JP2792630B2 - Method of manufacturing resin bellows hose with projection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is to simultaneously form a projecting body that is continuous over the entire circumference to form a resin bellows hose at the same time as forming a resin bellows hose for diversification or reinforcement. The present invention relates to a method of manufacturing a resin bellows hose with a projection.

[Conventional technology]

Conventionally, when a continuous projection is fixed to the outer periphery of a resin product over the entire circumference, there has been no alternative but to fit the projection to the outside after molding the resin product. Therefore,
In addition to dissatisfaction with strength and cost, the materials were limited to those of the same type.

[Problems to be solved by the invention]

This was attributable to the molding method peculiar to blow molding, in which the split mold must not be closed when the parison is hung (because the parison hits the mold and sags poorly).

However, recently, there has been proposed a molding method in which an air flow is caused to flow in the mold and the parison is dripped on the air flow (Japanese Patent Publication No. 58-47337). You don't have to.

The present invention makes it possible to form a continuous projection on the outer periphery of a resin bellows hose simultaneously with molding by effectively utilizing such a molding method.

[Means for solving the problem]

That is, according to the present invention, an airflow is caused to flow in a bellows-shaped mold space formed by a split mold in a combined state, and the parison is dripped on the airflow, and then the upper and lower ends of the parison are closed. In addition, in a method for manufacturing a resin bellows hose in which the parison is formed into the bellows shape by blowing air into the parison, an insert which is wound around the outer periphery of the formed bellows hose and becomes a projection is previously inserted into the mold space. The parison is held in a state where the inner peripheral part thereof is partially protruded into the inside, and after the parison is hung down, air is blown into the parison so that the protruding body comes to the outer periphery of the bellows hose. An object of the present invention is to provide a method of manufacturing a resin bellows hose with a projection, which is formed so as to be fitted in a partially buried state.

[Action]

By taking the above measures, that is, when the parison hangs, the split mold can be kept in a closed state. These projections can be formed on the outer periphery of the hose at the same time as the molding. In this case, since the projection can be fitted in a state where it is partially buried in the bellows hose, it does not move and is displaced, and the shape maintaining property against deformation force is high.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a sectional view showing the parison hanging in the split mold. The split molds 1 and 1 are located above and below the central main molds 1a and 1a.
b, 1b and the lower molds 1c, 1c can be opened and closed independently. Now, only the main dies 1a, 1a are closed and the upper die 1b, 1b and the lower dies 1c, 1c are opened.
From the parison 3. In this case, the master type 1
An intake pipe 5 is made continuous with the mold space 4 composed of a and 1a, and an airflow flowing downward in the mold space 4 is generated. Therefore, the airflow flows around parison 3 and
Even if the mold space 4 is bent in this way, the split mold 1,
With 1 closed, hang down the center without touching the surface of the surrounding split dies 1,1. By the way, in this case, after molding, a projection 7 continuous to the entire periphery of the product 6 to be formed is used as an insert 8 to insert the inner peripheral portion 8a into the mold space 4 beforehand. It is kept in a state where it has entered. Here, "partially intruding" means a state in which the inner end of the inner peripheral portion 8a is intruding at least into the mold space 4. That is, the inner peripheral portion of the insert 8
If the mold 8a protrudes into the mold space 4, when the air is blown and molded, the projection 7 is partially embedded in the product 6.

FIG. 2 is a cross-sectional view when the parison 3 has reached the lower dies 1c, 1c. In this state, the intake pipe 5 is removed to stop the supply of the parison 3, and at the same time, the upper dies 1b, 1b and the lower The molds 1c and 1c are closed, and the upper and lower ends of the parison 3 are closed. Next, the air pin 9 is passed through the upper die 1b, 1b or the lower die 1c, 1c (in this example, the upper die 1b, 1b. Therefore, a pin hole 10 is previously formed at a required portion of the upper die 1b, 1b. The air pin 9 blows air into the parison 3 to inflate the parison 3 so as to press the parison 3 against the inner peripheral surface of the split mold 1,1.
It is molded into the required shape.

FIG. 3 is a partial cross-sectional front view of the product 6. As described above, the inner peripheral portion 8a of the insert 8 is partially inserted into the mold space 4 and held in the split molds 1 and 1 in advance. Therefore, when air is blown into the molding, the parison 3 expands so that the inner peripheral portion 8a of the insert 8 is embedded in the outer periphery. As a result, the protruding body 7 is integrally formed on the outer periphery of the product 6 in a partially buried state. From this viewpoint, it is preferable to make the inner peripheral portion 8a appropriately wide from the standpoint of retaining.

FIG. 4 is a cross-sectional view showing the hanging state of the parison 3 when the projections 7 are fitted into the troughs of the hose when the product 6 is the bellows hose 6, and in such a case, it is the same as above. Then, the parison 3 may be hung in a state in which the split molds 1 and 1 in which the inserts 8 are fitted in advance are closed.

FIG. 5 is a front view of the bellows hose 6 formed in this manner, in which the projection 7 is fitted in the bellows valley of the bellows hose 6. In this case, the inner periphery of the insert 8
If the protrusion 8a is inserted into the mold space 4, the protrusion 7 is partially embedded in the outer periphery of the bellows hose 6 as described above. FIG. 6 is also a front view of the bellows hose 6. In this case, the bellows has a continuous spiral shape, and accordingly, the projection 7 is also fitted in a spiral shape. Become. In addition, if such a protrusion 7 is integrally fitted to the outer periphery of the bellows, deformation due to positive pressure and negative pressure can be suppressed, which is significant. In particular, in the case of a negative pressure, if only the conventional projection is simply fitted on the outer periphery, only the hose part is deformed separately from the projection, but the hose and the projection are integrated. If so, deformation is suppressed.

〔The invention's effect〕

As described above, according to the present invention, the protrusion 7 can be integrally formed on the outer periphery of the bellows hose 6 made of resin. In this case, since the protrusion 7 is partially buried in the outer periphery of the product, it does not move and suppresses the bellows hose 6 from being deformed. In this point, the strength is stronger than the conventional products in which separate parts are welded or semicircular parts are welded together. Further, the material of the projection 7 may be different from that of the bellows hose 6, for example, metal. Further, this projection 7 is a bellows hose 6
It can be formed at the same time as blow-molding, so that the cost does not increase.

[Brief description of the drawings]

1 and 4 are sectional views of the parison hanging state, and FIG.
The figure is a cross-sectional view in an air blowing state, FIG. 3 is a partial cross-sectional front view of a product, and FIGS. 5 and 6 are front views of other products. (Symbol) 1 split mold 3 parison 4 mold space 6 bellows hose 7 full-circle continuous projection body 8 insert 8a inner circumferential part of 〃

Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) B29C 49 / 02,49 / 04,49 / 20 B29C 49/48-49/54 B29C 67/18 B29C 33/12-33 / 18 B29D 23/18 B29K 105: 20 B29L 23:18

Claims (1)

(57) [Claims] An air flow is caused to flow in a bellows-shaped mold space (4) formed by the split molds (1) and (1) in a combined state, and the parison (3) is drooped on the air flow. Then, in addition to closing the upper and lower ends of the parison (3), a method of manufacturing a resin bellows hose for blowing air into the parison (3) to form the parison (3) into the bellows shape is provided. The insert (8) that is wound around the outer periphery of the bellows hose (6) after molding to form the projection (7) is previously inserted into the mold space (4).
After the inner periphery (8a) of the parison (3) is held down by the split dies (1) and (1), and the parison (3) is suspended, A method for producing a resin bellows hose with a projection, wherein the projection (7) is formed so as to be fitted in a state of being partially embedded in the outer periphery of the bellows hose (6) by blowing air to the hose.