JPH01222913A - Method for manufacturing closed vessel - Google Patents

Abstract

PURPOSE:To enable a molding to be done without any unevenness on the surface of a closed vessel and besides any troublesome handling of a previously magnetized magnet by magnetizing a resin combined type permanent magnet sealed into the closed contact part between the cap part of a closed vessel main body and main body. CONSTITUTION:A main body magnet 4 and a cap magnet 5 are sealed into the closed vessel main body 1 and cap 2, furthermore, a main body yoke 3 and a cap yoke 6 are sealed into the rear surface of the magnet. Inasmuch as the magnet 4 and yoke 3 may be decreased in its magnetic property if the gap occurs therebetween in their connection, they are sticked closely by an anaerobic adhesive agent and molded through the injection of polypropylene after setting in an injection molding die, and then the main body 1 is completed in such a way that the main body 1 leaving the molding half done is withdrawn and polypropylene is injected again into the gap formed between the main body and the magnet. The inner and outer two poles are magnetized by the use of a pulse magnetizing electric source and the magnetizing yoke connected thereof so that the injection molded main body 1 and cap part 2 are positioned wherein respectively different magnetic poles correspond each other. The magnets 4, 5 are made such that epoxy resin 2wt.% is added to Sm Co magnetic powder.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a closed resin container used for storing and transporting foods and the like.

[Conventional technology]

To manufacture airtight containers used for storing and transporting foods, etc., which are filled with resin-bonded permanent magnets, after the container is manufactured, magnetized permanent magnets are press-fitted into predetermined holes, etc., and then glued together. They were manufactured by fixing the container with material or resin, or by inserting a magnetized permanent magnet into the container when it was molded, such as by insert molding. In FIG. 3, a hole 7 was previously drilled in the part of the closed container body 1 made of resin that was in contact with the lid during molding, and a magnetized permanent magnet 8 was press-fitted with its magnetic poles aligned and fixed with an adhesive to form a completed product.

In addition, in Fig. 4, insert molding was carried out by setting a pre-magnetized permanent magnet 8 and main body yoke 3 at predetermined positions on the side of the closed container body 1 made of resin that is in contact with the lid. In the method shown, unless a magnet is used in either the sealed container body or the lid, the magnetic poles of the magnetized magnets must be aligned with the north and south poles in the same direction or alternately in order to ensure the attraction force of the magnet. Moreover, since it is fixed with an adhesive, the surface is likely to become uneven, and gaps between the magnet and the resin are likely to form, making it difficult to clean properly.
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In addition, with the method shown in Figure 4, the surface of the container is finished neatly and there are no gaps, but the magnetic poles of the magnetized permanent magnets must be aligned and set in the mold, and the permanent magnets may not be attracted to each other. There were problems such as being attracted to the magnetic metal structure of the molding machine and the complexity of aligning the magnetic poles.

The present invention is intended to solve these problems, and its purpose is to provide a sealed container containing a permanent magnet with a clean surface without any irregularities, yet to avoid the trouble of handling pre-magnetized magnets. Otherwise, in order to solve the above-mentioned problems by molding, the method for manufacturing an airtight container of the present invention is to form a sealed container that is used for storing or transporting foods, etc., at a close contact portion with the lid, or at the main body of the lid. In a sealed container in which a resin-bonded permanent magnet is enclosed in a portion corresponding to a portion in close contact with the container, the permanent magnet is magnetized after the sealed container is molded.

〔Example〕

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

In Fig. 1, a body magnet 4 and a lid magnet 5 are respectively enclosed in a closed container body 1 and a lid 2 having an inner diameter of 70II+m, and a body yoke 3 and a lid yoke 6 are enclosed in the back of each magnet. The portions are large with 100 rules.

FIG. 2 is an enlarged view of the sealed portion of FIG. 1.

Each of the magnets 4.5 described above has an outer diameter of 90 mm, an inner diameter of 80 mm, and a thickness of 90 mm, which has magnetic anisotropy in the thickness direction and is made by compression molding a mixture of rare earth magnet powder and epoxy resin in a magnetic field and heating and hardening it. It has a diameter of 1 mm and is magnetized with two poles in the inner and outer directions as indicated by N and S, respectively.

In addition, each yoke 3.6 is the same size as the magnet, and the magnet 4
．． It is attached to the back of 5.

First, regarding the magnet, the one used here is generally called 70 Ramakuzu, which is made by adding 2% by weight of epoxy resin to SmCo magnet powder called 2-17 series.

In addition, NdFeB-based magnets and those using thermoplastic resin can also be used, but when encapsulating heated resin by injection molding, pay attention to the softening temperature of the resin that makes up the permanent magnet so as not to destroy the shape of the magnet. Some effort is needed.

The ffJ fat (used for the sealed container body 1 and lid part 2) may be any material that is generally molded and used as a sealed container by injection molding.

Examples include polyethylene, polyethylene, and polyamide.

The molding is performed by insert molding using an injection molding machine with the main body magnet 4 and main body yoke 3 set in predetermined positions. Shape it until it touches the surface (the opposite side).

If there is a gap between the main body magnet 4 and the main body yoke 3, the magnetic properties (surface magnetic flux density - strength of the magnet) will deteriorate, so they are closely bonded with an anaerobic adhesive and set in an injection mold. HORIFF@R: The closed container body 1 is made by insulating and molding the lens, and then molding it halfway.
Retract the container body 1, and inject 60 pyrene again into the gap created between the body magnet 4 and the sealed container body 1.
completed.

There is also a method in which the main body magnet 4 is magnetized weaker than a predetermined magnetization level (the direction of magnetization does not matter) and then the main body yoke is attracted and adhered to it, but the attraction may peel off when injecting the resin. Adhesion may become poor.

Similarly, for the lid part 2, set the lid part magnet 5 shown in FIG. 1 with the yoke 6 tightly adhered up to the surface of the lid part magnet 5 in an injection mold, and then inject the mold into an injection mold. Then, the molded lid part 2 was moved back to the middle, and the cylinder was further injected to take out the molded lid part 2.

The airtight container body 1 and lid part 2 injection molded in this way are magnetized into two inner and outer poles using a whiteless magnetizing power source and a magnetizing cork connected to it so that the different magnetic poles are in opposing positions. I did it.

When the closed container main body 1 and the lid 2, each of which has magnetized magnets 4 and 5, are brought close to each other, they are naturally attracted at positions corresponding to different magnetic poles and are sealed as shown in FIGS. 1 and 2.

As a comparative example, molding was performed using a conventional technique.

In the method shown in FIG. 3, the surfaces of the closed container main body 1 and the lid part 2 were uneven, which caused stains and was difficult to clean.

Furthermore, in the method of insert molding a permanent magnet that has been magnetized in advance as shown in Fig. 4, the magnetized permanent magnet 8 may be attracted to other permanent magnets or the magnetic metal structure of the injection molding machine body. This made handling complicated.

In the embodiment of the present invention, permanent magnets were used for both the sealed container body 1 and the lid 2, but it is also possible to use a magnet for one side and a soft magnetic material that is attracted to the magnetic field for the other. As shown in FIG. 5, even if the attracting surface of a permanent magnet is radially magnetized with multiple poles alternately in N and S directions, it is possible to seal the container by attraction.

〔Effect of the invention〕

As described above, according to the manufacturing method of the airtight container of the present invention, it can be applied to the close contact portion with the lid of the airtight container body used when storing and transporting foods, etc., or the close contact portion of the lid with the main body. In the method for manufacturing a closed container made of resin in which a resin-bonded permanent magnet is enclosed in a part that is sealed, the surface of the container in which the permanent magnet is enclosed is saved by magnetizing the resin-bonded permanent magnet after molding the sealed container. It is beautiful and has no irregularities, and also has the effect that it can be manufactured without the need to align the magnetic poles of the permanent magnets, and without the attraction of magnetized permanent magnets during molding.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are cross-sectional views showing embodiments of the present invention. FIGS. 3 and 4 are sectional views showing conventional examples. FIG. 5 is a perspective view showing a multipolar magnetized permanent magnet. 1... Airtight container body 2... Lid 3... Body yoke 4... Body magnet 5... Lid magnet 6... Lid yoke 7... Hole 8
... Permanent magnet - Above - Applicant Seiko Epson Corporation Figure 2 76 Figure 3 4N

Claims (1)

[Claims] A closed container made of resin that has a resin-bonded permanent magnet sealed in the part that comes into close contact with the lid of the closed container body used when storing and transporting foods, etc., or in the part that corresponds to the part that comes into close contact with the lid and the main body. A method for manufacturing a closed container, characterized in that the resin-bonded permanent magnet is magnetized after molding the closed container.