JPS5819456B2 - Bent pipe forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an uncured resin pipe into a bent pipe and hardening the pipe.

The above-mentioned "uncured" refers to a state where the surface is not sticky, can be stored for several hours to several weeks, has a hardness that allows it to maintain its shape, softens once when reheated, and then completely hardens. For example, in the case of polyester, this state can be obtained by the following means.

Namely.

(a) A metal crosslinking method in which carboxyl groups of unsaturated polyester are bonded ionicly or coordinately with a divalent metal oxide or hydroxide.

(0) A chelate bonding method in which a quaternary ammonium salt, a mercaptan, and a metal soap are used together for chelate bonding.

(・→ A partial cross-linking method using a two-stage catalyst, in which the first stage is partially cross-linked using a low-temperature catalyst, and the second stage is completely cross-linked using a high-temperature catalyst, etc.

In addition, in (c), the polymerization reaction temperature is controlled using a high-temperature catalyst, cooling is performed through partial crosslinking, and complete curing is performed at a high temperature after secondary processing. There is a method of controlling catalyst promotion using two stages.

The present invention provides a method for forming a curved pipe by which an uncured resin pipe obtained by the above-mentioned method can be transformed into a freely curved pipe shape at any location and at low cost. will be explained based on the drawings.

That is, in the present invention, as shown in FIG. 1, first, a shape-retaining coil spring I is inserted into an uncured resin pipe 1.

And this uncured resin pipe 10 both ends connection portions IA, IB
are protected with jigs 2A and 2B.

The length L protected by the jigs 2A and 2B can be arbitrarily changed depending on the purpose of use and the connecting tool to be used.

Next, this uncured resin pipe 1 is placed in a tank 3 as shown in FIG.
It is placed on a curved tube mold 4 provided inside.

Tank 3rrJ, factory-installed (fixed) type, on-site assembly, and mobile type are used.

The curved tube mold 4 is supported by a pedestal 5, and has a molding surface 4 on its upper surface.
A is formed on both ends of the upper surface, and the jig receiver is formed with a surface 4A.
4B is formed.

Therefore, the uncured resin pipe 1 holds the jigs 2A and 2B on the surface 4.
A and 4B are brought into contact with each other to support the bent tube mold 4 side.

In this state, the uncured resin 1 is heated and softened.

Heat softening can be done by supplying heated gas such as air into the tank 3 or by supplying heated liquid such as water or oil.
In this embodiment, a state in which heating oil 6 is injected is shown.

The uncured resin pipe 1 is first heated and softened by the temperature of the oil, deforms into a hanging shape, and is brought into contact with the molding surface 4a as shown in FIG.

At this time, the uncured resin pipe 1 is held in a perfect circular shape by the coil spring 7.

Then, by subsequent heating, it is hardened in the deformed curved tube shape.

Therefore, by subsequently pulling it up, removing the jigs 2A and 2B, and then taking out the coil spring 7, it is possible to obtain a bent pipe having straight pipe-like connection portions IA and IB at both ends.

Note that the heating temperature and time are selected depending on the resin, catalyst, and amount.

In addition, in order to maintain the shape of the uncured resin pipe 1 during deformation,
Instead of the coil spring 1 described above, sand may be placed inside it.

According to the present invention described above, curved pipes can be formed freely according to various molding surfaces of the curved pipe mold, and curved pipes can be formed at any location by simply installing a tank, that is, even on-site. Compared to conventional dedicated molding, it can be molded more easily and at a lower cost, and it is possible to provide an inexpensive bent pipe.

In particular, according to the present invention, the uncured resin pipe can maintain its perfect circular shape during deformation by means of a coil spring or sand inserted therein, and therefore a curved pipe with a perfectly circular cross section at each location can be obtained.

[Brief explanation of drawings]

1 to 3 are partially cutaway front views showing one embodiment of the present invention. 1... uncured resin pipe, IA, IB... connection equivalent part,
2A, 2B... Jig, 3... Tank, 4... Molding mold, 4a... Molding surface, 6... Heating oil, 7... Coil spring.

Claims (1)

[Claims] 1. Insert a coil spring or sand into the inside of an uncured resin pipe, then protect the parts corresponding to the connections at both ends of the uncured resin pipe with a jig, and place the uncured resin pipe on a curved pipe mold in a tank. The inside of the tank is heated while the uncured resin pipe is placed on the pipe, and the uncured resin pipe is first softened by heating and made to fit along the molding surface of the curved pipe mold.
A curved tube forming method in which the tube is hardened by subsequent heating.