JPS6198512A - Manufacture of composite joint pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a composite pipe for construction, and more specifically, an inner pipe made of synthetic resin is covered with an outer pipe made of fiber-reinforced mortar,
Furthermore, the present invention relates to a method for manufacturing a composite joint pipe in which the end faces of the inner and outer pipes are matched. The joint pipe referred to here is an L-shaped pipe 1. This applies to three-way pipes, three-way pipes, four-way pipes, etc.

Water supply/drainage pipes and air supply/exhaust pipes used in buildings are required to be nonflammable according to the Building Law Enforcement Ordinance, and steel plate spiral pipes are generally used.
When used in toilets etc., condensation is likely to occur due to the high humidity environment, which can corrode within a few years and cause holes in the pipes.
This was causing water leaks, etc.

[Prior art] For this reason, attempts have been made to use synthetic resin pipes, but there are problems with fire resistance, so a synthetic resin pipe is used as the inner pipe, and the periphery is covered with fiber-reinforced mortar (hereinafter simply referred to as "Shichirutar"). Composite pipes have recently come into use.

The above-mentioned composite pipe has many advantages such as excellent earthquake resistance, corrosion resistance, chemical resistance, impact resistance, and sound insulation, low fluid resistance, light weight, and easy construction.

Although straight pipes of such composite pipes can be manufactured by wrapping cheesecloth coated with mortar or impregnated with mortar around a synthetic resin inner pipe, problems arise when it comes to joint pipes.

[Problem that the invention seeks to solve]

The conventional method for manufacturing the above-mentioned composite joint pipe is
Figure 4 will be explained.

In the nesting method shown in FIGS. 2 and 3, the inner tube 11, which has been formed in advance by injection molding, is
It is held in the formwork 12 with a closed space corresponding to the volume. In this case, if the inner tube 11 is not positioned within the formwork 12, the resulting product will have uneven thickness, so a nest (sweep) 13 is inserted into the gap between the inner tube 11 and the formwork 12, and The inner tube 11 is fixed so that the nest 13 does not move relative to the inner tube 11.
The outer tube 14 is formed by adhering to the outer surface of the outer tube 14 and filling and curing the remaining sealed space with solutar. However, since the outer surface of the inner tube 11 is curved, it is difficult to adhere the insert 13, and it is time-consuming to use it for each product. Also, if the insert 13 moves due to poor adhesion, the outer tube 1 with a uniform wall thickness may
There is a drawback that product No. 4 cannot be obtained.

In the plug-in pipe method shown in Fig. 4, the inner V! 11 joint socket 15
A method of forming the outer tube 14 by inserting an insertion tube (holder) 16 into the mold, holding it by the upper and lower molds of the mold, and then filling and curing mortar in the closed space from an injection port (not shown). It is.

In this method, mortar slurry may flow between the joint socket 15 and the insertion pipe 16 due to the casting pressure when placing the mortar. Since the plug-in tube whose end is contaminated with mortar is used repeatedly to make products one after another, the dirt at the joint socket 150 of the product becomes even worse, and it takes a great deal of effort to remove the dirt. Requires work.

[Means to solve the problem]

The present invention eliminates the drawbacks of the conventional manufacturing method described above.
The gist is a method for manufacturing a composite joint pipe, which is composed of an inner pipe made of synthetic resin and an outer pipe made of fiber-reinforced mortar covering the inner pipe, and in which the opening end surfaces of the inner and outer pipes are formed on the same plane. , the open end of the inner tube is formed in advance to extend slightly in the axial direction than the product dimension, and there is a sealed space between the split formwork and the inner tube, and between the upper and lower lids of the formwork. After clamping the extension of the inner tube, the sealed space is filled with a slurry of fiber-reinforced mortar and cured to form an outer tube, and after demolding, the extension of the inner tube is cut off. This is a manufacturing method for composite joint pipes.

〔Example〕

The present invention will now be described in detail with reference to FIG.

An inner tube 1 formed by blow molding is held in a mold frame 2 consisting of upper and lower molds. When the inner tube of a joint tube is formed by general Kfa molding, an unnecessary portion A-B is created which is not used as an inner tube due to its nature. The unnecessary portion A-B extends axially by a slight dimension beyond the respective open end of the product. In the present invention, the inner tube 1 is positioned within the mold frame 2 by holding the unnecessary portions A-B at the ends of the upper and lower molds, respectively. Unnecessary part A-B
A closed space to be filled with mortar is formed between the formwork 2 and the inner tube 1, as in the conventional manufacturing method.

The closed space is filled with mortar and cured to form the outer tube 3. In this case, by providing small holes in the bottom of the unnecessary portion B and the formwork opposite thereto, it is possible to pass a thermal fluid (hot steam, hot air), etc. to increase the mortar solidification rate. When the solidification of the metal is completed, it is removed from the mold, and unnecessary portions M and B are cut out along the cuts @4-4 and 5-5 shown in FIG.

Although the inner tube 1 was manufactured by blow molding in the above example, it can also be manufactured by injection molding. In this case as well, an extension part extending in the axial direction is formed in advance at the open end of the inner tube, and the inner tube is held in the mold via the extension part and removed after demolding. [Effects] Since the present invention is constructed as described above, there is no need for variations in the wall thickness of the outer tube as in the case of the nesting method, and there is no need for the complexity of using a nest, and there is no unnecessary part A-BO outer surface as in the case of a plug-in tube. Even if mortar slurry adheres to the concrete during pouring, there will be no problem as that part will be removed during the cutting process.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing an embodiment of the present invention, Fig. 2 is a vertical cross-sectional view showing a conventional manufacturing method, and Fig. 3 is a vertical cross-sectional view showing a conventional manufacturing method.
FIG. 4 is a vertical sectional view showing another conventional manufacturing method. 1...Inner tube, 2...Formwork, 3...Outer tube, A-B・
...The arc length of the inner tube.

Claims (1)

[Claims] 1. A method for manufacturing a composite joint pipe consisting of an inner pipe made of synthetic resin and an outer pipe made of fiber-reinforced mortar covering the inner pipe, and in which the open end surfaces of the inner and outer pipes are formed on the same plane, The open end of the inner tube is formed in advance to extend slightly in the axial direction than the product dimensions, and a sealed space is formed between the split formwork and the inner tube, and the above-mentioned inner tube is formed between the upper and lower lids of the formwork. A composite joint characterized in that after the extension of the pipe is clamped, an outer pipe is formed by filling and curing slurry of fiber-reinforced mortar in the closed space, and after demolding, the extension of the inner pipe is cut off. Tube manufacturing method.