell 31 and the inner shell 32, and is in a lower locked position (by a resilient repulsive force of a cushion 35 disposed on the inner shell 32. D) elastically biased in the direction.

  More specifically, the operating member 341 is inserted through the holding portion 324 of the inner shell 32 so as to be movable up and down, and the lower end side is passed through a slit 31 h provided in the outer shell 31 and extending in the front-rear direction. An operation member main body 343 protruding toward the lower surface 31d side, a thin plate-shaped head portion 344 provided at the upper end of the operation member main body 343 and in contact with the lower surface 35b of the cushion 35, and an intermediate portion of the operation member main body 343 And a locking claw 345 that selectively engages one of a plurality of engaging portions 31r provided on the outer shell 31, and a lower end of the operating member main body 343 that contacts the contact surface 31m. A retaining projection 346 and a screw 348 are attached to the lower end of the operation member main body 343 so as to hold the retaining projection 346. Vignetting is obtained a push button 347 constituting the operation end 349. The contact surface 31m is formed along the opening end of the slit 31h on the lower surface 31d of the outer shell 31, and the upward surface 346a of the retaining member 341 of the operating member 341 and the pushing surface 346a are pushed on the contact surface 31m. The upper surface 347a of the button 347 is brought into contact with the inner shell 32 and can be slid back and forth. In other words, the operation member 341 is provided at a position where the operation member 341 can be operated with a finger placed on the upper surface side of the seat 3, and the operation member 341 is maintained while the finger is placed on the seat 3. By operating the push button 347 of the 341, the main part of the seat 3 including the operation member 341 can be moved with respect to the outer shell 31, and the seating depth dimension of the seat 3 can be changed. . In other words, the operation of pushing the push button 347 with the finger becomes the disengagement operation as it is, and the upward surface 346a of the retaining projection 346 and the upward surface 347a of the push button 347 in the disengaged state. The inner shell 32 can be slid back and forth while sliding in contact with the contact surface 31m. The reason why the push button 347 is brought into contact with the contact surface 31m is to keep the operating range of the operation member 341 constant, to prevent excessive stress from acting on each part, and to improve the feeling of operation. The inner shell 32 is slid back and forth while the push button 347 is in sliding contact with the contact surface 31m, as described above, while maintaining the state where the finger is put on the upper surface of the seat 3 as described above. This is because the seating depth dimension can be changed by operating the push button 347 of 341.

  In addition, as shown in FIGS. 7 to 9, notches 324a and 31k for allowing the retaining projection 346 to pass therethrough are provided on the outside of the holding portion 324 and on the outside of the front end portion of the slit 31h, respectively. . The notch 324a provided on the outside of the holding portion 324 and the notch 31k provided on the outside of the front end of the slit 31h are positioned so as to coincide with each other when the inner shell 32 is moved forward most. Only in this state, the operation member 341 can be attached to the inner shell 32 and the outer shell 31. The inside of the holding portion 324 is integrated with a head protecting rib 323 of a guide slit 322 disposed on the left front side of the seat 3 via a connecting rib 324b. That is, the holding portion 324 is disposed adjacent to one of the guide slits 322.

  As shown in FIGS. 3 to 6 and FIGS. 8 to 12, the cushion 35 is, for example, a non-woven fabric stuck on the lower surface 35 b of molded urethane, and is placed on the upper surface 32 a of the inner shell 32. It is wrapped with the seat skin material 36 together with the peripheral edge portion 326 of the inner shell 32.

  As shown in FIGS. 1 to 5 and FIGS. 10 to 12, the seat skin material 36 includes a skin material body 361 having a flat bag shape that opens downward, and a bag stitch formed on the opening edge of the skin material body 361. A portion 362 and a string 362 a inserted through the bag stitch portion 362 are provided. The skin material main body 361 is formed by stitching a plurality of types of upholstery fabrics 361a and 361b having different elongation characteristics via a mim 363 protruding to the outer surface. Specifically, the skin material main body 361 is obtained by stitching a first tension fabric 361 a that is relatively thick and difficult to stretch, and a second tension fabric 361 b that is relatively thin and rich in elasticity via a mim 363. It is. In addition, as an element related to the difference in stretch characteristics of the tension fabric, there are a difference in thickness, a difference in material, a structural difference such as a woven fabric and a knitted fabric, and the like. The first upholstery 361a is mainly provided at a position that constitutes the seating surface P1, and covers the upper surface 35a and the front surface 35c of the cushion 35. The second upholstery 361b is provided in a region other than the seating surface P1, and covers the side surface 35d, the back surface 35e of the cushion 35, and the lower surface 326c of the peripheral edge 326 of the inner shell 32. The bag sewing portion 362 is brought into contact with the peripheral portion 326 lower surface 326c side of the inner shell 32 by being squeezed with the string 362a, and the inner shell 32 is attached to the outer shell 31 in a state where the inner shell 32 is attached. It fits in the gap between the outer shell 31. The inner shell 32 described above is directed from the center to the periphery due to the presence of the upright wall 325a that forms the stepped portion 325 and the upward wall 326d that is provided at the outermost edge and extends upward. Accordingly, it gradually extends upward. In other words, the inner shell 32 has a shape in a plan view, and the shape in the vicinity of the peripheral edge portion 326 used for a seat walnut stretched by tightening the seat covering material 36 is formed at the outermost edge. It keeps going up step by step. The bag stitch portion 362 of the seat cover material 36 is disposed along the outer side of the step portion 325 forming a step on the lower surface of the inner shell 32, and the bag stitch portion 362 extends from the lower surface of the inner shell 32. This prevents the inner shell 32 from interfering with the sliding operation. That is, a step is formed on the lower surface of the inner shell 32 inside and outside the step portion 325 so that the outer side is higher than the inner side. By arranging the bag sewing portion 362 outside the step, this step is performed. It can prevent that the bag sewing part 362 protrudes from the lower surface of the inner shell 32 to the outer shell 31 side. In addition, in FIGS. 3-5, FIG.11, and FIG.12, the seat skin material 36 is shown with the dashed-two dotted line.

<Back support>
As shown in FIGS. 3, 4, 6, 9, 15, and 16, the back support rod 4 includes a back support rod main body 41 made of thick steel plates and the like, and a back support rod main body 41. A shaft 42 for a tilt reaction force generating mechanism installed between the base end portions 41 a of the heel body 41, a distal end connecting member 43 that rigidly connects the distal ends of the back support ridge body 41, and the back support ridge body 41 A pair of left and right mounting plates 44 extending inwardly from the upper edge of the distal end portion 41c, and a rear shaft 45 for constituting the synchro-rocking mechanism 26 laid between the upper edges of the intermediate portion 41b of the back support rod main body 41 And is rotatably attached to the support base 2 via a main shaft 21 inserted through the shaft hole of the base end portion 41a. The intermediate portion 41b of the back support rod main body 41 is provided with a cover mounting hole 41d and a cover positioning projection 41e. A plurality of bolt insertion holes 44a are formed in the mounting plate 44, and nuts 44b are respectively fixed to the lower surfaces corresponding to the bolt insertion holes 44a by welding or the like. An upper surface 44c of the mounting plate 44 forms a mounting surface 44d for mounting the backrest 5. A gap 44e is formed between the mounting plates 44 for disposing the tip end portion of the gas spring for adjusting the backrest angle.

  As shown in FIG. 3 to FIG. 5, the synchro-rocking mechanism 26 is for tilting the seat 3 and the backrest 5 at a constant angle ratio, and the front end side of the outer shell 31 of the seat 3 is moved forward. It is supported by a front end portion of the support base 2 via a shaft 27 so as to be movable back and forth, and a rear end side of the outer shell 31 is supported by an intermediate portion 41b of a back support rod 4 via a rear shaft 45. is there. The front shaft 27 is provided in a long hole 22 provided in the front end portion of the support base 2 so as to be slidable in the front-rear direction. Both end portions of the front shaft 27 are provided on the front end side lower surface of the outer shell 31. It is held in the part 31n. The rear shaft 45 is constructed on the intermediate portion 41b of the back support rod 4 as described above, and both ends thereof are held by the rear shaft holding portion 31p provided on the lower surface of the outer shell 31 on the rear end side. Yes.

<Backrest>
As shown in FIGS. 1 to 6 and FIGS. 14 to 18, the backrest 5 includes a back plate 51, a cushion 52 that surrounds the back plate 51, and a back skin material 53 that covers the outside of the cushion 52. It is equipped with.

  3 to 5 and 14 to 18, the back plate 51 includes a back shell 54 having flexibility, the back joint 55 having rigidity attached to the back shell 54, and the back shell. 54, and a back under cover 56 having a front wall 562 facing the front surface 54e of the lower shell 54a of the back shell 54. The back wall 562 rear surface 564 of the back under cover 56 is provided. And a lower portion 54a front surface 54b of the back shell 54 is formed with a receiving portion 57 opened downward.

  As shown in FIGS. 3 to 5 and 14 to 18, the back shell 54 has a three-dimensional shape in which a waist portion 54 c corresponding to the waist of the seated person is greatly curved and approaches a flat plate as it goes upward. A shell main body 541 having an elastically deformable plate shape, a plurality of vertical ribs 542, horizontal ribs 543, and oblique ribs 544 integrally projecting from a front surface 541f of the shell main body 541, and a lower center portion of the shell main body 541 And a joint mounting portion 545 having a surrounding wall 546 protruding toward the front surface 541f of the shell body 541 and a front wall 547 closing the protruding end of the surrounding wall 546. is there. The protruding heights of the vertical rib 542, the horizontal rib 543, and the oblique rib 544 are set so that the vicinity of the center of the waist portion 54c of the back shell 54 is high and gradually decreases toward the periphery of the back shell 54. The projecting end surfaces 542a, 543a, and 544a of the vertical ribs 542, the horizontal ribs 543, and the oblique ribs 544 are configured to belong to one virtual common curved surface P4. A forward-facing surface 547a of the front wall 547 of the joint mounting portion 545 is configured to be flush with the virtual common curved surface P4. Further, on the front surface 541f of the shell body 541, a nut portion 541a for attaching a bag body for holding a lumbar support airbag 71 described later and a nut portion 541c for attaching the back under cover are integrally provided. The front end surface 541b of the nut portion 541a for attaching the bag body belongs to the virtual common curved surface P4. The shell main body 541, the vertical rib 542, the horizontal rib 543, the oblique rib 544, the joint mounting portion 545, the bag mounting nut portion 541a and the back under cover mounting nut portion 541c are made of synthetic resin. Are integrally molded.

The shell main body 541 is an elastically deformable plate that curves smoothly corresponding to the three-dimensional shape, and includes peripheral walls 541e that protrude forward at a constant height on both side edges and upper edges.
The space between the vertical ribs 542 in the left-right direction and the space between the horizontal ribs 543 in the vertical direction are set narrow in the vicinity of the center of the waist 54c and wide in the periphery. The lateral ribs 543 and the oblique ribs 544 of the back shell 54 are partially provided with guide portions 543b and 544b for guiding an air tube 76 that connects the airbag 71 and the pump unit 73. Yes.

  The joint attachment portion 545 is a concave portion of the lower portion of the shell main body 541, that is, a rectangular shape in a rear view from the lower edge central portion of the shell main body 541 to the central portion of the waist portion 54c. A mounting space 548 opened to the back side is formed by the wall 546 and the front wall 547. The surrounding wall 546 is integrally continuous with the vertical rib 542, the horizontal rib 543, and the oblique rib 544, and a reinforcing rib 547b is provided on the back side of the front wall 547. Further, the front wall 547 is provided with a plurality of bolt insertion holes 547c, and a counterbore 547d for accommodating the bolt 549 head 549a is formed on the front side of the bolt insertion hole 547c. Yes.

  As shown in FIGS. 3 to 6 and FIGS. 14 to 16, the back joint 55 extends forward from the joint body 551 fitted to the joint mounting portion 545 and the lower end portion of the joint body 551. The mounting arm portion 552 has an L shape in side view, and the mounting arm portion 552 is attached to the mounting surface 44 d of the back support rod 4. The joint main body 551 has a flat box shape with the front side that is closely fitted in the mounting space 548 open, and has a reinforcing rib 551a inside. A back surface 551 b of the joint body 551 is continuous with the back surface 54 d of the back shell 54. The joint main body 551 includes a nut portion 551c at a portion corresponding to the bolt insertion hole 547c of the joint mounting portion 545 of the back shell 54, and the joint main body 551 is fitted in the mounting space 548. The back joint 55 is attached to the back shell 54 by screwing the bolt 549 inserted through the bolt insertion hole 547c from the front surface 54e side of the back shell 54 into the nut portion 551c. A plurality of upward claws 551d are formed on the front surface of the lower end portion of the joint body 551.

  The mounting arm portion 552 is integrally extended from the lower end of the joint body 551, and includes a pair of left and right mounting walls 553 that contact the mounting surface 44d of the back support rod 4, and the two mounting walls 553. , And a hanging wall 555 suspended downward from the outer edges of the both mounting walls 553, corresponding to the nuts 44b of the back support rods 4 of the both mounting walls 553. Bolt insertion holes 553a are formed in the parts to be attached, and square holes 553b for attaching the cover are provided in the vicinity of the front ends of these mounting walls 553. The upper surface 554a of the central wall 554 is located above the upper surfaces 553c of the mounting walls 553. The attachment arm portion 552 is attached by a bolt 556 attached to the attachment surface 44d of the back support rod 4 from above. Specifically, the mounting arm portion 552 is placed on the mounting surface 44 d of the back support rod 4 such that the tip end portion 4 a of the back support rod 4 is accommodated between the hanging walls 555 of the mounting arm portion 552. The mounting arm portion 552 is fixed to the back support rod 4 by screwing the bolt 556 inserted into the bolt insertion hole 553a from the upper surface 552a side of the mounting arm portion 552 into the nut 44b of the back support rod 4. ing. In this way, the back shell 54 is attached to the back support rod 4 via the back joint 55.

  As shown in FIGS. 3 to 6 and FIGS. 14 to 17, the back under cover 56 includes a top wall 561 attached to the front surface 54 b of the lower end 54 a of the back shell 54, and a lower side from the front edge of the top wall 561. The front wall 562 is extended to the front wall 562, and a receiving portion 57 opened downward is formed between the back surface 564 of the front wall 562 and the lower end portion 54a front surface 54b of the back shell 54. Yes. Thus, the accommodating portion 57 is divided into left and right due to the presence of the mounting arm portion 552 of the back joint 55. The top wall 561 is provided with a mounting projection 563 having a screw hole 563a at its rear edge, and a screw 567 inserted through the screw hole 563a is screwed into a nut portion 541c for mounting the back under cover of the back shell 54. The back under cover 56 is attached to the back shell 54 by wearing. The front wall 562 includes a central front wall portion 565 having a plurality of downwardly bent downward claws 565a on the back surface side, and both front wall portions 566 continuous on both sides of the central front wall portion 565. In addition, a positioning wall 566a that is in contact with or close to the side surface of the mounting arm portion 552 of the back joint 55 is provided at the inner ends of the front wall portions 566 on both sides. A plurality of upward claws 54 f are formed on the front surface of the back shell 54 corresponding to the front wall portions 566 on both sides.

  As shown in FIGS. 5 and 15, the accommodating portion 57 plays a role of accommodating a lower end opening edge portion 531 a of the spine skin material 53, as will be described later, and the downward claw 565 a and the upward direction The claws 54 f and 551 d are for holding the lower end opening edge 531 a of the spine skin material 53. Moreover, the pump unit 73 of the air supply mechanism 72 which is a main part of the operating mechanism is accommodated in one of the accommodating portions 57 divided into the left and right as will be described later.

  As described above, the back plate 51 is mainly composed of the back shell 54, the back joint 55, and the back under cover 56. The back plate 51 is surrounded by a cushion 52 at almost all portions except for the mounting arm portion 552 of the back joint 55 and the vicinity of the opening end of the accommodating portion 57.

  As shown in FIGS. 3 to 6 and 15, the cushion 52 includes a molded urethane 521 attached to the front surface 54 e of the back shell 54 and a slab urethane 522 attached to the back surface 54 d of the back shell 54. Are joined in the vicinity of both side edges of the back shell 54, and as described above, the back plate 51 is entirely swollen. That is, the cushion 52 covers the back shell 54 and the joint body 551 of the back joint 55 attached to the back shell 54. The molded urethane 521 is made by foaming urethane in a mold, and a nonwoven fabric is attached to the back surface thereof. The back surface of the molded urethane 521 is shaped so as to correspond to the virtual common curved surface P4 of the back shell 54, and the protruding end surfaces 542a, 543a, 544a of the vertical rib 542, the horizontal rib 543, and the oblique rib 544 are formed. And it is set so that it may contact | abut to the front facing surface 547a of the said joint attaching part 545. FIG. A groove 521a for receiving the peripheral wall 541e of the back shell 54 is formed in the vicinity of the peripheral edge on the back surface of the molded urethane 521. The slab urethane 522 is obtained by cutting a foamed urethane material that has been previously molded to a predetermined thickness into a required shape, and the slab urethane 522 is not shown in FIGS. 15 and 16. The outer surface of the cushion 52 thus formed is wrapped with the spine skin material 53.

  As shown in FIGS. 1 to 5 and 15, the back skin material 53 includes a bag-shaped skin material main body 531 having the lower end opening edge 531 a at the lower end, and a lower end opening edge 531 a of the skin material main body 531. A synthetic resin central latching member 532 sewn on the front center portion of the lower end opening edge portion 531a, and a synthetic resin both-side latching member 533 sewn on both sides of the front side of the lower end opening edge portion 531a. A metal hook wire 534 held on the rear side of the lower end opening edge 531a is provided. In addition, in FIGS. 3-5, the spine skin material 53 is shown with the dashed-two dotted line.

  Specifically, the skin material main body 531 is formed by sewing a first tension fabric 535 that is relatively thick and difficult to stretch, and a second tension fabric 536 that is relatively thin and rich in stretchability via a mim 537. Is. The first upholstery 535 is mainly configured to continuously cover the front surface 52a, the upper end surface 52b, and the upper half 52d of the back surface 52c of the cushion 52. The second upholstery 536 is configured to cover the side surface 52f of the cushion 52 and the lower half portion 52e of the back surface 52c. A mim 537 positioned at the boundary between the first upholstery 535 and the second upholstery 536 has a ridge shape protruding outward, and covers the back skin material 53 on the cushion 52. At this time, the Mimi 537 portion can be picked and pulled. The central hooking member 532 has a front end portion 532a bent in a U shape in cross section, and the front end portion 532a is a lower edge of the back plate 51, that is, a central front wall of the back under cover 56. It hangs on the lower edge of the portion 565. The front end portion 532a of the center hook member 532 is sandwiched and held between the back surface 565b of the center front wall portion 565 and the downward claws 565a in the hooked state. The both-side latching member 533 has a front end portion 533a bent in a U-shape in cross section, and the front end portion 533a is a lower edge of the back plate 51, that is, both front front walls of the back under cover 56. It hangs on the lower edge of the portion 566. The hooking wire 534 is attached to the lower edge of the skin material main body 531 so as to be partially exposed, and is hooked to the lower edge of the back plate 51. That is, the hooking wire 534 is hooked on the upward claws 54f and 551d in a state where the hooking wire 534 is turned into the accommodating portion 57 together with the lower edge portion of the skin material main body 531.

  The backrest 5 formed as described above is attached to the upward mounting surface 44d of the back support 4 which does not have a rising portion, and the entire mounting portion is covered with the cover assembly 6. All components of the lumbar support device 7 are incorporated into the backrest 5 to form a unit.

<Cover assembly>
As shown in FIGS. 1 to 6 and FIGS. 14 to 16, the cover assembly 6 covers a lower back support cover 61 that covers the lower side of the back support rod 4 and an upper side of the back support rod 4. The first and second upper back support rod covers 62 and 63 are provided so that the first upper back support rod cover 62 and the second upper back support rod cover 63 are independent of each other. It can be attached and detached.

  As shown in FIGS. 1 to 6 and FIGS. 14 to 16, the lower back support cover 61 is provided integrally with the cover body 611 covering the lower side of the back support cover 4 and the cover body 611. A back plate closing portion 612 that closes the housing portion 57 of the back plate 51 and holds the lower end opening edge 531a of the back skin material 53 in the housing portion 57 is provided. The cover body 611 is provided on the bottom plate 613, the left and right side plates 614 rising from the left and right side edges of the bottom plate 613, and the lower surface 4b and the outer surface 4c of the back support rod 4 provided on the inner surface side of the both side plates 614. And a cover positioning rib 614b, which are integrally formed of synthetic resin. On the inner surfaces of the both side plates 614, there are projected cover mounting projections 614a having a cross rib shape engaging with the cover mounting holes 41d of the back support rod 4. The back plate closing portion 612 is integrally provided at the rear end of the cover body 611. The back plate closing portion 612 includes a horizontally long lid plate 615 with a central front edge continuing to the bottom plate 613 of the cover body 611, and left and right front plates 616 rising from the front edge of both ends of the lid plate 615. The cover body 611 and the synthetic resin are integrally formed. The lid plate 615 has a shape corresponding to the opening shape of the accommodating portion 57 that opens to the lower end of the backrest 5, and has both end mounting bosses 615 a that are paired on both ends and left and right on the middle portion. A pair of intermediate mounting bosses 615b is provided. The both-end mounting boss 615a and the intermediate mounting boss 615b are shaped so that a screw (not shown) can be inserted upward from the lower surface side, and the screw inserted into the both-end mounting boss 615a is the back undercover. 56, and a screw inserted into the intermediate mounting boss 615b is screwed into a lower back support cover mounting nut portion 541g provided in the back shell 54. It has become so. In such a mounted state, the housing portion 57 is closed by the cover plate 615 of the back plate closing portion 612. The left and right front plates 616 are continuous with the rear end of the side plate 614 of the cover main body 611 and are positioned so as to overlap the front wall 562 of the back undercover 56 with a gap in the mounted state. That is, the front portion of the lower end opening edge 531 a to which the both side hooking members 533 of the spine skin material 53 are attached is hidden by these front plates 616. In addition, the rear side of the lower end opening edge portion 531 a in the spine skin material 53 is accommodated and held in the accommodation portion 57 while being restrained by the rear edge of the back plate closing portion 612.

  As shown in FIGS. 3 to 6, the first upper back support cover 62 covers a portion corresponding to the mounting surface 44 d of the back support 4 and is attached to the mounting surface 44 d. The mounting arm portion 552 of the backrest 5 and the head portion 556 a of the bolt 556 that fixes the mounting arm portion 552 to the back support rod 4 are hidden by the upper back support cover 62. In other words, the mounting arm portion 552 and the head 556a of the bolt 556 can be exposed only by removing the upper back support rod cover 62, and the backrest 5 can be removed from the back support rod 4. It becomes possible. The first upper back support rod cover 62 has a flat downward channel shape, has a flange portion 621 that rises upward at the rear end, and has an attachment claw 622 whose lower end bends forward on the lower surface of the front end portion. The mounting claw 622 is engaged with the square hole 553b provided in the mounting arm portion 552, and the rear end side is pushed down to be in the mounted state. In the mounted state, the central hooking member 532 of the lower end opening edge portion 531 a of the spine skin material 53 is hidden by the flange portion 621 of the first upper back support rod cover 62.

  As shown in FIGS. 3 to 6, the second upper back support rod cover 63 covers an exposed portion other than the mounting surface 44 d of the back support rod 4. Are independent.

  Note that a window 617 through which the operation lever 74 of the lumbar support device 7 is inserted is formed in the back plate closing portion 612 of the lower back support cover 61 in the cover assembly 6 described above.

<Lumbar support device>
As shown in FIGS. 2 to 6 and FIGS. 14 to 19, the lumbar support device 7 includes a lumbar support airbag 71 disposed between the back shell 54 and the cushion 52 of the backrest 5. And the air supply mechanism 72 connected to the airbag 71 via an air tube 76 for supplying or discharging air to the airbag 71.

  As shown in FIGS. 3 to 5 and 18, the air bag 71 is a normal one that inflates and contracts when supplied with air, and a front surface of the back shell 54 through a flexible deformable bag body 77. 54e. The bag body 77 is open at least at one end in the left-right direction. By screwing screws 78 penetrating the left and right side portions of the upper end portion into the nut portion 541a for attaching the bag body of the back shell 54. Are attached to the front surface 54e of the back shell 54. The airbag 71 is accommodated in the bag body 77. That is, a deformable bag body 77 is attached to the projecting end surfaces 542 a, 543 a, and 544 a of the vertical rib 542, the horizontal rib 543, and the oblique rib 544 in the vicinity of the waist portion 54 c of the back shell 54. Further, the airbag 71 is held inflatable.

  As shown in FIGS. 2, 6, and 14 to 19, the air supply mechanism 72 includes a pump unit 73 that supplies air to the airbag 71, and an operation lever 74 that drives the pump unit 73. The pump unit 73 forming the main part of the air supply mechanism 72 is accommodated in the accommodating portion 57 formed in the lower portion of the backrest 5. In other words, the air supply mechanism 72 is attached to the operation lever 74 that can be operated on both sides of the reference position S2 and the operation lever 74 that is operated to one side, that is, the upper side with respect to the reference position S2. The pump 731 that is energized to supply air to the airbag 71 and the operation lever 74 that is operated to the other side, that is, the lower side with respect to the reference position S2, are energized to release the air in the airbag 71 to the outside. A release valve 732 that discharges to the rear side, and reverse operation suppression means 733 that prevents or suppresses the operation lever 74 from operating beyond the reference position S2 due to the reverse driving force from the pump 731. It has.

  As shown in FIGS. 16, 18, and 19, the pump unit 73 includes a lever support member 79 that supports the operation lever 74 so as to be rotatable in the vertical direction, the pump 731, the release valve 732, The reverse operation inhibiting means 733 is assembled into a unit, and the operation lever 74 is accommodated in the accommodating portion 57 so as to protrude outward from the lower end of the backrest 5. The lever support member 79 is a metal member that includes a top plate 791 that is screwed to the ceiling portion of the housing portion 57 and a lever mounting arm 792 that is suspended downward from both front and rear edges of the top plate 791. The base end portion 74a of the operation lever 74 is supported by the lever mounting arm 792 so as to be rotatable about a shaft. The pump 731 is a rubber balloon type having an air inlet 731a having an inflow check valve and a discharge port 731b having a discharge check valve. Then, when the internal air is discharged from the discharge port 731b and the pressing force is extinguished, the air is taken in from the air inflow port 731a and returns to its original shape. The release valve 732 is directly connected to the discharge port 731b of the pump 731. When the operation button 732a is not pressed, the discharge port 731b communicates with the airbag 71 through the air tube 76. The air in the airbag 71 is released into the atmosphere only while the operation button 732a is pressed. Since the pump 731 and the release valve 732 are ordinary ones, a detailed description of the structure is omitted. The reverse operation inhibiting means 733 includes a spring 733a that elastically biases the lever main body 74b in the reference position S2 direction in a region where the lever main body 74b of the operation lever 74 rotates from the reference position S2 to the other side. Is.

  As shown in FIGS. 1, 2, 4 to 6 and 14 to 19, the operation lever 74 includes the lever main body 74 b rotatably supported by the lever support member 79, and the lever main body. A pump pressing portion 74c for biasing the pump 731 when the lever main body 74b is rotated from the reference position S2 to one side; and the lever main body 74b is moved from the reference position S2 to the other side. In this embodiment, the pump pressing portion 74c and the valve pressing portion 74d are integrated with the lever main body 74b. The valve pressing portion 74d biases the release valve 732 when rotated. Is provided. The operation lever 74 is disposed with its distal end facing obliquely downward and outward. The pump 731 is lifted from the reference position S2 by pulling the distal operation portion 74f of the operation lever 74 upward. When the operation lever 74 is pushed down from the reference position S2, the operation button 732a of the release valve 732 is pressed and urged by the valve pressing portion 74d. The operation lever 74 is configured such that the base end portion 74e of the lever main body 74b, the pump pressing portion 74c, and the valve pressing portion 74d are accommodated in the accommodating portion 57. The distal end side of the lever main body 74 constituting the portion 74f is extended to the outside through a window 617 provided in the back plate closing portion 612 of the lower back support cover 61.

  Air discharged from the pump 731 of the pump unit 73 via the release valve 732 is guided to the airbag 71 via the air tube 76. The air tube 76 extends from the pump unit 73 housed on one side of the housing portion 57, passes between the back support rod 4 and the lower back support rod cover 61 and passes through the other side of the housing portion 57. To the back surface 77a side of the bag body 77 through the front surface 54e of the back shell 54 and connected to an unillustrated air outlet inlet of the airbag 71 exposed on the back surface 77a side. Has been.

  Hereinafter, in particular, the cover assembly 6 and the accommodating portion 57 will be described in detail.

  The lower back support cover 61 accommodates the end of the back skin material 53 in a housing portion 57 that opens downwardly at the lower end 54a of the back shell 54 and hides the housing portion 57. In other words, the lower back support cover 61 covers the lower ends of the back support cover 4 and the back plate 51 from below, the cover body 611 covering the lower side of the back support cover 4, A back plate closing portion 612 that is provided integrally with the cover body 611 and closes the receiving portion 57 of the back plate 51 to hold the lower end opening edge portion 531a of the back skin material 53 in the receiving portion 57. It is. The cover main body 611 that covers the lower side of the back support rod 4 and the back plate closing portion 612 that covers the lower side of the housing portion 57 are integrally formed of synthetic resin. The back plate closing portion 612 has a U-shaped side sectional view that opens upward, and includes the lid 615, the front plate 616 erected from the front edge of the lid 615, and the lid 615. And a rear plate standing up from the rear edge. The rear plate is covered from the outside by the back shell 54 with the lower back support cover 61 attached to the back plate 51. The width dimension of the cover body 611 corresponds to the width dimension of the back support rod 4, and the width dimension of the back plate closing portion 612 matches the opening width in the left-right direction of the housing portion 57. is there.

  The accommodation portion 57 covered by the lower back support rod cover 61 is an accommodation space formed between the lower end portion of the back plate 51 and the lower back support rod cover 61, and the bag-like back skin material. The lower end opening edge portion 531 a of 53, more specifically, the end portion of the back skin material 53 including the central hook member 532, the both side hook members 533, and the hook wire 534 is accommodated. More specifically, the lower end opening edge 531a of the back skin material 53 is a claw provided in the housing portion 57, specifically, a downward claw 565a of the back under cover 56 or an upward claw of the back shell 54. 54f and the upper claw 551d of the back joint 55 are locked, and the lower back support cover 61 is attached and concealed from the lower side thereof. In other words, the back surface 551 b of the joint body 551 is continuous with the back surface 54 d of the back shell 54, and the back surface 551 b of the joint body 551 and the back surface of the back shell 54 are also at the lower end of the backrest 5. The lower end opening edge portion 531a of the spine skin material 53 is connected to the outer surface 54d from the lower end portion 54a of the back shell 54 so as not to jump out of the lower end portion 54a of the back shell 54. Is accommodated in the upper portion, that is, in the accommodating portion 57.

  In addition, a pump unit 73 that is an operation part of the lumbar support device 7 is attached in the housing part 57. The pump unit 73 and the lever support member 79 for attaching the pump unit 73 are concealed from the outside by the lower back support rod cover 61, and the operation lever 74 attached to the lever support member 79 is The back support rod cover 61 protrudes from the window 617 so as to be operable.

  The first upper back support cover 62 covers the portion of the back support 4 corresponding to the mounting surface 44d, and the second upper back support cover 63 covers the back support 4 The exposed portion other than the mounting surface 44d is covered. That is, the cover that covers the upper side of the back support rod 4 has a front and rear divided structure, and the first upper back support cover 62 is located behind the seat 3 and the second upper back support rod The cover 63 is located below the seat 3.

  As described above, the chair C according to the present embodiment includes the back support rod 4, the back plate 51 supported by the back support rod 4, and the bag shape attached to the outside of the back plate 51. A spine cover material 53 and a lower spine support cover 61 that covers the spine support 4 from below are provided, and the back plate 51 is opened downward at a lower end thereof and at least the spine cover is provided. The lower back support rod cover 61 has a cover main body 611 that covers the lower side of the back support rod 4 and a cover main body 611 that has a lower end opening edge portion 531 a of the material 53. A back plate closing portion 612 that is integrally provided and closes the receiving portion 57 of the back plate 51 and holds the lower end opening edge portion 531a of the skin material 53 in the receiving portion 57 is provided. Therefore, the end portion of the upholstery 535, 536 disposed in the housing portion 57 and other operations can be performed only by covering the housing portion 57, which is the lower recess of the back plate 51, with the lower back support rod cover 61. Parts related to the chair C such as a mechanism can be easily hidden. In other words, by attaching only the lower back support cover 61 from the lower side to the back support 4 and the back plate 51, the lower end opening edge 531a of the back skin material 53 and the pump unit of the lumbar support device 7 are provided. It is possible to conceal the accommodating portion 57 which is an accommodating space for accommodating 73, and the assembly work of the back plate 51 supported by the back support rod 4 and the lower back support cover 61 covering the back support rod 5 is simplified. Can be done. Therefore, it is possible to facilitate the attaching process of the end portions of the upholstery 535 and 536 of the back skin material 53, to improve the appearance as the chair C, and to prevent the seated person from touching. Can be prevented from being exposed to the outside.

  In particular, the lower back support cover 61 of this embodiment is detachably attached to the back support 4, the back shell 54 and the back under cover 56 of the back plate 51. When maintenance is required, only the lower back support cover 61 needs to be removed. That is, the mechanism necessary for the maintenance can be exposed by simply removing the minimum cover.

  Further, the back support rod 4 has an upward mounting surface 44d at the tip end portion 4a, and the back plate 51 has a mounting arm portion 552 extending forward at the lower end, and the mounting arm portion 552. Is attached to the mounting surface 44d of the back support rod 4 from above with a bolt 556, so that the mounting arm portion 552 is attached to the back support rod 4 so as to open downward at the lower end. The back plate 51 having 57 can be attached to the back support rod 4.

  Further, since the back plate 51 includes a back shell 54 and a back joint 55 attached to the back shell 54 and having the mounting arm portion 552 at the lower end, the backrest including the back joint 55 is included. 5 can be attached to and detached from the back support rod 4 relatively easily.

  Further, the chair C of the present embodiment is provided with first and second upper back support covers 62 and 63 that cover the back support rod 4 from above and can be attached and detached independently of each other. The first upper back support cover 62 covers a portion corresponding to the mounting surface 44d of the back support rod 4, and the second upper back support cover 63 is attached to the mounting surface of the back support rod 4. Since the cover covers the exposed portion other than 44d, when the back plate 51 needs to be removed, the mechanism necessary for the removal can be exposed only by removing the first upper back support cover 62. it can. More specifically, when the first upper back support cover 62 is removed when the back plate 51 is removed from the back support rod 4, the back joint 55 attached to the attachment surface 44d of the attachment plate 44 of the back support rod 4 is removed. The mounting arm portion 552 can be accessed, and the head portion 556a of the bolt 556 that connects the back joint 55 and the back support rod 4 is exposed to the outside. In this state, if the screwed state of the bolt 556 screwed from the upper surface 553c side of the mounting wall 553 is released, the back joint 55 can be removed from the back support rod 4, and the back plate 51 can be removed. 4 can be removed. In this way, the back plate 51 can be removed with only a minimal cover removal. If the lower back support cover 61 is removed, the mechanism around the backrest 5 such as the gas spring for adjusting the backrest angle can be adjusted.

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

  The back plate is not limited to the back shell of the above-described embodiment. For example, a rib that protrudes to the back side of the shell body may be provided on the back side.

  Further, the accommodating portion may be any one as long as it is opened downward and accommodates at least the lower end opening edge of the skin material. About the shape accommodated therein, the shape of the accommodating portion, etc. Can be variously changed. That is, the accommodating part may not accommodate the pump unit shown in the above embodiment, and may accommodate other than the pump unit described above.

  Further, the skin material is not limited to the above-described material and can be variously changed. For example, the skin material is not limited to one composed of a plurality of stretch fabrics, and may be composed of a single stretch fabric. In addition to the above-described structure of the lower end opening edge of the skin material body, for example, the lower end opening edge includes a bag-like portion into which a string can be inserted, and the string inserted into the bag-like portion. It is also possible to squeeze under the back plate. In this case, a lower back support cover may be attached from the lower side of the lower end opening edge of the skin material body squeezed with the string so as to hide the lower end opening edge. Moreover, the lower end opening edge part of the skin material main body may be provided with a resin plate, and the resin plate may be fitted into a groove provided on the lower side of the back plate. As an example, the skin material is attached to the front side mounting member that is sewn on both sides of the front side of the lower end opening edge of the skin material body, and the rear side that is sewn to the rear side of the lower end opening edge. It is conceivable that the front-side mounting member and the rear-side mounting member are each made of a synthetic resin thin plate. The back shell, the back joint, and the back under cover are provided with a groove that opens downward corresponding to the thickness of the attachment member and the skin material body, and the attachment member is formed on the skin material body. What is necessary is just to make it attach to the said groove | channel in the state wound in with the lower end part. In addition, the said attachment member may be provided continuously over the front side both sides part of the lower end opening edge part, or the whole rear side, or may be provided intermittently.

  The upper back support cover may not be divided into a plurality of sheets. That is, a front cover portion that covers a portion corresponding to the mounting surface of the back support rod and a rear cover portion that covers an exposed portion other than the mounting surface of the back support rod are integrally formed, and this upper back support cover If it is removed from the back support rod, the mounting surface of the back support rod and the front portion of the mounting surface may be exposed. As such an upper back support cover, for example, as shown in FIG. 20, a single upper back support cover X64 that covers the back support cover 4 from above and can be attached to and detached from the back support cover 4 is provided. The upper back support cover X64 covers a portion corresponding to the mounting surface 44d of the back support 4 and an exposed portion other than the mounting surface 44d of the back support 4 And a front cover portion X63 that covers the surface. The rear cover part X62 and the front cover part X63 are connected by a resin hinge X65 so that the rear cover part X62 can be rotated with respect to the front cover part X63. In such a case, when it is desired to expose the mounting surface 44d of the back support rod 4, the rear cover portion X62 is lifted by lifting the rear end X623 of the rear cover portion X62 of the upper back support cover X64 upward. After rotating the rear cover portion X62, the front cover portion X63 is moved rearward by sliding the cover portion X62 while sliding the rear cover portion X62, and the upper back support rod cover X64 is removed from the back support rod 4. do it. If it does in this way, the front cover part X63 distribute | arranged to the part which is comparatively hard to access below a seat can be easily removed from the back support rod 4. FIG. Even when the upper back support cover is divided into a plurality of pieces, the first upper back support cover and the second upper back support cover are integrally connected using a hinge. What is necessary is just to comprise.

  Moreover, the lower back support cover may not be provided with a window for preventing interference with the operation lever as in the above-described embodiment.

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

C ... Chair 4 ... Back support 4a ... Tip 44d ... Mounting surface 51 ... Back plate 53 ... Skin material 531a ... Bottom opening edge 55 ... Back joint 552 ... Mounting arm 556 ... Bolt 57 ... Housing 61 ... Lower back Support cover 611 ... Cover main body 612 ... Back plate closing part 62 ... First upper back support cover 63 ... Second upper back support cover

Claims (4)

A back support, a back plate supported by the back support, a bag-like skin material that is attached to the outside of the back plate, and a lower back support cover that covers the back support from below A chair comprising:
The back plate has an accommodating portion that opens downward at its lower end and accommodates at least the lower end opening edge of the skin material,
The lower back support cover includes a cover main body that covers the lower side of the back support support, and a cover body that is provided integrally with the cover main body and closes the housing portion of the back plate to store the lower end opening edge of the skin material. A chair comprising: a back plate closing portion held in the portion. The back support rod has an upward mounting surface at the tip,
The said back board has the attachment arm part extended to the front at a lower end, The attachment arm part was attached with the volt | bolt with which it attached from the upper side to the said attachment surface of the said back support rod. Chair.   The chair according to claim 2, wherein the back plate includes a back shell and a back joint attached to the back shell and having the attachment arm portion at a lower end. Covering the back support rod from above and providing first and second upper back support covers that can be attached and detached independently of each other;
The first upper back support cover covers a portion corresponding to the mounting surface of the back support rod, and the second upper back support cover is an exposed portion other than the mounting surface of the back support rod. The chair according to claim 2 or 3, wherein the chair is covered.

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