JPS6216176B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of molding FRP when manufacturing bent joint pipes such as elbows, and particularly to a method of molding using an assembly mold.

Conventionally, when manufacturing curved joint pipes such as elbows using FRP, it is either molded in half (split into two) shape and then manufactured by secondary gluing these joints, or when the quantity to be manufactured is small. (1 to 2 pieces) are generally manufactured by integrally molding, for example, a mold material (core) of expanded polystyrene, and then breaking the mold material.

However, when manufacturing a curved joint pipe using the former method, it is extremely difficult to form a perfect circle on the inner circumferential surface, and the manufacturing cost is also high. Further, according to the latter method, it is possible to manufacture a product with a perfectly circular inner circumferential surface shape, but there is a problem that it is not suitable for mass production, and neither method is optimal.

The present invention has been made in view of the above problems, and when manufacturing a curved joint pipe using FRP, a splittable core-type mold is assembled into a predetermined shape, and then it can be rotated. It is supported and molded.

Hereinafter, the case of manufacturing a 90° elbow using the method of the present invention will be explained.

In the FRP molding method according to the present invention, first, the upper and lower molds 1 and 2 are assembled into an arc shape with a perfect circle in cross section using the assembly jig 3, and then the upper and lower molds 1 and 2 described above are assembled into an arc shape with a perfect circle in cross section.
The gap existing between the two is hermetically sealed with a metal tape 15 such as a silver tape to prevent resin from entering during molding.

Next, the mold assembled as described above is supported rotatably around a certain axis using a molding jig 4, and then the dust on the surface of the mold is removed, and then wax is applied. After applying and wiping thoroughly, apply polyvinyl alcohol thinly and evenly, and leave in this state at room temperature for 0.5 to 1 hour. _Thereafter , as shown in _FIG .
Glass fibers ₅₁ are laminated, and the resin is coated while rotating the mold so that the resin is evenly impregnated, and air bubbles are removed using a defoaming roller. Thereafter, the above-described lamination, coating, and defoaming operations are performed on the second layer of glass fibers ₅₂ and the third layer of glass fibers ₅₃ to form a predetermined shape.

After laminating the third layer of glass fiber ₅₃ , applying resin, and defoaming, the FRP was left at room temperature for 3 to 4 hours, and then removed from the molding jig 4 to remove the FRP protruding from both ends of the mold. Next, remove the assembly jig 3, cut the sealed metal tape 15 from the gap between the upper and lower molds 1 and 2 using a special knife 6 as shown in FIG. ,2
is extracted from the product.

By the way, the upper and lower molding molds 1 and 2 used in the method of the present invention are arc-shaped molds with a perfect circle in cross section, which are vertically divided into three parts, and the thickness of the middle mold is determined by the interval between the assembly jigs 3. It is approximately the same as the holding plate 7 and has been removed, and in this embodiment, the dividing line is diagonally shaped to make it easier to remove the upper and lower molds 1 and 2 from the product.

Further, the assembly jig 3 is fixed to a disc body 8 having a diameter slightly smaller than the circular shape when the upper and lower molds 1 and 2 are assembled, and on the surface diameter line of the disc body 8,
a spacing plate 7 having an appropriate shape and thickness that can be inserted into the spacing when the above-mentioned upper and lower molds 1 and 2 are combined in a superposed manner with a predetermined spacing;
The support plate 10 is fixed to the back surface of the disc body 8 at a suitable position at an angle of about 45 degrees, and has a support shaft 9 at its end. Note that the disk body 8
A suitable number of holes for fixing molds 1 and 2 are provided in the mold.

Furthermore, in this embodiment, the forming jig 4 has a base plate 1.
Angle members 12 and 13 are placed on top of the
are erected, and a concave groove 14 for inserting the support shaft 9 of the assembly jig 3 is provided at the upper end of both angle members 12 and 13.
It shows the one with .

As described above, the method of the present invention involves assembling a splittable core-type mold into a predetermined shape, rotatably supporting the mold, and carrying out lamination of glass fibers, coating of resin, and defoaming of the mold. Since this process is repeated a predetermined number of times and then integrally molded, the curved joint pipe manufactured by the method of the present invention can be manufactured with a perfectly round inner circumferential surface, improving quality. Since the mold is separated, demolding is extremely easy and molding time can be shortened. Furthermore, the mold can be reused, making it suitable for mass production compared to conventional molds made of expanded polystyrene.

[Brief explanation of the drawing]

Fig. 1 is a drawing showing an embodiment of the upper mold used in the method of the present invention, where A is a plan view, B is a front view, and Fig. 2 is a drawing showing an embodiment of the lower mold. In the figure, A is a plan view, B is a front view,
FIG. 3 similarly shows an embodiment of the assembly jig, in which A is a front view, B is a side view, and FIG. 4 is an explanatory view showing the assembled mold set in the molding jig. , Figure 5 is a development diagram of the glass fibers laminated in the same way, where A is the first layer and B is the second layer.
FIG. 6 is a perspective view showing an embodiment of the special knife. 1 is an upper mold, 2 is a lower mold, 3 is an assembly jig, and 5 ₁ to 5 ₃ are glass fibers.

Claims (1)

[Claims] 1 A mold formed by dividing an arc-shaped core having a perfect circle in cross section and a required length in the longitudinal direction so that there is a predetermined interval between the mating surfaces, and the mold at both ends thereof. A pair of assembly jigs each having a supporting shaft that is held in a predetermined shape by utilizing the end face and the above-mentioned spacing on the side, and that is integrally swung around a certain axis line and supported rotatably, and the assembly thereof. Using molding jigs that rotatably support and hold the molding die held between the jigs via the support shafts of each assembly jig, glass fibers are laminated on the outer periphery of the molding die while rotating the molding jig. A method for forming an FRP curved joint pipe, which is characterized by integrally forming the pipe by repeating resin application and degassing a predetermined number of times.