JPH03234991A - Drinage compound pipe - Google Patents

Abstract

PURPOSE:To prevent a noise such as a draining sound by providing a metallic outer tube and a synthetic resin inner tube, making the tube wall of the inner tube expand in the radius direction, forming the expanding parts continuously drawing spirals in the tube axial direction, filling a foaming resin in the clearance between the outer tube and the inner tube, and forming an air core at the center of the tube. CONSTITUTION:A drainage compound pipe 1 is formed of a metallic outer tube 2 made of a steel, aluminum, or the like, a synthetic resin inner tube 3 made of poly vinyl chloride, polyethlene, or the like, and a foaming resin layer 4 of an urethane system, epoxy system, or the like. In the inner tube 3, swelling parts 31 are formed continuously drawing spirals in the tube axial direction. On the inner wall surface of the inner tube 3, recessed spiral grooves 32 are formed at the parts responding to the swelling parts 31. As a result, the drainage flows down along the spiral grooves, an air core is formed at the center of the inner tube, and the pressure variation in the drain pipe is reduced in a high load condition.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a composite drainage pipe that is mainly used as a solid drainage pipe in high-rise buildings such as buildings and condominiums.

[Conventional technology]

JP-A-48-100957 and FR2251 are used as solid drainage pipes in high-rise buildings such as buildings and condominiums.
A drainage pipe in which a spiral protrusion or a spiral groove is formed on the inner circumferential surface of the pipe, as seen in Publication No. 673 (French patent), has been proposed and put into practical use. This drain pipe has a spiral groove that allows the waste water to flow down in a spiral along the wall surface of the pipe so that an air core is always formed in the center of the drain pipe. This function prevents the seal water from leaking from the trap, which occurs during high loads (when there is a large amount of water discharged), especially on lower floors, without having to install a separate ventilation pipe. It has the advantage of being able to prevent backflow.

[Problem to be solved by the invention]

However, it is very difficult to provide spiral protrusions or grooves on the inner wall surface of the drain pipe, and the manufacturing equipment becomes complicated, resulting in high manufacturing costs. Furthermore, residents of high-rise housing complexes such as condominiums are especially concerned about the sound of falling debris flowing down drain pipes. In particular, solid toilet drainage pipes and the like drop not only liquids but also solids. In the drain pipe mentioned in 2 above, if only liquid is flowing down along the pipe wall surface by the spiral groove, it is possible to reduce the sound of falling to some extent, but it is necessary to prevent the sound of falling solids. I couldn't do it. Moreover, there are cases in which metal pipes must be used due to building standards laws, but in the case of metal pipes, there is a risk that dew condensation may form on the outside wall surface of the pipe, which may have an adverse effect on the building. In view of these circumstances, the present invention not only allows wastewater to flow down in a spiral pattern to always form an air core in the center of the pipe, but also prevents noise such as drainage noise and eliminates problems such as dew condensation. The purpose of the present invention is to provide a new drainage composite pipe that is free of wastewater and can reduce manufacturing costs.

[Means to solve the problem]

In order to achieve the above object, the present invention includes an outer tube made of metal and an inner tube made of synthetic resin. The bulge is formed continuously in a spiral direction in the tube axis direction, and is inserted into the outer tube, and the gap formed between the inner tube and the outer tube is filled with foamed resin. The gist is a drainage composite pipe characterized by being filled with.

[For production]

With the above configuration, in the drainage composite pipe according to the present invention, when wastewater flows from above, the wastewater flows spirally along the groove on the inner wall surface of the inner pipe, which is created by the formation of the bulge in the inner pipe, and reaches the center of the inner pipe. An air core is always formed. Further, the sound of falling water generated inside the pipe is absorbed by the foamed resin layer formed in the gap between the inner pipe and the outer pipe, and does not leak to the outside of the pipe. Furthermore, the foamed resin layer acts as a heat insulator, and the metal outer tube is always kept at approximately the same temperature as the outside air without being affected by the temperature of the waste water flowing into the tube.

【Example】

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of a composite drainage pipe according to the present invention, with a portion thereof cut away and viewed diagonally from above. As shown in the figure, this drainage composite pipe 1 includes a metal outer pipe (hereinafter referred to only as the "outer pipe") 2, a synthetic resin inner pipe (hereinafter referred to only as the "inner pipe") 3, It is formed from a foamed resin layer 4. The outer tube 2 is formed of a normal metal tube such as steel, aluminum, stainless steel, or copper. The inner tube 3 is made of synthetic resin such as polyvinyl chloride or polyethylene, and its tube wall bulges every 90 degrees, and the bulges 31 continuously form a spiral in the tube axis direction. It is formed. Therefore, a recess is formed in the inner wall surface of the inner tube 3 at a portion corresponding to the bulge 31.
Four spiral grooves 32 are formed by this recess. Note that the number of bulging portions 31 is not limited to four, and can be increased or decreased as appropriate depending on the pipe diameter. The angle of the spiral groove 32 formed by this bulge 31 with respect to the tube axis (the angle formed by the spiral groove 32 with the tube axis direction when the tube is cut in the tube axis direction)
is preferably about 20° to 45°. In addition, this inner tube 3 can be made by a simple method such as inserting a synthetic resin tube obtained by a conventional method into a mold with a groove formed on the inner wall surface, and applying pressure to the inside of the tube while heating. It can be molded at low cost. Furthermore, if there are no problems such as soundproofing or fireproofing, only this inner pipe 3 may be used as a drain pipe. The resin forming the foamed resin layer 4 is not particularly limited as long as it has an excellent heat-insulating and sound-absorbing effect, and examples thereof include synthetic resins such as urethane-based, epoxy-based, and polyester-based resins. In addition, if the resin layer is made by foaming a synthetic resin mixed with inorganic powder such as silica sand or barium sulfate, the sound absorption effect will be even more excellent. The drainage composite pipe 1 of this embodiment can be manufactured, for example, as follows. ■ Prepare an outer tube 2 and an inner tube 3 of approximately the same size. (2) Apply foaming synthetic resin adhesive to the outer peripheral surface of the inner tube 3 or the inner peripheral surface of the outer tube 2. ■ Insert the inner tube 3 into the outer tube 2. ■ Heat the outer tube 2 to foam the adhesive. Through this foaming, a heat-insulating and sound-absorbing material layer 4 made of synthetic resin foam is formed in the gap between the outer pipe 2 and the inner pipe 3, and the outer pipe 2 and the inner pipe 3 are completely fixed and integrated through the heat-insulating and sound-absorbing material layer 4. be done. Heating can be done using hot water, steam, hot air, or infrared rays. This can be carried out by a known method such as induction heating, and in particular, in the case of urethane type, it is preferable to shower the outer surface of the outer tube 2 with hot water at about 60 to 90°C. The drainage composite pipe according to the present invention is not limited to the above embodiments. For example, small protrusions that protrude in the radial direction may be formed at a desired portion of the top of the bulge to prevent direct contact between the inner tube and the outer tube.

【Effect of the invention】

The drainage composite pipe according to the present invention is constructed as described above, and when wastewater flows from above, the wastewater flows down in a spiral along the spiral groove, and an air core is always formed in the center of the inner pipe. Even without providing a separate ventilation pipe, there is little pressure change in the drain pipe under high load, and there is no adverse effect on the traps in the branch pipes connected to this combined drain pipe. That is, since the water seal in the trap does not come out due to pressure changes, there is no problem of bad smells flowing back from the drain pipe due to the water seal coming off. In addition, the sound of falling drainage generated inside the pipe is absorbed by the foamed resin layer and rarely leaks out to the outside of the pipe, so even if not only liquid but also solid objects are dropped, the falling sound will not have much of an impact on the outside. do not. Therefore, the problem of drainage noise in apartment buildings can be solved. Furthermore, since the metal outer tube is always kept at approximately the same temperature as the outside air by the foamed resin layer, dew condensation does not occur on the surface of the outer tube, and the durability of the building is improved. Furthermore, since the outer tube is made of metal, there is no problem in terms of fire prevention, and it can be used in any type of building. Furthermore, since the inner tube can be molded by a simple method, manufacturing costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a partially cut away perspective view of one embodiment of a drain pipe according to the present invention. 1...Drain pipe 2...Outer pipe 3...Inner pipe 4...
・Foamed resin layer 31...bulging part

Claims (1)

[Claims] (1) Equipped with an outer tube made of metal and an inner tube made of synthetic resin, the tube wall of this inner tube bulges in the radial direction at a desired portion, and this bulge portion forms a spiral in the tube axis direction. It is characterized in that it is formed continuously and is inserted into the outer tube, and the gap formed between the inner tube and the outer tube is densely filled with foamed resin. Drainage composite pipe.