JPS5934485B2 - Manufacturing method of corrugated pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a corrugated pipe in which the outer circumferential surface of the pipe is corrugated, and the corrugated pipe is formed in a spiral shape, and in particular, the present invention relates to a method for manufacturing a corrugated pipe in which the outer circumferential surface of the pipe is corrugated and the corrugated pipe is spirally formed. Wrap the outer circumferential surface of the tube with yarn, and add other reinforcements as necessary.
It is an improved version of the endless steel belt used to form a tube by wrapping or covering the filler with a continuous forming device conventionally known as a Dorstholm machine. The present invention relates to a continuous manufacturing method for corrugated pipes, in which a continuous chevron formed of a heat-resistant elastic material is formed on the surface of the corrugated pipe, and a tube-forming material is directly wound around the chevron.

Conventionally, corrugated pipes, which are relatively thin-walled thermosetting resin pipes with a spiral waveform formed on their entire circumference, are widely known, and it is also well known that they are used for a variety of purposes. . Also, depending on the application, these corrugated pipes may have a corrugated shape for reinforcement, or may be a drainage pipe with many drainage holes using the valleys of the corrugation, or they may be used as a drainage pipe with many drainage holes using the corrugated valleys. It is also used as an elastic tube to buffer expansion and contraction, but conventional reinforcing tubes have achieved this purpose simply by forming ribs on the outer circumferential surface of the tube. However, when the pipe is used for the above-mentioned drainage, especially for expansion and contraction buffering, it is necessary that the wall thickness of the pipe be approximately uniform. The present invention relates to a method for continuously producing a tube in which the tube wall is substantially uniform and has a corrugated spiral.

On the other hand, the above-mentioned Drostholm machine is generally well known as a device for continuously manufacturing tubes, and this device involves winding an endless steel belt spirally around a rotating mandrel without gaps. A tubular molding material such as a thermosetting resin-impregnated fiber strip is sequentially wound spirally on the belt via a softened thermoplastic resin strip sheet or release tape, or a mixture of hardening resin materials is used. The thermosetting resin is cured by heating it while moving it toward the tip of the mandrel, and then the endless steel belt is separated from the forming tube and the inside is removed from the tip of the mandrel. The coil passes through the coil and returns to the winding start position. 5 That is, as shown schematically in FIG. 1, 1 is a mandrel whose base is fixed to a hollow shaft 4 installed almost horizontally.
is freely supported by bearings 8,8.

5 is a drive device which drives the hollow shaft 4 with an appropriate transmission means.
Rotate.

3 is a curved plate; 9 is a driven body mounted at equal intervals around the entire circumference of the mandrel base; these curved plate 3 and the driven body 9
Each time the mandrel 1 rotates once, the steel belt 2 is pushed toward the tip of the mandrel (toward the right in the drawing) by the width of the belt.

6 and 7 are steam circulation pipes for heating, and a heating medium is introduced into the inner peripheral surface of the mandrel 1.

The endless steel belt 2 is thus wound around the rotating mandrel 1 via a suitable tension holding device, and is pushed in one direction by the curved plate 3 and the follower 9 as described above. Therefore, a beam member provided with roller bearings to assist the lateral movement of the steel belt 2 is provided on the outer peripheral surface of the mandrel 1. Reference numeral 11 denotes a band-shaped sheet member, which is a band-shaped material impregnated with a thermosetting resin material, or a tube-forming material in a thermally softened state, and these are wound in layers in a spiral shape.

Reference numeral 12 denotes a thermosetting resin-impregnated fiber strip that is reinforced or further wound.These may be used alone or may be layered and wound together, and may be filled with other reinforcing materials or fillers if necessary. It is also possible to wrap the material in the middle.

Reference numeral 10 denotes a heater, and an appropriate heating means such as an infrared heater is used.

As a result, the steel belt 2' inside the pipe, which has been hardened and formed in the heater 10, is no longer needed for forming purposes, and is separated within the pipe as shown at 7, and a hole is now formed through the center of the mandrel 1. lead it to the other side through
It is wound around the mandrel 1 again. That is, at present, a flat plate-shaped endless steel belt 2 is used. Therefore, if you try to manufacture a corrugated pipe using such a Drostholm machine, the inner surface of the tube will be a nearly uniform inner surface with an endless steel belt, and only the outer peripheral surface will be affected by the spiral pitch of the wrapping material, the thickness of the wrapping material, etc. , or only a helical waveform can be formed by varying the winding tension. Therefore, a tube with a substantially uniform wall thickness and a spiral waveform as described above could not be formed using the generally known Drostholm machine. The present invention was made with attention to these points, and in particular, like the Drostholm machine, an endless steel belt is wound to form the core of the tube, a tube forming material is wrapped around it and hardened, and then the steel belt is formed. In the continuous continuous forming process in which the steel core is separated and rewound to form the core again, the shape of the endless steel belt is formed into a chevron shape to directly form a spiral waveform, and the chevron-forming material is made of a heat-resistant elastic material. It was formed by

FIG. 2 is an explanatory view of a corrugated pipe manufactured according to the present invention and the manufacturing process, with a part cut away. FIG. 3 shows a chevron-shaped steel belt used in the present invention, FIG. 4 shows a modified example of the steel belt, and FIG. 5 shows a partial sketch of another embodiment of the present invention. In FIG. 2, reference numeral 13 indicates a spirally corrugated tube formed according to the present invention, with a peak portion 14 and a valley portion 1.
5 is molded with almost uniform wall thickness and almost the same curvature.

Reference numeral 16 denotes a chevron-shaped belt suitable for carrying out the present invention; a portion thereof is shown wound around a mandrel (not shown), and a portion thereof is shown interrupted.

As shown in FIG. 3, the chevron-shaped steel belt 16 is constructed by attaching a chevron member 17 to the conventional flat steel belt 2 or a new flat steel belt 2 by adhesively or removably. The chevron-shaped members 17 are made of a heat-resistant elastic material, such as synthetic rubber such as Teflon, urethane, silicone rubber, or a synthetic resin material. It goes without saying that it follows the bending and curving of the belt 2 and does not hinder the movement of the steel belt 2. Therefore, the wall thickness and height of the chevron-shaped member 17 can correspond to these curvatures. Although it is preferable that the chevron member 17 and the steel belt 2 are bonded together using a suitable adhesive, they can be attached and detached for convenience when the shape of the chevron is changed or when the chevron member 17 is worn out and replaced. Sometimes it is done. FIG. 4 shows an embodiment in which the steel belt 2 is made detachable. A locking hole 19 is formed in the steel belt 2, and the locking hole 19 is composed of a large diameter part and a small diameter part, and the back surface thereof is Form a recess. Such latching holes 19 are provided in the steel belt 2 at regular intervals. On the other hand, chevron member 1
A pin shaft to be inserted into the locking hole 19 is buried in the bottom of the pin 7 and exposed, and the pin shaft forms a large diameter head at the top, and the head passes through the large diameter portion of the locking hole 19. It will be latched. At this time, the recess is formed so that the head of the pin shaft does not protrude from the back surface of the belt 2. These are shown in which a member forming a single chevron shape is attached to one steel belt, but the chevron shape is not limited to a single thread and may be configured as multiple rows. An example of an angle-shaped steel belt 16' with a diameter of 17' is shown. These are also attached to the belt 2 by adhesive or detachably in the same manner as described above.
Although the chevron-shaped members 17 are illustrated as having a perfect circular shape, they may also be a deformed circular curve or a chevron shape close to a trapezoid. Furthermore, these angle-shaped steel belts 16, 16'
The angle-shaped members 17, 17' extend over the entire steel belt.
However, when forming a joint part with a slightly enlarged diameter on a part of a spiral corrugated pipe, or when a part of the pipe body does not require a corrugation, it is necessary to provide it on the endless steel belt 2. It is also possible to form the chevron-forming member 17 higher by a specific length over the width of the steel belt 2, or to remove the chevron-forming member 17 only for a specific length of the endless steel belt 2. As described above, the present invention forms a pipe by continuous cyclical forming,
Furthermore, when this tube is continuously formed using an endless steel belt, a chevron-shaped member made of a heat-resistant elastic material is attached to the outer surface of the endless steel belt. It has become possible to continuously manufacture spiral corrugated tubes, and when configuring this chevron member to be detachably attached to the steel belt, it is possible to replace the chevron member with a different shape as necessary, or to change the shape of only appropriate parts. It is now possible to manufacture corrugated tubes according to the purpose of use.

[Brief explanation of drawings]

Figure 1 is a schematic explanatory diagram of a continuous pipe forming device that operates in a circular manner.
The figure is an explanatory diagram of a corrugated pipe manufactured according to the present invention using the apparatus shown in FIG. FIG. 3 shows a chevron-shaped steel belt used in the present invention, FIG. 4 shows a modified example of the steel belt, and FIG. 5 shows a partial sketch of another embodiment of the present invention. 1...Mandrel, 2...Steel belt, 3...
・Curved plate, 4...Hollow shaft, 5...
・Drive device, 6, 7... Steam circulation pipe,
8... Bearing, 9... Driven body, 10...
... Heater, 11 ... Band-shaped sheet, 12.
...Thermosetting resin impregnated strip, 13...
Spiral corrugated pipe, 14...Top part, 15...
・Tanibe, 16... Yamagata belt, 17...
・Chevron member.

Claims (1)

[Claims] 1. An endless belt is spirally wound around a rotating mandrel, and a tubular body forming material impregnated with and/or mixed with a thermosetting resin material is wound and/or coated onto the belt, and the endless belt is wound in the direction of the tip of the mandrel. In a method for manufacturing a circular tube, the endless belt is heated and cured while being moved to a molded tube, and after curing, the endless belt is unwound from the forming tube through the center of the mandrel, and returns to the winding start position again. A method for manufacturing a corrugated pipe, characterized in that a continuous chevron is formed with a heat-resistant elastic material in the direction of the belt, and a pipe forming material is wound around the chevron.