JPH0324326B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of rotomolding a resin container and a sink container formed by this method.

Conventionally, sink sets have been installed in vehicles such as camping cars to facilitate cooking, etc., but this sink set consists of a water supply section, a sink section through which water is supplied from the water supply section, and this sink section. These parts are formed separately by blow molding and then assembled using bolts, clips, etc.

However, in such a conventional sink set, for example, when providing a drainage hole in the sink,
There was a problem in that it was necessary to join the sink part and the drainage storage part, and at this time, special measures had to be taken to prevent water leakage at the joint part. In addition, since the water supply section and the drainage storage section are subject to flowing water pressure or the weight of water, the connection between the water supply section and the drainage storage section must have considerable strength, so the water supply section and the drainage storage section must be separated. The conventional method of molding requires the attachment of reinforcing members, resulting in an increase in weight. Furthermore, the construction method of separately molding parts and then joining them together is not desirable in terms of improving work efficiency.

This invention has been made by focusing on such conventional problems, and the first object of the invention is to provide a rotation method for a resin container that can integrally and easily form a container consisting of two container chambers. A second object of the present invention is to provide a sink container in which a sink part, a water supply part, and a drainage storage part are integrally joined by this rotational molding method.

Embodiments of the present invention will be described below based on the drawings.

First, the molding apparatus used in the rotational molding method of the present invention will be explained. In FIG. 1, reference numeral 1 indicates a flooring, and this flooring 1 has a hole 2 with an open top, and a reversible motor 3 for driving is installed inside this hole 2. ing. The rotation of this motor 3 is transmitted via a belt 4 to a swing shaft 7 that pivotally supports a bracket 6 of a base 5. Note that both ends of the swing shaft 7 are rotatably attached to the inner wall of the hole 2 of the flooring 1. Further, a pair of columns 8 are fixed on the base 5 at a predetermined distance, and rotating shafts 10 are attached to bearing portions 9 at the upper ends of each column 8 so as to face each other. Further, a pulley 12 is fixed to one end of one rotating shaft 10, and this pulley 1
2 is connected to a rotation motor 14 via a belt 13.

On the other hand, opposing sides of each rotating shaft 10 are connected to a flange portion of a lower mold 15 via a bracket 11, and the flange portion of the lower mold 15 is connected to an upper mold 16.
It is fixed to the flange portion of the body with a fastening bolt 17. Further, a burner stand 18 is provided above the base 5, and this burner stand 18 is connected to a gas cylinder 19.
is connected to. Here, the lower mold 15 and the upper mold 16 have a cavity in the shape of a container chamber shell, which will be described later.

In this way, the base 5 can swing around the drive shaft 7 by the drive motor 3, while the joined upper mold 16 and lower mold 15 are moved by the rotation motor 1.
4, it is rotatable around a rotating shaft 10. Further, the upper mold 16 and the lower mold 15 are heated by fire from the burner stand 18 during rotation.

Next, a container molded by such a molding apparatus will be explained. FIG. 2 illustrates a sink container, which includes a lower container chamber shell 20, an upper container chamber shell 21 joined to the lower container chamber shell 20, each shell 20,
21, and a partition plate 22 which separates the partition plate 21. A drain port 23 is provided below the lower container chamber shell 20, and a cap 24 is attached to the drain port 23. Further, the peripheral edge of the lower container chamber shell 20 is welded to the lower surface of the partition plate 22. Note that the lower container chamber 20 is formed from a thermoplastic resin such as polyethylene or vinyl chloride,
The partition plate 22 is made of a plate material with high heat transfer, such as aluminum or stainless steel.

Further, an annular groove 25 constituting a heat transfer means is bent at the outer peripheral edge of the partition plate 22, and the outer peripheral edge of the upper container chamber shell 21 is welded above the annular groove 25. Further, a recess 26 for sinking is formed on the upper surface of the upper container chamber shell 21, and a substantially central portion of the recess 26 is open. The outer peripheral edge of the upper end of a drain pipe 27 is welded to the opening of the recess 26, and the lower end of the drain pipe 27 is welded to an opening formed approximately in the center of the partition plate 22. In this way, the recess 26 of the upper container chamber shell 21 and the inside of the lower container chamber shell 20 are communicated through the drain pipe 27. Note that the upper container chamber shell 21 is made of thermoplastic resin similarly to the lower container chamber shell 20. Further, a mounting bolt 29 having a through hole is fixed to a mounting hole 28 formed in the side wall of the upper container chamber shell 21, and the lower end of the water supply pipe 30 is inserted through the through hole of the mounting bolt 29. Further, the upper end of the water supply pipe 30 faces the recess 26 of the upper container chamber shell 21, and a midway portion of the water supply pipe 30 is branched and connected to the water supply source 31. In addition, water supply pipe 3
A one-way valve 32 is provided at the branch 0, so that the water pumped up by the water supply source 31 is fed only in the direction of the recess 26 of the upper container chamber shell 21.

Next, the method for molding the sink container constructed as described above will be explained. First, as shown in FIG. do. Next, as shown in FIG. 3b, the partition plate 22
is placed on the upper part of the lower mold 15, and then the powder 34 is placed on the upper surface of the partition plate 22 (see FIG. 3c). Then, as shown in FIG. 3D, the flange portion of the upper mold 16 is joined to the flange portion of the lower mold 15, and the upper mold 16 and the lower mold 15 are fixed with fastening bolts 17. In this case, the outer peripheral edge of the partition plate 22 is in contact with the inner peripheral edge of the upper mold 16, and the upper end of the drain pipe 27 is in contact with the inner peripheral edge of the upper mold 16.
It is in contact with the upper inner surface of 6. Further, as shown in FIG. 4, a first extraction bolt 35 is inserted and fixed below the lower die 15, and a second extraction bolt 36 is inserted and fixed to the side of the upper die 16. A third extraction bolt 37 is inserted and fixed above the upper die 16. Note that the threaded portion formed at the tip of the first extraction bolt 35 forms the exhaust port 23 of the lower container chamber shell 20, and the threaded portion formed at the tip of the second extraction bolt 36 forms the exhaust port 23 of the lower container chamber shell 20. The threaded portion forms a mounting hole 28 in the upper container chamber shell 21. Further, the threaded portion at the tip of the third extraction bolt 37 is inserted into the upper end of the drain pipe 27 . As a precaution, a cavity is formed inside the upper mold 16 so that the upper container chamber shell 21 can be modeled.

The upper mold 16 and the lower mold 15 assembled in this way are attached between both supports 8 of the molding device, and are heated by fire from the burner stand 18. During this heating, the upper mold 16 and the lower mold 15 are rotated by the rotation motor 14 and swung by the drive motor 3 as appropriate. After rotational heating for a certain period of time, the heating is stopped to cool the upper mold 16 and the lower mold 15. After that, the upper mold 16 and the lower mold 15
and remove the extraction bolts 35, 36, and 37. Note that the resin welded to the tip surfaces of the first and second extraction bolts 36 and 37 is removed by a suitable drilling means to form the drain port 23 and the attachment hole 28.

In the above-described embodiment, the thermoplastic resin material was introduced before the mold assembly, but after the mold assembly is completed, the insertion of the bolts 35 and 36 for ejecting the lower mold 15 and the upper mold 16 is completed. The powder of the resin material may be introduced through the mouth.

Next, FIGS. 5 and 6 show other embodiments of the peripheral portion of the partition plate 22. FIG. First, in the case of FIG. 5, a thermoplastic resin 35 is welded to the peripheral edge of the partition plate 22 in advance as shown in FIG. 5a.
After that, the upper mold 16 and the lower mold 15 are assembled to proceed to molding (fifth
(see figure b). In this case, the welded thermoplastic resin 35 is of the same quality as the thermoplastic resin forming the container chamber shells 20, 21. In this way, by configuring the heat transfer means on the peripheral edge of the partition plate 22, the upper container chamber shell 21 and the lower container chamber shell 2
0 and both shells 2 and 2.
A view of unity between 0 and 21 is being promoted. In addition, in the case shown in FIG. 6, a communication hole 38 is bored in the peripheral edge of the partition plate 22 so that both container chamber shells 20,
The outermost peripheral edge 39 of the partition plate 22 is exposed to the outside of the upper and lower molds 15 and 16 in order to further enhance the heat transfer effect.

As explained above, according to the first invention, a resin container consisting of two container chamber shells can be rotomolded, which reduces the work process compared to the conventional method of individually molding and joining the containers. As a result, work efficiency can be improved. Further, the molding apparatus used in this method does not require special means for adjusting the temperature of the resin as in the blow molding method, and the mold can be formed by sheet metal processing, resulting in a significant cost reduction.

Further, according to the second invention, it is possible to provide a sink container in which the sink part and the drainage part are integrally joined via the partition plate, so that the sealing means is better than the conventional structure in which the sink part and the drain part are integrally joined together via the partition plate. There is no need to provide a special seal, and the seal quality is improved.

[Brief explanation of the drawing]

Fig. 1 is a front view of a molding device for explaining the rotational molding method of the first invention, Fig. 2 is a sectional view of a sink container which is the second invention, and Figs. 3a to 3d show the rotational molding method. FIG. 3a is a diagram explaining the process.
Figure 3b is a cross-sectional view when the resin powder is introduced into the lower mold, Figure 3b is a cross-sectional view when the partition plate is attached to the lower mold,
Figure c is a sectional view when resin powder is placed on the partition plate, Figure 3 d is a sectional view when the upper mold and lower mold are assembled, and Figure 4 is a sectional view inside the mold after molding. , FIGS. 5a and 5b are diagrams explaining other embodiments of the heat transfer means, FIG. 5a is a sectional view of the peripheral edge of the partition plate, and FIG. FIG. 6 is a cross-sectional view of another embodiment of the heat transfer means, and is a cross-sectional view of the partition plate assembled into the mold. 15...Lower mold, 16...Upper mold, 20...Lower container chamber shell, 21...Upper container chamber shell, 22...
... Partition plate, 23 ... Annular groove, 34 ... Thermoplastic resin powder, 38 ... Communication hole.

Claims (1)

[Scope of Claims] 1. Rotation of a container in which a thermoplastic resin material is introduced into a cavity formed between an upper mold and a lower mold and forms a container chamber shell, and then molded by heating while rotating both molds. In the molding method, after a thermoplastic resin material is put into the lower mold, a partition plate is attached to separate the lower mold and the upper mold, and then the thermoplastic resin material is placed on this partition plate, and then the lower mold is removed. A method for rotary molding a container, characterized in that a top mold is joined to a mold to form two cavities that shape container chamber shells, thereby molding a container having two container chamber shells. 2. The method for rotational molding of containers according to claim 1, wherein the partition plate is provided with a heat transfer means on the peripheral edge thereof to enhance heat transfer at the joint between the upper mold and the lower mold. 3. The method for rotomolding a container according to claim 2, wherein the heat transfer means is to form a communication hole in the peripheral portion for communicating between the upper container chamber cavity and the lower container chamber cavity. . 4. The method for rotationally molding a container according to claim 2, wherein the heat transfer means is to form an annular groove in the peripheral edge. 5. Claim 2, characterized in that the heat transfer means is to weld a resin of the same quality as the thermoplastic resin forming the container chamber shell to the peripheral portion before the partition plate is attached to the lower mold. A method of rotomolding the containers described. 6. An upper container chamber shell having a sink recess formed on the upper surface, a lower container chamber shell welded to this upper container chamber shell and having a drainage storage section formed inside, and this lower container chamber shell and the upper portion. A sink comprising: a partition plate which defines a container chamber shell and has a drain pipe connected to the inside of the lower container chamber shell and a concave portion of the lower container chamber shell, which is attached substantially in the center thereof; container. 7. The sink container according to claim 6, wherein the upper container chamber shell is connected to a water supply source and has one end facing the sink recess and fixes the other end of the water supply pipe.