JPH0688260B2 - Method for manufacturing foam-molded article with embedded insert - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a foam-molded article in which an insert is embedded in a foam body, such as a vehicle headrest or armrest, and in particular, a hollow having an opening. The present invention relates to a method for manufacturing a foam molded article in which a plastic insert is embedded.

(Prior Art) Conventionally, the production of a foam-molded product in which an insert is embedded is almost always performed by a so-called integral foam-molding method from the viewpoint of the appearance of the molded product and the manufacturing workability.

The integral foam molding method is to insert the insert into a molding die together with a skin material as necessary, and inject a liquid foaming resin raw material such as a polyurethane foam raw material into the die to foam the foam around the insert. It is a method for producing a foam-molded article in which an insert is embedded and, in some cases, covered with a skin material by forming.

By the way, the insert is used to reinforce or mount the foamed molded product, but a hollow product is often used to reduce the weight or to provide an adjusting mechanism. Further, the hollow insert may have an opening to allow loading or actuation of the adjustment mechanism.

However, when it is attempted to manufacture a foam-molded article in which the insert is embedded by the above-mentioned integral foam molding method using the hollow insert having the opening as it is, a part of the liquid foamed resin raw material is inserted from the opening when the foam is formed. It is conceivable that it will penetrate inside and foam within the insert.
If the liquid foam resin raw material enters the insert,
Problems such as the foam formed around the insert becoming smaller than the regular size or the internal adjusting mechanism not working properly occur.

Therefore, when manufacturing a foam molded article in which a hollow insert having an opening is embedded, a packing such as foam is arranged in the opening of the insert, and the packing is sandwiched between the insert and the mold surface of the molding die. By doing so, the opening is sealed.

(Problems to be Solved by the Invention) However, when the insert is installed in the molding die, the packing is easily displaced from the regular position or easily dropped off, and it is difficult to obtain a good sealing effect. Furthermore, when packing each insert, it takes a lot of time to set the packing, and in some cases, if the packing is not removed after foam molding, the adjusting mechanism in the insert cannot be operated well, and the removal work is difficult. The problem you need,
In addition, since the foamed raw material adheres to the packing, the packing cannot be reused and the cost of parts increases.

The present invention has the above-mentioned problems that the conventional manufacturing method has, that is, it is difficult to satisfactorily seal the insert opening, the sealing work and the sealing material (packing) removal work, and the packing problem. It aims to solve the problem of increased component costs.

(Means for Solving the Problems) The present invention provides a hollow plastic insert having an opening in a molding die, injecting a liquid foaming resin raw material into the molding die, and foaming the foamed material around the insert. In the method of manufacturing a foam molded article in which an insert is embedded by forming a mold, a part of the molding die is pressed against the outer peripheral surface of the opening of the insert, thereby deforming the outer peripheral surface of the opening to form the molding die. When the liquid foamed resin material is foamed, the outer peripheral surface of the opening is sealed by closely contacting with.

(Function) The pressing die digs into the outer peripheral surface of the opening of the insert installed in the molding die by pressing a part of the molding die,
Alternatively, the protrusions on the outer peripheral surface of the opening are crushed and deformed, and the portions closely contact the forming die. As a result, since the outer peripheral surface of the opening is completely sealed, the liquid foamed resin material in the mold foams without penetrating into the insert through the opening to form a foam around the insert. Therefore, it is possible to prevent problems caused by the liquid foamed resin raw material entering the insert.

Further, since the opening is sealed by pressing a part of the molding die against the outer peripheral surface of the opening of the insert, no packing is required, and a reliable sealing effect can always be obtained. It is possible to eliminate the defective seal caused by the defective setting. Moreover, since the sealing work only requires the pressure bonding of a part of the molding die and the work of removing the packing after the foam molding is not necessary, the work is extremely simplified. Furthermore, since no packing is used, the cost of parts can be saved.

(Embodiment) The present invention will be described with reference to manufacturing of a vehicle headrest as an example. Of course, the present invention is not limited to the manufacture of headrests, but can also be applied to the manufacture of other foam-molded products such as armrests.

First, the hollow plastic insert is installed in the mold. FIG. 1 is a schematic cross-sectional view when the apparatus is used, FIG. 2 is a cross-sectional view of an essential part after the apparatus, and FIG. 3 is a perspective view of a hollow plastic insert 10 and a part of a molding die.

The illustrated hollow plastic insert 10 is one in which two halves 10a, 10b made of a blow molded product or an injection molded product such as vinyl chloride resin or polypropylene are integrated by bolting or bonding, and the bottom (in the figure, Since it is upside down, there is a cylindrical opening at the top.
14 is provided as a through hole for a headrest mounting stay 16. The insert 10 has a structure that moves up and down with respect to the stay 16, and a vertical position adjusting mechanism is installed inside. As the vertical adjustment mechanism, there can be mentioned the one described in Japanese Patent Application No. 61-15489 filed by the applicant of the present application, but since the vertical adjustment mechanism does not constitute the gist of the present invention. , And will be omitted in the following description.

Further, the molding die 12 is a split mold, and a cavity surface 12a that has the same shape as the outer shape of the headrest when the mold is closed is formed in the die. On the other hand, an opening holding portion 13 for holding the outer peripheral surface of the opening 14 of the insert is formed in the upper part of the molding die. The opening holding part 13 is composed of two metal halves.
It is composed of 13a and 13b, and has a structure in which one opening 14 is sandwiched by closing the half bodies 13a and 13b. The opening sandwiching portion 13 has an inner diameter equal to or larger than the outer diameter of the opening 14 by a predetermined amount, and has a sharp ridge 15 formed in an annular shape on the inner peripheral surface thereof. The tip diameter of the protrusion 15 is smaller than the outer diameter of the opening 14.

It should be noted that the opening sandwiching portion 13 may have no protrusion on the inner peripheral surface, and in that case, the protrusion is formed in an annular shape on the outer peripheral surface of the opening 14 of the insert. FIG. 5 shows the opening holding portion 23.
FIG. 6 is a cross-sectional view showing a state of the insert 20 device when a ridge 21 is provided on the outer periphery of the opening of the insert 20 without providing a ridge on the insert 20. In the above description, the holding portions 13 and 23 are separated from the mold for convenience of explanation, but the holding portions 13 and 23 are fixed to the mold.

The apparatus for inserting the insert 10 into the molding die 12 is performed by holding the opening 14 of the insert by the opening holding portion 13 of the molding die.
As a result, the projection 15 of the opening holding portion is pressed against the outer peripheral surface of the opening 14 of the insert, and the outer peripheral surface of the opening 14 is deformed and bites into the opening 14. As a result, the outer peripheral surface of the opening 14 is projected.
It will come into close contact with 15 and be sealed. Further, when the protrusion 21 is provided in the opening portion of the insert 20 as shown in FIG. 5, the protrusion 21 is crushed and deformed by the pressure contact of the opening holding portion 23, and the protrusion 21 is opened. It comes into close contact with the inner peripheral surface of the sandwiching portion 23. As a result, the outer peripheral surface of the opening is sealed in the same manner as described above.

If necessary, a skin material A is provided on the cavity surface during molding as shown in FIG.

Next, a liquid foaming resin raw material such as a urethane foam raw material is poured into the molding die 12 and foamed in a closed mold state. The injected liquid foamed resin raw material is increased in volume by foaming to fill the periphery of the insert 10 and reach the upper portion inside the molding die 12. that time,
Opening 14 of insert
Since it is sealed by, the liquid foamed resin raw material is foamed without penetrating into the inside from the seal portion, and a foamed body is formed around the insert. As a result, it is possible to prevent problems caused by the liquid foamed resin raw material entering the insert through the opening of the insert and foaming.

After the foaming is completed, the molded product is removed from the mold to obtain a foamed molded product 30 in which an insert is embedded in a foam 32 as shown in FIG. At the time of demolding, the foam portion of the opening sandwiching portion 13 becomes a so-called undercut, but since the foam body 32 has elasticity, the foam molded article 30 can be demolded without any trouble. If the obtained foamed molded product 30 is covered with a skin material such as fabric or plastic leather, a desired vehicle headrest is obtained. As shown in FIG. 5, if the skin material A is installed on the cavity surface and the liquid foaming resin raw material is injected and foamed, the desired vehicle headrest can be obtained at the same time as demolding after the completion of foaming.

(Effect of the Invention) The present invention, when integrally foam-molding using a hollow plastic insert having an opening, presses a part of a molding die onto the outer peripheral surface of the opening, thereby deforming the outer peripheral surface of the opening. The portion is sealed by closely contacting it with a molding die. Therefore, since the outer peripheral surface of the opening and the molding die are not merely in contact with each other, but by the pressure contact of the molding die with the deformation of the outer peripheral surface of the opening, the pressure contact portion ensures that the outer peripheral surface of the opening and the molding die closely contact each other. Therefore, the sealing can be completed completely.

As a result, it was possible to prevent the liquid foamed resin raw material from entering the inside of the insert through the opening, and it was possible to manufacture a good foam molded article.

In addition, since the opening can be sealed only by inserting the insert into the molding die and there is no need to use packing or the like, the work at the time of the device is extremely easy, and the packing and the like are removed even after demolding. Since it was not necessary, the work at that time could be eliminated. Moreover, since no packing or the like is used, it is possible to prevent a sealing failure, which has conventionally been caused by a setting failure, and to save the cost of parts such as packing, so that the product can be made inexpensive.

[Brief description of drawings]

1 to 4 relate to an embodiment of the present invention. FIG. 1 is a sectional view of an insert and a molding die at the time of an inserter, and FIG. 2 is a sectional view of a main part of a molding die after the inserter. FIG. 3 is a perspective view of a part of the insert and the molding die, FIG. 4 is a perspective view of the foam-molded product obtained, and FIG. 5 is a cross section of the molding die after the insert device in another embodiment of the invention It is a figure. 10 …… Insert, 12 …… Mold, 14 …… Opening

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

Claims (4)

[Claims] 1. An embedding of an insert by placing a hollow plastic insert having an opening in a molding die, injecting a liquid foaming resin raw material into the die, and foaming to form a foam around the insert. In the method for producing a foamed molded product, a liquid foamed resin is obtained by pressing a part of a molding die onto the outer peripheral surface of the opening of the insert, thereby deforming the outer peripheral surface of the opening and closely contacting the molding die. A method for producing a foam-molded article in which an insert is embedded, characterized in that the outer peripheral surface of the opening is sealed when the raw material is foamed. 2. A method for producing a foam-molded article in which an insert is embedded according to claim 1, wherein a part of the mold is used as a ridge and the ridge is pressed against the outer peripheral surface of the opening of the insert. Method. 3. A foamed molded article in which the insert is embedded according to claim 1, wherein a protrusion is provided on the outer peripheral surface of the opening of the insert and a part of the molding die is pressed against the protrusion. Manufacturing method. 4. An embedded foam of an insert according to any one of claims 1 to 3, wherein at least a portion of the insert which is pressed against the outer peripheral surface of the opening is made of metal. Molded article manufacturing method.