Lumbar support and chair

Abstract

To provide a lumbar support and a chair capable of increasing the degree of freedom of design and providing good seating comfort.SOLUTION: A lumbar support 100 includes a main body connecting part 120 connectable to a chair main body 1A, and a load supporting part 110 supported by the main body connecting part 120 and supporting the load of the seated person from the rear, wherein the load supporting part 110 includes the base portion 113 that extends in a left-right direction, and the plurality of cantilever-shaped supporting pieces 115 that are disposed at intervals in the left-right direction, extend upward from the base portion 113, and are provided independently of each other, and the plurality of supporting pieces 115 have different elastic moduli.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a lumbar support and a chair. [Background technology]

[0002] For example, Patent Document 1 discloses a lumbar support having a plurality of support rings arranged concentrically. In this lumbar support, adjacent support rings are connected to each other by connection webs extending diagonally radially. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4987739 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in chairs, it is always desirable to improve the sitting comfort, not only in lumbar supports. However, in the lumbar support disclosed in Patent Document 1, even if an attempt is made to design a lumbar support to improve sitting comfort, the design freedom is limited by the connection webs that extend diagonally radially and connect adjacent support rings to each other. The present invention has been made to solve the above-mentioned problems, and has an object to provide a lumbar support and a chair that can increase design freedom and provide a comfortable sitting experience. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention employs the following aspects. (1) A lumbar support according to one embodiment of the present invention is a lumbar support attached to a chair body, and comprises: a body connection part connectable to the chair body; and a load support part supported by the body connection part and supporting the weight of a seated occupant from behind. The load support part comprises a base extending in the left-right direction, and a plurality of cantilever-shaped support pieces arranged at intervals in the left-right direction, extending upward from the base, and provided independently of one another, and the plurality of support pieces have different elastic moduli.

[0006] According to this aspect, a plurality of cantilever-shaped support pieces are provided independently of each other. As a result, when the upper end of each of the plurality of support pieces elastically deforms in the front-rear direction relative to the base end when the load of the seated person acts on it, the deformation is not hindered by the other support pieces. In addition, the plurality of support pieces have different elastic moduli. As a result, it is possible to make the amount of displacement of the upper end of the plurality of support pieces in the front-rear direction different when the load of the seated person acts on it. Therefore, when designing the lumbar support, it is possible to adjust the sitting comfort by making the elastic moduli of the plurality of support pieces different. As a result, it is possible to provide a lumbar support that can increase the degree of design freedom and provide a good sitting comfort.

[0007] (2) In the lumbar support relating to the above aspect (1), it is preferable that the multiple support pieces include a first support piece that is arranged at intervals in the left-right direction and has a pair of first vertical band portions extending upward from the base and a first horizontal band portion extending in the left-right direction to connect the upper ends of the pair of first vertical band portions, and a second support piece that is arranged at intervals in the left-right direction on the central side of the left-right direction relative to the pair of first vertical band portions and has a pair of second vertical band portions extending upward from the base, and a second horizontal band portion that is arranged below the first horizontal band portions and extends in the left-right direction to connect the upper ends of the pair of second vertical band portions. According to this aspect, when the load of the seated occupant acts from the front to the rear, the widthwise center portions of the first horizontal band portion of the first support piece and the second horizontal band portion of the second support piece are largely deflected rearward relative to the widthwise both end portions. Also, the upper end portions of the pair of first vertical band portions of the first support piece and the pair of second vertical band portions of the second support piece are largely deflected rearward relative to the base end portions connected to the base portions. Since the first support piece and the second support piece have different elastic moduli, when the weight of a seated person acts on the first support piece and the second support piece, the amount of displacement of the upper end of the first support piece in the front-rear direction can be made different. Therefore, when designing the lumbar support, the elastic moduli of the first support piece and the second support piece can be made different to adjust the sitting comfort.

[0008] (3) In the lumbar support relating to the above aspect (2), it is preferable that the first vertical belt portion is longer in the up-down direction than the second vertical belt portion, and therefore has a smaller elastic modulus than the second vertical belt portion. According to this aspect, the first vertical belt portion is softer than the second vertical belt portion by a simple means of setting the length of the first vertical belt portion to be greater than the length of the second vertical belt portion, and the amount of deformation when the load of the seated person acts on the first vertical belt portion is greater. That is, the elastic modulus of the first vertical belt portion can be made smaller than the elastic modulus of the second vertical belt portion. This allows the first support piece located above the second support piece on the back of the seated person to deform more significantly without complex design. Therefore, the seated person can be provided with a good sitting comfort.

[0009] (4) In the lumbar support according to the above aspect (2) or (3), it is preferable that the width dimension in the left-right direction of the first vertical belt portion and the second vertical belt portion is constant over the up-down direction. According to this aspect, the first vertical belt portion and the second vertical belt portion are prevented from locally bending, and each of them is elastically deformed as a whole, thereby providing a good sitting comfort to the seated occupant.

[0010] (5) In the lumbar support according to any one of the above aspects (2) to (4), it is preferable that the first horizontal band portion is longer in the left-right direction than the second horizontal band portion. According to this aspect, if the first and second horizontal belts have the same vertical dimension and front-rear thickness, the second horizontal belt is harder than the first horizontal belt. That is, the elastic modulus of the first support piece can be made smaller than that of the second support piece. This results in a smaller deformation amount of the second horizontal belt when the load of the seated person acts on the second horizontal belt than the first horizontal belt. This results in a larger deformation of the first support piece located higher than the second support piece on the back of the seated person. Therefore, a good sitting comfort can be provided to the seated person.

[0011] (6) In the lumbar support relating to any one of the above aspects (2) to (5), it is preferable that the multiple support pieces further include a third support piece that is provided on the left-right central side of the pair of second vertical band portions and extends upward from the base. According to this aspect, a third support piece is provided further inside the first support piece and the second support piece. The first support piece, the second support piece, and the third support piece have different elastic moduli, so that when the load of a seated person acts on the first support piece, the second support piece, and the third support piece, the amount of displacement of the upper end portion in the front-rear direction can be made different. Therefore, when designing the lumbar support, the elastic moduli of the first support piece, the second support piece, and the third support piece can be made different to adjust the sitting comfort.

[0012] (7) In the lumbar support relating to the above aspect (6), it is preferable that the third support piece is shorter in the vertical direction than the first vertical belt portion and the second vertical belt portion, and therefore has a greater elastic modulus than the first vertical belt portion and the second vertical belt portion. According to this aspect, in the center portion in the left-right direction, the first horizontal band portion of the first support piece, the second horizontal band portion of the second support piece, and the third support piece are arranged in sequence from top to bottom. Since the third support piece is shorter in the up-down direction than the first vertical band portion and the second vertical band portion, the third support piece is harder than the first vertical band portion and the second vertical band portion, and the amount of deformation when the load of the seated person acts is smaller. As a result, in the center portion in the left-right direction, the first horizontal band portion of the first support piece, the second horizontal band portion of the second support piece, and the third support piece are sequentially harder from top to bottom. That is, the elastic modulus can be increased in the order of the first support piece, the second support piece, and the third support piece. Such a lumbar support can provide a good seating feeling.

[0013] (8) In the lumbar support according to the above aspect (6) or (7), it is preferable that the third support piece has a width in the left-right direction greater than a length in the up-down direction. According to this aspect, it is easy to increase the elastic modulus in the front-rear direction starting from the lower end of the third support piece. Therefore, when the load of the seated person is input from above to the third support piece, it becomes easier to resist the load. Therefore, it is possible to provide a sense of firm support around the waist of the seated person.

[0014] (9) In a lumbar support relating to any one of the above aspects (6) to (8), it is preferable that the main body connection portion has a greater front-to-rear thickness than the load support portion and is arranged to overlap the left-to-right center portion of the base and at least a portion of the third support piece when viewed from the front-to-rear direction. According to this aspect, the main body connecting portion, which is thicker in the front-rear direction than the load support portion, is provided so as to overlap the left-right central portion of the base portion and at least a portion of the third support piece, thereby increasing the rigidity of the third support piece, thereby reducing the amount of front-rear displacement of the third support piece when the load of the seated person acts on the first support piece and the second support piece, and further improving the seating comfort.

[0015] (10) In the lumbar support relating to the above aspect (1), it is preferable that the multiple support pieces are arranged so that the elastic modulus decreases from the support pieces located at both left and right ends to the support pieces located in the center in the left and right direction. According to this aspect, the upper ends of the support pieces arranged at intervals in the left-right direction are displaced in the front-rear direction from both left-right ends toward the left-right center when the weight of the seated person acts on the support pieces. Such a lumbar support can provide a comfortable seating experience.

[0016] (11) In the lumbar support relating to the above aspect (10), it is preferable that the multiple support pieces are arranged so that their vertical length gradually increases from the support pieces located at both left and right ends to the support pieces located in the left and right center. According to this aspect, when the load of the seated person acts, the amount of displacement in the front-rear direction increases from the support pieces located at both left and right ends toward the support piece located at the center in the left and right direction. In other words, the elastic modulus can be made small from the support pieces located at both left and right ends to the support piece located at the center in the left and right direction. Such a lumbar support can provide a good seating feeling.

[0017] (12) A chair according to this aspect includes a lumbar support according to any one of the above aspects (1) to (11) and the chair body. According to this aspect, it is possible to provide a chair equipped with a lumbar support that increases design freedom and provides good seating comfort. Effect of the Invention

[0018] According to each of the above aspects, it is possible to increase the degree of freedom in design and provide a good seating comfort. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of a chair according to an embodiment of the present invention, seen from the left rear. [Diagram 2]FIG. [Diagram 3] FIG. 2 is a rear view of the load supporting portion of the lumbar support according to the embodiment of the present invention, as viewed from the rear. [Figure 4] 2 is a plan view of a load supporting portion of the lumbar support according to the embodiment of the present invention, viewed from above. FIG. [Diagram 5] 3 is a side cross-sectional view of a load supporting portion of the lumbar support according to the embodiment of the present invention. FIG. [Figure 6] FIG. 11 is a rear view of a load supporting portion of the lumbar support in a first modified example of the present embodiment. [Figure 7] FIG. 11 is a rear view of a load supporting portion of a lumbar support in a second modified example of the present embodiment. [Figure 8] FIG. 11 is a rear view of a load supporting portion of a lumbar support in a third modified example of the present embodiment. [Figure 9] FIG. 11 is a rear view of the load supporting portion of the lumbar support in a fourth modified example of the present embodiment. [Figure 10] FIG. 13 is a rear view of the load supporting portion of the lumbar support in a fifth modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Next, an embodiment of the present invention will be described with reference to the drawings. In the embodiments and modifications described below, the same reference numerals may be used to designate corresponding configurations, and the description may be omitted. In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," not only strictly indicate such arrangements, but also indicate a state in which the two surfaces are relatively displaced with an angle or distance to the extent that the same function is obtained. In this embodiment, "facing" does not only mean a case in which the orthogonal directions (normal directions) of the two surfaces are aligned with each other, but also includes a case in which the orthogonal directions intersect with each other.

[0021] [Chair 1] Fig. 1 is a perspective view of the chair 1 as seen from the rear left. Fig. 2 is a rear view of the chair 1. As shown in Fig. 1 and Fig. 2, the chair 1 has a chair body 1A and a lumbar support 100. The chair body 1A has a support structure 2, a seat 3, a backrest 4, and armrests 5. In the following description, the directions of front / back, up / down, left / right, etc. are the same as the directions of a person (seater) sitting in the chair 1 in a normal posture. In this case, the arrow UP in the drawings indicates the upward direction, the arrow FR indicates the forward direction, and the arrow LH indicates the left direction. In the following description, the side away from the center of the chair 1 in the front / back, up / down, and left / right directions may be referred to as the outer side, and the side toward the center of the chair 1 may be referred to as the inner side.

[0022] <Support structure 2> The support structure 2 includes a leg body 11 and a support base 12 . The leg body 11 includes a multi-pronged leg 13 and a leg column 14 . A caster 15 capable of running on a floor surface F is attached to each leg of the multi-legged stand 13.

[0023] The leg pillar 14 extends upward from the center of the multi-leg 13. A gas spring 16, which is a lifting mechanism for the chair 1, is built into the leg pillar 14. The gas spring 16 is configured such that an inner cylinder 16a is supported so as to be liftable and rotatable relative to an outer cylinder (not shown) provided within the leg pillar 14, for example.

[0024] The support base 12 is connected to the upper end of the leg pillar 14 (inner cylinder 16a). The support base 12 supports the seat 3 from below. The support base 12 supports the backrest 4 so that it can tilt.

[0025] <Location 3> The seat 3 is formed in a downwardly protruding arc shape when viewed from the front, and supports the portion of the seated person from the buttocks to the thighs from below. As shown in Figure 1, the seat 3 includes a seat shell 30 and a seat body 31. The seat shell 30 is a resin-molded plate-like member that forms the framework of the seat 3. The seat shell 30 is attached to the support base 12 in a state in which it covers the entire support base 12 from above. The seat main body 31 is supported from below by the seat shell 30. The seat main body 31 includes a cushioning material that is placed on the upper surface of the seat shell 30, and a skin material that covers the cushioning material from above.

[0026] <Backrest 4> The backrest 4 supports the seated occupant's lower back and back from behind. The backrest 4 is connected to the support base 12 so as to be tiltable about an axis along the left-right direction. However, the backrest 4 may also be connected to the support base 12 so as not to be tiltable.

[0027] The backrest 4 includes a back frame 41 and an upholstery material 42. The back frame 41 is a strength member that constitutes the outer shape of the backrest 4. The back frame 41 is integrally molded from a resin material or the like. The back frame 41 is formed in a circular arc shape that protrudes backward in a plan view, and in an S-shape in a side view. As shown in Figs. 1 and 2, the back frame 41 is formed in an 8 shape in a front view with the upper frame portion 41A and the lower frame portion 41B connected in the up-down direction. Specifically, the back frame 41 includes a pair of side frame members 43, a first connecting portion (connecting member) 51, a second connecting portion (connecting member) 52, and a third connecting portion (connecting member) 53.

[0028] Each of the pair of side frame members 43 has an upper side frame portion 44 and a lower side frame portion 45 . The upper side frame portion 44 has a first side frame portion 46 and a second side frame portion 47. The first side frame portion 46 constitutes the upper portion of the side frame member 43 and extends in the vertical direction. The first side frame portion 46 extends obliquely forward from the upper end portion to the lower end portion in a side view. The second side frame portion 47 extends downward from the lower end portion of the first side frame portion 46. The second side frame portion 47 extends obliquely backward from the upper end portion to the lower end portion in a side view. The second side frame portion 47 has a shorter length in the vertical direction than the first side frame portion 46. As a result, in the portion where the lower end portion of the first side frame portion 46 and the upper end portion of the second side frame portion 47 are connected, the upper side frame portion 44 has a bent portion in a portion located below the center in the vertical direction. Moreover, the first side frame portion 46 extends downward and outward in the left-right direction. The second side frame portion 47 extends downward and inward in the left-right direction from the lower end of the first side frame portion 46. As a result, in a front view, the pair of first side frame portions 46 are provided so as to gradually separate left and right as they go downward. Moreover, the pair of second side frame portions 47 are provided so as to gradually approach left and right as they go downward.

[0029] The lower side frame portion (third side frame portion) 45 extends downward from the lower end of the upper side frame portion 44. The lower side frame portion 45 extends downward and forward from the lower end of the second side frame portion 47 in a side view. In other words, the lower side frame portion 45 extends diagonally forward from the upper end to the lower end. The lower side frame portion 45 extends downward and outward in the left-right direction from the lower end of the second side frame portion 47. As a result, in a front view, the pair of lower side frame portions 45 are provided so as to gradually separate left and right in the downward direction. In a front view, the vertical middle portion of the lower side frame portion 45 overlaps with the outer end of the seat 3 in the left-right direction. The lower end of the lower side frame portion 45 is located below the seat 3. The front end of the lower side frame portion 45 is located forward of the bent portion of the upper side frame portion 44.

[0030] The first connecting portion 51 constitutes the upper end portion of the back frame 41. The first connecting portion 51 connects the upper ends of the first side frame portions 46 together. The first connecting portion 51 extends in the left-right direction in a convex arc shape toward the rear in a plan view. The vertical dimension of the first connecting portion 51 gradually increases toward the front.

[0031] The second connecting portion 52 connects the boundary between the lower end of the second side frame portion 47 and the upper end of the lower side frame portion 45. The second connecting portion 52 extends in the left-right direction in a convex arc shape toward the rear in a plan view. The thickness of the second connecting portion 52 in the up-down direction gradually increases from the rear to the front.

[0032] An upper frame portion 41A is configured by the first connecting portion 51, the upper side frame portion 44, and the second connecting portion 52. The upper frame portion 41A has an opening 41p that opens in the front-rear direction.

[0033] The third connecting portion 53 extends in the left-right direction and connects the lower ends of the lower side frame portions 45. The third connecting portion 53 is formed in a downwardly convex arc shape in a front view. The third connecting portion 53 is located forward of the second connecting portion 52 in a side view.

[0034] A base connecting portion (not shown) is provided in the left-right center of the third connecting portion 53. The back frame 41 is connected to the base 12 via the base connecting portion. An armrest attachment portion 57 is provided on each of both left and right ends of the third connecting portion 53. The armrest 5 is attached to the armrest attachment portion 57.

[0035] The upholstery material 42 forms a load-bearing surface that supports the upper body of the seated person, specifically, the waist to back of the seated person. The upholstery material 42 is provided so as to cover the opening 41p of the upper frame portion 41A from the front. The upholstery material 42 is configured to be elastically deformable, for example, by a membrane-like member such as mesh or cloth. The outer periphery of the upholstery material 42 is fixed to the outer surface of the upper frame portion 41A (the first connecting portion 51, the upper side frame portion 44, and the second connecting portion 52) so as to wrap the upper frame portion 41A. Note that the backrest 4 may be configured so that the back frame 41 is covered with a cushion and a skin material instead of the upholstery material 42.

[0036] <Armrest 5> The armrest 5 is connected to the back frame 41. The armrest 5 is attached to each armrest attachment part 57, and supports the portion of the seated occupant's elbow to forearm from below. The armrest 5 includes an armrest support member 80 and an armrest main body 81.

[0037] The armrest support member 80 is a member that connects the armrest attachment portion 57 and the armrest main body 81, and functions as a strength member of the armrest 5. The armrest support member 80 is formed in an L-shape when viewed from the front. The lower end of the armrest support member 80 is attached to the armrest attachment portion 57 from the outside in the left-right direction.

[0038] The armrest main body 81 is supported so as to be vertically movable relative to the armrest support member 80. The armrest main body 81 includes an armrest support 82 and an elbow rest portion 83. The armrest support pillar 82 is inserted from above the armrest support member 80 into an insertion hole 80a that vertically penetrates the armrest support member 80. The armrest support pillar 82 is configured to be able to move up and down along the insertion hole 80a.

[0039] The armrest 83 is provided on the upper end of the armrest support 82. The armrest 83 is formed, for example, by covering a shell and padding material with a skin material. The upper surface of the armrest 83 forms an armrest surface that supports the elbow of the seated occupant. The armrest 83 covers the armrest support 82 from above, and is attached to the armrest support 82 in a state where it protrudes in the front-to-back and left-to-right directions relative to the armrest support 82. The armrest 5 may be attached to the seat 3 or the support base 12. The armrest 5 may also be configured not to move up and down.

[0040] <Lumbar Support 100> A lumbar support 100 for supporting the waist of a seated person is provided in the center of the second connecting portion 52 in the left-right direction. The lumbar support 100 protrudes upward from the second connecting portion 52 so as to be positioned inside the upper frame portion 41A. The lumbar support 100 includes a lumbar support body 101 and an attachment portion 130.

[0041] Fig. 3 is a rear view of the load support portion 110 of the lumbar support 100 according to the embodiment of the present invention, as seen from the rear. Fig. 4 is a plan view of the load support portion 110 of the lumbar support 100 according to the embodiment of the present invention, as seen from above. Fig. 5 is a side cross-sectional view of the load support portion 110 of the lumbar support 100 according to the embodiment of the present invention. As shown in Fig. 1 and Fig. 3 to Fig. 5, lumbar support main body 101 includes load support portion 110 and main body connection portion 120. Lumbar support main body 101 is a molded product made of synthetic resin that is integrally formed by means of injection molding or the like. Although resin is given as an example of a material for forming lumbar support main body 101, materials other than resin may be used for lumbar support main body 101 as long as they are elastically deformable materials.

[0042] The load support portion 110 is a portion that comes into contact with the back of the seated person through the upholstery 42. The load support portion 110 supports the weight of the seated person from behind. The load support portion 110 is disposed in the center of the chair body 1A in the left-right direction. The load support portion 110 is formed in a plate shape along a plane intersecting the front-rear direction. Specifically, the load support portion 110 is formed in a circular arc shape that is convex toward the rear in the plan view shown in FIG. 4. Also, the load support portion 110 is formed in a circular arc shape that is convex toward the front in the vertical cross-sectional view shown in FIG. 5. The plate thickness of the load support portion 110 in the front-rear direction is uniform. The load support portion 110 is formed, for example, in a trapezoid shape when viewed from the front-rear direction as shown in FIG. 3.

[0043] As shown in FIG. 3, the load support portion 110 has a plurality of slits 111 and 112. In this embodiment, two slits 111 and 112 are formed in the load support portion 110. When viewed from the front, each of the slits 111 and 112 is formed in a U-shape that opens downward. The slit 112 is formed inside the slit 111 in a state in which the upper side and both the left and right sides of the slit 111 are surrounded. Each of the slits 111 and 112 penetrates the load support portion 110 in the plate thickness direction. The slits 111 and 112 have left and right extensions 111a and 112a and a pair of end extensions 111b and 112b. The left and right extensions 111a and 112a extend in the left and right direction along the upper side 110a of the load support portion 110. The end extensions 111b, 112b extend obliquely downward from both ends of the left and right extensions 111a, 112a in parallel with the side edges 110b on both left and right sides of the load support portion 110. In the illustrated example, the lower end of the slit 112 (left and right extension 112a) is located lower than the slit 111 (left and right extension 111a).

[0044] The load support portion 110 is formed with a base portion 113 and a plurality of support pieces 115 by the plurality of slits 111 and 112 . The base 113 is a portion of the load support portion 110 that is located below the slits 111 and 112. The base 113 extends in the left-right direction.

[0045] The multiple support pieces 115 are provided at intervals in the left-right direction. The multiple support pieces 115 are provided independently of each other. Each of the multiple support pieces 115 extends upward from the base 113. Each of the multiple support pieces 115 extends in a cantilever manner from a base end connected to the base 113 to a tip end. In this embodiment, a first support piece 116, a second support piece 117, and a third support piece 118 are provided as the multiple support pieces 115. In this embodiment, "independent" means that the support pieces 116 to 118 are not connected to each other except to the base 113, but each extends in a cantilever manner, and can be deformed without being affected by a load acting on the other support pieces 116 to 118.

[0046] The first support piece 116 is a portion of the load support portion 110 that is located above the base portion 113 and on the outer circumferential side of the slit 111. When viewed from the front, the first support piece 116 is formed in a U-shape that opens downward and extends along the outer circumferential edge of the load support portion 110 and the slit 111. The first support piece 116 has a pair of first vertical band portions 116a and a first horizontal band portion 116b. The pair of first vertical belt portions 116a are provided with a gap in the left-right direction. Each of the pair of first vertical belt portions 116a extends upward from both left-right ends of the base portion 113. The first vertical belt portion 116a extends upward from the base portion 113, inclining inward in the left-right direction. The first horizontal belt portion 116b extends in the left-right direction and connects the upper ends of the pair of first vertical belt portions 116a to each other. As shown in FIG. 5, the chamfered portion located at the upper edge of the first horizontal belt portion 116b has a larger radius of curvature than the chamfered portions formed on the peripheral portions of the other support pieces 116 to 118. That is, the thickness of the upper end portion of the first horizontal belt portion 116b in the front-rear direction gradually decreases as it goes upward. Such a first support piece 116 is formed as a cantilever that can elastically deform in the front-to-rear direction, with the base ends of a pair of first vertical belt portions 116a as fixed ends, and the upper ends of the first vertical belt portions 116a and the first horizontal belt portions 116b as free ends.

[0047] The first vertical band portion 116a has a height H1 in the up-down direction. The first vertical band portion 116a has a width W11 in the left-right direction that is constant throughout the up-down direction. The first horizontal band portion 116b has a width W12 in the up-down direction that is constant across the left-right direction. The first horizontal band portion 116b has a length L1 in the left-right direction.

[0048] The second support piece 117 is a portion of the load support portion 110 that is above the base portion 113 and is surrounded by the slits 111 and 112. When viewed from the front, the second support piece 117 is formed in a U-shape that is slightly smaller than the first support piece 117. The second support piece 117 has a pair of second vertical band portions 117a and a second horizontal band portion 117b. The pair of second vertical belt portions 117a are provided on the inner side (center side) of the pair of first vertical belt portions 116a in the left-right direction, with a gap therebetween. The pair of second vertical belt portions 117a are provided with a gap therebetween in the left-right direction. Each of the pair of second vertical belt portions 117a extends upward from the base portion 113. The second vertical belt portion 117a extends upward from the base portion 113, inclining inward in the left-right direction. The second horizontal belt portion 117b is provided below the first horizontal belt portion 116b with a gap therebetween. The second horizontal belt portion 117b extends in the left-right direction to connect the upper ends of the pair of second vertical belt portions 117a to each other. Such a second support piece 117 is formed as a cantilever that can elastically deform in the front-to-rear direction, with the base ends of a pair of second vertical belt portions 117a as fixed ends, and the upper ends of the second vertical belt portions 117a and the second horizontal belt portions 117b as free ends.

[0049] The second vertical band portion 117a has a height H2 in the up-down direction. The height H2 of the second vertical band portion 117a is lower than the height H1 of the first vertical band portion 116a. The second vertical band portion 117a has a width W21 in the left-right direction that is constant throughout the up-down direction. The width W21 of the second vertical band portion 117a is approximately the same as the width W11 of the first vertical band portion 116a. The second horizontal band portion 117b has a width W22 in the up-down direction that is constant across the left-right direction. The second horizontal band portion 117b has a length L2 in the left-right direction. The length L2 of the second horizontal band portion 117b is shorter than the length L1 of the first horizontal band portion 116b. In other words, the first horizontal band portion 116b is longer in the left-right direction than the second horizontal band portion 117b.

[0050] The third support piece 118 is provided on the inner side (center side) in the left-right direction with respect to the pair of second vertical band portions 117a. The third support piece 118 extends upward from the left-right center of the base portion 113. The third support piece 118 is formed in a trapezoidal shape when viewed from the front, and a left-right width W31 gradually decreases from the bottom to the top. Such a third support piece 118 is generally formed in a cantilever shape that is elastically deformable in the front-rear direction, with the base end connected to the base 113 serving as a fixed end and the upper end serving as a free end.

[0051] The third support piece 118 has a height H3 in the up-down direction. The height H3 of the third support piece 118 is lower than the height H1 of the first vertical belt portion 116a and the height H2 of the second vertical belt portion 117a. In other words, the third support piece 118 is shorter in the up-down direction than the first vertical belt portion 116a and the second vertical belt portion 117a. The width W31 of the third support piece 118 is wider than the width W11 of the first vertical belt portion 116a and the width W21 of the second vertical belt portion 117a. In other words, the third support piece 118 is longer in the left-right direction than the first vertical belt portion 116a and the second vertical belt portion 117a. In addition, the width W31 of the third support piece 118 is larger than the height H3. This suppresses the amount of deformation of the third support piece 118 when a load from a seated person acts on it.

[0052] The first support piece 116, the second support piece 117, and the third support piece 118 have a uniform thickness, and the height in the up-down direction and the width in the left-right direction are made different to make the elastic modulus different. Specifically, the elastic modulus increases in the order of the first support piece 116, the second support piece 117, and the third support piece 118. Therefore, the load support part 110 is set so that the elastic modulus increases from the outer periphery side to the inner periphery side. When a seated person leans against the backrest 4 and a part of the seated person's upper body (back) acts on the load support portion 110 of the lumbar support 100, the first support piece 116, the second support piece 117, and the third support piece 118 are displaced (elastically deformed) so that the upper end portion (tip portion) bends backward with respect to the base end portion connected to the base portion 113. At this time, the elastic modulus of the first support piece 116, the second support piece 117, and the third support piece 118 increases in the order of the first support piece 116, the second support piece 117, and the third support piece 118. For this reason, the first support piece 116 located on the outer periphery side of the lumbar support 100 is most likely to deform due to the load of the seated person, and the amount of deformation decreases in the order of the second support piece 117 and the third support piece 118. As a result, the seated person is supported softly by the outer periphery of the lumbar support 100, and feels a firmer support as the seated person approaches the inner periphery. When each of the multiple support pieces 115 is deformed, the intermediate portion between the base end and the upper end may or may not be bent in the front-rear direction (thickness direction of the support piece 115).

[0053] 2, a grip portion 121 is provided on each of both left and right ends of the lower end of the load support portion 110. Each grip portion 121 protrudes rearward from the load support portion 110. A seated person grips the grip portion 121 when, for example, adjusting the position of the lumbar support main body 101.

[0054] The main body connection part 120 is a part that connects the load support part 110 to the attachment part 130. The main body connection part 120 is provided at the center and lower part of the load support part 110 in the left-right direction. The main body connection part 120 protrudes rearward from the load support part 110. The main body connection part 120 has a greater thickness in the front-rear direction than the load support part 110. As shown in FIG. 3, the main body connection part 120 also extends in the up-down direction. The upper end part of the main body connection part 120 overlaps with the load support part 110 in the front-rear direction. The main body connection part 120 is provided so as to overlap with the center part in the left-right direction of the base part 113 and a part of the third support piece 118 when viewed from the front-rear direction. In addition, the lower end part of the main body connection part 120 protrudes downward from the load support part 110.

[0055] As shown in FIG. 2, the main body connection part 120 is connected to an attachment part 130 provided rearward of the load support part 110 . The mounting portion 130 is a member for mounting the lumbar support main body 101 to the chair main body 1A. The mounting portion 130 is attached to the left-right center of the second connecting portion 52 by a bolt (not shown) or the like. The mounting portion 130 extends upward from the second connecting portion 52. The mounting portion 130 incorporates a slide mechanism (not shown) that allows the main body connecting portion 120 of the lumbar support main body 101 to slide in the up-down direction. The slide mechanism is configured to be able to adjust the position of the main body connecting portion 120 to a plurality of positions in the up-down direction. This allows the lumbar support main body 101 to have an adjustable position in the up-down direction relative to the back frame 41.

[0056] The lumbar support 100 of this embodiment is provided with a plurality of cantilevered support pieces 115 arranged at intervals in the left-right direction, extending upward from a base 113, and arranged independently of one another, and the plurality of support pieces 115 are configured to have different elastic moduli. According to this configuration, the multiple cantilevered support pieces 115 are provided independently of each other. As a result, when the upper end of each of the multiple support pieces 115 elastically deforms in the front-rear direction relative to the base end when the load of the seated person acts on it, the deformation is not hindered by the other support pieces 115. The multiple support pieces 115 (the first support piece 116, the second support piece 117, and the third support piece 118) have different elastic moduli. As a result, it is possible to make the amount of displacement of the upper end of the multiple support pieces 115 in the front-rear direction different when the load of the seated person acts on it. Therefore, when designing the lumbar support 100, it is possible to adjust the sitting comfort by making the elastic moduli of the multiple support pieces 115 different. As a result, it is possible to provide a lumbar support 100 that can increase the degree of design freedom and provide a good sitting comfort.

[0057] In the lumbar support 100 of this embodiment, the multiple support pieces 115 are configured to include a first support piece 116 having a pair of first vertical band portions 116a and first horizontal band portions 116b, and a second support piece 117 having a pair of second vertical band portions 117a and second horizontal band portions 117b. According to this configuration, when the load of the seated person acts from the front to the rear, the first horizontal belt portion 116b of the first support piece 116 and the second horizontal belt portion 117b of the second support piece 117 mainly contact the back of the seated person. This ensures a large contact area between the first support piece 116 and the second support piece 117 and the seated person, and provides the seated person with a stable feeling of support. In addition, the pair of first vertical belt portions 116a of the first support piece 116 and the pair of second vertical belt portions 117a of the second support piece 117 are each bent backward by the load acting on the first horizontal belt portion 116b and the second horizontal belt portion 117b. Furthermore, the left-right center portions of the first horizontal belt portion 116b and the second horizontal belt portion 117b are also bent backward with respect to both left-right end portions connected to the pair of first vertical belt portions 116a and second vertical belt portions 117a. In this manner, the first support piece 116 and the second support piece 117 are elastically deformed as a whole, thereby providing a comfortable sitting experience. Since the first support piece 116 and the second support piece 117 have different elastic moduli, when the weight of a seated person acts on the first support piece 116 and the second support piece 117, the amount of displacement of the upper end in the front-rear direction can be made different. Therefore, when designing the lumbar support 100, the elastic moduli of the first support piece 116 and the second support piece 117 can be made different to appropriately adjust the sitting comfort.

[0058] In the lumbar support 100 of this embodiment, the first vertical belt portion 116a is longer in the up-down direction than the second vertical belt portion 117a, and is therefore configured to have a smaller elastic modulus than the second vertical belt portion 117a. According to this configuration, the first vertical belt portion 116a is softer than the second vertical belt portion 117a by a simple means of setting the length of the first vertical belt portion 116a to be greater than the length of the second vertical belt portion 117a, and the amount of deformation when the load of the seated person acts on the first vertical belt portion 116a is greater. That is, the elastic modulus of the first vertical belt portion 116a can be made smaller than the elastic modulus of the second vertical belt portion 117a. This allows the first support piece 116, which is located above the second support piece 117 on the back of the seated person, to deform more greatly without complex design. Therefore, the first support piece 116, which is located on the outer periphery of the lumbar support 100 and is easily deformed, can suppress the support reaction force from the lumbar support 100 from acting locally strongly on the seated person, thereby suppressing the occurrence of discomfort. In addition, the second support piece 117 located below the first support piece 116 is less deformed by the weight of the seated person, so the seated person feels a firm support for the waist area by the inner periphery of the lumbar support 100. Therefore, the seated person can feel a good sitting comfort.

[0059] In the lumbar support 100 of this embodiment, the first vertical belt portion 116a and the second vertical belt portion 117a are configured so that the width dimension in the left-right direction is constant over the up-down direction. According to this configuration, the first vertical belt portion 116a and the second vertical belt portion 117a are prevented from bending locally, and each of them is elastically deformed as a whole, thereby providing a comfortable sitting experience to the seated person.

[0060] In the lumbar support 100 of this embodiment, the first horizontal band portion 116b is configured to be longer in the left-right direction than the second horizontal band portion 117b. According to this configuration, the second horizontal belt portion 117b is harder than the first horizontal belt portion 116b. That is, the elastic modulus of the first support piece 116 can be made smaller than that of the second support piece 117. As a result, the second horizontal belt portion 117b is deformed less than the first horizontal belt portion 116b when the weight of the seated person acts on the second horizontal belt portion 117b. As a result, the first support piece 116, which is located higher than the second support piece 117 on the back of the seated person, is deformed more. Therefore, the seated person can be provided with a good sitting comfort.

[0061] In the lumbar support 100 of the present embodiment, the plurality of support pieces 115 further include a third support piece 118 on the left-right central side of the pair of second vertical band portions 117a. According to this configuration, the third support piece 118 is provided further inside the first support piece 116 and the second support piece 117. The first support piece 116, the second support piece 117, and the third support piece 118 have different elastic moduli, so that when the weight of a seated person acts on the first support piece 116, the second support piece 117, and the third support piece 118, the displacement amount in the front-rear direction of the upper end portion can be made different. Therefore, when designing the lumbar support 100, the elastic moduli of the first support piece 116, the second support piece 117, and the third support piece 118 can be made different to adjust the sitting comfort.

[0062] In the lumbar support 100 of this embodiment, the third support piece 118 is shorter in the vertical direction than the first vertical belt portion 116a and the second vertical belt portion 117a, and is therefore configured to have a greater elastic modulus than the first vertical belt portion 116a and the second vertical belt portion 117a. According to this configuration, in the center of the lumbar support 100 in the left-right direction, the first horizontal belt portion 116b of the first support piece 116, the second horizontal belt portion 117b of the second support piece 117, and the third support piece 118 are arranged in sequence from top to bottom. Since the third support piece 118 is shorter in the up-down direction than the first vertical belt portion 116a and the second vertical belt portion 117a, the third support piece 118 is harder than the first vertical belt portion 116a and the second vertical belt portion 117a, and the amount of deformation when the load of the seated person acts is smaller. In other words, the elastic modulus can be increased in the order of the first support piece 116, the second support piece 117, and the third support piece 118. As a result, in the left-right central portion of the lumbar support 100, the first horizontal belt portion 116b of the first support piece 116, the second horizontal belt portion 117b of the second support piece 117, and the third support piece 118 become harder from top to bottom. At the outer periphery of the lumbar support 100, the first support piece 116, which is easily deformed, suppresses the strong localized support reaction force from the lumbar support 100, thereby suppressing the occurrence of discomfort. In addition, the deformation amount due to the load of the seated person becomes smaller in the second support piece 117, the third support piece 118, and so on toward the inner periphery (downward) of the lumbar support 100, so that the seated person feels a firm support feeling around the waist. Such a lumbar support 100 can provide a good seating feeling.

[0063] In the lumbar support 100 of the present embodiment, the third support piece 118 is configured such that the width W31 in the left-right direction is larger than the length H3 in the up-down direction. This configuration makes it easy to increase the elastic modulus in the front-rear direction starting from the lower end of the third support piece 118. Therefore, when the load of the seated person is input from above to the third support piece 118, it becomes easier to resist the load. Therefore, a sense of firm support can be given to the seated person around the waist.

[0064] In the lumbar support 100 of this embodiment, the main body connection portion 120 is thicker in the front-to-rear direction than the load support portion 110, and is configured to overlap the left-to-right center portion of the base portion 113 and a portion of the third support piece 118 when viewed from the front-to-rear direction. According to this configuration, main body connection part 120, which is thicker in the front-rear direction than load support part 110, is provided so as to overlap with the left-right central part of base part 113 and at least a part of third support piece 118, thereby increasing the rigidity of third support piece 118. This reduces the amount of displacement of third support piece 118 in the front-rear direction when the load of a seated person acts on first support piece 116 and second support piece 117, thereby further improving the seating comfort.

[0065] The chair 1 of this embodiment includes the above-mentioned lumbar support 100 and a chair body 1A. According to this configuration, it is possible to provide a chair 1 equipped with a lumbar support 100 that increases the degree of freedom in design and provides a comfortable sitting experience.

[0066] (Modification of the embodiment) Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible without departing from the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the attached claims. In the above embodiment, the load support portion 110 of the lumbar support 100 is configured to include the first support piece 116, the second support piece 117, and the third support piece 118 as the multiple support pieces 115, but is not limited to this configuration. The outer shape of the load support portion 110 and the number and shape of the multiple support pieces 115 can be changed as appropriate. FIG. 6 is a rear view of the load supporting portion 110B of the lumbar support 100 in the first modified example of this embodiment. 6, the load support portion 110B of the lumbar support 100 may be rectangular in a front view. The load support portion 110B has a first support piece 116B, a second support piece 117B, and a third support piece 118B as a plurality of support pieces 115. A pair of first vertical belt portions 116a of the first support piece 116B and a pair of second vertical belt portions 117a of the second support piece 117B may extend in the up-down direction.

[0067] FIG. 7 is a rear view of a load supporting portion 110C of a lumbar support 100 in a second modified example of the present embodiment. As shown in FIG. 7, the upper side 110c of the load support portion 110C of the lumbar support 100 may be arc-shaped in front view. The load support portion 110C may have a first support piece 116C, a second support piece 117C, a third support piece 118C, and a fourth support piece 119C as the multiple support pieces 115. Each of the pair of first vertical bands 116a of the first support piece 116C, the pair of second vertical bands 117a of the second support piece 117C, and the pair of third vertical bands 118a of the third support piece 118C may extend upward and outward in the left-right direction. The first horizontal bands 116b of the first support piece 116C, the second horizontal bands 117b of the second support piece 117C, and the third horizontal bands 118b of the third support piece 118C may extend in an arc-shaped manner in front view.

[0068] FIG. 8 is a rear view of a load supporting portion 110D of a lumbar support 100 in a third modified example of the present embodiment. As shown in FIG. 8, the load support portion 110D of the lumbar support 100 in this modification includes support pieces 131A to 137A as the multiple support pieces 115. The support pieces 131A to 137A are provided at intervals in the left-right direction. The support pieces 131A to 137A extend upward from the base 113. Each of the support pieces 131A to 137A is formed in a cantilever shape with a base end connected to the base 113 as a fixed end and an upper end as a free end that can elastically deform in the front-rear direction. The support pieces 131A to 137A have different elastic moduli. The support pieces 131A to 137A are provided so that the vertical length gradually increases from the support pieces 131A and 137A located at both left-right ends to the support piece 134A located at the center in the left-right direction. As a result, the elastic modulus of the support pieces 131A to 137A decreases from the support pieces 131A, 137A located at both ends in the left-right direction toward the support piece 134A located in the center in the left-right direction.

[0069] In the lumbar support 100 of the third modified example of the above embodiment, the multiple support pieces 131A to 137A are configured so that the elastic modulus decreases from the support pieces 131A, 137A located at both left and right ends toward the support piece 134A located in the left and right center. According to this configuration, in the plurality of support pieces 131A-137A arranged at intervals in the left-right direction, the amount of displacement in the front-rear direction of the upper end of the support pieces 131A-137A increases from both left-right ends toward the left-right center when the weight of the seated person acts. That is, the elastic modulus can be made small from the support pieces 131A, 137A located at both left-right ends to the support piece 134A located at the left-right center. According to this lumbar support 100, a good seating feeling can be provided.

[0070] In addition, in the lumbar support 100 of the third modified example of the above embodiment, the multiple support pieces 131A to 137A are configured so that the length in the up-down direction gradually increases from the support pieces 131A, 137A located at both left-right ends toward the support piece 134A located in the left-right center. According to this configuration, the elastic modulus of the support pieces 131A to 137A decreases from both left and right ends toward the left and right center. As a result, the support piece 134A located at the left and right center is most easily deformed, and when the weight of the seated person acts on the lumbar support 100, the back of the seated person can be supported sequentially from the left and right center to both left and right ends of the lumbar support 100. According to this lumbar support 100, a comfortable seating feeling can be provided.

[0071] FIG. 9 is a rear view of a load supporting portion 110E of a lumbar support 100 in a fourth modified example of the present embodiment. As shown in Fig. 9, the load support portion 110E of the lumbar support 100 in this modification includes support pieces 131B-137B as the multiple support pieces 115. The support pieces 131B-137B are provided at intervals in the left-right direction. The support pieces 131B-137B may extend upward from the base 113 so as to expand outward in the left-right direction. Each of the support pieces 131B-137B may be formed so that the width in the left-right direction gradually increases from the bottom to the top.

[0072] FIG. 10 is a rear view of a load supporting portion 110F of a lumbar support 100 in a fifth modified example of the present embodiment. 10, the load support portion 110F of the lumbar support 100 in this modification has an upper side 110f that extends linearly in the left-right direction. The load support portion 110F is provided with support pieces 131C-137C as a plurality of support pieces 115. The support pieces 131C-137C may be configured such that the length of the support pieces 131C-137C gradually increases from the support pieces 131C, 137C located at both left-right ends toward the support piece 134C located in the left-right center by varying the length of the slits 114a-114f that extend downward from the upper side 110f.

[0073] (Other variations) Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible without departing from the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the attached claims. In the above embodiment, the configuration of each part of the chair body 1A has been described, but the configuration can be appropriately changed. In the above embodiment, the chair 1 is described as having the armrests 5, but the armrests 5 are not an essential component. In the above-described embodiment, the thickness of each support piece is uniform, and the length and width are different to make the elastic modulus of each support piece different, but this is not limited to the above configuration. The elastic modulus of each support piece may be different by changing at least one of the thickness, length, and width.

[0074] In addition, within the scope of the invention, the components in the above-described embodiments may be replaced with well-known components, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0075] 1 Chair 1A Chair body 100 Lumbar Support 110, 110B~110F Load support part 113 Base 115 Support piece 116, 116B, 116C First support piece 116a First vertical belt 116b First horizontal band 117, 117B, 117C Second support piece 117a Second vertical belt 117b Second horizontal belt 118, 118B, 118C Third support piece 120 Main unit connection part 131A~137A, 131B~137B, 131C~137C Support piece

Claims

1. A lumbar support attached to a chair body, A body connection part connectable to the chair body; a load support portion supported by the main body connection portion and supporting the load of a seated occupant from the rear; The load support portion is A base portion extending in the left-right direction; a plurality of cantilever-shaped support pieces that are arranged at intervals in the left-right direction, extend upward from the base, and are provided independently of one another; The plurality of support pieces have different elastic moduli. Lumbar support.

2. The plurality of support pieces include a first support piece including a pair of first vertical band portions spaced apart in the left-right direction and extending upward from the base, and a first horizontal band portion extending in the left-right direction and connecting upper ends of the pair of first vertical band portions; a second support piece including a pair of second vertical band portions provided at a left-right center side of the pair of first vertical band portions and spaced apart in the left-right direction and extending upward from the base, and a second horizontal band portion provided below the first horizontal band portion, extending in the left-right direction and connecting upper ends of the pair of second vertical band portions to each other; The lumbar support according to claim 1.

3. The first vertical band portion is longer in the up-down direction than the second vertical band portion, and therefore has a smaller elastic modulus than the second vertical band portion. The lumbar support according to claim 2.

4. The first vertical band portion and the second vertical band portion have a constant width dimension in the left-right direction along the up-down direction. The lumbar support according to claim 2.

5. The first horizontal band portion is longer in the left-right direction than the second horizontal band portion. The lumbar support according to claim 2.

6. The plurality of support pieces include a third support piece provided on a central side in the left-right direction of the pair of second vertical band portions and extending upward from the base portion. The lumbar support according to claim 2.

7. The third support piece is shorter in the up-down direction than the first vertical band portion and the second vertical band portion, and thus has a higher elastic modulus than the first vertical band portion and the second vertical band portion. The lumbar support according to claim 6.

8. The third support piece has a width in the left-right direction that is larger than a length in the up-down direction. The lumbar support according to claim 6.

9. The main body connection portion has a thickness in the front-rear direction greater than that of the load support portion, and is provided so as to overlap a left-right central portion of the base portion and at least a portion of the third support piece when viewed from the front-rear direction. The lumbar support according to claim 6.

10. The plurality of support pieces are provided such that the elastic modulus decreases from the support pieces located at both ends in the left-right direction toward the support pieces located at the center in the left-right direction. The lumbar support according to claim 1.

11. The plurality of support pieces are provided such that the vertical length gradually increases from the support pieces located at both left and right ends to the support pieces located at the center in the left and right direction. The lumbar support of claim 10.

12. A lumbar support according to claim 1 or 2; The chair body, A chair equipped with:

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