JPH0315527B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a method for manufacturing a hollow body having an insert therein, which is used as a skin material for a headrest or the like.

(Description of Prior Art) In the past, manufacturing of products such as head rests that have an insert inside and whose outer periphery is covered with a skin material has been carried out by molding a bag-shaped skin material and then molding one part of this skin material. The section is cut open, an insert is inserted into the skin material, and a synthetic resin foam raw material such as polyurethane foam is injected through the opening of the skin material.
This was done by foam-molding the cushion material within the skin material. However, in this method, it is necessary to cut open the skin material to insert the insert, which increases the number of work steps, and the synthetic resin foam raw material leaks from the cut-out part for insert insertion, causing a barrier to the outside. In order to form a burr, this burr removal work and a mold release agent application work to facilitate the burr removal were required, which was not a rational method. Furthermore, the cutout portion for inserting the insert is visible, which is not aesthetically pleasing.

(Object of the Invention) The present invention has been made in view of the above points, and provides a method for rationally manufacturing a hollow body having an insert inside, which is used as a skin material for headrests, etc. .

(Structure of the Invention) The present invention utilizes a rotational molding method using vinyl chloride resin paste or powdered polyethylene, etc., which is often used for manufacturing hollow bodies made of thermoplastic synthetic resin. The purpose of the present invention is to carry out rotational molding by holding a portion of the insert in the split mold and holding the insert in the mating portion of the split mold.

The present invention will be specifically explained below using the drawings.

FIG. 1 is a perspective view illustrating an embodiment of the present invention, and shows the manufacture of a headrest skin material. The mold used in the practice of the present invention is a split mold consisting of an upper mold 1 and a lower mold 2, and has cavities 1a and 2a that form a predetermined shape of the skin material of the headrest when the mold is closed. This structure allows the insert 3 to be held at the mating portion 2b of the lower die 2. The insert 3 also includes a portion 3a located within the skin material of the headrest and reinforcing the headrest.
and a stay portion 3b that supports the headrest on the upper part of the seat. The hollow body with an insert inside, which becomes the skin material of the headrest, is a part 3a of the insert in the cavity of the split mold.
The insert 3 is held in the mating part 2b of the split mold in the state in which the insert 3 is positioned, a thermoplastic synthetic resin paste or powder, such as vinyl chloride resin paste 4a, is injected into the cavity, the split mold is closed, and the split mold is It is obtained by heating the mold while rotating it to form a gelled vinyl chloride resin layer on the inner surface of the cavity, and removing the mold after cooling. still,
The split mold is closed by a clamp 5, and
Gas vent holes (not shown) are bored at predetermined positions in the split mold to allow gas generated within the cavity to escape. This gas vent hole can also be used as an injection port for a raw material for forming a cushion material when the cushion material is continuously formed within the skin material after the skin material is manufactured.

FIG. 2 is a partially cutaway perspective view of a headrest skin 6 having an insert therein manufactured in accordance with the present invention. The skin material 6 having an insert inside is integrated with the thermoplastic synthetic resin bag 4 having a hollow interior formed from the above-mentioned vinyl chloride resin paste, and a part 3a is located inside the bag 4. It consists of an insert 3. insert 3
In the part protruding from the bag body 4, the periphery of the insert 3 is sealed by the thermoplastic synthetic resin constituting the bag body 4, and even when the liquid cushion material raw material is injected into the bag body 4, the raw material is There is no risk of leakage.

(Effects of the Invention) The present invention provides a method for holding the insert in the mating portion of the split mold with a part of the insert positioned in the cavity of the split mold as described above,
Rotational molding is performed. Therefore, the obtained product has an insert inside, which eliminates the need for a post-process cut-out process for insert insertion, which was required in conventional manufacturing methods. Even if liquid cushion material raw material is injected, it will not leak to the outside. Furthermore, if the insert is held in a different way from the present invention, for example, if one of the split molds is provided with an insertion hole for holding the insert and the insert is set in this insertion hole, it will take time to set it up and it will be troublesome to remove it from the mold. Furthermore, repeated insertion of the insert will enlarge the insertion hole, making the fixation of the insert uncertain, causing leakage of the cushion material raw material, and increasing the burr removal process. Since the insert is held at the mating portion of the insert, the above-mentioned inconvenience does not occur.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a partially cutaway perspective view of the skin material of a headrest manufactured according to the present invention. 1... Upper mold, 2... Lower mold, 1a, 2a... Cavity, 3... Insert, 4a... Vinyl chloride resin paste.

Claims (1)

[Claims] 1. With a part of the insert positioned within the cavity of the split mold that forms a cavity of a predetermined shape when the mold is closed, hold the insert in the mating part of the split mold and insert it into the cavity by rotational molding. A method for manufacturing a hollow body having an insert inside, the method comprising forming a hollow body.