JP2012090791A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair comfortable to sit while maintaining the strength of a connection frame.SOLUTION: The rear ends of both side frames are inclined to be extended upward while gradually increasing the horizontal distance rearward, the connection frame has a trapezoidal flat surface portion in which the horizontal length of the rear edge is larger than that of the front edge, and the horizontal end edges of the connection frame are connected to the rear ends of the both side frames.

Description

  The present invention relates to a chair suitably used for school or office use.

  Conventionally, in this type of chair, a seat plate is mounted on a frame comprising left and right side frames, a rear connection frame that connects these side frames on the rear side, and a connection frame that connects the side frame on the front side. Various arrangements are considered (for example, see Patent Document 1).

  In such a chair, the front and rear connecting frames each having a rectangular shape in plan view are attached to the left and right side frames with a constant distance between the left and right by a method such as welding.

  By the way, it can be considered that these front and rear connecting frames reduce the contact area with the seat plate in order to reduce the feeling of bottoming of the seated person. However, if the front and rear dimensions of the connecting frame are reduced to reduce the contact area with the seat plate, the joint portion between the connecting frame and the side frame is reduced accordingly, and it becomes difficult to maintain the strength of the connecting frame.

  Such a problem is likely to occur particularly in the rear portion of the seat plate that is easily loaded.

JP-A-8-24081

  The present invention has been made paying attention to the above situation, and an object thereof is to provide a chair that is comfortable to sit while maintaining the strength of a connecting frame.

  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 seat plate disposed on the left and right seat receiving side frames and the rear seat receiving connecting frame that connects the rear ends of these side frames, The end portion is inclined so as to extend upward while gradually increasing the distance between the left and right toward the rear, and the connecting frame has a lateral length of the rear edge larger than a lateral length of the front edge. It has such a trapezoidal plane portion, and the left and right edges of the connecting frame are joined to the rear ends of the both side frames.

  If this is the case, the two sides of the trapezoidal connecting frame other than the parallel upper and lower bases are joined along the side frame in which the distance between the left and right is gradually increased toward the rear. Can do. Therefore, the joining portion can be made larger than the front-rear width of the connection frame without enlarging the front-rear dimension of the connection frame. Therefore, a comfortable chair can be provided while maintaining the strength of the connecting frame.

  As a preferable aspect of the connecting frame, one in which the left and right end edges of the flat portion are joined to the inclined rear end portions of the both side frames by welding is mentioned.

  The seat plate preferably has a shape in which a rear end portion corresponding to the connection frame is warped upward.

  If the seat plate is fastened and fixed to the connection frame with screws that penetrate the connection frame from the rear side, the mounting operation can be performed relatively easily.

  As a preferred aspect in the case where the seat receiving side frame is provided with an inclined portion formed so that the distance between the left and right gradually changes from the front end side to the rear end side, the seat plate may include the seat plate. A protrusion disposed along the inclined portion of the receiving side frame, and in a direction in which the protruding portion comes into close contact with the inclined portion of the seat receiving side frame by the tightening force of the screw; One configured to be energized.

  As a preferable aspect in the case where the connecting frame is a flat plate having only a flat portion, a plurality of support protrusions formed on the lower surface of the seat plate with a space in the left-right direction on the flat connecting frame. And a positioning projection that extends to the left and right along the edge of the connecting frame and positions the connecting frame in the front-rear direction.

  Since the present invention is configured as described above, it is possible to provide a comfortable chair while maintaining the strength of the connecting frame.

The whole perspective view of the chair which shows one embodiment of the present invention. The front view of the chair which shows the embodiment. The rear view of the chair which shows the embodiment. The right view of the chair which shows the same embodiment. The top view of the chair which shows the same embodiment. The bottom view of the chair which shows the embodiment. The disassembled perspective view of the chair which shows the same embodiment. The bottom view which shows the state which has not attached the protection sheet receiver in the seat plate of the embodiment. The center side sectional view of the embodiment. Sectional drawing which expands and shows the principal part of the embodiment. Sectional drawing which expands and shows the principal part of the embodiment. Sectional drawing which expands and shows the principal part of the embodiment. Explanatory drawing which decomposes | disassembles and shows the principal part of the embodiment. The sectional side view which expands and shows the attaching part of the backplate of the embodiment. Explanatory drawing which shows the stacking state using the chair of the embodiment. Explanatory drawing which shows the stacking state using the chair of the embodiment in a cross section.

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

  In this embodiment, the present invention is applied to a chair 1 that can be stacked in the vertical direction. The chair 1 is a chair body 2 that supports a seat plate 3 and a back plate 4.

  As shown in FIGS. 1 to 7 and 9 to 14, the chair body 2 includes left and right bases 21 that are placed on the floor via the grounding body 211, and extends upward from the front ends of the bases 21. Left and right front legs 22 that protrude, left and right rear legs 23 that extend upward from the rear end of each base 21, and left and right side frames 25 that connect an intermediate portion of the rear leg 23 and the upper end of the front leg 22 The front connection frame 26 erected between the front end vicinity portions of the side frames 25, the rear connection frame 24 erected between the rear legs 23 via the side frame 25, and the vicinity of the upper ends of the left and right front legs 22. And a front frame 27 installed between the sections. The side frame 25, the front connection frame 26, and the rear connection frame 24 are for arranging the seat plate 3 thereon, and constitute a seat receiving frame of the present invention. The seat receiving frame is disposed along the front, rear, left and right edges of the seat plate 3 and forms a closed quadrangular shape. The base 21, the front leg 22, the rear leg 23, and the side frame 25 are integrally formed by bending a common metal wire or a round pipe, and receive a load acting on the seat plate 3 and the back plate 4. It has the strength possible. The seat plate 3 is supported by the front connection frame 26 and the rear connection frame 24.

  As shown in FIGS. 6, 7, 9, and 10, the front connecting frame 26 is a flat plate that does not have a bent portion at the edge, and the left and right end edges 261 are welded to the both side frames 25. Are joined together. The front connection frame 26 has a trapezoidal flat portion 262 in which the length of the front edge 265 in the left-right direction is larger than the length of the rear edge 266 in the left-right direction. The left and right end edges 261 are joined to the front end portions 251 of the both side frames 25. In this embodiment, the front connecting frame 26 does not have any bent portions at the front edge 265 and the rear edge 266, and is composed only of the flat surface portion 262. Screw holes 263 for inserting screws 53 serving as fixtures are provided in the left and right end portions 264 of the front connecting frame 26, and only the left and right end portions 264 are fixed to the seat plate 3. The flat front connection frame 26 is made of metal having a thickness dimension that can be elastically deformed in the thickness direction by receiving a load applied to the seat plate 3.

  As shown in FIGS. 3, 6, 7, 8, and 11, the rear connecting frame 24 is a flat plate that does not have a bent portion at the edge, and the left and right end edges 241 are connected to the both side frames. 25 is welded. The rear connecting frame 24 has a trapezoidal flat surface portion 242 in which the horizontal length of the rear edge 246 is larger than the horizontal length of the front edge 245. Are joined to the rear end portions 252 of the both side frames 25. In this embodiment, the rear connecting frame 24 does not have any bent portions at the front edge 245 and the rear edge 246 and is configured only from the flat surface portion 242. Thereafter, screw holes 243 through which the screws 52 serving as fixtures are inserted are provided at both left and right ends 244 of the connection frame 24, and only the left and right ends 244 are fixed to the seat plate 3. This flat rear connection frame 24 is made of metal having a thickness dimension that can be elastically deformed in the thickness direction by receiving a load applied to the seat plate 3.

  As shown in FIGS. 2 to 4, 6, 7, and 9 to 14, the side frame 25 is formed such that the distance between the left and right sides gradually decreases from the front to the rear in plan view. And a steeply inclined portion 254 provided continuously with the rear end of the gently inclined portion 253 and formed so that the distance between the left and right gradually increases from the front to the rear. It looks like a letter. That is, in this embodiment, the rear end portion 252 of each side frame 25 forms a steeply inclined portion 254, and a portion other than the rear end portion 252 forms a gently inclined portion 253. Further, in a side view, the gently inclined portion 253 is gently inclined so as to gradually become lower toward the rear, and the steeply inclined portion 254 is inclined so as to become gradually higher toward the rear. The left and right end edges 261 of the front connecting frame 26 are joined to the inside of the front end portions 251 of the side frames 25 by welding over substantially the entire area. Further, the left and right end edges 241 of the rear connecting frame 24 are joined to the inside of the rear end portions 252 of the side frames 25 by welding over substantially the entire region. In other words, the rear connecting frame 24 connects between the rear end portions 252 of the left and right side frames 25 inclined rearward and upward. Therefore, the rear connecting frame 24 is connected to the rear end portion 252 of the side frame 25. It is inclined toward the back and upward along. And the screw hole 243 which stops the seat board 3 provided in the right-and-left both ends 244 of the rear connection frame 24 has faced diagonally front upper.

  The seat plate 3 is arranged on the chair body 2 formed as described above. The seat plate 3 is attached in a state where a gap 51 is formed between the lower surface and the upper surface of the side frame 25 to allow the seat plate 3 to bend downward.

  As shown in FIGS. 1 to 14, the seat plate 3 includes a seat plate main body 31, front and rear connecting frame engaging portions 32 and 33 provided on the lower surface of the seat plate main body 31, and the seat plate main body 31. Left and right side frame engaging portions 34 provided on the lower surface, left and right finger pinching preventing portions 35 provided on the lower surface of the front end portion of the seat plate body 31, and both left and right ends of the connecting frame engaging portions 32 and 33 The front end portion 38 has a shape that hangs downward, and the rear end portion 39 has a shape that warps upward. In this embodiment, the seat plate 3 is integrally formed of synthetic resin.

  As shown in FIGS. 1 to 14, the seat plate main body 31 includes a plurality of through holes 311 in an intermediate region. The through holes 311 are arranged in a straight line at the front edge portion of the seat plate main body 31 and are arranged so as to draw an arc at the rear edge portion, and the intermediate portion is gradually curved from the front toward the rear. Are arranged to draw an arc so that becomes large. The sizes of the through holes 311 are set so as to gradually increase from the front edge portion of the seat plate main body 31 toward the rear edge portion. Each through-hole 311 includes a cylindrical portion 316 provided in the upper half and a conical portion 317 provided in the lower half and expanding downward, and a boundary portion between the cylindrical portion 316 and the conical portion 317. A ridge line that is visible from the upper surface portion of the seat plate 3 is formed at 318.

  As shown in FIGS. 6 to 10, the front connection frame engaging portion 32 is for engaging the front connection frame 26 from below, and is spaced from the lower surface of the seat plate body 31 with a space in the left-right direction. The front-rear ribs 321 extending in the front-rear direction, the front-rear ribs 322 extending from the lower surface of the seat plate body 31 so as to connect the front edges of the front-rear ribs 321 and extending in the left-right direction, and the front-rear ribs 321 includes rear left and right ribs 323 projecting from the lower surface of the seat plate main body 31 so as to connect the rear edges of the 321 and extending in the left-right direction. That is, the front and rear ribs 321 and the front and rear left and right ribs 322 and 323 are integrated. The front and rear ribs 321 have their front ends abutted on the front connection frame 26, and are set to project dimensions that allow the front and rear ribs 321 to abut against the front connection frame 26 evenly. The front left and right ribs 322 extend along the front edge 265 of the front connection frame 26 and are dimensioned to protrude downward from the lower surface of the front connection frame 26. The rear left and right ribs 323 extend along the rear edge 266 of the front connection frame 26, and are dimensioned to protrude downward from the lower surface of the front connection frame 26. That is, the front connection frame 26 is covered from the front-rear direction.

  As shown in FIGS. 3, 6 to 9 and 11, the rear connecting frame engaging portion 33 is for engaging the rear connecting frame 24 from below, and is seated with a space in the left-right direction. Front and rear ribs 331 projecting from the lower surface of the plate body 31 and extending front and rear, and left and right ribs projecting from the lower surface of the seat plate body 31 so as to connect the front edges of the front and rear ribs 331 and extending in the left and right direction 332 and rear left and right ribs 333 projecting from the lower surface of the seat plate main body 31 so as to connect the rear edges of the front and rear ribs 331 and extending in the left and right directions. That is, the front and rear ribs 331 and the front and rear left and right ribs 332 and 333 are integrated. The front / rear ribs 331 have their tips abutted on the rear connection frame 24, and are set to project dimensions that allow the front / rear ribs 331 to uniformly contact the rear connection frame 24. The front left and right ribs 332 extend along the front edge 245 of the rear connection frame 24, and are set to dimensions that protrude downward from the lower surface of the rear connection frame 24. The rear left and right ribs 333 extend along the rear edge 246 of the rear connection frame 24, and are set to have a dimension that protrudes downward from the lower surface of the rear connection frame 24. That is, the rear connecting frame 24 is covered from the front-rear direction. The support protrusion of the present invention corresponds to the front and rear ribs 331 of the rear connecting frame engaging portion 33 of the present embodiment, and the positioning protrusion of the present invention is the rear connecting frame engaging portion 33 of the present embodiment. Corresponds to the front and rear left and right ribs 332 and 333.

  As shown in FIGS. 2 to 4, 6 to 9, and 11 to 14, the side frame engagement portion 34 is formed on the left and right ribs 341 that contact the upper surface of the side frame 25, and on the inner surface of the side frame 25. The front and rear ribs 342 extending along the front and rear ribs 342, and the protective sheet receiving attachment 301 provided intermittently along the inner surface of the front and rear ribs 342 are provided.

  The left and right ribs 341 are for forming a gap 51 between the side frame 25 and the seat plate main body 31, and a plurality of left and right ribs 341 are arranged at intervals in the front-rear direction. The plurality of left and right ribs 341 are set so that the amount of protrusion from the lower surface of the seat plate 3 gradually increases rearward. Specifically, the left and right ribs 341 are provided at three locations, the front and rear, and the middle portion, and the protruding amount of the left and right ribs 341 in the middle portion is larger than that of the front left and right ribs 341, The rear left and right ribs 341 are larger.

  The front and rear ribs 342 are arranged along the gently inclined portion 253 of the side frame 25, and are attached to the latter half of the gently inclined portion 253 via a protective sheet receiver 302 described later. The front and rear ribs 342 forming the left and right pairs are respectively formed continuously in the front and rear direction.

  The protective sheet receiver mounting portion 301 is for attaching a protective sheet receiver 302 having a protective sheet 303 attached to the lower surface thereof, and protrudes from the lower surface of the seat plate 3 and is provided integrally with the seat plate 3. The protective sheet receiver 302 is made of a resin that is separate from the seat plate 3, and is attached to the back surface of the seat plate 3 using screws 54 that are fixtures. More specifically, the protective sheet receiver 302 is a box-shaped member that is attached so as to cover the front and rear ribs 342 and the protective sheet receiver mounting portion 301 from the lower surface side, and corresponds to the protective sheet receiver mounting portion 301 on the bottom surface 304. A screw hole 305 is provided. The protective sheet receiver 302 is fixed to the seat plate 3 by screwing screws 54 inserted into the screw holes 305 of the protective sheet receiver 302 from the lower surface side into the protective sheet receiver mounting portion 301. The protective sheet receiver 302 is attached with a protective sheet 303 such as a foam sheet along a concave groove 306 formed on the bottom surface 304 side of the lower end portion, and the lower surface of the protective sheet 303 serves as a guide surface 307. These left and right guide surfaces 307 are formed so as to be inclined so that the distance between the left and right sides gradually decreases from the front end toward the rear, and the rear end portion 308 is warped up. As shown in FIGS. 15 and 16, these protective sheet receivers 302 are arranged at positions below the side frame 25 so as to extend in the front-rear direction along the seat receiving frame, and are the same during stacking to be described later. A guide surface 307 that can contact the upper surface of the seat plate S3 of the other chair S1 having the structure is formed. As shown in FIGS. 12 and 13, these protective sheet receivers 302 are provided with a cushioning layer 309 having a cushioning property. Specifically, the buffering layer 309 is provided on the bottom surface 304 of the protective sheet receiver 302. A protective sheet 303 to be formed is attached, and the lower surface of the protective sheet 303 is a guide surface 307. It should be noted that at least the guide surface 307 that is the tip of the protective sheet receiver 302 only needs to be located below the seat receiving frame, and the tip of the front and rear ribs 342 in this embodiment is below the side frame 25. It is not necessary to project, but even if the front and rear ends are removed, if the guide surface 307 projects downward from the side frame 25 in almost the entire length from the front part to the rear part, the effect becomes more certain. . Here, the protrusions of the present invention correspond to the front and rear ribs 342 of the left and right side frame engaging portions 34 of the present embodiment.

  As shown in FIGS. 8 and 10, the finger pinching prevention unit 35 is provided in a region where a gap 51 is formed between the lower surface of the seat plate body 31 and the upper surface of the side frame 25, and the elastic rib 351. And a reinforcing rib 352. The elastic rib 351 is integrally projected from the lower surface of the seat plate 3, and is configured to elastically contact the tip 356 with the outer surface of the side frame 25 inclined. Specifically, the elastic rib 351 is a plate-shaped member extending in the left-right direction, and its tip 356 is in contact with the upper surface of the front end 251 of the side frame 25 in an inclined state, and acts on the seat plate 3. It can be elastically deformed in the thickness direction by an overload. More specifically, the elastic rib 351 is in contact with the upper surface of the lower curved portion of the front end portion 251 of the side frame 25 and is elastically deformed in the direction in which the distal end 356 rotates forward and upward with respect to the base end by the seating load. The The reinforcing rib 352 is for restricting elastic deformation of the elastic rib 351. In this embodiment, the reinforcing rib 352 is provided integrally with the outer end 357 of the elastic rib 351. That is, the reinforcing rib 352 is provided at a position where the gap 51 is hidden, and the elastic rib 351 and the reinforcing rib 352 are formed to have an L shape in plan view. The reinforcing rib may be in contact with the side surface of the front end portion of the side frame, and may be elastically deformed in a direction in which the distal end rotates laterally upward with respect to the base end by a seating load.

  As shown in FIGS. 7, 8, and 10, the attachment portions 36 provided at the left and right ends of the front connection frame engaging portion 32 are used to firmly fix the front end portion 38 of the seat plate 3 to the front connection frame 26. A nut holding portion 361 having a tunnel shape integrally provided on the lower surface of the seat plate main body 31, and a plate nut 362 mounted in the nut holding portion 361. A through hole 363 is provided in a portion of the holding portion 361 corresponding to the female screw hole 366 of the plate nut 362. The seat plate 3 is fixed to the front connection frame 26 by screwing screws 53 inserted into the screw holes 263 of the front connection frame 26 from the lower surface side into the female screw holes 366 through the through holes 363. ing. The lower surfaces of the left and right nut holding portions 361 and the front end surfaces of the front and rear ribs 321 of the front connecting frame engaging portion 32 are set to have the same height position. That is, the upper surface of the flat front connection frame 26 is in contact with the lower surface of the nut holding portion 361 and the front end surfaces of the front and rear ribs 321.

  As shown in FIGS. 7, 8, and 11, the attachment portions 37 provided at the left and right ends of the rear connection frame engaging portion 33 tightly fix the rear end portion 39 of the seat plate 3 to the rear connection frame 24. A nut holding portion 371 having a tunnel shape integrally provided on the lower surface of the seat plate main body 31, and a plate nut 372 mounted in the nut holding portion 371. A through hole 373 is provided in a portion of the nut holding portion 371 corresponding to the female screw hole 376 of the plate nut 372. Then, the seat plate 3 is fixed to the rear connection frame 24 by screwing the screws 52 inserted through the screw holes 243 of the rear connection frame 24 from the rear side into the female screw holes 376 through the through holes 373. ing. The lower surfaces of the left and right nut holding portions 371 and the front end surfaces of the front and rear ribs 331 of the rear connecting frame engaging portion 33 are set to have the same height position. That is, the upper surface of the rear connecting frame 24 having a flat plate shape is in contact with the lower surface of the nut holding portion 371 and the front end surfaces of the front and rear ribs 331. In the present embodiment, the rear connection frame 24 and the rear end of the seat plate 3 are inclined so as to gradually increase rearward, so that the seat plate 3 is moved rearward by tightening the screws 52. The front and rear ribs 342 are set so as to be in close contact with the gently inclined portion 253 of the side frame 25 via the protective sheet receiver 302.

  As shown in FIGS. 1 to 7, 9 and 14, the back plate 4 includes a back plate main body 41 and mounting portions 42 which are integrally provided on the left and right sides of the back plate main body 41. The mounting portion 42 extends below the lower edge 411 of the back plate main body 41. The back plate 4 is supported by the chair body 2 by fitting a mounting hole 421 formed in the mounting portion 42 and opening downward to the upper end 231 of the rear leg 23. The rear leg 23 is inserted and fixed in the mounting hole 421 until the upper end 231 reaches a position substantially the same as the lower edge 411 at the center of the back plate main body 41. The back plate main body 41 is curved so that the central portion bulges rearward, and has an opening 412 on the upper side of the central portion. The opening 412 has a long hole shape extending in the left-right direction, and a flange portion 413 that bulges rearward is formed at the peripheral edge portion of the opening 412 on the back plate 4 back side.

  In the chair 1 described above, the space between the rear legs 23 is opened downward and rearward below the rear connection frame 24. Therefore, as shown in FIG. 15 and FIG. 16, other chairs S1 having the same structure are provided. Stack on top of each other. In the chair 1 stacked on the other chair S1, the lower surface of the grounding body 211 attached to the base 21 abuts on the base S21 of the other chair S1, and as shown in FIG. The plates 3 and S3 do not hit each other. More specifically, a gap is formed between the guide surface 307 and the upper surface of the seat plate S3 of the other chair S1 so that the guide surface 307 does not hit the seat plate S3 in a stacked state. In FIGS. 15 and 16, the components corresponding to the chair 1 of the present embodiment are denoted by the same reference numerals with “S” at the head, and detailed description thereof is omitted. Yes.

  As described above, the chair 1 according to the present embodiment has the seat plate 3 arranged on the left and right side frames 25 and the rear connection frame 24 that connects the rear end portions 252 of the side frames 25. The rear end portions 252 of the both side frames 25 are inclined so as to extend upward while gradually increasing the distance between the left and right sides, and the rear connecting frame 24 has a length in the left-right direction of the rear edge 246. It has a trapezoidal flat surface portion 242 whose length is larger than the length of the front edge 245 in the left-right direction. That is, the plane portion 242 of the rear connection frame 24 has a trapezoidal shape in plan view in which the lengths of the front edge 245 and the rear edge 246 are different and the left and right end edges 241 are inclined with respect to the front edge 245 and the rear edge 246. Since the left and right end edges 241 of the rear connecting frame 24 are joined to the rear end portions 252 of the both side frames 25, the trapezoidal rear connecting frame 24 other than the parallel front edge 245 and rear edge 246 The left and right sides can be joined along the side frame 25 in which the distance between the left and right is gradually increased toward the rear. Therefore, the joining portion can be made larger than the front-rear width of the rear connection frame 24 without greatly increasing the front-rear dimension of the rear connection frame 24. Therefore, it is possible to provide the chair 1 that is comfortable to sit while maintaining the strength of the rear connecting frame 24 that is likely to be subjected to a seating load. In particular, the rear connection frame 24 of the present embodiment has a trapezoidal shape that is symmetrical to the left and right, and the inclination of the left and right end edges 241 in the front-rear direction is the same as the inclination of the rear end 252 of the side frame 25 in the front-rear direction. Therefore, the rear connecting frame 24 and the side frame 25 can be welded without a gap.

  In the present embodiment, the effect similar to that of the rear connection frame 24 can be obtained for the front connection frame 26. That is, the seat plate 3 is arranged on the left and right side frames 25 and the front connection frame 26 that connects the front end portions 251 of these side frames 25, and the front end portions 251 of the both side frames 25 face rearward. The front connecting frame 26 is inclined so as to gradually reduce the distance between the left and right sides, and the front connecting frame 26 has a trapezoidal plane portion in which the length of the rear edge 266 in the left-right direction is smaller than the length of the front edge 265 in the left-right direction. 24, and the left and right end edges 261 of the front connecting frame 26 are joined to the front end portions 251 of the both side frames 25, so that the parallel front edges 265 of the trapezoidal front connecting frame 26 and The left and right sides other than the rear edge 266 can be joined along the side frame 25 in which the distance between the left and right is gradually reduced toward the rear. Therefore, the joining portion can be made larger than the front-rear width of the front connection frame 26 without enlarging the front-rear dimension of the front connection frame 26 so much. Therefore, it is possible to provide the chair 1 that is comfortable to sit while maintaining the strength of the front connection frame 26.

  Since the rear connecting frame 24 is formed by welding the left and right end edges 241 of the flat surface portion 242 to the inclined rear end portions 252 of the both side frames 25, the rear connecting frame 24 and the side frame 25 are connected in the front-rear direction. In addition, the welding can be performed obliquely with respect to the horizontal direction, and the length of the welding joint can be increased as compared with the conventional one. Therefore, the rear connection frame 24 can be strongly attached to the side frame 25. In particular, in the present embodiment, since the left and right end edges 241 of the rear connecting frame 24 are welded to the side frame 25 over the entire area, the bonding strength can be further increased.

  Since the seat plate 3 has a shape in which the rear end portion 39 corresponding to the rear connection frame 24 is warped upward, the seat plate 3 is formed on the rear end portion 252 of the side frame 25 inclined so as to extend upward rearward. Can be along.

  Further, since the rear connection frame 24 connects the rear end portions 252 of the left and right side frames 25 inclined rearward and upward, the rear connection frame 24 extends along the rear end portion 252 of the side frame 25. It is inclined toward the rear upper part. That is, the flat portion 242 of the rear connection frame 24 is attached to be inclined with respect to the horizontal. And the screw hole 243 which stops the seat board 3 provided in the right-and-left both ends 244 of the rear connection frame 24 has faced diagonally front upper. For this reason, the seat plate 3 is fastened and fixed to the rear connection frame 24 by screws 52 penetrating the rear connection frame 24 from the rear side, so that the work can be performed from the back side of the chair 1 during assembly, and the screws 52 are tightened. Work can be done easily.

  The side frame 25 includes a gently inclined portion 253 and a steeply inclined portion 254 that are formed so that the distance between the left and right gradually changes from the front to the rear. The front and rear ribs 342 that are protrusions arranged along the gently inclined portion 253 and the steeply inclined portion 254 are provided. By the tightening force of the screws 52, the front and rear ribs 342 are connected to the side frame 25 by the tightening force of the screws 52. Is formed between the seat plate 3 and the side frame 25 in a state in which the screw 52 is attached to the attachment portion 37. Shaking can be suppressed. That is, in this embodiment, the side frames 25 are pulled in the direction in which the side frames 25 are in close contact with the front and rear ribs 342 by tightening the screws 52 attached to the left and right attachment portions 37 located at the rear end portion 39 of the seat plate 3. It becomes.

  The rear connection frame 24 has a flat plate shape composed only of the flat surface portion 242, and a plurality of support protrusions formed on the lower surface of the seat plate 3 on the flat plate rear connection frame 24 at intervals in the left-right direction. The front and rear ribs 331 are in contact with the front and rear ribs 331 and 333 and 333, which are left and right along the front and rear edges 245 and 246 of the rear connecting frame 24 and serve as positioning protrusions for positioning the rear connecting frame 24 front and rear. Therefore, by aligning the left and right ribs 332 and 333 with the front and rear end edges 245 and 246 of the rear connecting frame 24, the seat plate 3 can be easily positioned during the assembly operation. In addition, after the assembly, even when the load is applied to the seat plate 3 and the center portion of the seat plate 3 is bent downward, the rear connection frame 24 is shifted in the front-rear direction beyond the left and right ribs 332 and 333. There is no fear and the seat plate 3 can be stably supported. Further, since the left and right ribs 332 and 333 are formed integrally with the front and rear ribs 331, the left and right ribs 332 and 333 and the front and rear ribs 331 are in a mutually reinforcing relationship. Therefore, the strength of the relatively long left and right ribs 332 and 333 can be increased. Even when a load is applied to the seat plate 3 and the center portion of the seat plate 3 is bent downward, the front ends of the front left and right ribs 332 and the front ends of the rear left and right ribs 333 are opened in a direction away from each other. Can be suppressed. In addition, although the left and right ribs 332 and 333 and the front and rear ribs 331 are relatively thin plate-shaped, they are connected at right angles, so the left and right ribs 332 and 333 and the front and rear ribs 331 are A certain level of strength can be obtained.

  In the present embodiment, the effect similar to that of the rear connection frame 24 can be obtained for the front connection frame 26. That is, the front connection frame 26 is a flat plate having only the flat portion 262, and a plurality of supports formed on the lower surface of the seat plate 3 on the flat front connection frame 26 with a space in the left-right direction. The front and rear ribs 321 that are protrusions are in contact with the front and rear ribs 321 that extend left and right along the front and rear edges 265 and 266 of the front connection frame 26 to position the front connection frame 26 in the front and rear direction. 323, the left and right ribs 322 and 323 are combined with the front and rear end edges 265 and 266 of the front connection frame 26, whereby the seat plate 3 can be easily positioned during assembly work. Further, after the assembly, even when the seat plate 3 is loaded and the center portion of the seat plate 3 is bent downward, the front connection frame 26 is shifted in the front-rear direction beyond the left and right ribs 322 and 323. There is no fear and the seat plate 3 can be stably supported.

  In particular, in this embodiment, the amount of protrusion of the left and right ribs 322, 323, 332, 333 from the seat plate 3 is larger than the amount of protrusion of the front and rear ribs 321, 331 from the seat plate 3, so The front and rear end edges 245, 246, 265, 266 of the front connection frame 26 or the rear connection frame 24 whose upper surfaces are in contact with the tips of the 321 and 331 may contact the standing wall surfaces of the left and right ribs 322, 323, 332, and 333. It is like that. In the state where no load is applied to the seat plate 3, the front and rear end edges 245, 246, 265, 266 of the front connection frame 26 or the rear connection frame 24, and the standing wall surfaces of the left and right ribs 322, 323, 332, 333 There is a small gap between them.

  Since the seat plate 3 of the present embodiment includes a large number of through holes 311, the air permeability can be improved. Therefore, even though the seat plate 3 is made of resin, it is difficult to give discomfort even if the user sits on the seat plate 3 for a long time. Further, depending on the resin material used for the seat plate 3, the degree of bending of the seat plate 3 can be adjusted by providing the through hole 311. As in the present embodiment, the rear end portion 39 side of the seat plate 3 that is particularly susceptible to load is made a through hole 311 having a relatively large diameter, and the front end portion of the seat plate 3 that wants to firmly support the thigh of the seated person Since the 38 side is made into the through-hole 311 of a comparatively small diameter, a bending condition can be changed with each location of the seat board 3, and a seating comfort can be made favorable. Moreover, since each through-hole 311 has a ridgeline in the cylindrical part 316, the cone part 317, and these boundary parts 318, the thickness dimension of the seat board 3 can be made thinner than it is actually. In other words, since the ridgeline of the boundary portion 318 is clear, the user who is visually recognized from obliquely above the seat plate 3 causes an illusion that the thickness of the seat plate 3 is only the thickness of the cylindrical portion 316. is there.

  Since the back plate 4 of the present embodiment is provided with a horizontally long opening 412 in the central portion, air permeability can be improved. The opening 412 can also be used as a handle when carrying the chair 1 or performing a stacking operation. In particular, since the flange portion 413 is provided around the opening 412 so as to surround the entire circumference of the opening 412, when the opening 412 is used as a handle, the flange portion 413 can be handled. . When a hand is put on the opening 412, only the opening edge can be increased in thickness by the flange portion 413, whereby the load applied to the hand can be dispersed, so that the effect that the hand does not hurt is obtained. Further, the flange portion 413 also has an effect of improving the appearance from the back of the chair 1. The rear leg 23 to which the back plate 4 is attached has more portions fitted to the cylindrical attachment portion 42 than the portion fitted to the shell-like back plate main body 41. Therefore, the rear leg 23 does not hinder the movement of the back plate 4 deforming backward when it receives a load. Further, the back plate main body 41 of the back plate 4 is curved so that the central portion protrudes rearward, and the portions corresponding to the attachment portions 42 at both left and right ends are flat without being curved. Therefore, while giving a feeling of holding that wraps the back of the seated person at the center of the back plate body 41, the seated person often occurs when used for school or office work, and turns the upper body to turn sideways. It is designed so as not to hinder.

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

  In addition to the flat plate having no bent part at the edge as described above, the connecting frame has an L-shaped side view having a bent part bent in the thickness direction at either the front edge or the rear edge, It may be a U-shaped side view having bent portions bent in the thickness direction at both front and rear edges.

  The support protrusion is not limited to a rib-like one that extends continuously in the front-rear direction, and may be a plurality of protrusions or the like provided one or intermittently.

  Further, the positioning protrusion is not limited to the lateral rib orthogonal to the support protrusion, but has a protrusion amount such that only one or a plurality of protrusions provided intermittently or a part of the rib performs positioning. May be. Further, the positioning protrusion may be provided only on either the front edge side or the rear edge side of the connection frame. Furthermore, the positioning protrusion is not limited to one formed integrally with the support protrusion.

  The inclined portion of the frame of the present invention may be provided in a part of the seat receiving side frame or may be provided in the entire portion. Further, the inclined portion of the protrusion corresponding to the inclined portion of the frame may be provided in a part or in all the portions. In the case of a protrusion provided in a part, the protrusion is not limited to a continuous rib shape as in the present embodiment, and a plurality of intermittent protrusions may be inclined and arranged. As an example of an arrangement in which a plurality of protrusions are arranged at intervals, an arrangement in which the arrangement of a plurality of cylindrical protrusions provided on the back side of the seat plate is inclined may be considered.

  The protrusion has only a front opening shape formed by inclining so that the distance between the left and right is gradually decreased from the front end toward the rear, and the distance between the left and right is gradually decreased from the rear end toward the front. It may consist only of a rear opening shape formed by being inclined.

Further, the protrusion may be arranged on the outside of the seat receiving frame, or may be arranged on both the inside and outside of the seat receiving frame. You may change it.

24: Rear seat receiving connection frame 241 ... End edge 242 ... Plane portion 245 ... Front edge 246 ... Rear edge 25 ... Seat receiving side frame 252 ... Rear end portion 253, 254 ... Inclined portion 3 ... Seat plate 39 ... Rear end portion

Claims (6)

A seat plate is arranged on the right and left seat receiving side frames and the rear seat receiving connecting frames that connect the rear ends of these side frames,
The rear end portions of the both side frames are inclined so as to extend upward while gradually increasing the distance between the left and right sides toward the rear, and the connecting frame has a left-right length of the rear edge in the left-right direction of the front edge. A chair having a trapezoidal flat surface portion that is larger than the length, and having left and right edges of the connecting frame joined to rear end portions of the both side frames. The chair according to claim 1, wherein the connecting frame is formed by welding the left and right end edges of the flat portion to the inclined rear end portions of the both side frames. The chair according to claim 1 or 2, wherein the seat plate has a shape in which a rear end portion corresponding to the connection frame is warped upward. The chair according to claim 1, 2, or 3, wherein the seat plate is tightly fixed to the connection frame by a screw penetrating the connection frame from the rear side. The seat receiving side frame includes an inclined portion formed so that a distance between left and right gradually changes from the front end side toward the rear end side, and the seat plate is an inclined portion of the seat receiving side frame. And is configured to urge the seat plate in a direction in which the protrusion comes into close contact with the inclined portion of the seat receiving side frame by the tightening force of the screw. The chair according to claim 4. The connecting frame has a flat plate shape composed only of a flat surface portion, and a plurality of support protrusions formed on the flat surface of the flat plate connecting frame on the lower surface of the seat plate at intervals in the left-right direction. The chair according to claim 1, 2, 3, 4, or 5, further comprising a positioning protrusion that extends left and right along an edge of the connection frame and positions the connection frame in the front-rear direction.

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