JP2978205B2 - Manufacturing method of different hardness cushion products - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing a cushion product of different hardness having a partially different surface hardness used as an automobile headrest or an automobile seat cushion.

(Prior Art) For example, in an automobile headrest 10 shown in FIG. 5, a head contact portion 14 of an elastic foam 14 constituting a pillow portion 12 is provided.
It is preferable to make a softer than the other part 14b to make the head abutment part soft, and in the case of the automobile seat cushion 18 shown in FIG. It is considered preferable that both side portions 20a, 20a of the body 20 be harder than the central portion 20b to enhance the occupant's posture retention. In the figures, reference numerals 16 and 22 denote skin materials.

By the way, as a main manufacturing method of the above-mentioned different hardness cushion product, there is the following method.

As shown in FIG. 7, a predetermined surface of a cushion product main body 26 made of an elastic foam having a predetermined hardness formed by foam molding or the like is cut from an elastic foam having a hardness different from that of the elastic foam by cutting or the like. A method of attaching a cushion material 28 having a predetermined shape to produce a desired cushion product having a different hardness.

As shown in FIG. 8 or FIG.
At predetermined positions of the cavity surfaces 34, 36, sheet-shaped or block-shaped cushion members 38, 40, 40 formed of an elastic foam having a predetermined hardness are arranged, and the cavity is formed.
A liquid foaming material for forming an elastic foam having a different hardness from the cushioning materials 38, 40, 40 is injected into the remaining portions of the cushioning materials 33, 35, and foamed integrally with the cushioning materials 38, 40, 40 on the cavity surface. A method for producing a desired cushion product having a different hardness.

(Problems to be Solved by the Invention) However, the above-described manufacturing method has the following problems.

In the manufacturing method of the above, there is a problem that a special process is required to cut the pasted cushion material 28 into a predetermined shape three-dimensionally and the work is not easy. When the thickness of the cushion material 28 is gradually changed (thinned) in order to prevent a sudden change in hardness at the boundary with the cushion product body 26 and reduce the sense of discomfort, it takes time to form and attach the cushion material 28 If a problem arises, and the cushion material sticking portion of the cushion product body 26 has a concave surface, there is also a problem that broken chicks easily enter the cushion material 28.

In one manufacturing method, cushion materials 38, 40, 40
It is not easy to arrange and hold the correct position on the cavity surface, and the cushion members 38, 40, 40 may be misaligned during integral molding, or may be easily lifted from the cavity surface,
There is a problem in that it is difficult to obtain a cushion product having a different hardness at a desired position. Further, in the manufacturing method, as shown in FIG.
When the protrusions 42, 42 are provided, a slit shape (groove shape) is formed on the surface of the cushion product by the projections 42, 42, and there is a problem that the cushion product is easily broken by the slit shape or a sense of incongruity is caused.

In view of the above, the present invention provides a cushion product having a different hardness with a simple operation, and a cushion product having a different hardness with less discomfort at the boundary where the hardness changes. It is intended to provide a method for manufacturing a hardness cushion product.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, a predetermined portion of a cavity surface of a foaming mold is formed by a convex surface in a cavity, and the molding forming the convex surface of the cavity is performed. The mold portion is constituted by a nesting mold that can be separated and fitted, and an elastic foam sheet is arranged on the cavity surface of the separated nesting mold, and the edge of the elastic foam sheet is fitted with the nesting mold. The nesting mold is fitted to the molding die, and the elastic foam sheet having the cavity convex surface is arranged in the cavity of the molding die. At the time of the fitting, the edge of the elastic foam sheet is formed at the fitting portion. The elastic foam sheet is made thinner as it approaches the edge of the elastic foam sheet by sandwiching and compressing the elastic foam sheet in a tension state, and then has a hardness different from that of the elastic foam sheet in a cavity of a molding die. The liquid foaming material for forming the elastic foam is injected and foamed integrally with the elastic foam sheet having the convex surface of the cavity.

(Operation) In the present invention, since the elastic foam sheet is arranged on the convex surface of the cavity surface, the elastic foam sheet does not rise from the cavity surface, and the edge of the elastic foam sheet has a nested shape. Since the elastic foam sheet is thinned as it approaches the edge of the sheet because it is sandwiched and pulled by the fitting portion, the hardness of the resulting cushion product having a different hardness becomes gradual.

(Example) An example of the present invention will be described below.

FIGS. 1 and 2 show one embodiment of the present invention.
70 is a sectional view of FIG.

The molding die 70 includes a front split mold 72 forming the front half of the pillow portion on the head contact side of the headrest, and a rear split mold 74 forming the rear half of the pillow portion. A cavity 80 having a pillow shape of a headrest constituted by a cavity surface 76 of the mold 72 and a cavity surface 78 of the rear split mold 74 is provided. The front split mold 72 has a part of the cavity surface 76 protruding in an arc shape into the cavity 80 to form a cavity convex surface 76a, and a part of the convex surface 76a is formed of a separable nest type 72a. . The cavity convex surface 76a of the nest 72a
Is for making the head contact surface of the headrest pillow part concave in the shape of the back of the head so as to make good contact with the head. In addition, positioning pins for properly locking an elastic foam sheet 86 described later are provided on fitting surfaces 73a, 73a of the nest type 72a.
79,79 are erected. On the other hand, a material injection hole 82 is formed in the upper part of the rear split mold 74. The front split mold 72 and the rear split mold 74 have an upper split surface 75 formed with a stay insertion hole 77.

Next, a method of manufacturing a headrest of different hardness using the above-described mold 70 will be described.

First, as shown in FIG.
Stay 87 integrated with reinforcing body 84 in the 5 stay insertion hole 77
And the reinforcing member 84 is held in the cavity 80. Also, a soft elastic foam sheet 86 having a size larger than the convex surface 76a of the nest 72a is placed on the cavity convex surface 76a of the nest 72a.
The edges 86a, 86a of the elastic foam sheet 86 are engaged with the positioning pins 79, 79 on the mating surfaces 73a, 73a of the nesting mold 72a, and the nesting mold 72a is moved as shown in FIG. The front split mold 72 is fitted. As a result, the elastic foam sheet 86 disposed on the cavity convex surface 76a of the nest 72a
a, 86a are compressed by being nested in a nested fitting portion 73 composed of a fitting surface 73a, 73a of a nesting mold 72a and a fitting surface 73b, 73b of a front split mold 72. By compression, the thickness of the elastic foam sheet 86 becomes thinner toward the edge. Moreover,
When fitting the nesting mold 72a as shown by the arrow A in FIG.
The edges 86a and 86a of the elastic foam sheet are
In this case, the elastic foam sheet 86 becomes thinner as it approaches the edge. Further, since the cavity surface of the nest 72a in which the elastic foam sheet 86 is arranged is a cavity convex surface 76a which is convex in the cavity, the elastic foam sheet 86
Does not rise from the cavity convex surface 76a, and since the edges 86a, 86a of the elastic foam sheet are pulled in the direction B as described above, the floating of the elastic foam sheet 86 is more reliably prevented.

Thereafter, a liquid foaming raw material 88a such as a urethane foam raw material that forms an elastic foam harder than the elastic foam sheet 86 of the nested cavity convex surface 76a is injected into the cavity 80 from the raw material injection hole 82, and the elastic foaming of the cavity convex surface is performed. Foam molding is performed integrally with the body sheet 86.

After foaming, the molded product is taken out of the molding die 70, and the edges 86a and 86a of the elastic foam sheet sandwiched by the nested fitting portion 73 are cut off and trimmed to obtain a desired shape as shown in FIG. A headrest 90 of different hardness is obtained. In the figure, reference numeral 88 denotes an elastic foam formed from the liquid foaming raw material 88a.

The thus-obtained different-hardness headrest 90 is constituted by an elastic foam sheet 86 in which the portion in contact with the head is softer than the other parts, and the thickness of the elastic foam sheet 86 becomes thinner toward the edge. As a result, the change in hardness at the peripheral portion a of the head contact portion is gradual, and there is almost no sense of discomfort during use.

FIG. 4 shows another embodiment, and is a cross-sectional view of the foaming mold 92 showing a time of manufacturing a seat cushion in which a seat surface center portion is softer than other portions. In this embodiment, a part of the cavity surface 93, i.
A convex cavity 93a is formed in the cavity 91, and a foam molding die 92 having a part forming the cavity convex 93a is formed by a nest 92a, and a fitting portion 95 of the nest 92a forms an edge of a soft elastic foam sheet 96. 96a, 96a is sandwiched, and the elastic foam sheet 96 is arranged on the nested cavity convex surface 93a, and then a liquid foaming raw material 98a forming an elastic foam harder than the elastic foam sheet 96 is placed in the cavity 91. Inject,
The seat cushion as a cushion cushion product having a different hardness is manufactured by integrally foaming the elastic foam sheet 96 having the convex surface of the cavity.

(Effect) In the present invention, since the nested cavity surface on which the elastic foam sheet is arranged is constituted by the cavity convex surface which is convex in the cavity, the elastic foam sheet is prevented from floating from the cavity surface during foam molding. It is possible,
There is an advantage that a good cushion product of different hardness can be obtained.

Further, in the present invention, since the edge of the elastic foam sheet having a predetermined hardness disposed on the convex surface of the nest type is sandwiched by the nest type fitting portion, the thickness of the elastic foam sheet is equal to the edge. As the thickness becomes smaller, the change in hardness of the resulting cushion product with a different hardness is gradual, and there is an effect that almost no uncomfortable feeling is generated in the hardness change portion of the cushion product.

[Brief description of the drawings]

1 and 2 are cross-sectional views of a foaming mold during foam molding according to one embodiment of the present invention, and FIG. 3 is a cross-sectional view of an automobile headrest as a cushion product having a different hardness obtained by implementing the present invention. FIG. 4 is a cross-sectional view of a foaming mold during foam molding in another embodiment of the present invention. FIG. 5 is a cross-sectional view of an automobile headrest with no change in hardness, FIG. 6 is a cross-sectional view of an automobile seat cushion with no change in hardness, and FIGS. It is sectional drawing which shows a manufacturing method. 70,92: Foaming mold, 72a, 92a: Nested type, 72: Front split type, 73,95: Nested type fitting part, 73a: Nested type fitting surface, 74: Rear split type, 76, 78, 93: cavity surface, 76a, 93a: nested cavity convex surface, 80, 91: cavity, 86, 96: elastic foam sheet, 86a, 96a: edge of elastic foam sheet, 88a, 98a: liquid foam raw material , 88: Elastic foam

Claims (1)

(57) [Claims] 1. A predetermined portion of a cavity surface of a foaming mold is constituted by a convex surface in a cavity, and a portion of the mold forming the convex surface of the cavity is constituted by a nestable mold capable of being separated and fitted. An elastic foam sheet is arranged on the cavity surface of the separated nest mold, and the edge of the elastic foam sheet is positioned on a fitting surface with the nest mold, and the nest mold is fitted to the mold. The elastic foam sheet having the cavity convex surface is arranged in the cavity of the molding die, and at the time of the fitting, the edge of the elastic foam sheet is pinched and compressed at the fitting portion in a stretched state, thereby forming the elastic foam sheet. The thickness of the elastic foam sheet is made thinner as it approaches the edge of the elastic foam sheet. Then, a liquid foaming material for forming an elastic foam having a hardness different from that of the elastic foam sheet is poured into the cavity of the molding die, and the cavity convex surface is formed. Method for producing a different hardness cushioning product, characterized in that foaming the elastic foam sheet integrally.