JP5472964B2 - Chair - Google Patents

Description

  The present invention relates to an office swivel chair suitably used in an office or the like.

  Conventionally, a chair in which a back support rod is supported on a support base, the back support rod is divided into an upper frame and a lower frame, and these upper and lower back frames are connected via a coupling portion. Have been proposed (see, for example, Patent Document 1).

Such a chair has been proposed by paying attention to the fact that the strength and the bending method required for the upper and lower sides of the back support rod are different. In other words, by making the shape and material different between the upper back frame and the lower back frame, it is possible to give suitable characteristics to each other, and by suitably adapting to the load and movement of the seated person's back, It is possible to provide a comfortable sitting comfort for the person.
JP 2004-129966 A

  However, in the case of the structure as described above, a large force is also applied to the joint itself between the upper back frame and the lower back frame. In order to give strength to the joint portion, for example, other special members are provided in the joint portion, and the joint portion is always combined with external forces in the front-rear direction, the width direction, and the twist direction. Since it is a place where it is applied, the strength and precision are required so that the joint location does not shift with respect to these external forces.

  This invention pays attention to such a malfunction, and provides the chair which has a structure which connects a back support bar up and down by strong and reliable positioning.

  In order to achieve such an object, the present invention takes the following measures. That is, the chair according to the present invention is a chair in which a back support rod is supported on a support base, and the back support rod includes a lower back frame having a base end attached to the support base, and the lower back frame. An upper spine frame connected to the front end portion of the joint through a joint portion, so that the joint portion has a tighter fitting degree in the coupling completion stage than the fitting degree in the coupling initial stage. It is configured.

  If it is such, by employ | adopting a coupling | bond part, in the coupling | bonding initial stage, it becomes possible to make a strong connection while guiding an upper back frame and a lower back frame to an exact position. That is, it is possible to provide a chair having a structure in which the back support rods are connected up and down by a strong and reliable positioning while having a simple structure.

Further, as a configuration for realizing a strong connection, the lower back frame is made of metal, the upper back frame is made of synthetic resin, and the coupling portion is a tip of the lower back frame. A tapered projection portion formed by gradually narrowing the portion toward the tip, and a narrow hole portion formed by denting the lower end of the upper back frame to taper-fit the tapered projection portion. Can be mentioned.

  In order to make it easy to make a strong connection between the upper back frame and the lower back frame, it is necessary that the connecting portions be fitted to each other immediately before the tapered protrusion portion is completely inserted into the narrow hole portion. It is desirable to have a staged mating element.

  In order to obtain a reliable connection with a simple configuration, the tip side of the lower back frame is provided with a vertical frame part that forms a pair of left and right, and a connecting plate part that connects these vertical frame parts, It is preferable to form the tapered protrusion portion in the vertical frame portion.

  In order to realize the final stage mating element without adding other members and incurring an increase in the number of parts, in the final stage of insertion of the vertical frame part provided on the side surface of the vertical frame part and the narrow hole part It is desirable to have an aspect constituted by a step portion closely engaged with the side surface.

Here in the present invention includes a bent portion that is bent to coupling plate portion along the side view shape of the back支桿has a nut portion positioned respectively on the upper and lower side of the bent portion, The screw fixed to the nut portion prohibits the taper protruding portion from coming out of the narrow hole portion , and if the lower nut portion is screwed, the upper side of the bent portion is narrower than the narrow portion. The hole portion and the tapered protrusion portion are arranged so as to gradually approach each other in the vertical direction. By applying such a configuration, it is possible to realize a strong connection with a simple configuration that effectively eliminates the use of other members.

  According to the present invention, the upper back frame and the lower back frame are connected at the initial stage of the coupling by adopting the coupling part configured so that the fitting degree in the coupling completion stage using the tapered surface becomes closer. In addition to being guided to an accurate position, it is possible to make a strong connection. That is, it is possible to provide a chair having a structure in which the back support rods are connected up and down by a strong and reliable positioning while having a simple structure.

  Hereinafter, an embodiment in which the present invention is applied to a synchro tilt type office rotary chair 100 will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the chair 100 includes a leg 1, a support base 2 that is supported on an upper portion of the leg 1 and can be turned horizontally, and a seat 3 that is disposed on the support base 2. The seat 4 held on the seat support 3, the back support 5 provided on the support base 2 so as to be able to tilt backward, the backrest 6 attached to the back support 5, and the seat support 3 And armrests 10 rising from both sides.

  As shown in FIGS. 1 and 2, the leg 1 includes a leg base 11 and a leg support 12 provided at the center of the leg base 11. The leg base 11 is provided by projecting leg wings radially from a hub provided at the center, and a caster is provided at each leg wing tip. The leg struts 12 are mainly composed of gas springs, and are normal ones that can elastically extend in the vertical direction and can be locked at a desired position.

  As shown in FIGS. 1, 2, 3, and 4, the support base 2 includes a housing 21 attached to an upper end portion of the leg support 12, and a rigid support to the housing 21 to connect the back support 5. It comprises a main shaft 22 that is supported so as to be able to tilt backward, and a tilting reaction force generating mechanism 23 that is provided in the housing 21 and generates a repulsive force against the backward tilting operation of the back support 5. The tilt reaction force generating mechanism 23 is a normal one that uses a coil spring, a gas spring, or the like, and thus the description thereof is omitted.

  As shown in FIGS. 1 and 2, the seat receiver 3 is a shell that holds the seat 4, and its front end is attached to the support base 2 so as to be movable back and forth, and its rear end is It is supported at the base end of the back support 5.

  As shown in FIGS. 1 to 5, the back support 5 is attached to a back support rod 51 supported on the main shaft 22 of the support base 2 so as to be able to tilt backward, and to an upper end portion of the back support rod 51. And mainly an elastic reed 52. The specific configuration of the back support 5 will be described in detail later.

  As shown in FIGS. 1, 2, and 5, the backrest 6 is mainly composed of a back plate 61. The back plate 61 includes a back plate main body 61a, side end attachment portions 61c provided on both right and left sides of the back plate main body 61a, and a lower end attachment portion 61b provided on a lower end portion of the back plate main body 61a. Thus, the side end mounting portion 61 c is connected to both ends of the elastic horizontal bar 52, and the lower end mounting portion 61 b is mounted to the lower back frame of the back support rod 51. The back plate body 61a is made of a synthetic resin, and includes a peripheral frame portion 61a1 having no holes and an intermediate surface portion 61a2 surrounded by the peripheral frame portion 61a1. The intermediate surface portion 61a2 includes a resin mesh region M provided with a plurality of holes and a resin shell region S having no holes. The resin mesh regions M and the resin shell regions S are alternately arranged. Yes. Specifically, the resin shell region S of the intermediate surface portion 61a2 has a horizontal belt shape and is arranged so as to connect the opposing portions of the peripheral frame portion 61a1. A plurality of the resin shell regions S having a belt shape are arranged in parallel in the vertical direction, and the resin mesh is formed between the resin shell regions S and between the resin shell region S and the peripheral frame portion 61a1. Regions M are formed respectively. The resin mesh region M is formed thinner than the resin shell region S and has a large number of holes 61d. The front surface of the resin shell region S and the front surface of the resin mesh region M are formed flush with each other.

  Here, the chair 100 according to the present embodiment is a chair 100 in which the support base 2 supports the back support rod 51, and the back support rod 51 has the base end portion 51 b 4 attached to the support base 2. The lower back frame 51b and the upper back frame 51a connected to the tip of the lower back frame 51b via a connecting portion 51c are provided. The connecting portion 51c is compared with the degree of fitting at the initial stage of the connection. A final fitting element X, which will be described in detail later, is provided so that the degree of fitting at the coupling completion stage becomes closer.

  Hereinafter, a specific configuration of the chair 100, in particular, the back support rod 51 and the back support rod cover 53 will be described.

  As shown in FIGS. 1 to 5, the back support rod 51 is coupled to a lower back frame 51b having a base end portion 51b4 attached to the support base portion 2 and a distal end of the lower back frame 51b via a coupling portion 51c. And an upper back frame 51a. The lower back frame 51b is made of metal, and the outer side thereof is covered with a cover described later, that is, a back support cover 53. The outer surface of the back support cover 53 is positioned so as to be continuous with the outer surface of the upper back frame 51a. The upper back frame 51a is integrally formed of synthetic resin, and its upper part is branched into two.

  As shown in FIGS. 3 to 7 and FIGS. 9 to 11, the lower back frame 51b is formed, for example, by appropriately molding and welding a high-rigidity metal. As described above, the base frame 51b is attached to the support base 2. In addition to the end portion 51b4, a vertical frame portion 51b1 forming a left and right pair forming the outer shape of the lower back frame 51b, a connecting plate portion 51b2 connecting the vertical frame portion 51b1 forming the pair by welding, and a seat receiving support Shaft 51b3. In addition, the base end portion 51b4 has two holes up and down in a side view, but in this embodiment, the upper hole is the center of rotation with respect to the support base portion 2.

  As shown in the figure, the vertical frame portion 51b1 is provided in the vicinity of the shaft insertion hole 51b13 for inserting the shaft 51b3 for seat receiving support and the coupling plate portion 51b2 in a place where the center portion in the front-rear direction is raised upward. Has a fixed shaft 51b14 for fixing the upper end of the tilt reaction force generating mechanism 23 described above. In the present embodiment, the right and left side surfaces of the vertical frame portion 51b1, that is, the right side surface of the right vertical frame portion 51b1 is used as the right positioning surface 51b11 according to the present invention, and the left side surface of the left vertical frame portion 51b1 is used. A back support cover 53 can be suitably attached as the left positioning surface 51b12 according to the present invention, but a detailed description will be given later. Further, the inner side surface 51b15 of the vertical frame portion 51b1 sandwiches a sandwiching step portion 51c21 formed in a back narrow hole portion 51c2 described later.

  As shown in the figure, the coupling plate portion 51b2 is mainly composed of a coupling plate 51b21, which is a metal plate that is connected by welding while slightly bending the upper end front side of the vertical frame portion 51b1. Three nut portions are formed in each direction. Then, among the nut portions, the upper four screw holes are used as frame fixing holes 51b23 for fixing the screws b in the connecting portion 51c described later to be connected to the upper back frame 51a, and the two lower nut portions are A back fixing hole 51b22 for fixing the lower end mounting portion 61b of the backrest 6 is provided. In the present embodiment, the lower end edge of the coupling plate 51b21 in the coupling plate portion 51b2 is a stepped portion 51b24 that constitutes a second attachment portion that is engaged with an elastic claw 53b2 of the front side lower cover 53b described later. The connecting plate portion 51b2 has a bent portion 51b25 bent at an intermediate portion of the upper four screw holes so as to incline the lower side from the vertically rising side so as to follow the side view shape of the back support rod 51. Furthermore, it is supposed to have By doing so, if the lower side of the frame fixing hole 51b23 is screwed, the upper side naturally comes into closer contact with the screw in the vertical direction. Will be described in detail later.

  As shown in the drawing, the seat receiving pivot support shaft 51b3 is for rotatably mounting the rear end portion of the seat receiving 3 as described above. In this embodiment, the seat receiving pivot support shaft 51b3 is used. By using the shaft 51b3 as the first mounting portion according to the present invention, the back support rod cover 53 is mounted together with the positioning surfaces 51b11 and 51b12 described above. The lower back frame 51b forms a tapered protrusion 51c1 that constitutes the coupling portion 51c by gradually narrowing the tip portion toward the tip. The coupling portion 51c will be described later.

  As shown in FIGS. 3 to 7 and FIGS. 9 to 11, the upper back frame 51a is integrally formed of, for example, synthetic resin, and has a base 51a1 connected to the lower back frame 51b on the lower end side, and the base It has the branch collar part 51a2 which branches into two forks on the upper side of 51a1.

  As shown in the figure, the base 51a1 is provided with a narrow hole portion 51c2 constituting a tapered connecting portion to be described later at the lower end portion, and at least a portion that can be visually recognized from the rear is disposed on the back surface of the back support rod 51. The rear side thick plate portion 51a11 to be formed, and the front side narrow portion 51a12 provided on the front side of the rear side thick plate portion 51a11 and inwardly from the left and right side edges of the rear side thick plate portion 51a11. A screw insertion hole 51a13 for inserting the screw b through the narrow hole portion 51c2, an upper cover insertion groove 51a14 for attaching a front side upper cover 53c to be described later, and a rear side cover 53a to be described later It has nut part 51a15 as the 2nd attachment part.

  As shown in the figure, the branch saddle 51a2 has at least a portion visible from the rear, like the base 51a1 described above, and a back-side thick plate 51a21 that forms the back of the back support rod 51, and the back side A front side narrow portion 51a22 provided on the front side of the thick plate and deviated inwardly from the left and right side edges of the back side thick plate portion 51a21, and the back side thick plate portion 51a21 are circulated to the upper end. A continuous upper surface side thick plate portion 51a23, and a component mounting portion 51a24 for attaching an elastic reed 52 provided continuously below the front surface side narrow portion 51a22 below the upper surface side thick plate portion 51a23. Yes.

  The coupling portion 51c is provided across the lower back frame 51b and the upper back frame 51a as described above, and the tapered projection portion 51c1 provided on the vertical frame portion 51b1 of the lower back frame 51b and the tapered projection portion 51c1 are provided. A deep narrow hole portion 51c2 formed by denting the lower end of the upper back frame 51a for taper fitting is provided. A sandwiching step portion 51c21 is formed on the inner side of the narrow hole portion 51c2 as a step portion for firmly positioning in the width direction by being sandwiched by the tapered projection portion 51c1 of the vertical frame portion 51b1 from the inside.

  As shown in the drawing, the elastic recumbent 52 is obtained by extending an arm part 52a supporting two intermediate parts at the upper end of the above-described branch reed part 51a2 to the left and right, and the left and right arm parts 52a. Is connected to the backrest 6.

  As shown in FIGS. 3 to 11, the back support cover 53 is made of, for example, a synthetic resin that covers the metal lower back frame 51b, and the back side that covers the lower back frame 51b from the rear, that is, from the back side. Cover 53a, front-side lower cover 53b covering the lower back frame 51b from the front, that is, from the front side relative to the back-side cover 53a, mainly near the rising position of the backrest 6 and the lower front side of the upper back frame 51a And a front upper cover 53c that covers the surface.

  The back cover 53a is formed by raising side walls 53ab from both sides of the rear wall 53aa positioned behind the lower back frame 51b, as shown in FIG. A bifurcated engagement piece 53a1 engaged with the provided seat receiving support shaft 51b3, a screw insertion hole 53a2 for screwing the upper portion of the rear wall 53aa to the upper back frame 51a, and a lower back frame on the inner surface side of the side wall 53ab Both covers are guided by a contact portion 53a3 for positioning in the width direction by fitting to the left and right positioning surfaces 51b11 and 51b12 which are the left and right surface portions of 51b, and guide ribs 53b5 described later of the front side lower cover 53b. And a wedge piece 53a5 (FIGS. 9 and 11) for positioning in the width direction. The bifurcated engagement piece 53a1 is formed by constricting the distal end side so that the opening width of the distal end portion is smaller than the diameter of the shaft 51b3 for seat receiving support, and utilizes temporary elastic deformation of the member. Thus, it can be engaged with the shaft 51b3 for seat support. The screw insertion hole 53a2 is provided at the center of the portion where the center of the upper end of the rear wall 53aa is slightly recessed, and the nut portion is naturally engaged with the bifurcated engagement piece 53a1 engaged with the shaft 51b3 for seat receiving support. It communicates with 51a15. The contact portion 53a3 is provided on the inner surface side of the side wall 53ab in the vicinity of the bifurcated engagement piece 53a1, and the left and right surface portions of the lower back frame 51b, that is, the right side surface of the right vertical frame portion 51b1 and the left vertical frame portion. It contacts the left side surface of 51b1.

  In this embodiment, as shown in FIGS. 7, 9, and 11, when the back cover 53a is attached to the lower back frame 51b, first, the forked engagement piece 53a153b1 is the first attachment portion. The member is elastically deformed by being pressed in accordance with the position of the shaft 51b3 for seat receiving support, and the forked engagement piece 53a1 is fitted. Thereafter, when the rear cover 53a is rotated upward about the seat receiving support shaft 51b3, the upper end of the rear wall 53aa comes into contact with the lower end of the upper back frame 51a. At this time, the screw insertion hole 51a13 naturally communicates with a nut portion 51a15 which is a second attachment portion provided in the upper back frame 51a. At the same time, since the abutting portion 53a3 inside the side wall 53ab abuts against the right side surface of the right vertical frame portion 51b1 and the left side surface of the left vertical frame portion 51b1 from the outside, positioning in the width direction is naturally performed. The above-mentioned rotation operation cannot be performed in a state where the front side lower cover 53b is attached in advance, but the bifurcated engagement piece 53a1 is set in the first attachment portion so as to be parallel to the direction of the front side lower cover 53b. If it is inserted toward the shaft 51b3 for seat receiving support, the bifurcated engagement piece 53a1 can be positioned in the vertical direction, the abutting portion 53a3 can be positioned in the width direction, and the end surface of the side wall 53ab contacts the front side lower cover 53b. Thus, the cover 53a on the back side is naturally positioned at an accurate position, and the screw b may be inserted and fixed to the screw insertion hole 51a13 and the nut portion 51a15 which is the second mounting portion communicating with the screw as it is.

  The front side lower cover 53b is formed by raising the side walls 53bb from both sides of the front wall 53ba positioned in front of the lower back frame 51b, as shown in FIGS. 3 to 5, 7, 9 and 11. A bifurcated engagement piece 53b1 engaged with a seat receiving pivot support shaft 51b3 provided on the back support rod 51, an elastic claw 53b2 for engaging the upper portion of the front wall 53ba with the coupling plate portion 51b2 of the lower back frame 51b, A contact portion 53b3 for positioning in the width direction by sandwiching the left and right surface portions of the lower back frame 51b from the outside on the inner surface side of the side wall 53bb, and a guide for guiding the wedge piece 53a5 in the width direction of the cover 53a on the back side Ribs 53a5 (FIGS. 9 and 11) are provided. The bifurcated engagement piece 53b1 is formed by constricting the distal end side so that the opening width of the distal end portion is smaller than the diameter of the shaft 51b3 for seat receiving support, and utilizes temporary elastic deformation of the member. It can be engaged with the shaft 51b3 for the seat support pivot. The elastic claw 53b2 is formed by projecting the two positions at the upper end of the front wall 53ba rearward. The coupling plate portion 51b2 is naturally in a state where the forked engagement piece 53b1 is engaged with the shaft 51b3 for seat support. The step portion 51b24 is engaged from the lower side. The contact portion 53b3 is provided on the inner surface side of the side wall 53bb in the vicinity of the bifurcated engagement piece 53b1, and the left and right surface portions of the lower back frame 51b, that is, the right side surface of the right vertical frame portion 51b1 and the left vertical frame portion. It contacts the left side surface of 51b1.

  In this embodiment, as shown in FIGS. 7, 9, and 11, when the rear cover 53 a is attached in advance, the bifurcated engagement is performed in a direction parallel to the direction of the rear cover 53 a. If the piece 53b1 is inserted toward the shaft 51b3 for seat receiving support that is the first mounting portion, the bifurcated engagement piece 53b1 can be positioned in the vertical direction and the contact portion 53b3 can be positioned in the width direction, and the end surface of the side wall 53bb can be By hitting the cover 53a on the back side, the elastic claw 53b2 positioned at the upper end of the front wall 53ba is naturally positioned at a position where the elastic claw 53b2 contacts the stepped portion 51b24 in the coupling plate portion 51b2 of the lower back frame 51b. . Then, by further pressing the front wall 53ba from the state in which the elastic claw 53b2 and the stepped portion 51b24 are in contact, the elastic claw 53b2 and the stepped portion 51b24 are engaged, and the attachment of the front side lower cover 53b is completed.

  On the other hand, when the back cover 53a is not attached to the lower back frame 51b, first, the forked engagement piece 53b1 is pressed in accordance with the position of the seat receiving pivot support shaft 51b3 which is the first attachment portion. Thus, the member is elastically deformed to fit the forked engagement piece 53b1. Thereafter, when the front side lower cover 53b is pivoted upward about the seat receiving support shaft 51b3, the elastic claw 53b2 located at the upper end of the front wall 53ba becomes the step portion of the coupling plate portion 51b2 of the lower back frame 51b. It will be positioned at a position where it contacts 51b24. Then, by further pressing the front wall 53ba from the state in which the elastic claw 53b2 and the stepped portion 51b24 are in contact, the elastic claw 53b2 and the stepped portion 51b24 are engaged, and the attachment of the front side lower cover 53b is completed.

  Here, as shown in detail in FIGS. 9 and 11, when the front side lower cover 53b is fitted, the guide ribs of the front side lower cover 53b are provided on the rear side cover 53a in the vicinity of the seat receiving support shaft 51b3. Since the wedge piece 53a5 is mounted while being correctly positioned in the width direction while being guided into the front side lower cover 53b, the outer surface 53a4 of the back cover 53a and the front side lower cover 53b are mounted as shown in FIG. The outer side surface 53b4 is flush with the outer side surface. The wedge pieces 53a5 and the guide ribs 53b5 may be provided on the opposite sides of the back side cover 53a and the front side lower cover 53b.

  Then, as shown in FIG. 10 in particular, the front upper cover 53c is located around the rising portion of the backrest 6 extending from the lower end of the joining plate portion of the lower back frame 51b to the screw insertion hole 51a13 on the lower front side of the upper back frame 51a. The covering plate portion 53c1 to be covered and the insertion plate portion 53c2 to be inserted into the cover insertion groove 51a14 provided in the upper back frame 51a from both sides of the covering plate portion 53c1 are provided. Then, as shown in the figure, the front upper cover 53c is inserted by inserting the covering plate portion 53c1 so as to be sandwiched from above the lower end mounting portion 61b of the backrest 6, and then inserting the insertion plate portion 53c2 into the cover insertion groove 51a14. If the cover 53a on the back side and the lower cover 53b on the front side are also attached, the surface of the lower back frame 51b can be covered over the front surface together with them.

  Thus, in the present embodiment, as shown in FIG. 11 in particular, in the state where both covers, that is, the back side cover 53a and the front side lower cover 53b are attached, the shaft for supporting the seat receiving support, which is a common first attachment portion. By engaging the bifurcated engagement pieces 53a1 and 53b1 with 51b3, not only accurate positioning with respect to the lower back frame 51b but also positioning in the front-rear direction between the back-side cover 53a and the front-side lower cover 53b is performed accurately. It has become. Further, the back side cover 53a and the front side lower cover 53b respectively contact the abutting portions 53a3 and 53b3 on the right side surface of the right vertical frame portion 51b1 and the left side surface of the left vertical frame portion 51b1, respectively. By being in contact with each other, positioning in the width direction of the lower and rear cover 53a and the front lower cover 53b is accurately performed. As a result, both the covers, that is, the rear side cover 53a and the side wall outer surfaces 53a4 and 53b4 of the front side lower cover 53b are substantially flush with each other.

  Here, the chair 100 according to the present embodiment includes a final-stage fitting element X in which the coupling portion 51c is fitted to each other immediately before the tapered protrusion portion is completely inserted into the narrow hole portion. It has become. Such a final stage fitting element X will be described in detail below with reference to FIGS. 14 is an end view corresponding to the position of the upper screw fixing hole 51a13 in FIG. 13, and FIG. 15 is an end view corresponding to the position of the lower screw fixing hole 51a13.

  As shown in the figure, the final stage fitting element X is provided on the side surface of the vertical frame portion 51b1, strictly speaking, the inner side surface 51b15 which is the side surface of the vertical frame portion 51b1 in the tapered protrusion portion 51c1, and the narrow hole portion 51c2. The sandwiching step portion 51c21 that is the stepped portion is formed. As shown in FIG. 13, in the final insertion stage after inserting the back narrow hole portion 51c2 from above the tapered protrusion portion 51c1, the screw insertion hole 51a13 and the frame fixing hole 51b23, which are nut portions, are connected by screws b. By fixing, the tapered protrusion 51c1 is prohibited from coming out of the back narrow hole 51c2. Specifically, as shown in the figure, first, the screw b is fastened to the lower frame fixing hole 51b23, whereby the engagement between the inner side surface 51b15 and the clamping step portion 51c21 becomes dense. In addition, due to the action of the bent portion 51b25 provided in the coupling plate portion 51b2, the deep narrow hole portion 51c2 and the tapered protrusion portion 51c1 gradually approach each other in the vertical direction in the portion above the bent portion 51b25. Further, by fastening the upper frame fixing hole 51b23 with screws, the tapered projection portion 51c1 is closely fitted in the front and rear direction and the vertical direction with respect to the narrow hole portion 51c2, so that the lower back frame 51b portion and A strong connection with the upper back frame 51a is possible.

  By adopting the above configuration, the chair 100 according to the present embodiment employs the coupling portion 51c as described above, so that the upper back frame 51a and the lower back frame 51b are accurately positioned at the initial stage of the coupling. It is possible to establish a strong connection. That is, in the present embodiment, a chair 100 is provided that has a simple structure and has a structure in which the back support rod 51 is connected up and down by strong and reliable positioning regardless of the material to be connected.

  In the present embodiment, as a specific configuration for realizing a strong connection, the coupling portion 51c is formed as a single protrusion formed by gradually narrowing the tip of the lower back frame 51b toward the tip. A tapered projection 51c1 and a narrow hole 51c2 formed by denting the lower end of the upper back frame 51a to taper-fit the tapered projection 51c1. The frame 51b is made of metal, and the upper back frame 51a is made of synthetic resin. That is, even when completely different materials are connected, the connecting portion 51c according to the present invention enables a strong connection.

  In the present embodiment, by providing the final stage fitting element X, the upper back frame 51a and the lower back frame 51b can be firmly and easily joined securely.

  In order to obtain a reliable connection with a simpler structure, in the present embodiment, the front end side of the lower back frame 51b is formed with a pair of left and right vertical frame parts 51b1 and a connecting plate part for connecting these vertical frame parts 51b1 to each other. 51b2 is provided, and the tapered projection portion 51c1 is formed in the vertical frame portion 51b1, so that the tapered projection portion 51c1 is realized only by processing the tip of the vertical frame portion 51b1.

  In the present embodiment, the above-described final stage fitting element X is constituted by the inner side surface 51b15 of the vertical frame part 51b1 and the clamping step part 51c21 formed in the narrow hole part 51c2, so that other than screws used for normal mounting. Makes it possible to have a strong bond without needing anything.

  In the present embodiment, a frame fixing hole 51b23 that is a nut portion is provided in the coupling plate portion 51b2, and the taper projection portion 51c1 is prohibited from coming out of the narrow hole portion 51c2 by a screw b fixed to the nut portion. Is applied, a strong connection is realized with a simple configuration that is normally used, which effectively eliminates the use of a special member for coupling.

  Although the embodiment of the present invention has been described above, the specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the coupling portion has a single protrusion shape in side view, but the single protrusion has another shape such as a conical shape, or the coupling portion is formed from a plurality of protrusions. It may be what you did.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

The external view of the chair which concerns on one Embodiment of this invention. The side view of the chair which concerns on the same embodiment. The figure which shows the principal part of the chair which concerns on the same embodiment. The structure explanatory view of the chair concerning the embodiment. The figure which decomposes | disassembles and shows the principal part of the chair which concerns on the same embodiment. The principal part enlarged view of the chair which concerns on the same embodiment. The other principal part enlarged view of the chair which concerns on the same embodiment. The figure which shows the cover of the back side of the chair which concerns on the same embodiment. The enlarged view which shows the cover of the back support rod which concerns on the same embodiment. The principal part enlarged view of the back support rod which concerns on the same embodiment. The typical sectional view which shows the axis | shaft for the cover of a back support rod, and a seat receiving pivot. A typical sectional view showing a joint part of a back support rod. The other typical sectional view of the joint part. FIG. 14 is an end view of the coupling portion according to FIG. 13. FIG. 13 is another end view of the coupling portion according to FIG. 12.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Chair 2 ... Support base 51 ... Back support frame 51a ... Upper back frame 51b4 ... Base end part 51b ... Lower back frame 51b1 ... Vertical frame part 51b15 ... Inner side surface (side surface of vertical frame part)
51b2 ... coupling plate part 51b23 ... nut part (frame fixing hole)
51c ... Coupling part 51c1 ... Tapered protrusion part 51c2 ... Back narrow hole part 51c21 ... Step part (clamping step part)
X: Final stage mating element

Claims (4)

A chair having a support base supported on a back support rod, wherein the back support rod includes a lower back frame having a base end portion attached to the support base, and a front end portion of the lower back frame via a coupling portion. An upper back frame connected to each other, and the coupling portion is configured such that the degree of fitting in the coupling completion stage is closer than the degree of fitting in the coupling initial stage,
The lower back frame is made of metal, the upper back frame is made of synthetic resin, and the coupling portion is formed by gradually narrowing the tip of the lower back frame toward the tip. A tapered projection part, and a narrow hole part formed by denting the lower end of the upper back frame to taper-fit the tapered projection part,
The front end side of the lower back frame is provided with a vertical frame portion that forms a pair on the left and right sides, and a coupling plate portion that couples the vertical frame portions to each other, and the coupling plate portion has a side view shape of the back support rod. A bent portion bent to follow, and nut portions positioned on the upper side and the lower side of the bent portion, respectively.
The screw fixed to the nut part prohibits the tapered protrusion part from coming out of the narrow hole part,
If the lower nut portion is screwed, the back narrow hole portion and the tapered protrusion portion gradually approach each other in the vertical direction above the bent portion. .   The chair according to claim 1, wherein the coupling portion includes a final-stage fitting element that is fitted to each other immediately before the tapered protrusion portion is completely inserted into the narrow hole portion.   The chair according to claim 1, wherein the tapered protrusion portion is formed on the vertical frame portion. The final stage engaging elements, the side surface of the vertical frame portion, of the inner Semaana portion provided according to claim 2 which is the side with the step portions mutually involved closely with the insertion final stage of the vertical frame portion Chair.

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