JPS6126039Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mold for forming a reinforced plastic tube, such as a straight tube or a curved tube.

Conventionally, such reinforced plastic tubes have been formed using a densely spirally wound stainless steel belt or a flexible bulb as a core mold, as disclosed in JP-A No. 48-69872. use,
With this core mold in a straight shape, a molding material such as fiber mat or cloth impregnated with resin is wound around the core mold, and the core mold is bent into a predetermined shape until the resin gels. After curing the resin, there is a method of pulling the core mold to reduce its diameter and removing it from the molding pipe. However, with this method, when the molding material is wound around the core mold, the core mold is deformed due to the winding force of the molding material, making it impossible to maintain the core mold in a predetermined shape. The drawback was that it was not possible to obtain reinforced plastic tubes.

The present invention was developed with the aim of solving these conventional drawbacks, and its gist is that the cylindrical wall of the elastic cylinder is notched in the axial direction from one end to the other. A mold for forming a reinforced plastic tube is provided, in which a gap is formed, a gap retaining material is inserted into the gap, and a rigid core rod is inserted into the inside of the elastic cylinder.

Hereinafter, the present invention will be explained with reference to the drawings. Reference numeral 1 designates a mold for forming a reinforced plastic tube according to the present invention, which is constructed by fitting a core rod 3 into an elastic cylindrical body 2.

As shown in FIG. 2, the cylindrical wall of the elastic cylindrical body 2 is cut out over the entire axial direction to form a gap, and a gap retaining material having a shape approximately equal to the shape of this gap is inserted into this gap. 4 has been inserted. The outer surface of the elastic cylindrical body 2 into which the gap retaining material 4 is inserted has a predetermined shape, and the core rod 3 is fitted inside so as to maintain the shape.

The elastic cylinder 2 is made of elastic natural rubber,
The cylindrical body is made of an elastic material such as synthetic rubber or soft plastic, and a straight cylindrical body made of an elastic material such as silicone rubber, ethylene-propylene rubber, or urethane rubber is particularly preferably used.

The material and thickness of the gap retaining material 4 are not particularly limited, and may be determined as appropriate depending on the diameter and degree of curvature of the pipe to be formed, or the material and wall thickness of the elastic cylinder. When molding, it is preferable to use wood, plastic, or the like, which can be deformed to any desired curvature along with the elastic cylinder 2 during the bending process.

The core rod 3 has rigidity and has an outer shape that is approximately the same as the inner surface shape of the elastic cylinder 2.
The gap retaining material 4 can be held and inserted into the gap.

Next, one mode of use for manufacturing a reinforced plastic curved pipe using the mold of the present invention will be described. As shown in FIG.
is inserted, and a core rod 3 is inserted into the elastic cylindrical body 2.A molding material 5, which is a glass rope or the like impregnated with an unsaturated polyester resin liquid, is wound around the mold 1 and molded. After forming the material layer, the core rod 3 is pulled out before the molding material layer is hardened, and as shown in FIG. 5, it is pressed against a bending die 6 to form an unhardened curved pipe and is heated and hardened. After curing, the gap retaining material 4 inserted into the gap of the elastic cylinder 2 is pulled out as shown in FIG. 4, the elastic cylinder 2 is deformed to reduce its diameter, and then the elastic cylinder 2 is demolded to produce a reinforced plastic curved tube. do. Incidentally, during the deformation into the bent pipe and during heat curing, a core rod 7 bent to a predetermined curvature is placed inside the elastic cylinder 2, as shown in FIG.
By inserting the tube 7' and deforming and hardening it, a high quality curved tube with excellent outer diameter and inner diameter accuracy can be obtained.

In addition, when manufacturing a straight pipe, the core rod 3 is replaced with the elastic cylinder 2.
The core rod 3, gap retaining material 4, and elastic cylinder 2 may be removed from the mold in this order.

The reinforcing plastic tube molding mold of the present invention is constructed as described above, in which the cylindrical wall of the elastic cylinder is cut out in the axial direction to form a gap, a gap retaining material is inserted into this gap, and the elastic cylinder is Since a rigid core rod is fitted inside the body, the elastic cylinder does not deform even when the molding material is wound around the molding die, and the formed molding material layer is not hardened. By taking out the core rod and bending it, a bent pipe can be easily formed. Further, since the elastic cylinder can be reduced in diameter by pulling out the gap retaining material, it can be easily demolded. In this way, a curved pipe can be formed by forming a tubular molding material layer in a straight state and then bending it, so it is possible to efficiently create a curved pipe with any curvature with uniform shape and excellent molding dimensional accuracy of the inner and outer diameters. It can be manufactured easily and cheaply. Furthermore, since curved pipes with different curvatures can be formed using one mold, various curved pipes can be formed with a reduced number of molds.

[Brief explanation of the drawing]

Fig. 1 is a front view showing one embodiment of the mold for forming reinforced plastic tubes of the present invention, and Fig. 2 is the same as Fig. 1.
3 is a schematic view showing the manufacturing state of the reinforced plastic tube of the present invention, FIG. 4 is a sectional view showing the reduced diameter state of the elastic cylinder, and FIG. 5 is a state of post-processing into a curved pipe. FIG. 6 is a schematic diagram showing a state of hardening using a curved shaft core. DESCRIPTION OF SYMBOLS 1... Molding mold, 2... Elastic cylinder, 3... Core rod, 4... Gap retaining material.

Claims (1)

[Claims for Utility Model Registration] 1. The cylindrical wall of the elastic cylinder is cut in the axial direction from one end to the other to form a gap, and a gap retaining material is inserted into the gap. A rigid core rod is fitted inside the elastic cylinder. Mold for forming reinforced plastic tubes. 2. A mold for forming a reinforced plastic tube according to claim 1, wherein the gap retaining material is a long plastic plate.