JPS6159228B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a reinforced plastic profiled tube, and more particularly to a method for continuously shaping an uncured tube formed by spirally rotating it on a mandrel.

The first step in forming an uncured tube on a mandrel is to wrap a strip of sheet around the mandrel to form a cylindrical body, onto which material is supplied and molded into the final product. Since it is rotated and driven forward during this period, it is absolutely necessary to have great strength.

However, in order to shape an uncured tube, the cylindrical body is required to have the property of being easily deformed, so the above-mentioned conditions for the cylindrical body are rather detrimental to the shape-shaping operation. That is, the cylindrical body requires contradictory conditions in terms of strength when forming an uncured tube and when shaping it into a different shape, and for this reason, it is considered technically difficult to continuously shape an uncured tube.

The present invention achieves continuous deformation of an uncured tube by satisfying both of these contradictory conditions for a cylindrical body using a clever method.

However, in the method of manufacturing a reinforced plastic deformed tube according to the present invention, a cylindrical body made of a belt-like sheet is spirally rotated and a molding material is supplied onto the cylindrical body to continuously form an uncured tube. With the same circumference, the cross section is circular at the proximal end and gradually becomes oval or other irregularly shaped as it approaches the distal end, and the core mold with a cutting blade protruding from the circumferential surface on the proximal end is rotatable. A cut groove is formed in the axial direction with a cutting blade only in the cylindrical body existing on the inner surface of the uncured tube extruded from the tip of the mandrel, and the uncured tube is shaped into a core-shaped cross-sectional shape as it advances. The gist is that it has been transformed into a different shape.

An embodiment of the method of the present invention will be described below based on the drawings. FIG. 1 shows an apparatus for forming an uncured tube into a different shape. 1 is a mandrel with a circular cross section whose base end 1a is supported on a support 2; 3 is the mandrel 1;
It is a core type that is rotatably attached to the tip 1b of the. The circumferential length of this core mold 3 is the same as that of the mandrel 1 in any part in the axial direction, but the cross section is at the proximal end 3a.
is circular, and gradually becomes irregularly shaped, for example, oval, as it approaches the tip 3b. Further, a plurality of cutting blades 4 are provided protruding from the peripheral surface of the base end side of the core mold 3.
In the illustrated example, the final irregular shape of the core mold 3 is extended by a certain length L in the axial direction.

Next, the process of forming an uncured tube into a different shape using this device will be explained based on FIG. 2. First, the proximal end is A belt-shaped sheet 8 made of paper or plastic film is supplied around the circumferential surface of the side mandrel 1 and wound spirally with the belt 7 to form a cylindrical body 9. And this cylindrical body 9
is spirally rotated by the belt 7 and advanced toward the mandrel tip 1b, a release film 10 is wound on the cylindrical body 9, and a predetermined molding material is further supplied thereon to form an uncured tube 11. Shape.

For example, in the case of molding a Sanderch pipe, the molding materials include an inner reinforcing material 12, a mixture of a curable resin and a filler, such as resin concrete 13,
This can be done by supplying the protective material 14 and the outer reinforcing material 15 in that order. Incidentally, the mixture 13 is supplied onto the inner surface reinforcing material 12 by a roll 16 provided with a constant gap from the mandrel 1. Moreover, the protective material 14 is made of this mixture 1
Immediately after supplying the mixture, it is wrapped over the mixture so that it does not peel off.

The uncured tube 11 continuously molded in this way is rotated and advanced by the driving force of the belt 7,
It advances from the mandrel tip 1b to the core mold base end 3a, but in this case, since the core mold 3 is rotatable, it is rotated by the rotation of the uncured tube 11. Therefore, the uncured tube 11 only moves forward relative to the core mold 3, and for this reason, the cylindrical body 9 is formed with a cut groove along the axial direction that is easily deformed into an irregular shape by the cutting blade 4. be done. Since the cylindrical body 9 is further advanced with such a groove formed, the uncured tube 11 is deformed to match the cross-sectional shape of the core mold 3, and
The hardening furnace 17 is suitably deformed to the final shape.
The tube is cured to obtain a deformed tube. The cutting blades 4 may be fixed blades or may be disk-shaped cutters as shown in FIG. Further, the disc cutter may be forcibly driven to rotate by an appropriate drive source such as a motor. On the other hand, the height of the protrusion of the cutting blades 4 from the core circumferential surface, or in other words, the depth of the cutting grooves, differs depending on the cutting pitch.
As a rough guide, the depth should be such that the cylindrical body is deformed by transmitting a slight force. For this purpose, it is most preferable to cut the cylindrical body in the axial direction, but since there is a risk of damaging the uncured tube formed on it, it is best to cut it as much as possible without damaging the uncured tube. Deeper is better. Also, the gaps between the cutting blades 4 may be set at equal intervals, but the intervals corresponding to the portions with a small radius of curvature of the irregularly shaped pipe should be small, and conversely, the gaps should be large in the portions corresponding to the portions with a large radius of curvature. This is desirable. Furthermore, the cutting blades 4 may be arranged in a zigzag pattern around the core mold as shown in FIG. 4.

As explained above, the method for manufacturing a reinforced plastic deformed tube according to the present invention is based on a core-shaped base rotatably provided at the tip of the mandrel on a cylindrical body of an uncured tube that is continuously formed while spirally rotating on a mandrel. This process is performed by forming a cut groove on the end side to make it easily deformable, and then shaping the uncured tube with the core mold, so that it is possible to continuously manufacture irregularly shaped tubes, and to make the uncured tube into a deformable state. During tube forming, the cylindrical body has sufficient strength, so it is possible to form an uncured tube into a beautiful circular cross section.On the other hand, when shaping the tube, the properties of the cylindrical body are changed so that it is easily deformed. Therefore, the uncured pipe can be smoothly shaped into a beautiful shape with no irregularities. Therefore, it is possible to manufacture high quality deformed tubes.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a device for carrying out the method of the present invention, Fig. 2 is a diagram showing a state in which the method of the present invention is carried out by this device, and Fig. 3 is a sectional view showing an example of a cutting blade. , FIG. 4 is a diagram showing another possible arrangement of cutting blades. 1... Mandrel, 1b... Tip, 3... Core type, 3a... Base end, 3b... Tip, 4... Cutting blade, 8... Band-shaped sheet, 9... Cylindrical body, 12,1
3, 14, 15... Molding material.

Claims (1)

[Claims] 1. At the tip of a mandrel, which continuously forms an uncured tube by spirally rotating a cylindrical body made of a band-shaped sheet and supplying a molding material thereon, a mandrel with the same circumference as the mandrel, a circular cross section at the base end, and a tip end is placed on the mandrel. A core mold that gradually becomes irregularly shaped such as an oval shape as it ages, and has a cutting blade protruding from the proximal circumferential surface is rotatably provided, and the uncured tube extruded from the tip of the mandrel is A reinforced plastic deformed tube in which a cut groove is formed in the axial direction only on the cylindrical body on the inner surface, and the uncured tube is deformed to match the cross-sectional shape of the core as it advances. manufacturing method.