JP3065525U - Double tube - Google Patents

Abstract

(57) [Summary] A double tube having an inner cylinder that can be manufactured at low cost. [Solution] An inner cylinder 5A manufactured by extrusion molding is provided.
Double tube inside metal tube 7A.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a double tube, and more particularly, to a double tube in which an inner cylinder formed by extrusion molding is provided inside an outer metal tube.

[0002]

[Prior art]

 Conventionally, in a metal tube made of a metal material such as aluminum, as shown in FIG. 6, when the body of the metal tube 7A is pressed in order to extract the adhesive or the like as a content, the body is temporarily stopped. When the part is pressed and deformed, in order to maintain the state of the body part, after a certain amount of content is extracted from the mouth, the content is continuously extracted from the mouth. Then, a phenomenon occurs in which the content drips at the mouth. Then, in order to prevent this dripping phenomenon, the inner tube 5A as an elastic body is provided inside the metal tube 7A, and the metal tube 7A is restored by the elastic restoring force of the inner tube 5A for restoring the body of the metal tube 7A. The body part returns to its original shape, and the dripping phenomenon at the mouth of the contents is prevented.

As shown in FIG. 7, in a metal tube 7B for storing a strong alkaline or acidic substance such as a hair dye, when the inner surface of the metal tube comes into direct contact with the hair dye, the metal tube 7B corrodes from the inside. Therefore, in order to prevent this, the inner cylinder 5B made of a synthetic resin such as polyethylene is inserted into the metal tube 7B.

Conventionally, as a method for manufacturing the inner tube of these double tubes, there has been a method shown in FIGS. In FIG. 8, reference numeral 50 is a sectional view showing a mold 50 for blow molding. That is, a parison, which is a test tube made of a synthetic resin material before being inflated with compressed air, is inserted into the mold 50, and then the compressed air is blown into the mold 50 to expand the parison. , The inner cylinder 51 is formed. Next, as shown in FIG. 9, the front end 51b and the bottom 51c of the inner cylinder main body 51a were cut off to form the inner cylinder main body 51a. In the case of injection molding, there is no cutting step as described above, but it is necessary to manufacture a mold in the same manner.

[0005]

[Problems to be solved by the invention]

 However, according to such a conventional method of manufacturing the inner tube of the double tube, the manufacturing cost of the mold 50 for the blow molding or the injection molding is expensive, and therefore, the formed inner cylinder main body 51a is not provided. There was a disadvantage that it became expensive and the overall manufacturing cost of the double tube became high.

The present invention has been made in view of such a conventional problem, and the manufacturing cost of the inner cylinder housed in the double tube is manufactured at a low cost, so that the entire manufacturing cost of the double tube is reduced. The aim is to reduce.

[0007]

[Means for Solving the Problems]

 In order to solve this problem, the present invention is to continuously form a single-layer or multi-layer synthetic resin into a tubular shape by extrusion, cut the formed tubular body to a desired length, and then By inserting the cylindrical body into the mandrel, the molded resin was heated and softened, and the desired mold was brought into contact with the mandrel, and the molded inner cylinder was inserted into the metal tube. Features.

[0008]

[Embodiment of the invention]

 Next, an embodiment of the present invention will be described with reference to the drawings. In FIGS. 6 and 7, reference numerals 5A and 5B denote inner cylinders provided inside metal tubes 7A and 7B. The inner cylinders 5A and 5B are made of a synthetic resin such as polyethylene or polypropylene. The method of manufacturing the inner cylinders 5A and 5B, that is, the inner cylinder 5 shown in FIGS. 4 and 5, will be described. As shown in FIG. 1, a synthetic resin material is heated in an extruder (not shown). It is pressurized and melted into a fluid state. Then, a continuous cylindrical body 1 is extruded from the die 2. Next, as shown in FIG. 2, the cylindrical body 1 is cut to a desired size, and a plurality of cylindrical bodies 3 are manufactured. Thereafter, as shown in FIG. 3, the mandrel 4 is inserted into the cut cylinder body 3, and the portion of the cylinder body 3 formed by the molding die 6 in the next step is softened by heating ( (See site H in FIG. 3). The tip 4a of the mandrel 4 to be inserted is formed in a shape corresponding to the shape of the mouth and shoulder of the inner cylinder 5 in which the cylinder main body 3 is formed.

Next, as shown in FIG. 4, a molding die 6 is brought into contact with a heated portion (a portion H in FIG. 3) of the cylinder main body 3, and a distal end portion 5 a and a shoulder portion 5 b of the inner cylinder 5. Is molded. Then, as shown in FIG. 5, after cooling, the inner cylinder 5 is extracted from the mandrel 4, and the inner cylinder 5 is manufactured. Needless to say, the shape of the inner cylinder 5 shown in FIG. 5 can be appropriately formed into a desired shape.

Then, as shown in FIG. 6, an inner cylinder 5A is provided inside a metal tube 7A of a metal tube 8A in which an adhesive is stored as a content, or as shown in FIG. The inner tube 5B is provided inside the metal tube 7B of the double tube 8B in which the hair dye is stored. In addition, the present invention may be applied to a double tube containing relatively alkaline and acidic contents such as pharmaceuticals and foods.

Next, the operation of the present invention will be described. The inner cylinder 5 in the present invention does not require expensive molds such as blow molding and injection molding. Further, since it is not necessary to cut the mouth and the bottom after the molding, the production is easy.

[0012]

[Effect of the invention]

 As described above, according to the present invention, since the manufacturing cost of the inner cylinder housed in the double tube can be reduced, the manufacturing cost of the double tube can be reduced as a whole. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state in which a cylindrical body is continuously extruded from an extruder in a process of manufacturing an inner cylinder according to the present invention.

FIG. 2 is a cross-sectional view showing a state in which the extruded cylinder is cut into a plurality of cylinder bodies in a process of manufacturing the inner cylinder according to the present invention.

FIG. 3 is a cross-sectional view showing a state in which a mandrel is inserted into a cylinder main body in a process of manufacturing the inner cylinder according to the present invention.

FIG. 4 is a cross-sectional view showing a state in which the molding die is in contact with the mandrel to form the inner cylinder in the manufacturing process of the inner cylinder according to the present invention.

FIG. 5 is a sectional view showing a state in which the inner cylinder is formed and then cooled in the manufacturing process of the inner cylinder according to the present invention.

FIG. 6 is a sectional view showing a state in which the inner cylinder according to the present invention is housed in a metal tube for storing an adhesive.

FIG. 7 is a cross-sectional view showing a state in which the inner cylinder according to the present invention is housed in a metal tube for storing a hair dye.

FIG. 8 is a sectional view showing a manufacturing process of a conventional inner cylinder.

FIG. 9 is a sectional view showing a manufacturing process of a conventional inner cylinder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical body 3 Cylindrical body 4 Mandrel 5 Inner cylinder 5A Inner cylinder 5B Inner cylinder 6 Mold 7A Metal tube 7B Metal tube 8A Double tube 8B Double tube

Claims (1)

[Utility model registration claims] 1. A single-layer or multi-layer synthetic resin is formed into a continuous cylinder by extrusion molding, and the formed continuous cylinder is cut into a desired length to produce a cylinder main body. Inserting the cylinder body into a mandrel, heating and softening the resin surface of the portion to be molded, contacting a desired mold with the mandrel to form an inner cylinder, and mounting the inner cylinder in a metal tube. Features a double tube.