JPH1170280A - Manufacture of multilayered, different-hardness cushion, multilayered different-hardness cushion manufactured thereby, and seat and back of chair using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sufficient cushioning property and a fit even if overall thickness is reduced, to maintain sufficient strength to support the load of a user, etc., and to keep the boundary between soft and hard parts from being felt by the user. SOLUTION: A liquid of a first hard plastic foam 5 is poured over one end of the upper surface of a female mold 1, and after the liquid of the first plastic foam 5 has slightly foamed, a liquid of a second plastic foam 6 softer than the first plastic foam 5 is injected over almost the center of the upper surface of the female mold; after the liquid of the second plastic foam 6 has slightly foamed, a liquid of a third plastic foam 7 further softer than the second plastic foam 6 is poured over the other end of the upper surface of the female mold 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a cushion body having a plurality of layers having different hardnesses useful as a cushion material for a chair, a cushion body manufactured by the manufacturing method, and the cushion body. On the seat and back of a chair using

[0002]

2. Description of the Related Art Conventionally, as a cushion body having a plurality of layers having different hardnesses and a chair seat using the same, for example, JP-A-61-290013 and JP-B-62-37
No. 998, Japanese Utility Model Application Laid-Open No. 62-1915, Japanese Utility Model Application Publication No.
There is one disclosed in JP-A-2-8783.

[0003]

In each of these conventional devices, foams having different hardnesses are simply stacked one on top of another, or a hard foam is locally embedded in a soft foam. Or only the thickness of any of the layers was locally changed, and did not necessarily provide an optimal cushioning property to the human body.

[0004] Further, the conventional one is usually applied to a molded cushion body having a large thickness, such as an automobile seat, and is used for an office chair having a relatively small thickness. When it is applied to a cushion body for seats, etc., it lacks cushioning and fit, and does not have sufficient strength to support a seated person's buttocks, or a soft plastic foam and a hard plastic foam. There is a problem that the border is perceived by the occupant and the sitting comfort is impaired.

In view of the above problems, the present invention provides sufficient cushioning and fit even if the overall thickness is reduced, and has sufficient strength to support a user's load and the like. And a method for manufacturing a multi-layered cushion with a different hardness, in which a user can not feel the boundary between the soft part and the hard part to obtain a comfortable feeling of use. It is an object of the present invention to provide a cushion body using the method, and a seat and back of a chair using the cushion body.

[0006]

According to the present invention, the above-mentioned problem is solved as follows. (1) A stock solution of a hard first plastic foam is injected into one end of the upper surface of the lower mold, and after the stock solution of the first plastic foam slightly foams, it is softer than the first plastic foam. An undiluted solution of the second plastic foam is injected into a substantially central portion of the upper surface of the lower mold, and after the undiluted solution of the second plastic foam is slightly foamed, the second undiluted foam is softer than the second plastic foam. The stock solution of the plastic foam of No. 3 is injected into the other end of the upper surface of the lower mold.

(2) In the above item (1), the stock solution of the second plastic foam is sunk below the stock solution of the first plastic foam from the center of the upper surface of the lower mold to the one end. And, from the other end to the center of the lower mold, the undiluted solution of the third plastic foam is sunk below the undiluted solution of the second plastic foam, and the first, second and third undiluted plastic foams are removed. The undiluted solution of plastic foam,
By foaming and curing together in the foaming mold,
A first hardened region made of a first plastic foam, the first hardened region being continuous with the hardened region, and the upper layer gradually decreasing in occupation ratio from one end to the other end;
The lower layer is formed of a third plastic foam whose occupancy gradually increases from one end to the other end, and a second layer is formed between the two layers. A composite region in which a layer made of plastic foam is formed, and a soft region on the other end side which is continuous with the composite region and in which a second plastic foam forms an upper layer and a third plastic foam forms a lower layer. And are formed.

(3) In the above item (1), from the central portion of the upper surface of the lower mold to the one end portion, the stock solution of the second plastic foam is sunk below the stock solution of the first plastic foam, And, over the center of the other end of the lower mold,
The stock solution of the third plastic foam is sunk under the stock solution of the second plastic foam, and the stock solutions of the first, second and third plastic foams are put together in the foaming mold. Foamed and hardened to form a composite region in which the first plastic foam and the first plastic foam are continuous with the first plastic foam and the second plastic foam at approximately the same ratio. An intermediate region which is continuous with the composite region and is composed of only the second plastic foam; and an intermediate layer which is continuous with the intermediate region and the upper layer is formed of the second plastic foam and the lower layer is formed of the third plastic foam. And a soft region on the other end formed from a body.

(4) A multi-layer cushion with different hardness manufactured by the method according to claim 1 or 2, wherein a stock solution of the second plastic foam is applied from the center of the upper surface of the lower mold to the one end. Sink under the undiluted solution of 1 plastic foam, and over the center of the other end of the lower mold,
The stock solution of the third plastic foam is sunk under the stock solution of the second plastic foam, and the stock solutions of the first, second and third plastic foams are put together in the foaming mold. Foamed and hardened to form a composite region in which the first plastic foam and the first plastic foam are continuous with the first plastic foam and the second plastic foam at approximately the same ratio. An intermediate region which is continuous with the composite region and is composed of only the second plastic foam; and an intermediate layer which is continuous with the intermediate region and the upper layer is formed of the second plastic foam and the lower layer is formed of the third plastic foam. And a soft region on the other end formed from a body.

(5) A multi-layer cushion with different hardness, manufactured by the method according to claim 1 or 3, wherein said one end side hard region made of a first plastic foam is connected to said hard region. A composite region in which the first plastic foam and a second plastic foam softer than the first plastic foam overlap at substantially the same ratio; and a continuous, continuous composite region consisting of only the second plastic foam It is assumed that an intermediate region and a soft region on the other end side, which is continuous with the intermediate region, has an upper layer formed of a second plastic foam, and a lower layer formed of a third plastic foam.

(6) In the above item (4) or (5), a hard extension portion made of a first plastic foam and extending toward the other end side is provided on both sides of the hard region at one end portion. Provide.

(7) In the above item (4) or (6), in the composite area, the first and third plastic foams are wedge-shaped so that their respective tips point in opposite directions. 2 polymerizes on the upper and lower surfaces of the plastic foam.

(8) A chair seat using the multilayered different hardness cushion body according to any one of the above (4) to (7),
Being substantially horizontal, the first plastic foam is located at the rear and bottom, and the third plastic foam is located at the front and top.

(9) A back of a chair using the multilayered different hardness cushion according to any one of the above (4) to (7),
Being substantially vertical, the first plastic foam is located at the lower end and the third plastic foam is located at the upper end.

[0015]

4 to 8 show a first embodiment in which a multi-layered cushion cushion of the present invention is used for a chair seat, and FIGS. 1 to 3 illustrate a manufacturing method thereof. It is a schematic diagram.

First, the manufacturing method will be described with reference to FIGS. 1 to 3, and then the completed seat cushion will be described with reference to FIGS. As shown in FIG. 1, a concave portion (2) facing forward and upward is formed on the upper surface of the lower mold (1) constituting the foaming mold, the shape being in conformity with the shape of the upper surface of the seat cushion body. ing.

As shown in FIG. 5 and the like, the rear surface (3a) of the upper surface of the seat cushion body (3) is slightly raised, and
(3b) and the front part (3c) smoothly continue to the rear part (3a).

According to the shape of the upper surface of the seat cushion body (3), the concave concave surface (2) of the lower mold (1) has a valley (2a) corresponding to the rear part (3a) and a central part (2). 3b) and an upwardly inclined surface (2b) corresponding to the front part (3c).

The lower mold (1) is placed horizontally so that its valley (2a) is at the bottom (FIG. 1).

Then, the nozzle (4) is brought directly above the center of the valley (2a), and the stock solution of the hard first plastic foam is injected from the nozzle (4) into the valley (2a). As shown by the arrow in FIG. 2, the nozzle (4) is moved in the left-right direction so that the undiluted liquid pool (5 ′) of the first plastic foam (5), which is long in the left-right direction, is placed in the valley (2a). ) Is formed.

After the completion of this step, the nozzle (4) is moved to the center of the upwardly inclined surface (2b) of the recess (2) as shown by the arrow in FIG.

When the undiluted solution of the first plastic foam (5) injected long in the lateral direction begins to foam, the nozzle (4) moved to the center of the upwardly inclined surface (2b) passes through the nozzle (4). A second plastic foam softer than the first plastic foam
The stock solution (6) is injected to form a pool (6 ') at the center of the upwardly inclined surface (2a).

Next, as shown by the arrow in FIG. 1, the nozzle (4) is moved forward of the upwardly inclined surface (2b) of the recess (2).

When the undiluted solution of the second plastic foam (6) starts to foam, the nozzle (4) moved forward of the upwardly inclined surface (2b) further moves away from the second plastic foam. An undiluted solution of the soft third plastic foam (7) is injected to form a pool (7 ') in front of the upward inclined surface (2a).

Finally, as shown in FIG. 3, when the upper mold (8) is placed on the lower mold (1), the undiluted solution of the three types of injected plastic foams (5), (6) and (7) is obtained. Diffuses around as shown by the arrows in FIG. As shown in FIG. 3, the undiluted solution of the second plastic foam (6) injected after the first plastic foam (5) is injected first, and the first plastic foam is expanded while expanding upward. Foaming in all directions while sunk under the stock solution of foam (5),
The undiluted solution of the third plastic foam (7) injected from the back of the plastic foam (6) is foamed in four directions while dipping under the undiluted solution of the second plastic foam (6), Finally, the space defined by the lower mold (1) and the upper mold (8) is filled with the plastic foam (5) (6) (7).

At this time, as shown in FIG. 4, the undiluted solution of the hard plastic foam (5) diffused in the left and right direction reaches both side edges of the foaming mold and cannot be further diffused in the lateral direction. , Extending forward and forming a forward facing hard extension (9).

The completed cushion body (3) is shown in FIGS.
As shown in the figure, one end of the first plastic foam (5)
The other end is formed of a soft region (C) formed of the third plastic foam (7), and the intermediate portion thereof is formed from one end toward the other end. The occupation ratio of the plastic foam (5) gradually decreases, and the occupation ratio of the soft plastic foam (7) gradually increases, and the second occupancy between the two foams (5) and (7) increases. It consists of a composite area (B) on which a layer of plastic foam (6) is formed, and a hard extension (9) facing forward is formed at both ends of the hard area (A). I have.

In the composite area (B), the first plastic foam (5) and the third plastic foam (7) form a wedge shape whose respective tips point in opposite directions.
It is polymerized on the upper and lower surfaces of the second plastic foam (6).

The cushion body (3) is substantially bent so that the first plastic foam (5) is located at the rear and the bottom and the soft plastic foam (7) is located at the front and the top. By using it as a horizontal chair seat, sufficient cushioning and fit can be obtained even if the overall thickness is reduced, and sufficient strength to support the load of the user etc. can be maintained. In addition, the boundary between the soft part and the hard part is not perceived by the user, and a comfortable feeling of use is obtained.

In the second embodiment shown in FIGS. 9 to 13, the injection amount at the center of the hard plastic foam (5) is smaller than that of the first embodiment, and By increasing the amount of the plastic foams (6) and (7), the front-to-rear width of the central portion of the composite area (B) is shortened, and the intermediate area (C) comprising only the second plastic foam (6) is reduced. )When,
A second plastic foam continuous with the middle area (C)
A soft region (D) comprising (6) and the third plastic foam (7) is formed.

By adopting the structure as in the second embodiment, the cushioning property can be improved as compared with the first embodiment, and the buttocks of the seated person can be comfortably wrapped by the hard region (A). Can be supported.

Next, a third embodiment in which the multi-layered cushion cushion of the present invention is used on the back of a chair will be described with reference to FIGS.

First, the manufacturing method will be described with reference to FIGS. 14 to 16, and then the completed back cushion body will be described with reference to FIGS.

On the upper surface of the lower mold (10), a concave (1) facing forward and upward, which has a shape matching the shape of the front surface of the back cushion body.
1) is formed.

As shown in FIG. 17 and the like, the back cushion body
(12) has a substantially U shape in side view, and its lower part (12a), central part (12b) and upper part (12c) are smoothly continuous.

The concave portion (11) of the lower mold (10) has a valley (11a) corresponding to the lower portion (12a) of the back cushion body (12), a central portion (12b) and a front portion (11). 12c) and a corresponding upwardly inclined surface (11b).

The valley (11a) of the lower mold (10) and the upwardly inclined surface (11b)
In the same manner as in the first embodiment, the first, second, and third
Pool of stock solution of plastic foam (5) (6) (7)
(5 ') (6') (7 ') is formed, the upper mold (13) is placed on the lower mold (10), and three kinds of injected plastic foams (5)
(6) The stock solution of (7) is foamed.

As shown in FIGS. 17 and 18, the completed cushion body (12) has a hard region (A) made of a first plastic foam (5) at one end and a third region at the other end made of a third plastic foam (5). A soft region (C) made of a plastic foam (7), and an intermediate portion thereof moves from one end to the other end.
The occupancy of the first plastic foam (5) gradually decreases and the occupancy of the soft plastic foam (7) gradually increases, and the second occupancy between the two foams (5) and (7) increases. Composite area (B) on which a layer of plastic foam (6) is formed
At both ends of the hard region (A), forward hard extension portions (9) facing forward are formed.

The cushion body (12) is used as a back of a chair such that the first plastic foam (5) is located at the lower part and the soft plastic foam (7) is located at the upper part. Therefore, even if the overall thickness is reduced, sufficient cushioning and fit can be obtained, and sufficient strength to support the load of the user can be maintained. The user is not perceived by the boundary with the user, and a comfortable feeling of use is obtained.

Further, as in the second embodiment, the hard region
(D), a composite region (E), an intermediate region (F), and a soft region (G) are formed to form a back cushion body, with the hard region (D) as a lower portion and the soft region (G) as an upper portion. May be used.

Although the embodiment in which the multilayer different hardness cushion body of the present invention is used as a seat and a back of a chair has been described in detail, the multilayer different hardness cushion body of the present invention can be used for other purposes. In this case, the same effect as described above can be obtained.

[0042]

According to the present invention, the following effects can be obtained. (a) According to the first, second and fourth aspects of the present invention, a cushion body after molding obtained by foaming and hardening stock solutions of three types of plastic foams having different hardnesses in a foaming mold, One end portion is formed of a hard region, and the other end portion is formed of a soft region, and further, the middle portion gradually increases and decreases the occupation ratio of the first hard plastic foam and the third soft plastic foam, Since there is a composite area in which a second plastic foam layer having an intermediate hardness between both foams is formed between the two foams, even if the overall thickness is reduced, the soft area has more cushioning properties. And the hard region provides a fit, and the hard portion can maintain sufficient strength to support a load or the like of a user. Further, since the composite region is formed between the soft portion and the hard portion, the user does not feel the boundary between the soft region and the hard region, so that a comfortable feeling in use can be obtained.

(B) According to the first, third, and fifth aspects of the present invention, a cushion after molding is obtained by foaming a stock solution of three types of plastic foams having different hardness together in a foaming mold. The body has one end composed of a hard region, and the other end composed of a soft region.
The occupancy of the rigid first plastic foam and the soft third plastic foam gradually increases and decreases, and between the two foams, the second plastic foam having an intermediate hardness between the two foams. Since it is composed of a composite region in which a layer is formed and an intermediate region made of the second plastic foam, even if the overall thickness is reduced, sufficient cushioning is obtained in the soft region, and a fit feeling in the hard region is obtained. Is obtained,
Further, the rigid portion can maintain sufficient strength to support a load or the like of the user. In addition, since the composite region and the intermediate region are formed between the soft portion and the hard portion, the user does not feel the boundary between the soft region and the hard region, and a comfortable feeling of use can be obtained.

(C) According to the sixth aspect of the present invention, the buttocks and the back of the occupant can be supported by wrapping the buttocks and the back of the occupant from the left and right sides by the hard extension portions on both sides, and a comfortable sitting feeling can be obtained. Can be

(D) According to the seventh aspect of the invention, the occupation ratio of the soft portion and the hard portion can be gradually changed without the user perceiving the boundary between the soft portion and the hard portion.

(E) According to the eighth aspect of the present invention, the rear portion of the buttocks or the like that must support a large load is formed of a hard material, and the front portion is required to have cushioning properties for foot movement and the like. Is formed of a soft material, and the soft material is always disposed on the upper surface side which directly hits the occupant, thereby providing a comfortable seating of a chair in which a comfortable cushioning property and a feeling of fit are obtained. Can be.

(F) According to the ninth aspect of the present invention, the lower portion is formed of a hard material capable of firmly supporting the waist, and the upper portion is formed of a soft material which is required to have a cushioning property for movement of the upper body. In addition, a soft material is always disposed on the upper half side directly contacting the occupant, thereby providing a comfortable seat back with comfortable cushioning and fit. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing a lower mold and a stock solution injection nozzle for explaining a method of manufacturing a cushion body according to a first embodiment of the present invention.

FIG. 2 is a plan view of the lower mold shown in FIG.
It is a figure explaining diffusion of the stock solution of the 2nd and 3rd plastic foam.

FIG. 3 is a longitudinal sectional view of a foaming mold showing a foam that has completed foaming in a foaming mold composed of upper and lower molds.

FIG. 4 is a front view of the first embodiment of the seat cushion manufactured by the manufacturing method of the present invention.

FIG. 5 is a sectional view taken along line VV in FIG. 4;

6 is a sectional view taken along the line VI-VI of FIG.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 4;

FIG. 8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a front view of a second embodiment of the cushion body of the present invention.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

FIG. 11 is a sectional view taken along the line XI-XI in FIG. 9;

FIG. 12 is a sectional view taken along the line XII-XII in FIG. 9;

FIG. 13 is a sectional view taken along the line XIII-XIII of FIG. 9;

FIG. 14 is a longitudinal sectional view schematically showing a lower mold and a stock solution injection nozzle for describing a method of manufacturing a cushion body according to a third embodiment of the present invention.

FIG. 15 is a plan view of the lower mold shown in FIG. 14, illustrating the diffusion of the undiluted first, second and third plastic foams.

FIG. 16 is a longitudinal sectional view of a foaming mold showing a foam that has completed foaming in a foaming mold composed of upper and lower molds.

FIG. 17 is a front view of a third embodiment of the back cushion manufactured by the manufacturing method of the present invention.

FIG. 18 is a sectional view taken along the line XVIII-XVIII in FIG. 17;

[Explanation of symbols]

 (1) (10) Lower mold (2) (11) Concavity (2a) (11a) Valley (2b) (11b) Upward inclined surface (3) Cushion body for seat (3a) Rear part (3b) Central part (3c) Front (4) Nozzle (5) First plastic foam (5 ′) Pool of stock solution of first plastic foam (6) Second plastic foam (6 ′) Second plastic foam Pool of stock solution of body (7) Third plastic foam (7 ') Pool of stock solution of third plastic foam (8) (13) Upper mold (9) Hard extension (12) Cushion for back (12a) Lower part (12b) Middle part (12c) Upper part (A) (D) (H) Hard area (B) (E) (I) Composite area (C) (G) (J) Soft area (F) Middle region

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 105: 04

Claims (9)

[Claims] 1. An undiluted solution of a rigid first plastic foam is injected into one end of an upper surface of a lower mold, and after the undiluted solution of the first plastic foam is slightly foamed, the first undiluted foam is removed from the first plastic foam. An undiluted solution of a soft second plastic foam is injected into the lower mold at approximately the center of the upper surface, and after the undiluted solution of the second plastic foam is slightly foamed,
A method for producing a multilayered cushion having a different hardness, wherein a stock solution of a third plastic foam, which is softer than the plastic foam, is injected into the other end of the upper surface of the lower mold. 2. From the center of the upper surface of the lower mold to the one end, the stock solution of the second plastic foam is sunk under the stock solution of the first plastic foam, and
From the other end to the center of the lower mold, the undiluted solution of the third plastic foam is sunk under the undiluted solution of the second plastic foam, and the first, second and third plastic foams are removed. The undiluted solution is foamed and cured together in the foaming mold, so that the hard region on the one end side made of the first plastic foam and the hard region are continuous with each other, and the upper layer is formed from the other end from the one end side. Towards the end,
The lower layer is formed of a third plastic foam whose occupancy gradually increases from one end side to the other end side, which is formed by a first plastic foam whose occupancy gradually decreases, and A composite region in which a layer made of a second plastic foam is formed between the layers; and a second plastic foam forming an upper layer and a third plastic foam forming a lower layer which is continuous with the composite region. 2. The method for manufacturing a multilayered cushion having different hardness according to claim 1, wherein the soft region on the other end side is formed. 3. A stock solution of a second plastic foam is sunk below the stock solution of the first plastic foam from the center of the upper surface of the lower mold to the one end, and the other end of the lower mold is provided. Over the central portion of the above, let the stock solution of the third plastic foam dive below the stock solution of the second plastic foam, and these stock solutions of the first, second and third plastic foams are subjected to the foam molding. By foaming and curing together in the mold, the first plastic foam and the second plastic foam, which are continuous with the hard region on the one end side made of the first plastic foam and are continuous with the hard region, have substantially the same ratio. A composite region overlapping at a rate, an intermediate region continuous with the composite region and consisting solely of the second plastic foam, continuous with the intermediate region, the upper layer is formed from the second plastic foam, and the lower layer is The method according to claim 1, wherein a soft region on the other end formed from a third plastic foam is formed. 4. A multi-layer cushion body having a different hardness produced by the method according to claim 1 or 2, wherein said one end side hard region made of a first plastic foam is continuous with said hard region. The upper layer is formed of a first plastic foam whose occupation ratio gradually decreases from one end to the other end, and the lower layer is a third plastic occupation ratio that gradually increases from one end to the other end. And a composite region formed between the two layers and having a second plastic foam layer between the two layers, and a second plastic foam layer continuous with the composite region. And a soft plastic region on the other end side, wherein the third plastic foam forms a lower layer. 5. A multi-layered cushion member having a different hardness according to claim 1 or 3, wherein the first region is formed of a first plastic foam and is continuous with the first region. And a second plastic foam, which is softer than the first plastic foam, in a composite area where the plastic foam and the second plastic foam overlap each other at substantially the same ratio. A multi-layer comprising an area and a soft area on the other end side formed of a second plastic foam, the lower layer being continuous with the intermediate area, the lower layer being formed of a third plastic foam. Different hardness cushion body. 6. The multi-layer structure according to claim 4, wherein a hard extension made of a first plastic foam and extending toward the other end is provided on both sides of the hard region at one end. Hardness cushion body. 7. In the composite area, the first and third plastic foams are superposed on the upper and lower surfaces of the second plastic foam such that their respective tips are in the form of wedges that point in opposite directions. The multilayer different hardness cushion body according to claim 4 or 6. 8. A method according to claim 4, wherein the first plastic foam is located at the rear and the bottom, and the third plastic foam is located at the front and the top, while being substantially horizontal. A chair seat using the multi-layered cushioning body according to any of the above aspects. 9. The method according to claim 4, wherein the first plastic foam is located at the lower end and the third plastic foam is located at the upper end while being substantially vertical. The back of a chair using a multi-layer cushion body of different hardness.