Chair cushion and manufacturing method of the same

Abstract

To provide a form that facilitates bending deformation even if a three-dimensional network state body composed of entwined resin fiber is used, in a chair cushioning material having a deformation allowable part capable of entanglement.SOLUTION: A seat 2 is provided with a resin-made inner shell 9 and a two-layer type cushioning material 10 stretched thereon, and the two-layer type cushioning material 10 (33, 34) is composed of a three-dimensional network state body. In the front part of the inner shell 9, there is formed a deformation allowable part 9a which is made of an oblong main slit 12 and a belt-like blank 14, and in the front part of the cushioning material 10, there is formed a deformation allowable part 10a which has a groove strip 35. Also, in the rear face of the deformation allowable part 10a of the cushioning material 10, there is arranged an auxiliary cushioning material 37 made of non-woven fabric and urethane resin. The three-dimensional network state body constituting the cushioning material 10 has a high elastic force, but because of the formation of the deep groove strip 35, entanglement can be facilitated.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a cushioning material for use in the seat or backrest of a chair and a manufacturing method thereof, and more particularly to a cushioning material that is configured to be rollable or bendable. [Background technology]

[0002] In chairs, the position of the front end of the seat is adjustable according to the physique and preferences of the user. Means for adjusting the position of the front end of the seat include moving the entire seat back and forth, and rolling the front part of the seat downward, an example of the latter being disclosed in Patent Document 1.

[0003] In the cited document 1, a plurality of horizontally long grooves are formed in the front part of the cushioning material, thereby making the front part of the cushioning material a deformation-permitting part, but the grooves are of a closed type, with thick parts on both the left and right sides. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-103068 A Summary of the Invention [Problem to be solved by the invention]

[0005] Now, urethane foam is often used as a cushioning material for the seats and backs of chairs, and it is believed that the cushioning material in Patent Document 1 is also made of urethane foam. However, urethane foam has problems such as poor breathability, not necessarily high elasticity, and a tendency for it to become worn out, which reduces its elastic restoring force over use.

[0006] On the other hand, there exists a nonwoven three-dimensional net-like material made by intertwining and bonding highly elastic resin fibers, which has excellent breathability, high resilience, and durability. By adjusting the fiber thickness and density, it is possible to achieve a fairly soft feel.

[0007] Therefore, this three-dimensional net-like body is being used as a cushioning material for seats and backrests, but when the three-dimensional net-like body is used as a cushioning material for roll-up seats, etc., problems arise in that the three-dimensional net-like body has a large elastic resistance, making it difficult to roll up smoothly or requiring a large force to roll up.

[0008] The object of the present invention is to solve this problem. [Means for solving the problem]

[0009] The present invention includes various configurations, examples of which are specified in each claim. The invention in claim 1 is directed to a cushioning material, "A chair cushion material having a bending deformation allowance portion that can be bent around a virtual axis, A three-dimensional network structure formed by three-dimensionally intertwining a group of twisted elastic fibers made of synthetic resin. A groove for facilitating bending deformation is formed on the back surface of the bending deformation-permitting portion on the side opposite to the side on which the load of the seated person is applied, so as to extend over the entire length in the imaginary axis direction. The structure is as follows.

[0010] The invention of claim 2 is an example of the development of claim 1. "The grooves are arranged in parallel, the bending deformation allowance portion is formed in a bellows shape, and the density is higher at the bottom of the grooves than at other portions." The structure is as follows.

[0011] The invention of claim 3 is an example of the development of claim 2, "A seat cushion material in which the front part is a bending deformation allowable part that can be rolled down, A plurality of grooves are formed on the lower surface of the bending deformation allowance portion, spaced apart from each other in the front and rear directions, so as to extend over the entire left and right length. The structure is as follows.

[0012] The invention of claim 4 is a development example of claim 2 or 3, "An auxiliary cushioning material (auxiliary elastic material) made of nonwoven fabric or foamed elastic material is layered on the back surface of the bending deformation allowance portion." The structure is as follows.

[0013] The invention of claim 5 also embodies claim 2 or 3, "The grooves are at least half the depth of the cushioning material." The structure is as follows.

[0014] The invention of claim 6 is directed to a manufacturing method. That is, it is a manufacturing method of a cushion material for a chair having a bending deformation allowance part that can be bent and deformed around a virtual axis line, and this manufacturing method is as follows: "A process for preparing a sheet-like material having a substantially uniform thickness formed by three-dimensionally intertwining a group of elastic fibers made of synthetic resin; a heat pressing process for forming a groove extending long in the imaginary axis direction by heat pressing on a back surface of the material at a portion that becomes the bent portion deformation allowance portion and that faces the seat occupant; It is equipped with The structure is as follows.

[0015] The invention of claim 7 is an example of the development of claim 6. "A method of manufacturing a seat cushion material in which the front part is a bending deformation allowable part that can be rolled down, In the portion of the material that will become the bending deformation allowance portion, a plurality of the grooves aligned in the bending direction are formed so as to extend over the entire left and right length. The structure is as follows. Effect of the Invention

[0016] The cushioning material of the present invention is composed of a three-dimensional net-like body, and therefore has excellent breathability, cushioning properties, and durability, but since grooves are formed on the back surface along the entire length, the deformable portion can be easily bent and deformed. Therefore, the three-dimensional net-like body can be used as the cushioning material while ensuring the ease of bending of the deformable portion. Also, since the grooves are formed on the back surface, the unevenness does not appear on the front surface. Therefore, there is no deterioration in aesthetics.

[0017] The number of grooves may be set according to the function of the cushioning material, but in cases where the width of the deformation-allowing portion is larger than a certain extent, such as in roll-up type cushioning materials, by forming multiple grooves as in claims 2 and 3, the deformation-allowing portion can be bent into a neat shape with light force.

[0018] If the bottom portion of the groove is made to have a higher density than other portions as in claim 2, the shape retention function of the deformable portion is increased by the bottom portion, so that when the deformable portion is rolled (bent) around an imaginary axis, torsional deformation can be suppressed and the portion can be rolled neatly (it can be rolled neatly, just like rolling a blind).

[0019] By arranging an auxiliary cushioning material on the back side of the deformable portion as in claim 4, it is possible to ensure the ease of bending deformation of the deformable portion while preventing it from being deformed by the user's body pressure, thereby ensuring shape stability.

[0020] The depth of the grooves can be set arbitrarily, but if the depth is set to more than half the thickness of the cushioning material as in claim 5, bending deformation can be facilitated while the cushioning material maintains a high elastic restoring force. In this case, if an auxiliary cushioning material is arranged in combination with claim 4, deformation of the deformation-permitting portion in the thickness direction can be reliably prevented, stabilizing the shape of the cushioning material and improving its quality. Another advantage is that even if the fibers that make up the cushioning material break due to repeated use of the deformation-permitting portion, generating fragments (broken pieces), the auxiliary cushioning material can prevent the fragments from falling to the floor.

[0021] Although it is possible to manufacture the cushioning material with the grooves already formed using a special mold, this poses problems such as increased manufacturing costs due to the need for an expensive mold and the time required for filling the fibers, as well as the time required for changing dimensions. In contrast, if the grooves are formed by hot pressing using a sheet material as in claim 5, commercially available sheet materials can be used, which reduces costs and stabilizes quality.

[0022] In addition, since the density of the fibers is high at the bottom of the grooves, the support strength of the deformation-permitting portion is not reduced, and the shape is stable. In particular, when a plurality of grooves are provided to form the deformation-permitting portion in a bellows shape as in claim 7, it is preferable because it has the same effect as that described in claim 2. [Brief description of the drawings]

[0023] [Figure 1] 1A to 1C are diagrams of a chair to which an embodiment of the present invention is applied, where (A) is a perspective view seen from the front, (B) is a partially separated perspective view seen from the front, (C) is a perspective view seen from below and behind, and (D) is a partial perspective view of the inner shell. [Diagram 2] FIG. 1B is an exploded perspective view of the chair, and FIG. 1B is a perspective view of the seat from below. [Diagram 3] 1A and 1B are perspective views showing an inner shell and a slider separated from each other, and FIG. 1C is a partial side view showing the relationship between the inner shell and the slider. [Figure 4] FIG. 4 is a bottom view showing the inner shell and the cushioning material separated from each other. [Diagram 5] FIG. 5 is a cross-sectional view taken along line VV of FIG. 4. [Figure 6] FIG. 6 is another example view taken at the same location as FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to the seat of a swivel-type rocking chair that is widely used for office work. In this application, terms such as "front and back" and "left and right" are used to specify directions, but these are based on the orientation of a person sitting in a normal posture. A front view is the direction facing the person sitting.

[0025] (1) Basic structure of chair and seat As shown in the figure, the chair to which this embodiment is applied is a swivel chair that is often used in offices, and the chair has as its basic elements a leg device 1, a seat 2, and a backrest 3. The leg device 1 has a structure in which a leg support 4 made of a gas cylinder is erected in the center of a base having five leg blades, and a caster is provided at the tip of each leg blade.

[0026] A base 5 is fixed to the upper ends of the leg supports 4, and left and right first tilting frames 6 and a second tilting frame 7 are connected to the base 5, and a backrest 3 is attached to these tilting frames 6, 7. A seat support mechanism 8 is attached to the base 5 for moving the seat 2 backward and tilting it backward in conjunction with the backward tilting of the backrest 3, and a seat outer shell (seat support shell body) (not shown) is fixed to the seat support mechanism 8, and the seat 2 is fixed to the outer shell.

[0027] As shown in Fig. 2(A), the seat 2 comprises an inner shell (seat plate) 9 made of synthetic resin, a cushion material 10 placed on top of the inner shell, and an upholstery (skin material) 11 covering the cushion material 10 from above. The inner shell 9 is concave upward when viewed from the front and is deeper at the rear when viewed from the side, and the cushion material 10 and the upholstery 11 are also shaped in the same way.

[0028] As shown in Figs. 4 and 5, a plurality of (five) horizontally long main slits 12 are formed in the area of ​​the front portion of the inner shell 9. Therefore, the area having the horizontally long main slits 12 is a deformable portion 9a that can be rolled up downward. The area behind the deformable portion 9a is a wide base portion 9b that does not deform, and the area in front of the deformable portion 9a is a narrow front rigid portion 9c that does not deform. When a pair of left and right joint brackets 13 protruding downward from the front rigid portion 9c are pulled backward, the deformable portion 9a is rolled up downward. This allows the front-rear position of the front end of the seat 2 to be adjusted.

[0029] The horizontally long main slit 12 of the inner shell 9 extends over the entire left-right length, and a pair of front and rear strip-shaped blanks 14 extending over the entire left-right length are disposed between adjacent horizontally long main slits 12. Each pair of strip-shaped blanks 14 is disposed in a downwardly spreading position, separated from each other by a horizontal sub-slit, and both left and right ends of each pair of blanks 14 are connected by an upper bridge 15, and both left and right ends of adjacent strip-shaped blanks 14 sandwiching the horizontally long main slit 12 are connected by a lower bridge 16.

[0030] The strip-shaped blank 14 located at the rear end is also connected to the base portion 9b by a lower bridge 16, and the strip-shaped blank 14 located at the front end is also connected to the front rigid portion 9c by a lower bridge 16. Therefore, the deformation-permitting portion 9a is composed of a group of strip-shaped blanks 14 and a group of upper and lower bridges 15, 16.

[0031] As shown in Fig. 1(D), the upper bridge 15 is disposed in the notched groove 17 at the upper part of the strip-shaped blank 14. Therefore, the upper end of the upper bridge 15 is at about the same height as the upper end of the strip-shaped blank 14. On the other hand, as shown in Fig. 3, for example, the lower bridge 16 protrudes below the strip-shaped blank 14. Therefore, the lower bridge 16 is easily deformed.

[0032] As shown in Figures 2(B) and 3, a group of boss bodies 18 for fixing to the outer shell are protrudingly provided on the underside of the inner shell. In addition, downward engaging projections 19 for fixing the front edge of the upholstery 11 are formed and scattered in the left and right direction on the front edge of the inner shell 9, and engaging holes 20 for fixing the left and right side edges and rear edge of the upholstery 11 are formed and scattered on the left and right side edges and rear edge of the inner shell 9.

[0033] 5, a band-shaped resin edge member 21 is attached or otherwise fixed to the peripheral edge of the upholstery 11, and the left, right, and rear end edge members 21 are formed with locking claws (not shown) that fit elastically from below into engagement holes 20 in the inner shell 9, and the front end edge member 21 is formed with engagement holes 22 that elastically fit into engagement protrusions 19 of the inner shell 9. Therefore, by overlapping the upholstery 11 on the cushion material 10 and then pressing the edge members 21 against the inner shell 9, the upholstery 11 is held in a state in which it does not come off the inner shell 9, and the cushion material 10 is fixed to the inner shell 9.

[0034] As shown in FIG. 2, the seat support mechanism 8 comprises left and right side members 25 in the front-to-rear longitudinal direction supported by the base 5 and the first tilting frame 6, and a base plate 26 fixed to the left and right side members 25. A sliding plate 27 having a portion protruding forward is attached to the base plate 26 so as to be able to slide forward and backward, and joint members 28 provided on both the left and right ends of the sliding plate 27 are connected to joint brackets 13 of the inner shell 9.

[0035] Specifically, as shown in FIG. 3, the joint bracket 13 is formed in a gate type when viewed from the front, having an opening 29, while the joint member 28 has a recess 30 into which the lower part of the joint bracket 13 fits, and a hook portion 31 that engages with the opening 29 of the joint bracket 13, and with the hook portion 31 engaged with the opening 29, the joint bracket 13 is held in the recess 30 of the joint member 28 so as not to be able to move up and down.

[0036] Therefore, when the joint member 28 and the slide plate 27 move back and forth, the joint bracket 13 moves back and forth and the deformation allowable portion 9a is rolled in and out. The back and forth movement of the slide plate 27 is performed by rotating a handle 32 shown in FIG.

[0037] (2) Cushioning material The cushioning material 10 is made of a three-dimensional net-like structure in which numerous elastic and twisted resin fibers such as polyester fibers are entangled and bonded together, thus providing a breathable structure. In this case, as shown in Fig. 5, the cushioning material 10 is made of a tough base layer 33 made of thick fibers and a soft surface layer 34 made of fine fibers densely entangled, and these two layers are heat-sealed together. The two-layer structure provides softness to the user's body while also providing elasticity and durability.

[0038] The portion of the cushion material 10 that overlaps with the deformation allowance portion 9a of the inner shell 9 also constitutes the deformation allowance portion 10a, and in order to facilitate bending deformation, a plurality of downwardly opening grooves 35 are formed in the deformation allowance portion 10a of the cushion material 10 so as to extend over the entire left-right length. The grooves 35 are located above the horizontally elongated main slits 12 of the inner shell 9.

[0039] The depth H of the groove 35 is greater than half the depth T / 2 of the thickness T of the cushion material 10. A recess 36 having a depth of several mm is formed over the entire left-right length on the back surface (lower surface) of the deformation-allowing portion 10a of the cushion material 10, and an auxiliary cushion material 37 made of a resin nonwoven fabric is disposed in this recess 36. The auxiliary cushion material 37 may be simply fitted into the recess 36, or may be fixed with an adhesive.

[0040] The cushioning material 10 is manufactured using a commercially available sheet material, and the part corresponding to the base layer 33 and the part corresponding to the surface layer 34 are overlapped and pressed (hot pressed) in a heated mold to integrate the base layer 33 and the surface layer 34 and molded into a shape that follows the profile of the inner shell 9. At this time, the grooves 35 are also processed at the same time. The parts of the cushioning material 10 where the grooves 35 are formed are compressed and deformed, so that the surface of the deformation-permitting part 10a becomes denser, as shown by the cross-hatched area in Fig. 5.

[0041] In the above configuration, the cushioning material 10 is made of a three-dimensional net-like material, so it has excellent breathability and excellent cushioning properties due to its high elastic recovery force. It is also highly durable and does not easily wear out. Furthermore, the surface layer 34 of the cushioning material 10 is made of fine fibers, so it is not stiff and feels good to the touch.

[0042] When the front rigid portion 9c of the inner shell 9 is pulled backward by the slide plate 27 shown in Fig. 3, the deformable portion 9a of the inner shell 9 and the deformable portion 10a of the cushioning material 10 are bent and deformed, and the deformable portions 9a, 10a are rolled downward. This allows the position of the front end of the seat 2 to be moved backward. Therefore, the position of the front end of the seat 2 can be adjusted according to the physique and preferences of the user.

[0043] When the deformation allowance portion 9a of the inner shell 9 is rolled in, the pair of strip-shaped blanks 14 change their postures so that the distance between their lower ends narrows, and the postures of adjacent strip-shaped blanks 14 across the horizontal main slit 12 also change so that the distance between their lower ends narrows. That is, when bending (rolling in), the postures of the group of strip-shaped blanks 14 change so that the distance between their lower ends narrows.

[0044] As the inner shell 9 bends, the deformation-permitting portion 10a of the cushioning material 10 is permitted to bend by narrowing the front-to-back distance at its lower end, but since a group of grooves 35 is formed corresponding to the horizontally elongated main slits 12 of the inner shell 9, the deformation-permitting portion 10a can be easily bent even in the cushioning material 10 made of a three-dimensional net-like body. Also, since the grooves 35 are formed by hot pressing, the upper part of the base layer 33 has a high density, but since the depth H of the grooves 35 is a dimension equal to or more than half the total thickness T of the cushioning material 10, resistance to bending can be greatly suppressed.

[0045] In addition, since the grooves 35 of the cushioning material 10 are formed continuously over the entire length, the deformable portion 10a can bend evenly over the entire length. This prevents partial swelling, realizing a smooth and beautiful appearance and providing a soft feel against the user's thighs.

[0046] In addition, because the auxiliary cushion material 37 is disposed on the back surface of the deformable portion 10a of the cushion material 10, the deformable portion 10a of the cushion material 10 has excellent shape retention, and bending deformation (rolling) can be performed in a neat state. In other words, the surface of the deformable portion 10a does not become uneven, and it has a smooth appearance. Furthermore, because the nonwoven fabric constituting the auxiliary cushion material 37 offers almost no resistance to bending, the provision of the auxiliary cushion material 37 hardly increases the resistance of the deformable portions 9a, 10a to bending operations.

[0047] In the embodiment of Fig. 5, the auxiliary cushion material 37 is configured as a single sheet and fitted into the recess 30, but as shown as a modified example in Fig. 6, it is also possible to fit auxiliary cushion material 37 formed in strips into each groove 35. In this case as well, the same effect as in Fig. 5 can be obtained.

[0048] Although the embodiment of the present invention has been described above, the present invention can be embodied in various other ways. For example, the cushioning material can be applied to a cushioning material that bends at a single hinge portion. In addition, in the case of a cushioning material for a seat, it is also possible to arrange a plurality of deformable portions in a state separated into the front and rear. In other words, it is also possible to adopt a configuration in which the front and rear portions of the seat bend downward independently.

[0049] The target components are not limited to seats, but can also be applied to backrests. In the case of backrests, it is possible to configure the upper or lower part or both to be rolled back. It can also be applied to headrests (neck rests). It is also possible to make the auxiliary cushioning material have a laminated structure. Needless to say, chairs also include single-seater or multi-seater sofas and benches. [Industrial Applicability]

[0050] The present invention is applicable to cushioning materials for chairs and is therefore industrially applicable. [Explanation of symbols]

[0051] 2nd seat 5. Bass 8 Seat support mechanism 9 Inner shell 9a Deformation allowance section 9b base 9c Front rigid part 10 Cushioning material 10a Deformable section 11 Upholstery 12 Horizontal main slit 13 Joint bracket 14 Strip blank 15 Upper Bridge 16 Lower Bridge 27 Slide plate 28 Joint material 32 Adjustment handle 33 Base layer 34 Surface layer 35 Groove 36 Recess 37 Auxiliary cushioning material

Claims

1. A chair cushion material having a bending deformation allowance portion that can be bent and deformed around a virtual axis line, A three-dimensional network structure formed by three-dimensionally intertwining a group of twisted elastic fibers made of synthetic resin. A groove for facilitating bending deformation is formed on the back surface of the bending deformation allowance portion on the side opposite to the side on which the load of the seated person is applied so as to extend over the entire length in the virtual axis direction. Chair cushioning.

2. A plurality of the grooves are arranged in parallel, the bending deformation allowing portion is formed in an accordion shape, and the density of the bottom portion of the grooves is higher than that of other portions.

2. A chair cushion material according to claim 1.

3. A seat cushion material having a front portion that can be rolled downward to allow bending deformation, A plurality of grooves are formed on the lower surface of the bending deformation allowance portion so as to extend across the entire length of the bending deformation allowance portion, the grooves being spaced apart from each other in the front and rear directions.

3. A chair cushion material according to claim 2.

4. An auxiliary cushioning material made of a nonwoven fabric or a foamed elastic body is superimposed on the back surface of the bending deformation allowance portion.

4. A chair cushion material according to claim 2 or 3.

5. The grooves are at least half the thickness of the cushioning material.

4. A chair cushion material according to claim 2 or 3.

6. A method for manufacturing a chair cushion material having a bending deformation allowance portion that can be bent about a virtual axis, comprising the steps of: A step of preparing a sheet-like material having a substantially uniform thickness formed by three-dimensionally entangling a group of elastic fibers made of synthetic resin; a heat pressing process for forming a groove extending long in the imaginary axis direction by heat pressing on a back surface of the material at a portion that becomes the bent portion deformation allowance portion and that faces the seat occupant; Equipped with A manufacturing method for chair cushioning.

7. A method for manufacturing a seat cushion material in which the front part is a bending deformation allowable part that can be rolled down, A plurality of the grooves arranged in the bending direction are formed in a portion of the material that will become the bending deformation allowance portion so as to extend over the entire left and right length. A method for producing the chair cushion material according to claim 6.

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