JPH074872B2 - Bathtub manufacturing method and mold - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bathtub manufacturing method and a molding die, and more particularly to a bathtub manufacturing method and a molding die in which a part of a side wall is projected outward. Regarding

(Prior Art) As a type of bathtub, there is a type having an armrest portion on a side wall. 6 and 7 show an example thereof.
As shown in the figure, in the case of a conventional bathtub with armrests of this kind, the portion from the intermediate height position of the side wall 100 to the upper edge is projected outward and the armrest portion 10 is provided on the inner surface side thereof.
There were two.

The armrest portion 102 is provided in such a conventional form because of the problem of demoldability when the molded bathtub is demolded from the molding die. That is, for example, when a part of the side wall on the lower side from the upper edge is partially projected outward and the armrest part is formed on the inner surface side of the side wall, the molded product (bath) is formed by the conventional general molding method. Since it is not possible to demold from the inner surface molding die, considering the demoldability, the part from the middle part of the side wall to the upper edge, that is, the part from the opening side edge of the bathtub The armrest portion is formed by projecting it outward.

(Problems to be Solved by the Invention) However, when the armrest portion is provided in such a form, the width of the flange portion 104 at the upper end edge of the bathtub becomes so narrow that the bathtub feels poor. Alternatively, the width of the bottom portion 106 of the bathtub becomes narrower, which makes the bathtub feel cramped.

However, if the mold is a split mold, the mold can be removed even if the armrest portion is provided by partially projecting the intermediate portion that does not reach the upper end edge of the side wall outward. However, when the mold is a split mold, the molding material enters the gap between the molds to generate burrs and the inner surface of the bath becomes dirty. Alternatively, a great deal of labor is required for the work for finishing it.

(Means for Solving the Problem) The present invention has been made to solve such a problem, and its gist is to provide a flexible member for a portion for forming an overhanging portion of a mold for molding the inner surface of a bathtub. And the inside of the overhanging portion forming portion is bent inward after the bath forming, so that the molded product is released from the mold.

(Operation and Effect of the Invention) As described above, according to the present invention, the portion for forming the overhanging portion of the forming die on the inner surface of the bath is made of a flexible material, and the portion is bent inward when the die is released. .

In this way, even if the side wall is formed with an outwardly projecting portion, or even if the shape of the projecting portion does not reach the opening at the upper edge of the bathtub, the bathtub molded product can be molded. Can be easily demolded. In other words, according to the present invention, it is possible to form a bathtub having an outwardly projecting portion of this kind on the side wall even without using a split mold.
When the overhang is formed in such a form, the width of the flange and the width of the bottom are not narrowed at all. Therefore, when the armrest is formed on the inner surface side by forming the overhang of such a form, the bathtub is It can be luxurious and spacious.

In addition, it is necessary that the portion for forming the overhanging portion, which is made of a flexible material, retains a predetermined shape when forming the bath. Various means can be used as the shape maintaining means. For example, by applying pressure from the inside of the part made of flexible material using gas, liquid, powder (including sand) as a medium,
The shape can be retained, or a backup mold may be applied to the inside of the portion for forming the overhanging portion to retain the shape.

As described above, according to the present invention, it is possible to form a bathtub having an outwardly projecting portion at the side wall intermediate portion without using a split mold. In this case, since burrs along the split parting line are not generated on the inner surface of the bathtub, the inner surface of the bathtub can be finished into a neat surface without any special finishing process.

(Example) Next, the Example of this invention is described in detail based on drawing.

In FIG. 2 and FIG. 3, 10 is an FRP bathtub, which has a bottom portion 12, side walls 14a and 14b, and a flange portion 16 at the top edge of the side wall.

The pair of side walls 14a are provided with overhanging portions 18 formed by partially projecting outwardly a portion lower than the upper end edges by a certain distance, and armrest portions for placing arms on the inner surface sides of these overhanging portions 18. 20 are formed.

FIG. 1 shows the structure of a molding die for molding the inner surface of the bathtub 10. As shown in the figure, the molding die 22 is composed of a continuous surface layer 24 made of an elastic material such as rubber and a backup layer 26 made of a hard material such as wood for backing up the surface layer 24.

The molding die 22 has a bulging portion 27 for molding the overhanging portion 18 in the bath 10. In the bulging portion 27, the backup layer 26 is not provided, and instead, a backup die 28 made of a hard material is detachably attached, and the convex surface of the backup die 28 is made of cloth, wire material or the like. It is applied to the back side of the surface layer 26 via a flexible reinforcing layer 30.

By laminating and molding a bath forming material such as a resin on the surface using such a molding die 22, as shown in FIG. 4 (A), the overhanging portion 18 is formed on the side wall 14a simultaneously with the molding of the bath 10. That is, the armrest portion 20 can be molded. When the molded product is released from the mold after the molding material has hardened, the backup mold 28 is removed as shown in the figure, and the bulging portion 27 is bent in the inward direction indicated by the arrow P in the figure. The molded product can be easily removed from the molding die 22. The bathtub 10 thus formed
Despite the existence of the armrest portion 20, the flange portion 16,
The width of the bottom portion 12 does not become narrow at all.

In the case where the outer surface of the bathtub 10 is molded by using the outer surface molding die 32 as shown in FIG. 4 (B) (for example, an artificial marble tone having a resin concrete layer as an intermediate layer).
In the case of molding a FRP bathtub), the outer surface molding die 32 can be a split mold composed of split molds 32a, 32a, and in this case, even if burrs occur on the outer surface of the bathtub 10,
Since the outer surface of the bathtub 10 is not exposed to the outside in the installed state, there is no particular problem.

Further, as shown in FIG. 5, the bulging portion is formed by using gas, liquid, or powder as a medium without using the backup mold 28 as described above.
The pressure is applied from the inside of 18 so that the flexible bulge 18
It is also possible to maintain the shape of the.

In the method using the backup mold 28 shown in FIG. 1, since the shape of the surface layer 24 is maintained by the backup mold 28, the reinforcing layer 30 made of cloth or the like can be omitted.

Others The present invention can be configured and implemented in variously modified forms based on the knowledge of those skilled in the art within a range not departing from the gist of the present invention, such as being applicable to the formation of a bathtub having an overhanging part other than the above-mentioned forms. Is.

[Brief description of drawings]

FIG. 1 is a sectional view of a molding die which is an embodiment of the present invention, and FIG.
FIG. 3 and FIG. 3 are perspective views and sectional views of a bath formed by the molding die of FIG. 1, respectively, and FIGS. 4 (A) and 4 (B) are each a manufacturing method using the molding die of FIG. Explanatory drawing, fifth
The figure is an explanatory view of a state in which pressure is applied to a mold bulging portion made of a flexible material to maintain its shape, and FIGS. 6 and 7 are perspective views of a conventionally known bathtub with armrests and FIG. 10: Bathtub, 14a, 14b: Side wall 18: Overhang part, 20: Armrest part 22: Mold, 24: Surface layer 26: Backup layer, 27: Bulging part 28: Backup type, 30: Reinforcing layer

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Claims (4)

[Claims] 1. A method of manufacturing a bathtub in which a part of a side wall is partially projected outwardly, wherein at least the portion for forming the overhanging portion of a molding die for molding the inner surface of the bathtub is formed. A method for manufacturing a bathtub, which is formed of a flexible material, and the molded product is released from the mold by bending the portion for molding the overhanging portion inward after the bath is molded. 2. The method of manufacturing a bathtub according to claim 1, wherein the bathtub is an FRP bathtub. 3. A molding die for molding an inner surface of a bathtub in which a part of a side wall is partially projected outward, wherein at least a portion for molding the protruding portion is made of a flexible material. A mold for a bathtub, characterized in that, when the mold is removed from the mold after the bath is molded, the overhanging part molding portion is bent inward. 4. The mold for a bathtub according to claim 3, wherein the bathtub is an FRP bathtub.