JPS588343B2 - Double tube forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a double tube comprising an outer tube made of a mixture of inorganic fibers and an inorganic binder and a hollow inner tube.

In the past, synthetic resin drain pipes and their joints were damaged or burnt down due to fires, etc., which resulted in the generation of toxic gases, which caused great damage such as endangering human life.

Therefore, it is an object of the present invention to develop a method for manufacturing fireproof double pipes in which an outer layer made of inorganic fibers and an inorganic binder is applied to the outer peripheral surface of the synthetic resin straight pipe and its joint, and to eliminate the above-mentioned drawbacks. It is.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 shows an apparatus for forming a double pipe using a synthetic resin pipe 1 in a hollow core type, and a partially cutaway sectional view of the formed double pipe.

In FIG. 1, reference numeral 2 denotes a foamable intervening body attached to the outer peripheral surface of the synthetic resin pipe 1. As shown in FIG.

Furthermore, a coating 3 made of inorganic fibers, an inorganic binder, and water is formed on the outer surface of the foamable intervening body 2 to form a fireproof layer.

In this example, asbestos is used as the inorganic fiber and cement is used as the inorganic binder, and a mixture of these with an appropriate amount of water is used, but other materials other than asbestos or cement can have the same effect. You can also use the one you have.

Furthermore, if a small amount of an admixture such as polyvinyl alcohol, gelatin, or methyl cellulose is added to the above mixture, the water retention property will be improved, the qualitative structure of the molded product will be uniform, there will be no fear of the formation of cavities, and the strength will be high. Become.

FIG. 2 shows an apparatus for forming a double pipe using a synthetic resin pipe joint 4 in a hollow core type, and a partially cutaway sectional view of the formed double pipe.

In FIG. 2, reference numeral 5 denotes a foamable intervening body attached to the outer surface of the synthetic resin pipe joint 4. As shown in FIG.

Furthermore, a coating 6 made of inorganic fibers, an inorganic binder, and water is formed on the outer surface of the foamable intervening body 5 to form a fireproof layer.

7 is the opening of the synthetic resin pipe joint.

Note that the molded products shown in Figures 1 and 2 used a synthetic resin hollow core mold, but a metal hollow core mold is used when the purpose is to insulate the fluid flowing inside. You can also do that.

Further, in this embodiment, a synthetic resin pipe with a foamable intermediary member attached thereto was used, but if the pipe is used in a situation where temperature changes are small, the foamable intermediary member may not be attached.

Next, an apparatus for manufacturing fireproof double pipes that implements the method of the present invention will be described.

In the first embodiment shown in FIGS. 3.4.5, FIG. 4 is a side view of the fixed mold 8 and the movable mold 9 in the closed position.

The fixed mold 8 and the movable mold 9 constitute an outer mold that forms a molding recess according to the outer shape of the molded product, and the outer mold is made of reinforced resin or metal.

When the movable mold is closed, semicircular holes 13, 13, 13, 15, 15.1 provided in each opening of the fixed mold 8 and the movable mold 9
The outer circumferential surfaces of the core positioning members 12, 12, 12 are fitted into the positioning members 5.

In addition, the inner walls 13a, 13a, 13a of the fixed mold 8, the movable mold 9
The end faces of the openings 7, 7.7 of the synthetic resin pipe joint 4 are brought into close contact with the inner walls 15a, 15a, 15a of the synthetic resin pipe joint 4.

An injection port is provided in the center of the movable mold 9 to press the mixture into the mold by a piston type or one screw type extrusion method.

In this example, the injection port is provided at one location on the movable mold 9, but it may be provided on the fixed mold 8, or may be provided at two or more locations.

Further, in order to drain excess water in the mixture out of the fixed mold and the movable mold, a plurality of small holes may be provided in one or both of these molds.

Furthermore, in the case of materials with a small moisture content, small holes for drainage are not necessary.

The middle mold 10 shown in FIG.
is detachably attached to the inner surface of the movable mold 9.

17 is a hole drilled in the middle mold 11.

This medium size is made of reinforced resin, iron plates, nets, etc.
They are selected and used depending on the type and shape of the molded product.

Furthermore, a small mesh can be inserted between the medium mold 10, 11 and the fixed mold 8 and movable mold 9 to promote drainage of moisture and facilitate removal of the medium mold.

The insertion of the mesh makes it possible to prevent the formation of air bubbles within the mixture and forms a strong coating.

Core type positioning members 12, 12. shown by dashed lines in FIG.
12 is adapted to be attached to each opening 7, 7.7 of the synthetic resin pipe joint 4 to which the foamable intervening body 5 is attached.

When the synthetic resin pipe joint 4 with the core positioning member 12 mounted thereon is further placed on the inner surface of the fixed mold 8 shown in FIG. 3, and the movable mold 9 is moved to the closed position, the synthetic resin pipe joint A molding space 14 is formed between the outer peripheral surface of the mold 4 and a middle mold mounted on the fixed mold and the movable mold.

Next, the operation of the manufacturing apparatus that implements the present invention will be described.

The movable mold 9 is moved in the direction of the arrow in FIG. 4 and stopped at the open position.

Then, the middle mold 10 shown in FIG. 5 is mounted on the inner surface of the fixed mold 8, and the middle mold 11 is mounted on the inner surface of the movable mold 9.

Next, the core type positioning members 12, 12, 12 are inserted into the respective openings 7, 7, 7 of the synthetic resin pipe joint 4 to which the foamable intervening body 5 is attached.
(see the one-dot chain line in Figure 2), and the synthetic resin pipe joint 4 with these core type positioning members 12, 12.12 installed.
is placed on the fixed mold 8, the end surfaces of the openings 7, 7, 7 of the synthetic resin pipe joint 4 are placed on the inner wall 13a of the fixed mold 8. 13a,
13a, and the outer peripheral surface of the core positioning member 12, 12.12 fits into the semicircular hole 13, 13.13 of the fixed mold 8.

In this way, when the movable mold 9 is moved to the closed position, the core positioning members 12, 12.12 fit into the semicircular holes 15, 15.15 of the movable mold, and the synthetic resin pipe joint 4 is fitted with the core positioning members 12, 12.12. The end faces of the openings 7, 7.7 are the inner walls 15a, 15a of the movable mold 9.
, 15a.

In this way, the synthetic resin pipe joint 4 is fixed by the fixed mold 8, the movable mold 9, and the core positioning members 12, 12.12.

Therefore, a mixture of asbestos, cement, and water is extruded into the injection port 16 using a piston method or one-screw extrusion method.
When the mixture is press-fitted from the hole 17, the molding space 14 is filled with the mixture.

When the press-fit filling operation is completed in this manner, the movable mold 9 is moved to the open position.

At this time, because the medium mold 11 is in close contact with the molded product due to the adhesiveness of the asbestos and cement materials, the molded product is left on the fixed mold 8 with the medium mold 11 in close contact with it.

Then, the molded product is taken out from the fixed mold 8 while the middle molds 10 and 11 are in close contact with the molded product, and is dried and hardened.

Straight pipes can be formed in a manner similar to the pipe joint forming operation described above, and this is illustrated in FIG.

18 is a fixed type, 19 is a movable type, 20 is an injection port, and 21 is a core positioning member.

In this embodiment, the shape of the straight tube is circular, but it can also be polygonal.

Next, a second embodiment shown in FIGS. 6, 7, and 7a will be described.

In the second embodiment, each opening 24 of the fixed mold 22 and the movable mold 23
, 24, 24, 25, 25.25 have threads a cut on their outer peripheral surfaces, and the core type positioning members 26, 26.26 have truncated cone-shaped protrusions 27, 27.27 in the center. This embodiment is different from the first embodiment in that it has a cap nut shape and has a female thread b cut in the nut portion.

Note that the convex portion 27 may have a cylindrical shape.

28 and 29 are medium-sized pipes, 30 is a synthetic resin pipe joint, 31 is a molding space, and 32 is an injection port.

FIG. 1a is a plan view of the core positioning member 26. FIG.

In the second embodiment, screws were used to fix the core positioning member 26, but a plurality of protrusions were provided on the outer peripheral surface of each opening of the fixed mold 22 and the movable mold 23, and the core positioning member 26,
26.26 may be provided with protrusions which engage each other to secure the core positioning member in the openings of both molds.

The method for producing a fireproof double pipe of the present invention press-fills a certain amount of the mixture into the molding space in one molding operation, thereby eliminating waste of the mixture and saving the mixture.

When using a mixture that takes a relatively long time to set and harden, such as asbestos/cement mortar, the molded product is removed from the fixed mold along with the middle mold, and is dried and hardened as is, so there is no damage to the molded product and the occurrence of defective products. To prevent.

In addition, if a large number of medium molds that can be attached to the inner surface of the fixed mold or movable mold are provided, the molded product can be taken out together with the medium molds without waiting for the molded product to harden, and the molding work can be performed continuously. , extremely efficient.

Furthermore, since the molded product produced by the method of the present invention can withstand the heat of fire, when used in a building, it is useful for fire prevention and can prevent damage caused by the spread of fire.

[Brief explanation of drawings]

Figure 1 shows a double pipe molding device using a synthetic resin pipe in a hollow core mold, and a partially cutaway cross-sectional view of the molded double pipe, and Figure 2 shows a machine for forming a double pipe using a synthetic resin pipe in a hollow core mold. 1 shows a double pipe forming device and a partially cutaway sectional view of a molded double pipe. Figure 3 is a view of the medium type attached to the fixed type, Figure 4 is a side view of the fixed type and movable type in the closed position, Figure 5 is a side view of the medium type, and Figure 6 corresponds to Figure 4. Figure 7 showing an example of
This figure shows another embodiment corresponding to FIG. 2, and FIG. 7a is a plan view of the core positioning member.

Claims (1)

[Scope of Claims] 1. A mixture of inorganic fibers, an inorganic binder, and water is prepared, a plurality of outer molds and a hollow core mold of synthetic resin are prepared, and the plurality of outer molds in which molding recesses are formed and molding thereof. The mixture is press-fitted into the molding space formed by the synthetic resin hollow core mold inserted into the recess, and after the molding is completed, the outer mold is opened to take out the molded product, and the synthetic resin hollow core is molded. A method for manufacturing a fireproof double pipe, characterized in that the mold is used as is as an inner pipe of the fireproof double pipe. 2 Prepare a mixture of inorganic fibers, an inorganic binder, and water, prepare a plurality of outer molds with a plurality of medium molds attached to the inner surface, and a hollow core mold of synthetic resin, and prepare the plurality of outer molds in which molding recesses are formed. The mixture is press-fitted into the molding space formed by the middle mold attached to the mold and the hollow core mold of the synthetic resin inserted into the middle mold, and after the molding is completed, the outer mold is opened to form the middle mold. A method for producing a fire-resistant double pipe, which comprises taking out the molded product, removing the middle mold after hardening, and using the synthetic resin hollow core mold as it is as the inner pipe of the fire-resistant double pipe.