JPS60136688A - Spiral corrugated double pipe and manufacture thereof - 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 The present invention relates to a spirally corrugated double pipe and a method for manufacturing the same, and more particularly, a plastic outer pipe exhibiting a spiral waveform,
The present invention relates to a spirally corrugated double pipe in which a contact portion with an inner pipe is fixed to the inner pipe and has a helical waveform gentler than that of the outer pipe, and a method for manufacturing the same.

2. Description of the Related Art Plastic pipes with spiral waves that prevent deformation due to external pressure have been known for use as transport pipes for fluids, drainage pipes, electric cable conduits, etc. to which electric wires are introduced. However, these plastic pipes with spiral waves,
l101 formed on the outer peripheral surface! A spiral wave having the same shape as the swirling wave is also formed on the inner peripheral surface. Therefore, when fluid flows through a plastic pipe with spiral waves, the spiral waves cause turbulence or stagnation in the fluid flow, reducing the flow velocity, and deposits tend to adhere to the recesses of the spiral surface, further reducing the flow velocity. let In addition, in large-diameter drainage pipes, the shape of the spiral wave becomes large, making it easy for sediment to adhere to the recesses of the spiral surface, and if the adhered sediment contains seeds such as flowers,
The problem is that the sediment can cause plants and flowers to grow, obstructing the flow and causing blockages.

Furthermore, when used buried, there is a risk that the tube will be deformed or damaged due to lateral pressure, so there is a need for a large diameter tube body with excellent strength such as lateral pressure resistance.

The present invention has been developed in view of the above-mentioned difficulties, and includes a spirally corrugated double pipe that does not cause turbulence or stagnation in fluid flow and has excellent strength, and a manufacturing method for continuously manufacturing the spirally corrugated double pipe. The purpose is to provide Its feature is that the contact portion between the outer tube, whose circumferential surface exhibits a spiral waveform, and the inner tube, whose circumferential surface exhibits a spiral waveform that is gentler than the spiral waveform of the outer tube, is fixed.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 shows the structure of a double pipe, and the general reference numeral 10 indicates a double pipe made of plastic with spiral waves.

This double tube 10 consists of an outer tube 12 and an inner tube 14,
A spiral wave is formed on the circumferential surface of the outer tube 12, and a gentle spiral wave is similarly formed on the circumferential surface of the inner tube 14. Then, the spiral wave trough 17 of the inner tube 14 is fixed to the spiral wave trough 16 of the outer tube 12, and the cross-sectional shape of the spiral space formed by the outer tube 12 and the inner tube 14 is formed into a crescent shape. (See Figure 1(a)).

Alternatively, the double pipe 10 may be formed by fixing the crests 19 of the gentle spiral waves formed on the inner pipe 14 so that they coincide with the troughs 16 of the outer pipe 14 (Fig. reference).

In addition, in both the double tubes 10 shown in FIG. The troughs 16 of the outer tube 12 and the troughs 17 of the inner tube 14 are aligned and fixed so that two ridges 19 of the inner tube 14 correspond to one ridge 18 of the tube 12. Similarly, the inner tube 1 may be connected to one peak 18 of the outer tube 12.
A plurality of peak portions 19 of No. 4 may correspond to each other. Furthermore, the contact portion between the spiral wave of the outer tube 12 and the spiral wave of the inner tube 14 may be fixed. In this way, even if a pipe body is formed as a large-diameter flow path, no stagnation occurs, and a double pipe with excellent strength can be obtained.

Next, a method for manufacturing a double pipe will be explained.

FIG. 2 shows a first embodiment of a double pipe manufacturing apparatus.

20 is an extrusion molding machine with a cross throat 2 at its tip.
2 and a cap 24 are provided.

The cap 24 forms an annular space between the die 26 and the nipple 28, and an annular intermediate spider 3 is formed in this space.
0, the extrusion passage 32 for plastic material is divided into two to form a concentric interval, and the outer annular interval of this concentric circle is used as the first extrusion port 34, and the inner annular interval is used as the second extrusion port 34. It is assumed that the exit is 36. 38 is a passage formed within the intermediate spider 30 and through the die 26, and through this passage 38, the gap 40 between the outer tube 12 and the inner tube 14 is
In order to adjust the pressure of the air, air is ejected at an appropriate pressure. Reference numeral 42 denotes a homer provided at the tip of the base 24, and a spiral surface 44 is formed on the inner peripheral surface of the homer 42. Also, inside the homer 42 there is an outer tube 1.
An annular cooling chamber 46 for cooling the homer 42 is formed, and an annular water leakage prevention device 48.
48 is provided to circulate a cooling medium within the cooling chamber 46.

Reference numeral 50 denotes a sealing member, which maintains airtightness between the homer 42 and the die 26, and creates a negative pressure chamber 52 between the homer 42 and the outer tube 12 extruded from the die 26 and the first extrusion port 34.
is formed. This negative pressure chamber 52 is communicated with a negative pressure source (not shown) through a communication path 54 formed through the die 26, and the outer tube 12 extruded from the first extrusion port 34 is connected to the helical surface of the homer 42. 44. On the other hand, the inner tube 14 extruded from the second extrusion port 36 is
The outer tube 1 is extruded along a mandrel 58 on which a gentle spiral surface 56 is formed by the same pinch as the spiral surface 44 of the outer tube 1.
The trough 16 of No. 2 and the trough 17 of the inner tube are pressure welded. A cooling chamber 60 for cooling the inner tube 14 is formed inside the mandrel 58, and a cooling medium is circulated through cooling pipes 64, 64 passing through a hollow section 62 at the center of the mandrel 58.

The homer 42 is rotated by an appropriate drive source (not shown) via a gear 65 provided on the outer peripheral surface, while the mandrel 5
8 passes through the center of the nipple 28, is rotatably supported in a hollow cylinder 66 in the crosshead 22 via a bearing 68, and is rotated by a drive source (not shown) provided at the rear end of the mandrel 58. . The rotation of the homer 42 and the mandrel 58 is caused by the rotation of the first extrusion port 34 of the extrusion molding machine 20.
and the outer tube 12 extruded from the second extrusion port 36, respectively.
The rotation is performed so that the extrusion speed of the inner tube 14 and the waves and progress of the homer 42 and mandrel 58 are synchronized.

In the above embodiment, the mandrel 58 was formed so that the trough 16 of the polar rotation wave of the outer tube 12 and the trough 17 of the l1g1I rotation wave of the inner tube 14 coincided with each other, but the trough 16 of the outer tube 12 The double pipe 10 shown in FIG. By making other appropriate changes, a double pipe 10 as shown in FIG. 1 (C1) can be formed.

Next, the operation of the manufacturing apparatus of the first embodiment will be explained. First, a cooling medium is circulated through the respective cooling chambers 46, 60 of the homer 42 and the mandrel 58, and the plastic material is heated and melted and extruded from the first extrusion port 34 and the second extrusion port 36 formed in concentric circles. By communicating the negative pressure chamber 52 with a negative pressure source (not shown), the first
The outer tube 12 extruded from the extrusion port 34 is connected to the homer 42
is pressed against the spiral surface 44 of. On the other hand, the inner tube 14 extruded from the second extrusion port 36 is Il! of the mandrel 58! l
! A rotating plane 56 and a constant plane 56 advance. At this time, the gap 40 between the outer tube 12 and the inner tube 14 is set to an appropriate pressure via the passage 38, so that the outer tube 12 and the inner tube 14 are pressed against the homeer 42 and the helical surface 44, 56 of the mandrel 58, respectively. , the trough portion 16 of the outer tube 12 and the trough portion 17 of the inner tube 14 are pressure welded. On the other hand, by rotating the homer 42 and the mandrel 58 so that the extrusion speed of the plastic material and the progress of the waves on the spiral surface 44 of the homer 42 are synchronized, the double pipe 10 with spiral waves is sequentially cooled and solidified.
is sent out. Then, it is sufficient to linearly take it off with an appropriate take-off means, and a long double-walled pipe 10 can be obtained.

In addition, in the above embodiment, by arranging a cylindrical mandrel 58 having a linear circumferential surface instead of the mandrel 58 having a spiral wave on the circumferential surface (see FIG. 3),
It is possible to form a double tube 10 having a straight inner tube 14 (see FIG. 1 (dl)).
The structure of the mandrel with 6 is similar.

Next, a second embodiment showing a double pipe manufacturing apparatus will be described. FIG. 4 shows the device. In the extrusion molding machine 20 of the first embodiment, the hollow cylinder 6 in the nipple 28
Instead of the mandrel 58 which is rotatably supported in the inner tube 6 through a bearing 68, high pressure air is blown out from the inside of the inner tube 14 being pushed out.

For example, an ejection pipe 70 is provided so as to penetrate through the nipple 28 and the hollow cylinder 66 in the crosshead 22, and a circular ifc-shaped piece 74 is provided at the center of the high-pressure air ejection lower 2 that is ejected from the tip of the ejection pipe 70. ing. Therefore, the shape of the inner tube 14 is determined by the level of air pressure ejected from the ejection lower 2. If the air blowing pressure is extremely high, the outer tube 12 should be
A double tube 10 can be obtained in which the spiral space formed by the inner tube 14 has a crescent-shaped cross-section.

In addition, by adjusting the air blowing pressure appropriately,
As shown in FIG. 1 (d+), a double tube 10 is formed having an inner tube 14 formed in a straight line.

The operation of the apparatus of this embodiment is almost the same as that of the apparatus of the first embodiment, but instead of rotating the mandrel 58, high-pressure air at an appropriate pressure is constantly ejected from the ejection pipe 70. A heavy pipe 1O can be formed.

Next, a third embodiment of a double pipe manufacturing apparatus will be described. FIG. 5 shows the device. In this embodiment, the pomer 42 and the mandrel 58 disposed at the front of the extrusion molding machine 20 of the first embodiment are fixed in a non-rotating state, and a pull-out device 76 is further provided at the front of them. .

The pull-out device 76 may include, for example, a spiral surface 80 formed on the inner circumferential surface of a ring-shaped rotating body 78, similar to the positive constant surface 44 of the homeer 42, and a gear 82 provided on the outer circumferential surface of the rotating body 78. The rotating body 78 is rotated by an appropriate drive source (not shown) through the double pipe 10, and the double pipe 10 is pulled out while being rotated. Therefore, a long double pipe can be continuously formed. Other structures and operations are similar to those of the first embodiment.

Note that in this embodiment, the second mandrel 58 is replaced with the mandrel 58.
The double pipe 10 can also be formed by disposing the same ejection pipe 70 as in the embodiment.

In this way, according to the present invention, since it is composed of an outer pipe with spiral waves and an inner pipe with gentle spiral waves located inside the outer pipe, it has excellent strength against external pressure, and can be used by being buried in the soil. It will not be deformed or damaged.

Further, even when used as a transport pipe, a drainage pipe, etc., turbulence and stagnation are less likely to occur in the flow of fluid, and sediments are less likely to adhere to the pipe, thereby preventing clogging of the pipe. Further, the outer tube extruded from the extrusion molding machine is brought into contact with Homer's IJg whirl surface due to the pressure difference between the inside and outside of the outer tube, and a spiral wave is formed, and the inner tube is moved along the mandrel or by high-pressure air. While pressure welding is applied to the inner peripheral surface of the valley,
By circulating the cooling medium in the cooling chamber in the homer to cool and solidify the double tube, the homer and mandrel, or by rotating the mandrel, are sent out sequentially, or by taking the double tube with a take-up device as needed, the spiral can be formed. It has remarkable effects such as being able to form double pipes extremely efficiently and continuously.

Although the present invention has been variously explained above using preferred embodiments, it goes without saying that the present invention is not limited to the above-mentioned embodiments, and many modifications may be made without departing from the spirit of the invention. Of course, it is possible to give.

[Brief explanation of drawings]

The drawings show preferred embodiments of the present invention, and FIG. 3 to 5 are cross-sectional views showing other embodiments of the extrusion molding machine. 10...Double pipe, 12...Outer pipe 14... Inner tube, 16.17... Valley portion. 18.19... Peak portion, 20... Extrusion molding machine. 22... Cross head, 24... Mouthpiece. 26...・Gui, 28... Nipple, 30... Intermediate spider, 32... Extrusion passage. 34... First extrusion port, 36... Second extrusion port. 38... Passage, 40...・Gap, 42...homer, 44...ds, fixed surface, 46...cooling chamber, 48...
・Annular water leakage prevention device, 50...Seal member, 52...
・Negative pressure chamber, 54...Communication path, 56...Spiral surface, 58
... Mandrel, 60 ... Cooling chamber, 62 ... Hollow part, 64 ... Cooling pipe, 65 ... Gear, 66 ... Hollow cylinder, 68 ... Bearing, 70 ... spout pipe, 7
2... spout. 74... piece, 76... drawer device. 78...Rotating body, 80...Spiral surface, 82...Gear. Patent applicant Torii Kasei Co., Ltd. Representative Kiyoshi Saito Figure 3 Figure 4 0 Figure 5 Tsuyoshi

Claims (1)

[Claims] L3 is characterized in that the contact portion between the outer tube whose peripheral surface exhibits a carp spiral waveform and the inner tube whose peripheral surface exhibits a spiral waveform that is gentler than the spiral waveform of the outer tube is fixed. do! a! Double pipe with swirling wave. 2. Extrude an outer tube and an inner tube into a double tube shape from the mouthpiece of an extrusion molding machine, and press the outer tube against the helical surface of a homer whose inner circumferential surface is formed into a spiral surface, which is placed in front of the mouthpiece. A spiral surface is provided to the peripheral surface of the outer tube while the inner tube is placed along the spiral surface of a mandrel whose outer peripheral surface is formed into a spiral surface, and the inner tube is placed at the tip of the mouthpiece. At the same time as giving a spiral surface to the surface, the contact portion of the outer tube and the inner tube is welded between the homer and the mandrel, and the outer tube and inner tube welded at the contact portion are cooled and solidified. 1. A method for producing a spirally corrugated double pipe, characterized in that the spirally corrugated double-pipe is drawn by. 3. The method for manufacturing a spirally corrugated double pipe according to claim 2, wherein the taking-off means sequentially sends the double pipe forward by rotating a homer and/or a mandrel. 4. The method for manufacturing a spirally corrugated double pipe according to claim 2, wherein the pulling means draws out the outer tube and the inner tube while rotating them together. 5. Extrude an outer tube and an inner tube into a double tube shape from the mouthpiece of an extrusion molding machine, and press the outer tube against the spiral surface of a homer whose inner circumferential surface is formed into a spiral surface, which is placed in front of the mouthpiece. applying a spiral surface to the circumferential surface of the outer tube, adjusting the pressure between the gap between the outer tube and the inner tube and the inner space of the inner tube so that the pressure is higher in the inner space of the inner tube; The outer circumferential surface of the corresponding inner tube is pressed against and welded to the inner surface of the valley of the outer tube to which the a-swivel has been applied, and the pressure difference causes the portion of the inner tube not in contact with the outer tube to bend outward. A double pipe with spiral waves, which forms a spiral surface on the outer circumferential surface of the inner pipe, and is characterized in that the double pipe of the outer pipe and the inner pipe welded at the part is cooled and solidified, and is appropriately taken off by a taking means. Method of manufacturing heavy pipes. 6. The method for manufacturing a spirally corrugated double pipe according to claim 5, wherein the taking-up means sequentially sends the double pipe forward by rotating a homer. 7. The method for manufacturing a spirally corrugated double pipe according to claim 5, wherein the pulling means pulls out the outer tube and the inner tube while rotating them together.