JPS61213137A - Manufacture of pipe made of fiber reinforced plastics - Google Patents

Abstract

PURPOSE:To improve accuracy in the title method, by a method wherein after a filament layer has been formed by winding a filament obtained by impregnating a continuous fiber with resin round a cylindrical mold, the filament layer is spread out into a molding chamber from the inside and then molding is performed. CONSTITUTION:A mold 1 for filament winding is formed by inserting a cylindrical core mold 2 into an elastic pipe 3, and a filament layer 4 is formed by winding a filament for FRP molding obtained by impregnating a continuous fiber with resin an external circumferential surface. Then the core mold 2 is pulled off from the elastic pipe 3 and a molding tool 7 is charged with the pipe 3. Caps 11, 12 are fitted to both end parts of the elastic pipe 3, along with clogging of the cap 11 an inner pressure loading device is connected with the cap 12, inner pressure is made to load by filling the inside of the elastic pipe 3 with a pressure medium and after the filament layer 4 has been spread out into a molding chamber along with the elastic pipe 3, the resin is made to cure thermally. With this construction, a pipe in a complicated shape can be manufactured highly accurately, in good quality and inexpensively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a fiber-reinforced plastic (hereinafter referred to as FRP) vibrator having a complex shape such as a deformed pipe or a bent pipe.

[Conventional technology and its problems]

In recent years, FRP has been widely used as a structural material for aircraft, automobiles, etc., taking advantage of its properties such as lightness, high strength, and corrosion resistance.

As this demand expands, the shape of F'RP is not only cylindrical, but also irregularly shaped pipes with square cross sections.
Or, curves with curvature are becoming more and more complex, such as pipes.

By the way, as a method for manufacturing cylindrical FRP,
The filament winding method involves winding a filament made of continuous fibers impregnated with resin around a mold and then heating and hardening the resin. This method has extremely high performance because the continuous fibers are regularly arranged and the fiber content is high. FRP
A cylindrical body can be formed.

Therefore, an object of the present invention is to provide a method for manufacturing FRP pipes having a complex shape with high precision and high performance using the filament winding method.

[Rounding method to solve problems]

In this invention, a mold for filament winding is formed by covering a cylindrical core mold with an elastic pipe, and a filament layer made of continuous fibers impregnated with resin is wound on the surface of the mold for filament winding. After forming, the core mold inside the elastic pipe is extracted, and then the elastic pipe having the filament layer on the outer surface is filled into a mold having a molding chamber of a predetermined shape, and then internal pressure is applied inside the elastic pipe. is applied to force the filament layer together with the elastic pipe into the molding chamber of the mold.

[For production]

In this method, a filament made of continuous fibers impregnated with resin is first wound around a cylindrical filament winding mold to form a cylindrical filament layer, and then this filament layer is forced into the molding chamber from the inside and spread. Since the fibers are shaped using a single process, there is no stress concentrated on one part of the continuous fibers during winding, making it easy to manufacture pipes of various shapes with uniform wall thickness and high fiber content. can do.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, as shown in FIG. 1, a cylindrical core mold 2 is inserted into an elastic pipe 3 made of an elastic material such as rubber to form a mold 1 for filament winding. Next, a filament layer 4 is formed by winding a filament for FRP molding, which is a continuous fiber made of glass fiber, carbon fiber, etc., impregnated with resin by a filament winding method.

The core mold 2 may be a single cylindrical body, but in order to make it easier to remove the core mold 2 from the elastic pipe 3 in the next step, as shown in FIG. Preferably, it is constructed by mold 6.

Next, the core mold 2 is extracted from the elastic pipe 3, and the mold 7 is filled with the elastic pipe 3 having the filament layer 4 on the outer peripheral surface.

The mold 7 shown in FIGS. 3 and 4 is made up of an upper mold 8 and a lower mold 9, and a bent pipe A as shown in FIG. 5 is formed on the opposing surfaces of the upper mold 8 and lower mold 9. A molding chamber 10 for forming is provided. In order to easily fill the elastic pipe 3 having the filament layer 4 on the outer peripheral surface into the molding chamber 10,
It is preferable that the outer diameter of the filament calendar is made slightly smaller than the product diameter at the time of winding, and therefore it is preferable that the diameter of the elastic pipe 3 and the product inner diameter are also made smaller. In addition, the mold 7 does not need to be a split mold in the case of a straight pipe such as a cylindrical body having an irregular cross section, but it is preferable that the mold 7 is divided into two or more parts in consideration of demoldability.

After that, caps 11 and 12 are attached to both ends of the elastic pipe 3, one cap 11 is closed, and the other cap 1 is closed.
2 is connected to an internal pressure loading device that supplies a pressure medium such as air or oil, and after preheating, the elastic pipe 3 is filled with a pressure medium to load internal pressure on the inner surface of the elastic pipe 3. After the filament layer 4 is expanded together with the elastic pipe 3 into the molding chamber 10 of the mold 7, the resin in the filament layer 4 is heated and hardened.

After this, when the mold is removed, a curved pipe A as shown in FIG. 5 is formed.

Next, if the elastic pipe 3 is pulled out from the molded product, the FR
A pipe with only P is formed.

In addition, when providing a rubber lining such as a corrosion-resistant layer or a gas leak prevention layer on the inner surface of the FRPM pipe,
The elastic pipe 3 may be left as it is on the inner surface of the pipe as a lining layer without being pulled out.

〔effect〕

Since the present invention is as described above, it has the following effects.

In other words, by winding continuous fibers impregnated with resin into a cylindrical shape and then pushing and spreading them over the inner surface of a mold, FRP pipes with various complex shapes depending on the molding chamber of the mold are formed. , does not require complicated molds, is easy to form, and also eliminates the problems of cutting and creating voids at some corners when winding continuous fibers. It can be manufactured at low cost with high precision and quality and fewer man-hours.

Further, according to the present invention, it is possible to easily manufacture a complicated-shaped pipe whose inner surface is lined with rubber or the like.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing a state in which a filament layer is formed on the outer peripheral surface of the core mold and elastic pipe, and Figure 2 is a schematic diagram showing the state in which a filament layer is formed on the outer peripheral surface of the core mold and elastic pipe.
Figure 3 is a plan view of the mold with the upper mold removed.
FIG. 4 is a perspective view of the mold with a portion of the upper mold cut away, and FIG. 5 is a perspective view of an example of a pipe manufactured according to the present invention. 1. Mold for filament winding, 2. Core mold, 3. Elastic pipe, 4. Filament layer, 7. Molding mold, 10. Molding chamber.

Claims (5)

[Claims] (1) An elastic pipe is placed over a cylindrical core mold to form a mold for filament winding, and a filament made of continuous elastic fibers impregnated with resin is wound around the surface of this mold for filament winding to form a filament layer. After forming the
The core mold inside the elastic pipe is extracted, and then the elastic pipe having the filament layer on the outside is filled into a mold having a molding chamber of a predetermined shape, and then internal pressure is applied inside the elastic pipe to make the elastic pipe A method for manufacturing a fiber-reinforced plastic pipe, which also involves pushing and expanding a filament layer into the molding chamber of the mold. (2) Claim 1 is characterized in that when a filament layer is formed by winding a filament around the elastic pipe, the outer diameter of the filament layer is smaller than the inner diameter of the molding chamber of the mold. The method for manufacturing the fiber-reinforced plastic pipe described above. (3) The method for manufacturing a fiber-reinforced plastic pipe according to claim 1, wherein the outer diameter of the elastic pipe is smaller than the inner diameter of the pipe molded by the mold. (4) The method for manufacturing a fiber-reinforced plastic pipe according to claim 1, wherein the mold is divided into two or more parts. (5) The method for manufacturing a fiber-reinforced plastic pipe according to claim 1, wherein the core mold is divided into three or more parts.