JP2023125218A - Chair - Google Patents

Abstract

To allow an attachment structure for attaching a lumbar support to be inconspicuous in a backrest support body.SOLUTION: A backrest support body includes a supporter part 43 and a backrest body is supported by the supporter part 43. A lumbar support 61 is supported by the supporter part 43. The lumbar support 61 includes: a support body 62 extending in a right and left direction of the backrest body; and supporting bodies 63 for allowing the support body 62 to be supported by the supporter part 43. The supporter part 43 includes a first plate part 56 and a second plate part 57. Each of the supporting bodies 63 includes: a first support member 66 having a first outside support wall 74; and a second support member 67 having a second outside support wall 77. The supporter part 43 is held between the first outside support wall 74 and the second outside support wall 77 in a support area of each one of the supporting bodies 63.SELECTED DRAWING: Figure 6

Description

The present invention relates to a chair with a lumbar support in a backrest structure.

As shown in Patent Document 1, some chair backs are equipped with a lumbar support. The lumbar support is configured to be attachable to the backrest afterward, and to be removable.

Patent No. 6566543

The mounting structure for attaching the lumbar support to the backrest must also be designed to be used when the lumbar support is not attached to the chair. Therefore, from the viewpoint of improving the design of the backrest, it is desirable that the configuration and structure related to the attachment of the lumbar support not be visible from the outside when the lumbar support of the chair is not attached.

A chair that solves the above problems is a chair including a backrest structure, the backrest structure being a backrest support connected to a seat structure, and having a support section extending upward from a lower part. the backrest support body, a backrest main body supported by the backrest support body, and a lumbar support supported by the pillar part and disposed between the pillar part and the backrest main body; The lumbar support includes a support body that extends in the left-right direction of the backrest body, and a support that supports the support body on the support column, and the support body has a first outer surface and a support body that supports the support body on the support column. , a second outer surface facing in a direction different from the first outer surface, and the support body includes a first support member including a first outer support wall supported by the first outer surface; a second support member including a second outer support wall supported on two outer surfaces, and in the support area of the support body in the support column, the first outer support wall and the second outer support wall are , sandwiching the support portion.

According to the above configuration, the lumbar support is supported by the support body sandwiching the support area of the column part. Therefore, the structure for attaching the lumbar support to the column can be made less noticeable in appearance.

In the above-mentioned chair, the support section is arranged such that an outer surface width between the first outer surface and the second outer surface of the support section is larger than the width between the tip of the first outer support wall and the second outer surface of the support. The first outer support wall and the second outer support wall are configured to be located so as to cover the engagement portion. You can also. According to the above configuration, the first outer support wall and the second outer support wall are positioned so as to cover the engagement portion, so that the lumbar support can be attached to the support column.

In the above chair, the support section includes a first plate section including the first outer surface, and a second plate section including the second outer surface, and the first plate section and the second plate section are connected at the proximal end side, and configured such that the outer surface widths of the distal end portion of the first outer surface and the distal end portion of the second outer surface are wider than the proximal end side, and the distal end portion of the first outer surface and a distal end portion of the second outer surface is the engaging portion, and the first support member and the second support member are connected from each other from the distal end side or the proximal end side of the first plate portion. The engaging portion may be covered and the first outer surface and the second outer surface may be sandwiched.

According to the above configuration, the first support member and the second support member cover the engaging portion from the distal end side or the proximal end side of the first plate part and sandwich the first outer surface and the second outer surface, A lumbar support can be attached to the column.

In the above chair, the support section includes a first plate section including the first outer surface, and a second plate section including the second outer surface, and the first plate section and the second plate section are connected on the proximal side, and the outer surface width of the top portion on the proximal side is wider than the tips of the first outer surface and the second outer surface at the tip portion of the first outer surface and the tip portion of the second outer surface The top part is the engaging part, and the first support member and the second support member are connected to each other so that the first plate part has a width larger than the outer surface width thereof, and the top part is the engagement part, and the first support member and the second support member The engaging portion may be covered and the first outer surface and the second outer surface may be sandwiched.

Also with the above configuration, the first support member and the second support member cover the engagement portion from each distal end side or base end side of the first plate portion and sandwich the first outer surface and the second outer surface. This allows you to attach a lumbar support to the column.

In the above-mentioned chair, the support section may include a shape-changing section for regulating vertical displacement of the support body with respect to the support area. According to the above configuration, the support body can restrict vertical displacement of the support column from the support area.

In the above chair, the support portion includes a first plate portion having the first outer surface, and a second plate portion having the second outer surface, and has a constant shape region having a constant shape in the vertical direction. , the support region is provided in the constant shape region, and the shape changing portion is located on the inner surface of at least one of the first inner surface of the first plate portion and the second inner surface of the second plate portion. The engaging portion may be provided on a side surface and engage with the support body, and the engaging portion may be located corresponding to at least one of an upper end and a lower end of the support area. can.

According to the above configuration, since the support body engages with the engaging portion, the support body becomes difficult to shift in the vertical direction with respect to the support area even in the constant-shape area. The engaging portion can be made less visible by providing it on the inner surface of the plate portion.

In the above chair, the engaging portion is a rib that is integral with at least one of the first inner surface and the second inner surface, and the tip of the rib is at least connected to the first plate portion. It can also be configured to be lower than either the tip or the tip of the second plate portion. According to the above configuration, the rib can be hidden by the first plate part and the second plate part, making it less noticeable.

In the above chair, the support section includes a constant shape region having a constant shape in the vertical direction, and an upper adjacent region and a lower adjacent region adjacent to the constant shape region, the upper adjacent region and the lower adjacent region. At least one of the adjacent regions has a shape different from the constant shape region, the boundary between the constant shape region and the adjacent region is the shape changing portion, and the region includes the boundary. may be the support area. According to the above configuration, since the support region includes the shape-changing portion whose shape changes, the support becomes difficult to shift in the vertical direction with respect to the support region.

In the above chair, the support portion includes a first plate portion having the first outer surface and a second plate portion having the second outer surface, and gradually becomes thicker or thinner from top to bottom. , one of the first support member and the second support member has an inner surface on the back side with respect to one of the first outer surface and the second outer surface. an outer interference portion including an inner support portion that supports the outer support portion, and at least one of the outer support portion of the first outer support wall and the second outer support wall interferes with an outer surface facing the outer support portion; The shape changing portion may be configured such that at least one of the inner interference portions of the inner support portion that interferes with the inner surface facing the inner support portion is the shape changing portion.

According to the above configuration, the outer support part interferes with the outer surface, making it difficult to shift from the support area in either the up or down direction, and the inner support part interferes with the inner surface, making it difficult for the support area to shift upward or downward. It can be made difficult to shift from one area to another.

According to the present invention, the mounting structure for mounting the lumbar support on the backrest support can be made inconspicuous.

FIG. 2 is a perspective view of the chair seen from the front side in the first embodiment. It is a rear view of the chair in a 1st embodiment. It is a side view of the chair in a 1st embodiment. It is an exploded perspective view of the backrest structure of a chair in a 1st embodiment seen from the front side. It is a perspective view of the lumbar support used for a chair in a 1st embodiment. It is an exploded perspective view seen from the front side of a lumbar support in a 1st embodiment. It is an exploded perspective view seen from the rear side of a lumbar support in a 1st embodiment. 6 is a sectional view taken along line 8-8 in FIG. 5. FIG. 6 is a sectional view taken along line 9-9 in FIG. 5. FIG. FIG. 3 is a side view of the backrest structure showing the support area of the lumbar support in the first embodiment. It is a principal part perspective view explaining the support area of the lumbar support in a column part in a 1st embodiment. It is a sectional view explaining an engaging part in a 1st embodiment. It is a 2nd embodiment which is a modification of a 1st embodiment, and is a sectional view explaining a modification of an engaging part. It is a 4th embodiment, Comprising: It is a principal part perspective view explaining the support area of the lumbar support in a support|pillar part. It is a perspective view of a 5th embodiment. (a) is a cross-sectional view explaining that the support body in the fifth embodiment does not shift downward from the support area, and (b) is a cross-sectional view explaining that the support body does not shift upward from the support area. It is a diagram. FIG. 3 is a cross-sectional view of a support column in which a V-shaped opening is formed by a first plate part and a second plate part. FIG. 3 is a cross-sectional view of a support column in which each of the first plate part and the second plate part has an uneven thickness shape. FIG. 18 is a cross-sectional view showing a state in which the first support member and the second support member are attached to the support area of the support column shown in FIG. 17 from the opening side of the support column. FIG. 19 is a sectional view showing a state in which the first support member and the second support member are attached to the support region of the support column shown in FIG. 18 from the opening side of the support column. FIG. 18 is a cross-sectional view showing a state in which the first support member and the second support member are attached to the support region of the support column shown in FIG. 17 from the proximal end side of the support column. FIG. 19 is a sectional view showing a state in which the first support member and the second support member 67 are attached to the support region of the support column shown in FIG. 18 from the proximal end side of the support column. FIG. 19 is a cross-sectional view showing a state in which the first support member and the second support member are attached from the opening side of the support region to the support region of the support support having an uneven thickness shape different from that of the support support shown in FIG. 18;

An embodiment of a chair will be described below with reference to FIGS. 1 to 23.
(First embodiment)
(Overall composition of the chair)
As shown in FIGS. 1 and 2, the chair 1 includes leg members 11, a seat structure 12, and a backrest structure 13. In this embodiment, the seat 22 of the seat structure 12 of the chair 1 is open so that the chair 1 can be sat on. This open side is the front side, and the side where the backrest structure 13 of the seat structure 12 is located is the rear side. Further, in this embodiment, when the seat structure 12 is viewed from the front side, the left and right directions are the right side and the left side, the seat side with respect to the leg member 11 is the upper side, and the leg member 11 side with respect to the seat part 22 is the lower side.

The leg member 11 is a leg member with casters. The leg member 11 includes a pedestal 11a. Leg portions 11b extend radially from the lower end of the pedestal 11a. Casters 11c are attached to the tips of the legs 11b. The pedestal 11a has a built-in gas spring. This gas spring adjusts the height of the pedestal 21 in accordance with the operation of the first operating lever 16 included in the seat structure 12 . Further, a second operating lever 17 is provided near the first operating lever 16. The second operating lever 17 includes a knob for adjusting the backrest reaction force during reclining.

The seat structure 12 includes a pedestal 21 and a seat 22. A seat 22 is attached to the upper part of the pedestal 21. The seat portion 22 is constructed by laminating a cushioning material such as urethane foam on a seat plate and covering it with cloth or the like.

(Backrest structure)
As shown in FIGS. 2 and 3, the backrest structure 13 has a symmetrical shape when viewed from the front and rear directions. The backrest structure 13 includes a backrest support 31 and a backrest main body 32. The backrest main body 32 includes a back support member 33.

(Backrest support)
As shown in FIGS. 2 to 4, the backrest support 31 is connected to the seat structure 12 by a connecting member 39. As shown in FIGS. The backrest support 31 includes a lower support part 42, a column part 43, and an upper support part 46. The connecting member 39 is a member that connects the seat structure 12 and the lower support part 42, and extends from the rear side to the front side of the lower side of the pedestal 21, and extends to the vicinity of the pillar 11a. The connecting member 39 is fixed to the lower support part 42 by a fixing member such as a screw. Note that the connecting member 39 and the lower support portion 42 may be a series of integrally molded members.

The lower support part 42 extends in the left-right direction on the rear side of the seat part 22. The length of the lower support portion 42 in the longitudinal direction extending from side to side is approximately the same length or shorter than the rear edge of the seat portion 22 . As shown in FIG. 3, the lower support part 42 is fixed to the connection member 39 on the surface on the pillar 11a side. Furthermore, a swing support mechanism 45 that swingably supports the backrest main body 32 is configured on the rear surface of the lower support portion 42 . The swing support mechanism 45 is configured at a position on the opposite side of the connecting portion of the connecting member 39.

The strut section 43 includes a pair of left strut section 43l and right strut section 43r. The pair of left support portion 43l and right support portion 43r extend upward from the lower support portion 42 while gently curving. Specifically, the pair of left strut portions 43l and right strut portions 43r are spaced from each other diagonally rearward from below and extend upward (first spacing C1). Next, the pair of left support portion 43l and right support portion 43r extend upward while the distance between them narrows toward the front side (second distance C2). Thereafter, the pair of left support portion 43l and right support portion 43r linearly extend upward at approximately the same interval (third interval C3). Thereafter, the pair of left support portions 43l and right support portions 43r open in the left-right direction to form an upper support portion 46. That is, in the portion constituting the first interval C1, a first curved portion 47a is formed that swells diagonally to the rear side so that the interval between them opens. A second curved portion 47b that swells toward the front is formed in the portion that constitutes the second interval C2. The pair of left support portions 43l and right support portions 43r are curved in a direction approaching each other from the first curved portion 47a to the second curved portion 47b, so that the interval between them is larger than the first interval C1 on the lower side and the second interval C1 on the upper side. It narrows at the interval C2. As a result, the portion above the second curved portion 47b becomes a straight portion 47c having a linear shape, and becomes a narrow portion with respect to the first curved portion 47a. A support region 48b for attaching the lumbar support 61 is defined in a partial range in the vertical direction of the second curved portion 47b.

The upper support portion 46 connects the upper ends of the left support portion 43l and the right support portion 43r, and projects outward in the left-right direction. That is, the upper support portion 46 includes a connecting portion 46a that connects the upper end of the left support portion 43l and the upper end of the right support portion 43r, a left extension portion 46l extending leftward from the upper end of the left support portion 43l, and a right support portion 43r. The right extension part 46r extends rightward from the upper end of the right extension part 46r.

The upper part of the backrest main body 32 is fixedly supported by the left connecting portion 49l, which is an inner corner formed by the connecting portion 46a and the left support portion 43l. The upper part of the backrest main body 32 is also fixedly supported by the right connecting portion 49r, which is the inner corner formed by the connecting portion 46a and the support portion 43r.

(Backrest body)
As shown in FIG. 4, the backrest main body 32 has an annular frame shape, for example. The backrest main body 32 includes an upper fixed part 51, a lower connecting support part 52, a left vertical frame part 53l and a right vertical frame part 53r that connect the left and right sides of the upper fixed part 51 and the left and right sides of the lower connecting support part 52. , is equipped with. The upper fixing part 51 has a curved shape that follows the curve of the upper support part 46 of the backrest support 31. The vertical frame portions 53l and 53r extend diagonally forward from the upper fixing portion 51 toward the lower connection support portion 52. The lower connection support part 52 has a U-shape, and both sides of the lower connection support part 52 protrude more forward than the left and right sides of the upper fixed part 51, and the center part is curved so as to protrude rearward. The lower connection support portion 52 is connected to the lower sides of the vertical frame portions 53l and 53r on both left and right sides thereof. In the curved lower connection support part 52, a protruding piece 54 constituting the swing support mechanism 45 protrudes downward from the center portion located at the rearmost position.

A back support member 33 is stretched over the backrest main body 32. The back support member 33 is, for example, a tension member. The back support member 33 has a mesh shape, for example, and is stretched across the upper fixed part 51, the lower connection support part 52, and the vertical frame parts 53l and 53r so as to appropriately receive the load from the front. .

Both the backrest support 31 and the backrest main body 32 are made of, for example, reinforced plastic in which glass fiber is contained in a synthetic resin such as nylon. It is configured to have more flexibility than the support body 31.

(swing support mechanism)
The swing support mechanism 45 supports the protrusion 54 in the center of the lower support portion 42 so as to be swingable in the left-right direction. As an example, the projecting piece 54 has a through hole formed therein. A shaft portion provided in the lower support portion 42 is inserted into the through hole. As a result, the backrest main body 32 has an upper portion fixed to the backrest support 31 and a lower portion supported by the swinging support mechanism 45 so as to be swingable in the left-right direction.

(lumbar support)
Incidentally, a lumbar support 61 is arranged on the backrest structure 13, and the lumbar support 61 supports the user's ideal sitting posture. Specifically, the lumbar support 61 is attached to the support pillars 43l, 43r in a space 60 (see FIG. 3) between the support pillars 43l, 43r and the backrest main body 32.

As shown in FIG. 4, the lumbar support 61 includes a support main body 62 that supports the user's lower back and its surroundings, and left and right supports 63l and 63r arranged at both left and right ends of the support main body 62. We are prepared.

(Support body)
The support main body 62 is a long plate member, and has a length that extends between the support columns 43l and 43r. That is, the support body 62 extends in the left-right direction of the backrest structure 13. The support body 62 includes a resin plate. Further, the support main body 62 includes a cushioning material, such as a high-repulsion cushion, a low-repulsion cushion, a cushion in which a high-repulsion cushion and a low-repulsion cushion are combined in multiple layers, or the like. The support body 62 may be made of only a resin plate, or may have a structure in which a cushion is supported by a resin plate.

The support body 62 is provided with attachment pieces 64l, 64r at both left and right ends for attachment to the supports 63l, 63r. The mounting pieces 64l and 64r are made of a rigid resin molded body, a metal piece, or the like. The mounting pieces 64l, 64r are configured with rough or uneven surfaces, so that they have high friction with the contact surfaces of the supports 63l, 63r. Thereby, the mounting pieces 64l, 64r are configured to be difficult to shift in the vertical direction with respect to the supports 63l, 63r. Hereinafter, the mounting pieces 64l and 64r will also be collectively referred to simply as the mounting piece 64.

In this embodiment, the distance between the left support 43l and the right support 43r to which the supports 63l and 63r are attached is larger than the distance between the left vertical frame 53l and the right vertical frame 53r of the backrest main body 32. narrow. The length of the support body 62 in the longitudinal direction can also be configured to match the interval between the left vertical frame portion 53l and the right vertical frame portion 53r. In such a case, the positions of the mounting pieces 64l, 64r match the spacing between the support columns 43l, 43r. That is, the positions of the attachment pieces 64l and 64r are inside the left and right ends of the support body 62 in the longitudinal direction. The ends of the support body 62 protrude beyond the attachment pieces 64l and 64r.

(Support)
As shown in FIGS. 4 and 5, the supports 63l and 63r are symmetrical and have the same configuration. Hereinafter, the supports 63l and 63r will also be collectively referred to simply as the support 63. 6 and 7 show the support 63l and are exploded perspective views of the support 63l. The support body 63 includes a first support member 66, a second support member 67, and a mounting member 68. In a state where the first support member 66 and the second support member 67 sandwich the column 43, the first support member 66 is located inside near the center between the column 43l and 43r. The second support member 67 is located outside the support columns 43l and 43r.

(Support area of column)
Here, as shown in FIG. 4, FIG. 6, and FIG. 7, the support columns 43l and 43r to which the lumbar support 61 is attached include a first plate portion 56 and a second plate portion 57, so that It is configured to have a V-shaped cross section. As an example, the thickness of the first plate part 56 and the second plate part 57 are the same and constant. The first plate portion 56 includes a first outer surface 56a and a first inner surface 56b. The second plate portion 57 includes a second outer surface 57a and a second inner surface 57b. The first inner surface 56b and the second inner surface 57b are opposing surfaces. Further, in the support portions 43l and 43r, a V-shaped opening is formed by the distal end of the first plate portion 56 and the distal end of the second plate portion 57, and is connected at the proximal end side. The strut portions 43l and 43r are configured such that the distal end outer surface width (W1) of the distal end portion of the first outer surface 56a and the distal end portion of the second outer surface 57a is wider than the proximal outer surface width (W2). , and become engaging portions that are held in the supports 63l and 63r (see FIGS. 8 and 9). The V-shaped opening side of the support columns 43l and 43r faces the front side of the chair 1, and the base end side faces the rear side of the chair 1. The first plate portion 56 is located on the inside near the center between the support portions 43l and 43r. The second plate portion 57 is located outside the first plate portion 56 from the center between the support portions 43l and 43r. The first plate portion 56 is shorter than the second plate portion 57.

The support portions 43l and 43r are thickest at the root portion relative to the lower support portion 42, and then thickest at the first curved portion 47a. The straight portion 47c gradually becomes thinner toward the second curved portion 47b, and the straight portion 47c is configured to be thinner than the second curved portion 47b. As shown in FIG. 11, the region of the second curved portion 47b has, for example, a constant-shape region 48a. The constant shape region 48a is a region whose shape, such as the direction of curvature, curvature, and thickness, is constant. In the second curved portion 47b, the constant shape region 48a includes a support region 48b that supports the lumbar support 61. The lower portion closer to the first curved portion 47a than the constant shape region 48a has a different shape, such as the direction of curvature, curvature, and thickness, from the second curved portion 47b. The upper portion closer to the straight portion 47c than the constant shape region 48a also has a different shape, such as the direction of curvature, curvature, and thickness, from the second curved portion 47b. Here, the lower portion closer to the first curved portion 47a than the constant shape region 48a is thicker, and the upper portion closer to the straight portion 47c than the constant shape region 48a is thinner.

At the upper and lower ends of the support region 48b defined in the constant-shape region 48a, engaging portions 88 are provided to restrict displacement of the support body 63 in the vertical direction. The engaging portion 88 is a rib that is integrally provided on the first inner surface 56b and the second inner surface 57b (see FIGS. 11 and 12).

The root portion of the rib constituting the engaging portion 88 relative to the first inner surface 56b is the same as the tip of the first plate portion 56. Note that the root portion of the rib with respect to the first inner surface 56b may be lower than the tip of the first plate portion 56. Further, the root portion of the rib constituting the engaging portion 88 with respect to the second inner surface 57b is the same as the tip of the second plate portion 57. Note that the root portion of the rib relative to the second inner surface 57b may be lower than the tip of the second plate portion 57. The ribs constituting the engaging portion 88 are substantially perpendicular to the first inner surface 56b and the second inner surface 57b of the second plate portion 57. The height of the rib is set so that it does not protrude from the virtual plane connecting the tip of the first plate part 56 and the tip of the second plate part 57. As a result, the engaging portion 88 is hidden behind the first plate portion 56 and the second plate portion 57 and becomes less noticeable.

The engaging portions 88 are provided at the upper and lower ends of the support region 48b, and the support body 63 is disposed between the upper and lower engaging portions 88. The support area 48b is between the upper and lower engaging portions 88. This prevents the support body 63 from shifting in the vertical direction with respect to the support region 48b.

The backrest support 31 is molded by injection molding. The molding die includes a first mold for molding the front side of the backrest support 31 and a second mold for molding the rear side. In the backrest support 31, a first mold and a second mold are clamped together, a cavity is filled with molten resin, and then the molds are released. In molding the engaging portion 88, since the engaging portion 88 is a rib extending in the mold removal direction, it can be molded without adding a new mold.

(First support member)
As shown in FIGS. 6 and 7, the first support member 66 is a member located inside the column part 43 in the left-right direction of the backrest support 31, and has a shape that follows the shape of the first plate part 56. A main body portion 71 is provided. The front surface of the main body portion 71 is provided with a mounting groove 72 into which the mounting piece 64 is engaged. The mounting groove 72 has a length that allows the mounting piece 64 to move in the vertical direction. The groove bottom surface 72a of the mounting groove 72 is configured with a rough or uneven surface so as to be able to engage with the rough or uneven surface on the back surface of the mounting piece 64.

The attachment groove 72 is formed between an inner groove wall 72b and an outer groove wall 72c that extend in the vertical direction. The inner groove wall 72b is a wall lower than the outer groove wall 72c. The inner groove wall 72b is a wall closer to the center between the support portions 43l and 43r. The support main body 62 extends from the support portion 43 toward the other support portion 43 over the tip of the inner groove wall 72b. Attachment portions 73 for attaching the attachment piece 64 to the attachment groove 72 are provided in an area further above the upper end of the attachment groove 72 and an area further below the lower end of the attachment groove 72. Further, the surface of the outer groove wall 72c opposite to the mounting groove 72 serves as a contact surface 70 against which the contact wall 78 of the second support member 67 contacts. The upper and lower ends of the attachment member 68 are attached to the attachment portion 73 by fixing members 87 .

The main body portion 71 includes a first outer support wall 74 on a surface opposite to the surface on which the mounting groove 72 is provided. The first outer support wall 74 is a first outer support portion 74a that comes into contact with the first outer surface 56a of the first plate portion 56. The first outer support portion 74a has a shape that follows the first outer surface 56a in the support region 48b. Further, the surface of the main body portion 71 on which the first outer support wall 74 is erected is an abutting surface 71a against which the tip of the first plate portion 56 abuts. The end of the abutment surface 71a is an inner support portion 71b against which the second inner surface 57b of the second plate portion 57 is abutted. The inner support portion 71b is configured with an inclined surface that follows the shape of the second inner surface 57b.

The main body portion 71 includes a mounting protrusion 75 on the side surface for attaching the second support member 67. The attachment protrusion 75 is fixed by the fixing member 86 while being engaged with the engagement recess 79 of the second support member 67 . The second support member 67 is positioned with respect to the first support member 66 by the attachment protrusion 75 being engaged with the engagement recess 79 .

(Second support member)
The second support member 67 is a member located outside the support column 43 in the left-right direction of the backrest support 31, and includes a main body portion 76 that follows the shape of the second curved portion 47b. The main body portion 76 includes a second outer support wall 77 that abuts the second outer surface 57a of the second plate portion 57. The second outer support wall 77 is a second outer support portion 77a that comes into contact with the second outer surface 57a of the second plate portion 57. The second outer support portion 77a has a shape that follows the second outer surface 57a in the support region 48b. Further, the main body portion 76 includes an abutment wall 78 on the opposite side from the second outer support wall 77, which abuts against the abutment surface 70 of the outer groove wall 72c. The outer groove wall 72c and the abutting wall 78 are fixed by a fixing member in an overlapping state. Specifically, the main body portion 76 includes an engagement recess 79 into which the attachment protrusion 75 is engaged.

(Mounting material)
The mounting member 68 is a member that is disposed on the mounting groove 72 to prevent the mounting piece 64 from coming off from the mounting groove 72. The mounting member 68 includes an elongated restraining part 81 that prevents the mounting piece 64 from coming off from the mounting groove 72, and fixing pieces 82 arranged at the upper and lower ends of the restraining part 81. The fixing piece 82 is fixed to the mounting portion 73 by a fixing member 87. In the mounting member 68, when the fixing piece 82 is fixed to the mounting part 73, the mounting piece 64 and the support body 62 extend from a gap formed below the restraining part 81. The back surface of the holding portion 81 is a surface facing the mounting piece 64, and, like the groove bottom surface 72a, has a rough or uneven surface so as to be able to engage with a rough or uneven surface formed on the surface of the mounting piece 64. It can also be composed of

(How to install lumbar support)
As shown in FIG. 10, the support body 62 is inserted into the space 60 between the support columns 43l, 43r and the backrest body 32. Further, in each of the support columns 43l and 43r, supports 63l and 63r are attached to the support region 48b of the second curved portion 47b. At the same time, an attachment piece 64l is attached to the support body 63l, and an attachment piece 64r is attached to the support body 63r. The lumbar support 61 is attached to support columns 43l and 43r, which are parts of the backrest support 31 that are relatively strong among the backrest support 31 and the backrest main body 32. The lumbar support 61 can be attached more stably than when attached to the backrest main body 32.

Specifically, as shown in FIG. 8, the first support member 66 is arranged along the first outer surface 56a. The second support member 67 is arranged along the second outer surface 57a. The attachment protrusion 75 of the first support member 66 is engaged with the engagement recess 79 of the second support member 67 . The first support member 66 and the second support member 67 are placed over the support portion 43 from the open end side formed by the tip of the first plate portion 56 and the tip of the second plate portion 57. be done. The fixing member 86 that connects the first support member 66 and the second support member 67 is composed of a nut and a bolt. A nut is arranged on the mounting protrusion 75. Then, the bolt is inserted into the through hole formed in the engagement recess 79 and fastened to the nut. Thereby, the first support member 66 and the second support member 67 are coupled. The first outer support portion 74a and the second outer support portion 77a have a V-shape corresponding to the first outer surface 56a and the second outer surface 57a in the support region 48b.

Further, as shown in FIG. 8, the attachment piece 64 of the support body 62 is engaged with the attachment groove 72 of the first support member 66. The mounting member 68 is arranged in the mounting groove 72 so as to cover the mounting groove 72. The fixing piece 82 is then placed on the mounting portion 73. The fixing member 87 that connects the first support member 66 and the mounting member 68 is composed of a nut and a bolt. A nut is arranged in the attachment part 73. Then, the bolt is inserted into the through hole formed in the fixing piece 82 and fastened to the nut (see FIG. 9). Thereby, the first support member 66 and the attachment member 68 are coupled.

As an example, the first support member 66 and the second support member 67 are fixed by a fixing member 86 to the support regions 48b of the support columns 43l and 43r. The support region 48b is a region between the engaging portions 88, which are shape changing portions provided above and below the support region 48b, and its position can be easily identified by visual inspection. The first support member 66 and the second support member 67 are such that even when the fixing member 86 is fully tightened, the first outer support portion 74a is crimped to the first outer surface 56a, and the second outer support portion 77a is not crimped to the second outer surface 57a. The first outer support portion 74a is supported in contact with the first outer surface 56a, and the second outer support portion 77a is supported in contact with the second outer surface 57a. Vertical displacement of the support body 63 with respect to the support area 48b is regulated by engaging portions 88 provided at upper and lower positions of the support area 48b.

In the support region 48b, the V-shaped opening side of the support columns 43l and 43r faces the front side, and the base end side is located at the rear. The first support member 66 and the second support member 67 attached to the support region 48b are attached so as to cover each other from the open end side formed by the tip of the first plate portion 56 and the tip of the second plate portion 57. That is, the first support member 66 and the second support member 67 sandwich the support columns 43l and 43r so as to grip them from the front side. The support opening width (W3) of the open end formed by the tip of the first outer support part 74a and the tip of the second outer support part 77a is the It is narrower than the outer surface width (W1) on the distal end side of the distal end portion. The first plate part 56 and the second plate part 57 are covered with the first outer support wall 74 and the second outer support wall 77 on the outside. In this state, the first outer support portion 74a and the first outer surface 56a are in contact with each other, and the second outer support portion 77a and the second outer surface 57a are in contact with each other. The support body 63 becomes difficult to fall off from the front sides of the support columns 43l and 43r.

Note that the range (engaging portion) where the first outer support wall 74 overlaps the first outer surface 56a is not the entire first outer surface 56a, but from the tip of the first plate portion 56 constituting the open end to the tip. and the proximal end, or to any point between the distal end and the middle. Furthermore, the range in which the second outer support wall 77 overlaps the second outer surface 57a is not the entire second outer surface 57a, but extends from the tip of the second plate portion 57 to the center between the tip and the base end, or up to any position between the tip and the center.

(Effect of lumbar support)
As shown in FIG. 11, when the length of the constant shape region 48a in the vertical direction is longer than the length of the first outer support portion 74a and the second outer support portion 77a in the vertical direction, the support body 63 is There is a possibility that it will shift in the vertical direction from 48b within the constant shape region 48a. Note that in FIGS. 11 to 13, the support body 63 is shown in a simplified manner.

In this regard, as shown in FIGS. 11 and 12, the first inner surface 56b of the first plate part 56 and the second inner surface 57b of the second plate part 57 are provided with engaging parts 88. The engaging portions 88 are provided above and below the support region 48b, and the support body 63 is disposed between the upper and lower engaging portions 88. In this case, the support region 48b is between the upper and lower engaging portions 88. As a result, when the support body 63 tries to shift vertically, the inner support portion 71b and the engaging portion 88 interfere with each other, thereby preventing the support body 63 from shifting in the vertical direction with respect to the support region 48b.

The vertical position of the lumbar support 61 maintained in the support area 48b can be finely adjusted by moving the support body 62 up and down with respect to the support body 63. That is, when no load is applied to the backrest structure 13, the mounting piece 64 of the support body 62 is not pressed against the groove bottom surface 72a and the back surface of the restraining portion 81. Although it is difficult to move due to friction, it can be manually moved up and down within the range of the mounting groove 72. Even if the position is determined by the user, the support body 62 does not move up and down under its own weight due to friction. When a user sits on the chair 1 and applies a load to the backrest structure 13, the load causes the back surface of the attachment piece 64 to come into pressure contact with the groove bottom surface 72a through the pressed support body 62. Further, the suppressing portion 81 is pressed against the surface of the support body 62. As a result, while the user is applying a vertical load to the backrest structure 13, the support body 62 becomes more difficult to move than before the load is applied due to increased friction.

(Effects of the first embodiment)
According to the first embodiment, the following effects can be obtained.
(1) The lumbar support 61 can be retrofitted to the backrest structure 13. That is, the lumbar support 61 can be inserted into the space 60 between the support pillars 43l, 43r and the backrest main body 32 and attached to the support pillars 43l, 43r.

(2) Even when the lumbar support 61 is not attached to the chair 1, the only structure for the lumbar support 61 is the engaging portion 88 as a shape changing portion. The engaging portion 88 is arranged between the first plate portion 56 and the second plate portion 57 that constitute the support portions 43l and 43r. This location is visually inconspicuous. Moreover, the opening formed by the tip of the first plate part 56 and the tip of the second plate part 57 is not easily noticeable because the backrest main body 32 is located nearby. Therefore, even when the lumbar support 61 is not attached to the chair 1, the engaging portion 88 is not noticeable, and deterioration in the design of the chair 1 can be suppressed.

(3) By sandwiching the support columns 43l and 43r between the first support member 66 and the second support member 67, the lumbar support 61 can also be easily attached to the support region 48b. Specifically, the support opening width (W3) formed by the tip of the first outer support wall 74 and the tip of the second outer support wall 77 is equal to It is narrower than the width (W1) of the distal end side outer surface of the distal end portion. This makes it difficult for the support body 63 to fall off from the front sides of the support columns 43l and 43r.

(4) The supports 63l and 63r, which sandwich the pillar parts 43l and 43r between the first support member 66 and the second support member 67, can move up and down the support area 48b by engaging the inner support part 71b with the engagement part 88. It becomes difficult to shift in the direction. As a result, the lumbar support 61 also becomes difficult to shift from the support region 48b in the vertical direction.

(5) The supports 63l and 63r sandwich the first plate part 56 and the second plate part 57 from the direction of the distal end of the first plate part 56 and the distal end of the second plate part 57, which are widely spaced. It becomes difficult to fall off from the direction of the tip of the first plate part 56 and the tip of the second plate part 57.

(6) The first support member 66 includes an inner support portion 71b. Therefore, in the second plate section 57, the second outer surface 57a is supported by the second outer support section 77a, and the second inner surface 57b is supported by the inner support section 71b. This makes it difficult for the supports 63l and 63r to shift in the vertical direction with respect to the support region 48b.

(7) The engaging portion 88 is lower than the tip of the first plate portion 56 and the tip of the second plate portion 57. Therefore, the engaging portion 88 can be made more inconspicuous.
(8) The ribs constituting the engaging portion 88 are walls extending in the direction of mold removal, and have a simple configuration. The engaging portion 88 can be molded without complicating the mold.

(Second embodiment)
As shown in FIG. 13, the engaging portion 88 is provided with an engaging groove 89 in the first support member 66 and the second support member 67 so that the engaging portion 88 provided in the support area 48b is engaged with the engaging groove 89. may be configured. Such a configuration also prevents the support body 63 from shifting in the vertical direction with respect to the support region 48b.

(Third embodiment)
When the length of the constant shape region 48a in the vertical direction and the length of the support region 48b match, the upper adjacent region adjacent to the upper side of the support region 48b has a curved direction, curvature, thickness, etc. of the support region 48b. Constructed in different shapes. Further, the lower adjacent region adjacent to the lower side of the support region 48b is also configured to have a different shape from the support region 48b in terms of the direction of curvature, curvature, thickness, etc. In such a case, the boundary between the constant shape region 48a and the upper adjacent region, which coincides with the range of the support region 48b, is a shape changing portion. Further, the boundary between the constant shape region 48a and the lower adjacent region is also a shape changing portion. The greater the degree of shape change in the shape change portion, the more difficult it is for the support body 63 to shift in the vertical direction from the support region 48b.

In the third embodiment, the support body 63 supported by the support region 48b is prevented from shifting in the vertical direction by the upper and lower shape changing portions. In such a third embodiment, there is no need to provide the engaging portion 88 or the engaging groove 89, and the vertical displacement of the support body 63 can be suppressed only by a change in shape due to a change in the curvature of the support portion 43. As a result, it is not necessary to provide the engagement portion 88 for attaching the lumbar support 61 to the support column 43, and the shape can be simplified.

(Fourth embodiment)
As shown in FIG. 14, in the support portions 43l and 43r, the position of the second curved portion 47b has a constant shape region 48a. Note that in FIG. 14, the support body 63 is shown in a simplified manner. Also in the fourth embodiment, the support body 63 includes a first support member 66, a second support member 67, and a mounting member 68. The upper adjacent region 48c adjacent to the upper side of the constant shape region 48a is configured to have a different shape from the constant shape region 48a in terms of direction of curvature, curvature, thickness, etc. A lower adjacent region 48d adjacent to the lower side of the constant shape region 48a is also configured to have a different shape from the constant shape region 48a in terms of direction of curvature, curvature, thickness, etc. The boundary between the constant shape region 48a and the upper adjacent region 48c is a point of change in shape, and is an upper shape change portion 48e. The boundary between the constant shape region 48a and the lower adjacent region 48d is a point of change in shape, and is a lower shape change portion 48f.

In the fourth embodiment, the support region 48b is a position that includes the upper shape-changing portion 48e or a location that includes the lower shape-changing portion 48f. The upper support region 48b is a region spanning the constant shape region 48a including the upper shape changing portion 48e and the upper adjacent region 48c. The support body 63 has a shape corresponding to the shape of the upper shape changing portion 48e. When the support body 63 is attached to the upper support region 48b, it is sandwiched between the first support member 66 and the second support member 67 so as to include the upper shape changing portion 48e, so that displacement in the vertical direction is suppressed. (position of the solid line of the support body 63).

The lower support region 48b is a region spanning the constant shape region 48a including the lower shape changing portion 48f and the lower adjacent region 48d. The support body 63 has a shape corresponding to the shape of the lower shape changing portion 48f. When the support body 63 is attached to the lower support region 48b, it is sandwiched between the first support member 66 and the second support member 67 so as to include the lower shape changing portion 48f, so that it does not shift in the vertical direction. can be suppressed (position of the dotted chain line of the support body 63).

In such a fourth embodiment, there is no need to provide the engaging portion 88 or the engaging groove 89, and the vertical displacement of the support body 63 can be suppressed simply by changing the shape of the support portion 43. As a result, it is not necessary to provide the engagement portion 88 for attaching the lumbar support 61 to the support column 43, and the shape can be simplified.

(Fifth embodiment)
As shown in FIG. 15, the fifth embodiment has a configuration in which the support portion 43 gradually becomes thinner from the top to the bottom. That is, the support portion 43 includes a first plate portion 56 and a second plate portion 57, and has a V-shaped cross section, and the distance between the tip of the first plate portion 56 and the tip of the second plate portion 57 is It is designed to gradually become wider from top to bottom. Specifically, the first plate part 56 is straight in the vertical direction, whereas the second plate part 57 is curved so as to gradually move away from the first plate part 56 as it goes downward. ing. Further, the first plate portion 56 and the second plate portion 57 have the same plate thickness, for example.

The support body 91 used for such a support column 43 includes a first outer support wall 92a and a first inner support wall 92b for sandwiching the tip of the first plate part 56 in the support region 48b. The first outer support wall 92a has a shape that follows the first outer surface 56a in the support region 48b. The first inner support wall 92b has a shape that follows the first inner surface 56b. Further, the support body 91 includes a second outer support wall 93a and a second inner support wall 93b for sandwiching the tip of the second plate portion 57 in the support region 48b. The second outer support wall 93a has a shape that follows the second outer surface 57a in the support region 48b. The second inner side support wall 93b has a shape that follows the second inner side surface 57b. Like the support body 63, the support body 91 also includes a first support member 66, a second support member 67, and a mounting member 68. The first support member 66 includes a first inner support wall 92b, and the second support member 67 includes a second inner support wall 93b.

As shown in FIG. 16(a), when the support body 91 is about to descend from the support area 48b, the second outer support wall 93a interferes with the second outer surface 57a. Note that in FIG. 16(a), the first inner support wall 92b and the second inner support wall 93b are omitted. This prevents the support body 91 from shifting downward from the support region 48b. On the second outer surface 57a, an outer contact surface serving as an outer interference portion with the second outer support wall 93a is a shape changing portion 94a.

Further, as shown in FIG. 16(b), when the support body 91 tries to rise from the support area 48b, the second inner side support wall 93b interferes with the second inner side surface 57b. Note that in FIG. 16(b), the first outer support wall 92a and the second outer support wall 93a are omitted. This prevents the support body 91 from shifting upward from the support region 48b. In the second inner side surface 57b, an inner contact surface serving as an inner interference portion with the second inner support wall 93b is a shape changing portion 94b.

Even in such a fifth embodiment, vertical displacement of the support body 63 can be suppressed simply by changing the shape of the support portion 43 without providing the engagement portion 88 or the engagement groove 89. As a result, it is not necessary to provide the engagement portion 88 for attaching the lumbar support 61 to the support column 43, and the shape can be simplified.

(Modified example)
Note that the first to fifth embodiments described above can be implemented with appropriate modifications as described below.

- In the fifth embodiment (see FIGS. 15 and 16), the support body 91 may include only the second outer support wall 93a and omit the second inner support wall 93b. In this case, the support body 91 can only be prevented from shifting downward from the support region 48b. Further, the support body 91 may include only the second inner support wall 93b and omit the second outer support wall 93a. In this case, the support body 91 can only be prevented from shifting upward from the support region 48b.

- In the fifth embodiment, the configuration of the support column 43 is not limited to the examples shown in FIGS. 15 and 16. For example, both the first plate part 56 and the second plate part 57 may be curved so that the distance between them gradually increases from top to bottom. In this case as well, the first outer support wall 92a and the first inner support wall 92b that follow the first outer surface 56a, as well as the second outer support wall 93a and the second inner support wall 93b, are arranged vertically with respect to the support area 48b. It can be made to be difficult to shift in the direction. Further, the second plate portion 57 may be curved so as to gradually move away from the first plate portion 56 as it goes upward. That is, the strut portion 43 may be configured to become gradually thicker toward the bottom, or may be configured to become gradually thinner.

- In the fourth embodiment, the upper shape changing portion 48e and the lower shape changing portion 48f may have only a change in curvature, a change in thickness, or a change in the direction of curvature. Furthermore, the shape changing portion may be configured by combining these elements.

- In the first embodiment and the second embodiment, the ribs constituting the engaging portion 88 may be provided only on the first inner surface 56b of the first plate portion 56, or may be provided on the second inner surface of the second plate portion 57. It may be provided only on the side surface 57b. Further, the rib may be higher than the tip of the first plate portion 56 and the tip of the second plate portion 57. For example, in the first embodiment, the ribs are configured so as not to protrude beyond the imaginary plane connecting the tips of the first plate part 56 and the second plate part 57; You can leave it there.

- The structure of the engaging portion 88 may be any structure that interferes with the support body 63 when the support body 63 is vertically displaced from the support area 48b, and may have a shape such as a protrusion, a pin, or a piece. It may be. The portion of the support body 63 that engages with the engagement portion 88 is not limited to the inner support portion 71b. For example, it may be a protrusion or a piece protruding from the edge of the first support member 66 or the second support member 67.

- The engaging portion 88 may be provided only at a position corresponding to the lower end of the support region 48b. In this case, it is possible to restrict downward movement due to the weight of the lumbar support 61 and the load when the user leans on it. Furthermore, the engaging portion 88 may be provided only at a position corresponding to the upper end of the support region 48b. In this case, when the user is leaning on the user, it is possible to restrict the movement of the support body 63 from shifting upward due to the load when the user is leaning on the user.

- In the description of the first embodiment, the inner support portion 71b is included in the first support member 66 and is configured to support the second inner surface 57b of the second plate portion 57. In this regard, the inner support portion 71b may be configured such that the first support member 66 supports the first inner surface 56b of the first plate portion 56. Further, the second support member 67 may be configured to support the second inner surface 57b of the second plate portion 57. Furthermore, the second support member 67 may be configured to support the first inner surface 56b of the first plate portion 56. Furthermore, each of the first support member 66 and the second support member 67 may be provided with an inner support portion 71b to support the first inner surface 56b and the second inner surface 57b.

- The inner support portion 71b may be omitted from the first support member 66 and the second support member 67.
- The attachment member 68 may be provided integrally with the second support member 67.

- The connection between the first support member 66 and the second support member 67 is not limited to the fixing member 86 composed of nuts and bolts, but can be performed using fixing means such as snaps, hooks, and fasteners. You can do it like this.

- The connection between the first support member 66 and the mounting member 68 is not limited to the fixing member 87 composed of nuts and bolts, but may be made using fixing means such as snaps, hooks, and fasteners. Good too.

- The configuration for finely adjusting the vertical position by moving the support body 62 up and down with respect to the support body 63 can also be configured as follows. For example, the mounting groove 72 is provided with a rack member having a rack portion. The rack part has teeth arranged in the vertical direction so as to have a sawtooth shape. The teeth forming the rack part have elasticity. The length of the rack member in the longitudinal direction corresponds to the range of fine adjustment of the support body 62 in the vertical direction.

On the other hand, the mounting piece 64 includes an engaging member. The engagement member includes one or more engagement claws that engage with the rack portion. The engaging pawl is configured to have higher rigidity than the rack portion, and engages with the rack portion. When the support body 62 is moved up and down, the engaging claws bend the elastic teeth and move over the elastic teeth to the next position. The position of the support body 62 is difficult to move because the engaging pawl engages with the teeth of the rack part, and the adjusted position is maintained. The support body 62 can be moved little by little in the pressing direction by being pressed in either the up or down direction. Specifically, fine adjustment can be made by the size of one tooth. Thereby, the vertical position of the support body 62 can be finely adjusted.

- The support column 43 is not limited to a V-shape, but may have an H-shaped cross section in which the intermediate position in the height direction of the two plate parts is connected by a connecting plate, or one end of the two plate parts It may also be concave or U-shaped in cross section, with sections connected by a connecting plate. It is preferable that the support section having an H-shaped or U-shaped cross section has a configuration in which the distance between the tips is the widest. Furthermore, the cross-sectional shape may be rectangular or circular, and may be cylindrical without an open end.

- The strut portion 43 may have a solid structure with no internal cavity and no flesh loss.
- The shape of the support column 43 and the first support member 66 and second support member 67 corresponding to the shape can also be configured as follows.

For example, as shown in FIG. 17, the support portion 43 has a V-shaped opening formed by a first plate portion 56 and a second plate portion 57, similar to the above-mentioned example. As an example, the thickness of the first plate part 56 and the second plate part 57 are the same and constant. In addition, the distance between the struts 43 is wider on the distal end side than on the proximal end side. That is, in the support column 43, the distal end outer surface width (W1) of the distal end portion of the first outer surface 56a and the distal end portion of the second outer surface 57a is configured to be wider than the proximal outer surface width (W2). The open end portion is a top portion and is an engaging portion where the first outer support wall 74 and the second outer support wall 77 engage.

Further, as shown in FIG. 18, although the support portion 43 has a V-shaped opening formed by the first plate portion 56 and the second plate portion 57, the first plate portion 56 and the second plate portion 57 Each has an uneven thickness shape. That is, both the first plate part 56 and the second plate part 57 have flat inner surfaces. The outer surface has first inclined parts 56x, 57x which gradually become thicker from the distal end to the proximal end, and a second inclined part which becomes gradually thinner towards the proximal end after passing the top parts 56y, 57y. 56z and 57z. Each outer surface has a chevron shape. In such a support column 43, the proximal outer surface width (W2) of the top 56y of the first outer surface 56a and the top 57y of the second outer surface 57a is wider than the distal outer surface width (W1). There is. The portion of the proximal outer surface width (W2) is an engagement portion where the first outer support wall 74 and the second outer support wall 77 engage.

FIG. 19 shows an example in which the first support member 66 and the second support member 67 are attached to the support region 48b of the support column 43 shown in FIG. 17 from the opening side of the support column 43. The support opening width (W3) formed by the tip of the first outer support wall 74 and the tip of the second outer support wall 77 is narrower than the width of the outer surface on the tip side (W1). Here, the range (engaging portion) where the first outer support portion 74a overlaps with the first outer surface 56a is not the entire first outer surface 56a, but the area from the distal end forming the open end to the distal end and the proximal end. or to any position between the tip and the center. Further, the range in which the second outer support portion 77a overlaps with the second outer surface 57a is not the entire second outer surface 57a, but extends from the tip constituting the open end to the center between the tip and the base end, or up to any position between the tip and the center. This makes it difficult for the support body 63 to fall off from the front sides of the support columns 43l and 43r even if the overlap with the outer surface of the support column 43 is small.

FIG. 20 shows an example in which the first support member 66 and the second support member 67 are attached to the support region 48b of the support column 43 shown in FIG. 18 from the opening side of the support column 43. In this case, the first outer support portion 74a and the second outer support portion 77a have shapes that follow the first outer surface 56a and the second outer surface 57a, and each tip extends beyond the top portions 56y, 57y. It is located at the second inclined portions 56z and 57z. Therefore, the first outer support wall 74 and the second outer support wall 77 are farthest apart at the positions of the top portions 56y and 57y, and then narrow at the positions of the second sloped portions 56z and 57z. That is, the support opening width (W3) formed by the tip of the first outer support wall 74 and the tip of the second outer support wall 77 is narrower than the proximal side outer surface width (W2). The first outer support portion 74a and the second outer support portion 77a also do not cover the entire first outer surface 56a and second outer surface 57a. With such a configuration as well, the support body 63 is difficult to fall off from the front side of the support columns 43l and 43r even if the overlapping margin with the outer surface of the support column 43 is small.

FIG. 21 shows an example of attaching the first support member 66 and the second support member 67 to the support region 48b of the support column 43 shown in FIG. 17. In FIG. 21, the first support member 66 and the second support member 67 are placed over the first plate part 56 and the second plate part 57 from their proximal ends. In this case, the first outer support portion 74a and the second outer support portion 77a cover the entire first outer surface 56a and second outer surface 57a. Each tip of the first outer support part 74a and the second outer support part 77a includes a first locking piece 74x and a second locking piece 77x bent inward. As an example, the support opening width (W3), which is the distance between the tip of the first locking piece 74x and the tip of the second locking piece 77x, is narrower than the width of the outer surface on the tip side (W1). As a result, the first locking piece 74x is locked to the tip of the first plate portion 56, and the second locking piece 77x is locked to the tip of the second plate portion 57. Therefore, even with such a configuration, the support body 63 becomes difficult to fall off backward from the support columns 43l, 43r.

FIG. 22 shows an example of attaching the first support member 66 and the second support member 67 to the support region 48b of the support column 43 shown in FIG. 18. In FIG. 22, the first support member 66 and the second support member 67 are placed over the first plate portion 56 and the second plate portion 57 from their proximal end sides. In this case, the first outer support portion 74a and the second outer support portion 77a are farthest apart at the positions of the top portions 56y, 57y, and then narrow at the positions of the first slope portions 56x, 57x. The first outer support portion 74a and the second outer support portion 77a cover the second slope portions 56z, 57z and the first slope portions 56x, 57x halfway beyond the top portions 56y, 57y. That is, the support opening width (W3) formed by the tip of the first outer support wall 74 and the tip of the second outer support wall 77 is narrower than the proximal side outer surface width (W2). The first outer support portion 74a and the second outer support portion 77a also do not cover the entire first outer surface 56a and second outer surface 57a. With such a configuration as well, the support body 63 is difficult to fall off from the front side of the support columns 43l and 43r even if the overlapping margin with the outer surface of the support column 43 is small.

As a modification of the support column 43 shown in FIG. 18, a plurality of top portions 56y and 57y may be provided on the first outer surface 56a and the second outer surface 57a. For example, on the first outer surface 56a and the second outer surface 57a, the top portions 56y and 57y are provided at positions having the same distance from the tip. The top portions 56y, 57y provided at positions corresponding to each other in this manner have the same height. Further, for example, when the top portions 56y and 57y are provided at three locations on the first outer surface 56a and the second outer surface 57a, the top portions 56y and 57y at the first position on the distal side, and the top portion at the second position in the middle. 56y, 57y and the tops 56y, 57y at the third position on the proximal end may have different heights. Further, the first outer surface 56a and the second outer surface 57a may have top portions 56y, 57y provided at different distances from the tip.

Further, as shown in FIG. 23, in the support portion 43, each of the first plate portion 56 and the second plate portion 57 has an uneven thickness shape. Both the first plate part 56 and the second plate part 57 have flat inner surfaces. The outer surface includes first inclined parts 56o and 57o which are inclined so as to narrow the interval from the opening end, and second inclined parts 56q and 57q via valley parts 56p and 57p. The second inclined portions 56q, 57q are inclined in the opposite direction to the first inclined portions 56o, 57o. Further, the outer surface includes third inclined parts 56s and 57s which are inclined in the same direction as the first inclined parts 56o and 57o via the top parts 56r and 57r. That is, in the strut portion 43, the distal end outer surface width (W1) of the distal end portion of the first outer surface 56a and the distal end portion of the second outer surface 57a is configured to be wider than the proximal outer surface width (W2). . The opening end portion is an engaging portion where the first outer support wall 74 and the second outer support wall 77 engage.

The first outer support part 74a and the second outer support part 77a have shapes that follow the first outer surface 56a and the second outer surface 57a, and their tips are located in the valleys 56p and 57p. The support opening width (W3) formed by the tip of the first outer support wall 74 and the tip of the second outer support wall 77 is narrower than the width of the outer surface on the tip side (W1). With such a configuration as well, the support body 63 is difficult to fall off from the front side of the support columns 43l and 43r even if the overlapping margin with the outer surface of the support column 43 is small.

- The number of support portions 43 may be one, or three or more. For example, if there is one support 43, the lumbar support 61 will be supported by the single support 43. When there is one support 43, there is one support 63, and when there are three support 43, all supports 43 may be provided, or supports (two) may be provided on both sides of the support. may be provided.

- The chair 1 does not need to include the swing support mechanism 45. That is, in the chair 1, the backrest main body 32 may be attached to the backrest support 31 on both the upper side and the lower side so as not to swing.

- The chair 1 may be a leg member without casters 11c.
Further, the seat portion 22 may be provided with an armrest portion.

12... Seat structure 13... Backrest structure 31... Backrest support 32... Backrest main body 33... Back support member 39... Connection member 43 (43l, 43r)... Support column 47a... First curved part 47b... First 2 Curved part 47c... Straight line part 48a... Constant shape area 48b... Support area 56... First plate part 56a... First outer surface 56b... First inner surface 57... Second plate part 57a... Second outer surface 57b... Second Inner surface 60... Space portion 61... Lumbar support 62... Support body 63 (63l, 63r)... Support body 64 (64l, 64r)... Mounting piece 66... First support member 67... Second support member 68... Mounting member 71b... Inner support part 72...Mounting groove 74...First outer support wall 74a...First outer support part 77...Second outer support wall 77a...Second outer support part 81...Resistance part 88...Engagement part

Claims (9)

A chair including a backrest structure,
The backrest structure is a backrest support connected to the seat structure, and includes the backrest support including a column extending upward from a lower part, and a backrest supported by the backrest support. comprising a main body, and a lumbar support supported by the support and disposed between the support and the backrest main body,
The lumbar support includes a support body extending in the left-right direction of the backrest body, and a support body that supports the support body on the support column,
The support column includes a first outer surface and a second outer surface facing in a different direction from the first outer surface,
The support body includes a first support member including a first outer support wall supported by the first outer surface, and a second support member including a second outer support wall supported by the second outer surface. Prepare,
In the support area of the support body in the support column, the first outer support wall and the second outer support wall sandwich the support support. The chair. The support section is configured such that an outer surface width between the first outer surface and the second outer surface of the support section is equal to the width of the outer surface between the first outer surface and the second outer surface of the support. an engaging portion that is larger than the width of the support opening between the tip and the tip of the support member;
The chair of claim 1, wherein the first outer support wall and the second outer support wall are positioned over the engagement portion. The support section includes a first plate section having the first outer surface, and a second plate section having the second outer surface, and the first plate section and the second plate section have a base end side. The distal end portion of the first outer surface and the distal end portion of the second outer surface are configured such that outer surface widths are wider than the proximal end side, and the distal end portion of the first outer surface and the second outer surface are connected to each other. The tip portion of the outer surface is the engaging portion,
By being connected, the first support member and the second support member cover the engagement portion from the distal end side or the proximal end side of the first plate portion, and cover the first outer surface and the second outer surface. The chair according to claim 2, wherein the sides are sandwiched. The support section includes a first plate section having the first outer surface, and a second plate section having the second outer surface, and the first plate section and the second plate section have a base end side. connected, and the outer surface width of the top portion of the first outer surface and the second outer surface on the proximal end side of each tip of the first outer surface and the second outer surface is the outer surface width of the tip portion of the first outer surface and the tip portion of the second outer surface. wider, the top portion being the engaging portion;
By being connected, the first support member and the second support member cover the engagement portion from the distal end side or the proximal end side of the first plate portion, and cover the first outer surface and the second outer surface. The chair according to claim 2, wherein the sides are sandwiched. The chair according to any one of claims 1 to 4, wherein the support column includes a shape changing section for regulating vertical displacement of the support body with respect to the support area. The support section includes a first plate section including the first outer surface, and a second plate section including the second outer surface, and
comprising a constant shape region having a constant shape in the vertical direction, and comprising the support region within the constant shape region,
The shape changing portion is an engaging portion that engages with the support, and is provided on at least one of the first inner surface of the first plate portion and the second inner surface of the second plate portion. The chair according to claim 5, wherein the engaging portion is located corresponding to at least one of an upper end and a lower end of the support area. The engaging portion is a rib that is integral with at least one of the first inner surface and the second inner surface, and the tip of the rib is at least connected to the tip of the first plate portion and the second inner surface. The chair according to claim 6, wherein the chair is lower than one of the tips of the two plate parts. The support portion includes a constant shape region having a constant shape in the vertical direction, and an upper adjacent region and a lower adjacent region adjacent to the constant shape region,
At least one of the upper adjacent region and the lower adjacent region has a shape different from the constant shape region,
The chair according to claim 5, wherein a boundary between the constant shape region and the adjacent region is the shape changing portion, and a region including the boundary is the support region. The support portion includes a first plate portion including the first outer surface and a second plate portion including the second outer surface, and gradually becomes thicker or thinner from top to bottom,
One of the first support member and the second support member supports an inner surface on a back side with respect to an outer surface of either the first outer surface or the second outer surface. Equipped with an inner support part that
an outer interference portion in which the outer support portion of at least one of the first outer support wall and the second outer support wall interferes with an outer surface facing the outer support portion; The chair according to claim 5, wherein at least one of the inner interference parts that interferes with the inner surface facing the inner support part is the shape changing part.

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