JPH0684017B2 - Method for manufacturing bare heads with different hardness - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a bare headrest used by adhering it to a seat back of an automobile or the like, and particularly to a method of manufacturing a bare headrest in which the hardness of the surface varies depending on the part. It relates to a manufacturing method.

(Prior Art) In recent years, vehicle headrests are mounted on most vehicles to ensure safety, but when viewed from the material of the skin, they are roughly classified into those of plastic skin and those of cloth skin. .

On the other hand, looking at the manufacturing method, the former plastic skin has the bag-shaped plastic skin because it is easy to obtain a desired hollow bag shape from soft vinyl chloride resin or the like by hollow molding. In a predetermined foaming mold and inserting a predetermined insert (reinforcing body) into the skin, and pouring a liquid foaming raw material such as polyurethane foam into the remaining skin to foam the skin and the insert. The manufacturing method of the headrest which integrates is widely used.

On the other hand, in the latter case of the cloth made of cloth, it is necessary to sew in order to make the surface of the cloth a hollow bag, and when a liquid foaming raw material such as polyurethane foam is injected into the cloth made of the same material as described above. In addition to impairing the soft texture of the epidermis by impregnating the constituent fibers and the like of the cloth with the liquid raw material, and further leaching from the weave and the like of the cloth and hardening, it can be put to practical use in appearance. It cannot be a product. Therefore, in the case of the head rest of the conventional cloth skin, a desired bag-like skin is manufactured by sewing in advance, while a foam mold having a predetermined cavity is used, and an insert is installed in the foam mold, or a device is used. First, a foam material (commonly called a bare headrest) is manufactured by injecting a foaming raw material into the other cavity and foaming. If this foam body does not have an insert, insert the insert, etc. It has been practiced to apply the cloth skin to the.

By the way, in recent years, headrests are required to have a good feel (softness) on the head contact surface in addition to a protective function, and there is a tendency that cloth-made skins are often used. Attempts have been made to make the body softer.

(Problems to be Solved by the Invention) However, when the inner foam is made softer in the headrest of the cloth skin described above, the cloth skin is sewn easily because the bag shape, its size, and the like are likely to vary. However, there is a tendency that the ridge line shape of the foam collapses during the attachment or the suturing of the opening of the epidermis, sagging of the cloth epidermis, wrinkles, and other problems are likely to occur.

(Means for Solving the Problems) Accordingly, the present invention is intended to provide a novel foam for a headrest that solves the above problems, that is, a manufacturing method capable of obtaining a so-called bare headrest. Whereas, a method of manufacturing a bare headrest of a foam having a desired shape by injecting a foaming raw material into the remaining cavity with or without inserting an insert into a mold having a desired cavity and foaming In the above, a sheet made of a soft foam is stretched in advance on a part of the surface of the mold cavity, and the surface of the foam sheet is impregnated and integrated with the foaming raw material.

(Function) A flexible foam sheet is, as its name implies, a fine cell.
It has a structure, and when it is stretched in a mold and a liquid foaming raw material is injected, the liquid foaming raw material begins to be impregnated so that a part of the liquid raw material enters the cells on the surface of the foam sheet. After that, most of the liquid raw material, that is, the liquid foam raw material that has not been impregnated in the foam sheet, is free-foamed with the increase in viscosity due to the polymerization of itself to form a foam along the mold cavity. On the other hand, the liquid foaming raw material impregnated into the above-mentioned foam sheet causes an increase in viscosity as described above, so that the impregnation is kept to a certain small thickness, and further the surface layer of the foam sheet is hardly disturbed by the cell wall and is hardly foamed. It will be cured by. And the foam molded by this and the said foam sheet are integrated. Further, at this time, since the cured layer of the liquid foaming raw material is formed on the surface of the foam sheet as described above, the surface of the foam to be formed is soft on the soft foam sheet sticking surface and slightly enters the inside from the surface. Since it has a hardened layer, it is possible to obtain molded foams having different surface hardnesses.

(Embodiment) To explain the present invention with reference to the drawings, FIG. 1 is a perspective view of one embodiment of a mold used in the present invention, and FIG. 2 is a central longitudinal sectional view of the mold of FIG. 1 in a closed state. 3 is a rear perspective view of a bare headrest which is a molded product.

The mold 10 is composed of split molds 11 and 12, each of which is provided with a cavity 13 corresponding to a substantially half body of a bare headrest 30 which is a molded product. Further, the mating surfaces of the split molds 11 and 12 are provided with one half of an injection hole 14 for injecting the liquid foaming raw material and one half of a stay hole 15 for suspending and supporting the headrest insert (reinforcing body) 20. The headrest insert 20 is built in the bare headrest 30 that is a molded product to reinforce the bare headrest, and includes a main body 21 usually made of plastic or metal and a supporting stay 22 protruding from one end thereof. Consists of. The supporting stay 22 is retained in the stay hole 15 to hold the insert main body 21 at a predetermined position in the mold cavity 13 and is used for mounting on the seat back in the headrest after molding. When a rotating function for adjusting the angle of the headrest is incorporated in the insert main body 21, the device may not be installed in the mold when molding the bare headrest, but may be assembled after molding the bare headrest.

Next, a method of manufacturing the headrest of the present invention, which is an example using the mold 10 and the headrest insert 20, will be described.

First, a sheet 40 made of soft foam is stretched at a predetermined position of the mold cavity 13 shown in FIG. 1 as shown in FIG. Various materials can be used as the soft foam, but a soft vinyl chloride resin foam, a soft polyurethane resin foam, and the like are preferable. More preferably, those having an open cell structure are preferable. The foam sheet 40 is, for example, the third
Side 31 and / or back of the bare headrest 30 shown
Pre-punched into a predetermined shape, such as shape 32, is stretched so that its peripheral edge corresponds to the ridge of the bare headrest, or a single sufficiently large foam sheet is stretched along the cavity surface. It is preferable that the extra portion is stretched so as to be sandwiched between the divided surfaces 16 of the eleventh and twelve. In the case of the tensioning, a locking pin (not shown) erected on the cavity surface, a double-sided tape, or the like is used so as to substantially match the curved shape of the cavity surface.

Next, a predetermined headrest insert 20 is installed in the mold cavity 13 by means of a supporting stick 22 or the like provided thereon, and the mold 10
Close.

After that, a liquid foaming raw material for forming a soft foam, for example, a polyurethane raw material, is injected into the remaining mold cavity 13 through the injection hole 14 to foam. Then, as described above, a part thereof is impregnated into the surface of the foam sheet 40, and the remaining liquid foaming raw material is foamed, so that the soft foam sheet 40 is pressed against the cavity surface to form a cavity shape and one foam body. That is, forming a bare headrest 30. At this time, when the foam sheet 40 is punched into a predetermined shape by punching or the like and is stretched, the peripheral edge and a part of the cavity side surface continuing to the peripheral edge are also impregnated, and the foam is formed in the bare headrest after molding. The sticking periphery of the body sheet 40 becomes harder than other sticking parts. On the other hand, the surplus portion of the foam sheet 40 is divided into
When sandwiched by 16, the foam sheet 40 along the dividing surface
The thickness is reduced by pulling the peripheral edge of the foam, that is, the density of the foam in the part is increased, and impregnation and curing of the liquid foaming raw material occurs in that state, so that the peripheral edge of the foamed sheet is hardened as described above. Will be things.

The thickness of the foam sheet 40 described above is determined by the hardness, feel and the like required for the surface of the bare headrest to which the foam sheet is adhered, but it is preferably about 2 to 6 mm from the viewpoint of hardness and feel.

(Effect) As described above, according to the conventional method for manufacturing a bare headrest, the desired surface of the bare headrest can be made to have different hardness by stretching and integrating the soft foam sheet at a predetermined position of the mold cavity. It is possible to make the head receiving surface and the like softer. Further, since the peripheral edge of the adhered foam sheet becomes harder than other adhered surfaces, the shape of the headrest does not collapse even when a cloth skin is adhered by aligning the peripheral edge with the ridge line of the bare headrest, and further the skin is further covered. It is possible to provide a headrest having a predetermined shape that does not cause slack or wrinkles. Furthermore, these have the effect of increasing the degree of freedom in designing the headrest.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a mold used in the present invention, FIG. 2 is a central longitudinal sectional view of the mold of FIG. 1 in a closed state, and FIG. 3 is a rear view of a bare headrest which is an example of a molded product. It is a perspective view.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display area B29L 31:58 4F

Claims (3)

[Claims] 1. A method of manufacturing a bare headrest of foam having a desired shape by pouring foaming material into a cavity with or without a headrest insert in a mold having a desired cavity to foam. In the above method, a sheet of soft foam is stretched on a part of the surface of the mold cavity in advance, and the surface of the foam sheet is impregnated with and integrated with a foaming raw material. Method. 2. The method of manufacturing a bare headrest of different hardness according to claim 1, wherein the peripheral edge of the soft foam sheet is stretched along a cavity corresponding to a desired edge of the bare headrest. 3. The method of manufacturing a bare headrest of different hardness according to claim 1, wherein the surplus portion of the soft foam sheet is sandwiched between the divided surfaces of the mold.