JP3268486B2 - Manufacturing method of cushion body for backrest of chair - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushion for a backrest of a chair made of a foam having a plurality of layers having different hardnesses.
Foaming the body almost simultaneously in one foaming mold ,
On how to manufacture.

[0002]

Foams or with different layers of the Related Art Hardness
Conventionally, for example , a technique described in JP-B-62-37998 has been used for foaming the backrest cushion body of a chair made of the same almost simultaneously in one foaming mold.
Used .

[0003] According to such a simultaneous foam molding method , a plurality of layers having different hardnesses are separately formed and then bonded to each other to form a cushion body having a different hardness. In addition, the number of the foaming molds is one, and there is no need for the step of bonding a plurality of layers having different hardnesses. Further, there is an advantage that there is no possibility that the bonding surface is peeled off during use of the cushion body. Can be

[0004] Known as this simultaneous foam molding method, the upper layer with which the occupant comes in contact is formed of a soft plastic foam so that a good feel is obtained, and the lower layer is formed of a relatively hard material. Formed with plastic foam to ensure support to the occupant, and the center in the left-right direction, formed of soft plastic foam,
In some cases, a good feeling can be obtained, and all or a part of both sides in the left-right direction is formed of a relatively hard plastic foam to ensure the support to the occupant.

[0005]

However, these conventional techniques
The method is usually applied to a molded cushion body having a large thickness, such as an automobile seat, and is used as a cushion for a backrest of a chair having a relatively thin cushion body. when applied to the body, a plastic foam soft upper layer, but also because the plastic foam of relatively rigid lower layer is arranged, the elastic lack of overall cushion body, firmly support the lumbar region of the occupant This cannot be performed, and the posture of the seated person is likely to be lost. Also,
A soft plastic foam on the surface of the cushion ,
Some are lined with relatively rigid plastic foam
But, in this thing, the boundary of the hardness in the cushion body will feel the seat occupant, comfort becomes a loss cracking Rukoto.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem by providing an intermediate portion and a lower portion of a cushion body for a backrest such as an office chair having a relatively thin cushion body. Has appropriate elasticity, and by firmly supporting the vicinity of the waist of the seated person, prevents the posture of the seated person from being distorted, and the upper part of the cushion body gives the seated person a soft feeling, It is an object of the present invention to provide a method of manufacturing a backrest cushion body that is comfortable to sit on and that prevents a seated person from feeling the boundary between the lower and upper hardness portions of the cushion body.

[0007]

According to the present invention, the above-mentioned problem is solved as follows. (1) A valley and a front and rear inclined surface inclined toward the valley are provided in the concave recess on the upper surface of the lower mold, and the undiluted solution of the hard plastic foam is applied to the valley or the rear inclined surface. Inject left and right long and narrow, and after the undiluted solution of the hard plastic foam starts to foam, inject the undiluted solution of the soft plastic foam into the center of the front inclined surface, which is the upper side of the molded cushion in the lower mold. As well as the upper and lower molds
To cover the undiluted solution of the soft plastic foam.
Dipping under the stock solution of the rising rigid plastic foam
While foaming .

[0008] (2) the backrest cushion of the chair, its
When molding using a foaming mold so that the front surface of the foaming mold is on the lower side, the concave recess on the upper surface of the lower mold of the foaming mold is formed in the middle of the cushion body after molding in the vertical direction protruding forward. And a valley corresponding to the valley, and the front and rear slopes inclined toward the valley shall be formed, and the stock solution of the hard plastic foam is applied to the lower mold valley or the rear slope, After the raw solution of the hard plastic foam is slightly foamed in the left and right direction with the center as the center, the front solution of the lower mold, which becomes the upper side of the cushion body after molding, is made of the stock solution of the soft plastic foam. was injected into the central portion of the surface, to bottom from the center of the front inclined surface of the lower die, a stock solution of the plastic foam soft, not submerge below the stock solution of the plastic foam rigid, Oyo these hard By both foaming and curing the stock of plastic foam soft in the foaming mold, and the lower regions of plastic foam rigid,
The rigid plastic foam forms the lower layer and the soft plastic foam forms the middle transition region of the upper layer and the upper region consisting of the soft plastic foam.

[0009]

[Function] A stock solution of a hard plastic foam is injected along the left-right direction of a valley of a lower mold, and after slightly starting to foam, a stock solution of a soft plastic foam is used as a cushion for a backrest after molding. By injecting into the center of the front inclined surface of the lower mold that is the upper side of the body, the stock solution of the hard plastic foam is foamed from the valley toward the front and rear inclined surfaces, and the valley in the foaming mold is formed. The rear part is filled with hard plastic foam, while the stock solution of soft plastic foam is foamed radially from the center of the front slope of the lower mold toward the front slope, and Fill part with stock solution of soft plastic foam.

[0010] When the stock solutions of both plastic foams start to come into contact with each other at the stage of foaming as described above, the soft plastic foam which has been foamed later is moved upward and downward at the center in the left-right direction of the front inclined surface of the lower mold. From below the center of the direction, it sneaks below the rigid plastic foam.

This is because a rigid plastic foam is
Foam to fill the rear inclined surface of the lower mold and
This causes the rear inclined surface of the lower die to be pressed.

[0012]

1 to 3 show a chair according to the invention.
It is a schematic diagram explaining the manufacturing method of the cushion body for backrests .

As shown in FIG. 1, the upper surface of the lower mold (1) constituting the foaming mold has a shape conforming to the shape of the front surface of the cushion body (3) for backrest shown in FIGS. A concave (2) is formed.

As shown in FIG. 5 or FIG. 11, the shape of the front surface of the backrest cushion body (3) is an intermediate portion (3a) in the vertical direction, and more specifically , a portion slightly below the center in the vertical direction. , Protruding forward and its upper (3b) and lower (3c)
Is gently inclined backward from the intermediate portion (3a).

[0015] The upper surface of the lower mold (1) recessed (2) is fit to the front surface shape of the backrest cushion body (3), a valley portion corresponding to the middle portion (3a) (2a) , Front side corresponding to the upper part (3b)
And a (Figure 1, left) inclined surface (2b), and (right in FIG. 1) side after corresponding to the lower (3c) inclined surface (2c).

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

[0017] Then, as shown in phantom in FIG. 1, with the nozzle (4), directly above the center of the valley (2a) or is positioned on the side inclined surface (2c) after the rear nozzle (4), a stock solution of the plastic foam rigid, valleys (2a) or while injecting at the back, to move the nozzle (4) in the lateral direction Turkey
Thus, as shown by the arrow in FIG. 2, a pool (5) of the hard plastic foam stock solution which is long in the left-right direction is formed at or behind the valley (2a).

[0018] After this step is completed, the nozzle (4), as indicated by <br/> arrows in FIG. 1, is moved to the central portion of the front inclined surface of the recessed (2) (2b).

When the stock solution of the hard plastic foam injected long in the left-right direction starts to foam, the front inclined surface
The nozzle is moved to the central portion of (2b) (4), injecting a stock solution of the plastic foam soft, the central portion of the front inclined surface (2b), reservoir stock solution of the plastic foam soft (6) Is formed.

[0020] Finally, as shown in FIG. 3, the stock solution of the upper die (7) Ru placed over the lower mold (1), reservoir of injected hardness two plastic foam (5) (6) As shown by the arrow in FIG. 2 , the soft
Stock solution of the plastic foam, as shown in FIG. 3, is injected earlier, while foaming, continue to foam while slip under the stock solution of the upper and the plastic foam hard extending back and forth, and finally, Fill the space defined by the lower mold (1) and the upper mold (7).

[0021] At this time, as shown in FIG. 4, stock solution of the plastic foam rigid diffused in the lateral direction, to reach the opposite side edges of the foam molding mold, you can not diffuse any more laterally, the upper die On the lower surface of (7), the concave (2) on the upper surface of the lower mold (1)
Proceed into the upward recess (9) formed so as to face the peripheral edge.
As a result, a hard side edge 8 facing upward is formed .

The completed cushion body (3) has a rigid plastic foam area as shown in FIGS.
(A), a transition region (B) that gradually changes from a hard plastic foam to a soft plastic foam, and a region (C) of a soft plastic foam.

FIG. 9 shows a region of a rigid plastic foam.
FIG. 6A shows a cross section, and FIGS. 6 to 8 show the distribution of hard side edges 8 in the change region.

The embodiment shown in FIGS. 10 to 15 is the same as the embodiment described above, except that the conditions for foaming, for example, the soft
The composition of the undiluted solution of the plastic foam , the injection time, the injection amount, etc. are different, and the finished cushion body (3)
In its shape of the changing area (B), plastic foam, soft
The state of the body 's undiluted solution is different.

Although the manufacturing method of the present invention has been described in detail, the region of the hard plastic foam, particularly the state of formation of the side edge (8) depends on the lower mold (1) of the stock solution of the hard plastic foam .
By infusion length along the recessed (2), depends largely monkey.

The undiluted solution of the soft plastic foam may not be injected at one central point as described above, but may be injected at the left and right locations.

[0027]

(A) The backrest cushion body formed by foaming and hardening stock solutions of hard and soft plastic foams together in a foaming mold has a relatively small thickness of the cushion body. even backrest cushion of thin office chairs or the like, since the vertically intermediate portion and a lower portion protruding forward of the cushion body, and has a plastic foam rigid, with suitable elasticity, The vicinity of the waist of the seated person is firmly supported , and the posture of the seated person can be prevented from being lost.

(B) Since the surface of the cushion body is made of a soft plastic foam, it gives a soft feeling to the occupant.

[0029] (c) both foam at an intermediate of the changing area, the upper part plastic foam soft is, becomes lower part plastic foam is rigid, and gradually since the ratio is varied, both the foam A seated person does not feel the boundary of hardness, and a comfortable cushion body can be obtained.

[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 the manufacturing method of the present invention.

[Figure 2] a plan view of the lower mold shown in FIG. 1, injected hard及
FIG. 4 is a view for explaining diffusion of a stock solution of a soft plastic foam.

FIG. 3 is a longitudinal sectional view showing a foam body that has completed foaming in a foaming mold including an upper mold and a lower mold.

FIG. 4 is a front view of a first embodiment of a backrest cushion body 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 sectional view taken along line IX-IX in FIG. 4;

FIG. 10 is a front view of a second embodiment of a backrest cushion body manufactured by the manufacturing method of the present invention.

FIG. 11 is a sectional view taken along the line XI-XI in FIG. 10;

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

FIG. 13 is a sectional view taken along the line XIII-XIII of FIG. 10;

FIG. 14 is a sectional view taken along the line XIV-XIV in FIG. 10;

FIG. 15 is a sectional view taken along the line XV-XV in FIG. 10;

[Explanation of symbols]

(1) Lower mold (2) Concavity (2a) Valley (2b) Front slope (2c) Rear slope (3) Cushion (3a) Middle (3b) Upper (3c) Lower (4) Stock solution Nozzle for injection (5) Pool of stock solution of hard plastic foam (6) Pool of stock solution of soft plastic foam (7) Upper die (8) Side edge (9) Upward recess (A) Hard Plastic foam area (B) Change area (C) Soft plastic foam area

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 39/02-39/12 B29C 39/22-39/36 A47C 27/14-27/15 A47C 7 / 18-7/20 A47C 7/40 B68G 5/02 B68G 7/00-7/02 B60N 2/00

Claims (2)

(57) [Claims] 1. A concave portion on the upper surface of a lower mold is provided with a valley and an inclined surface on the front and rear sides inclined toward the valley. After the stock solution of the hard plastic foam starts to foam, the stock solution of the soft plastic foam is applied to the front side, which is the upper side of the molded cushion body in the lower mold. thereby injected into the central portion of the inclined surface, the lower
Put the upper mold on the mold and make a stock solution of soft plastic foam
Of the undiluted solution of the foaming rigid plastic foam
A chair characterized by foaming while being sunk underneath
Of manufacturing a cushion body for a backrest . 2. The method of molding a cushion body for a backrest of a chair using a foaming mold so that a front surface thereof is on a lower side, wherein an upper surface of a lower mold of the foaming mold is used. Is formed of a valley portion corresponding to an intermediate portion in the up-down direction projecting forward in the cushion body after molding, and a front-rear inclined surface inclined toward the valley portion. A stock solution of the body is elongated in the left-right direction around the center of the lower mold valley or the rear inclined surface, and the stock solution of the hard plastic foam is slightly foamed. Is injected into the center of the front slope of the lower mold, which is the upper side of the cushion body after molding, and from the center of the front slope of the lower mold downward, the stock solution of the soft plastic foam is Hard plastic The raw solution of the hard and soft plastic foams is sunk under the stock solution of the foamed foam, and the stock solution of the hard and soft plastic foams is foamed and cured together in the foaming mold, whereby the lower side of the hard plastic foam is formed. and regions, the plastic foam rigid with the lower, backrest chair plastic foam soft to the upper layer of the intermediate of the changing area, characterized in that to form the upper region of a plastic foam soft
Method of manufacturing cushion body .