JPS60166439A - Manufacture of bend made of fiber reinforced plastic - Google Patents

Abstract

PURPOSE:To manufacture a bend made of FRP having high dimensional accuracy, and to eliminate the need for finishing processing, etc. by curing and molding a winding material under the state in which a core die and an outer die are combined. CONSTITUTION:A bent core die 2 is used in order to obtain a bend 1 made of FRP. A hollow pipe may be employed as the core die 2 besides a solid bar, and a woven fabric 3 impregnated with a resin is wound on an outer circumference except the end sections of the core die. The woven fabric is wound, the whole winding section is covered by using two outer dies 5 with die grooves 4, and a winding material is cured and molded. Sections projecting to the outside from the outer dies are gripped as the outer dies are applied as they are and the core die 2 is drawn out after curing, and the outer dies 5 are mold-released, thus obtaining a bend made of FRP. When the core die 2 is made of a metal, it is desirable that aluminum abounding in flexibility or an alloy thereof is employed as a blank. When a thermoplastic resin is used as the blank, Teflon, polyethylene, nylon, etc. having excellent sliding properties are preferable. It is desirable that a reinforcing fiber materials is included in the inside at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for manufacturing fiber reinforced plastic (hereinafter abbreviated as FRP) split tubes.

(b) Prior art and its problems FRP pipes are used for various purposes, such as gas and liquid transfer pipes, but such pipes are useless as straight pipes alone, and are used as joints. 9 bent pipe or T
Something called a ji-tube is necessary.

Conventionally, when manufacturing bent pipes, the inner mold (core mold) is split into two parts in consideration of mold removal and closing, and then the pipe is made using a filament winding method or wrapping with resin-impregnated cloth. A commonly used method is to create a prototype, cover it with an outer mold, and then harden and mold it.

In addition to this, there is also a method in which the original tube is formed into a pre-cured shape, the inner mold is removed after it is semi-hardened, the tube is bent, and then the tube is hardened.

However, the former method requires expensive divided molds and has the disadvantage that the number of man-hours required for assembling and demolding the divided molds increases.

On the other hand, the latter method allows the use of a one-piece inner mold, but the outer periphery of the tube is molded and hardened after the inner mold is removed, resulting in poor dimensional accuracy of the product and the need for machining later. (be.

(c) Means for solving the problems The present invention has been made to eliminate the above-mentioned problems.
The first method is to bend a solid bar of metal or thermoplastic resin. A hollow hollow fibre is used as a core, and a resin-impregnated fabric 41 or a tape-like fiber continuous in one direction is wound on it (J-ke), and an outer mold protruding from the end of the core is further covered. The special feature is to harden and mold a 1-inch piece after rolling it, then attach the outer mold, remove one bow from the core, and then remove the outer mold.
In addition, the second method of the present invention, method Q) of NS1, is a method for manufacturing bent pipes made of fiber-reinforced plastic. In this method, one pipe is covered with a thermoplastic resin tube and the other is used as the core mold.

(Four Embodiments The attached drawings show one embodiment of the method of the present invention.
In order to obtain the FRP curved surface Ii'9+'1 as shown in the figure, in the present invention, the woman 11 < [11
Use the core mold 2 that has been processed. This core mold 2 may be a hollow pipe other than the illustrated solid rod, and a woven cloth 3 impregnated with resin is wrapped around the outer periphery excluding the ends as shown in FIG. . The woven fabric used at this time is preferably a so-called bias-cut woven fabric in which the fibers are diagonal to the cutting line at an angle of 4 to 5 degrees from the cutting line, since it is highly flexible and can easily follow the core shape. Because of this ζ, even if a tape-like bundle of fibers extending in one direction is impregnated with resin and wrapped, it will adhere well to the core mold.

After winding the resin-impregnated woven fabric or tape-like fiber, use two outer molds 5 having mold grooves 4 as shown in FIG. The whole is covered, and in this state it is heated and pressurized to harden and form a roll (=J product (original tube)).

After curing, the core mold 2 is pulled out by covering it with the outer mold by grasping the part that protrudes from the outer mold, but if the FRP bent pipe is misaligned due to this pulling out, there is a risk of cracks in the pipe. It is preferable that the groove 4 of the outer mold has a step 4a corresponding to the thickness of the bent pipe at both ends so that the force applied to the bent pipe can be received by the outer mold.

In addition, when the core mold 2 is made of metal, it is desirable to use aluminum or an alloy thereof, which is more flexible than other metals, in consideration of ease of extraction.

On the other hand, when the thermoplastic resin is a base material 4A, Teflon, polyethylene, nylon, etc., which have excellent lubricity, are suitable.

In addition,...crack-resistant core types tend to lack strength, so internal O
It is desirable to use a reinforcing material such as glass fiber, carbon fiber, or Kevlar (trade name) m fiber.

Furthermore, as shown in FIG. 5, if the core mold 2' is made by covering a bent metal solid rod 2a or a hollow pipe in place of it with a thermoplastic resin tube 2b similar to that described in 2 above, the strength of the core mold 2' is And it is easy to ensure smoothness. In this case, tube 2b (.

Needless to say, it may be reinforced with a reinforcing material.

In the present invention, after pulling out such a core mold, the outer mold 5 is demolded to obtain a bent FRP pipe.

Note that the resin impregnated into the woven fabric etc. is a thermosetting resin, heat ii
Depending on the intended use of the pipe, one may be selected from among engineering plastics that have both plasticity and thermosetting properties, or other resins.

0→Effect The method of the present invention, which consists of the above steps, hardens and molds the wound material with the core mold and outer mold combined, so it is possible to form an F with good dimensional accuracy.
RP bent pipes can be manufactured, eliminating the need for finishing.

In addition, since the core mold is not divided, demolding and assembling are easy and the number of man-hours can be reduced.

Furthermore, since fibers continuous in the circumferential direction can be used as a reinforcing material, a highly reliable product with excellent mechanical performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a bent FRP pipe obtained by the method of the present invention, FIG. 2 is a perspective view showing an example of a core mold according to the present invention, and FIGS. 3 and 4 are views according to the present invention. FIG. 5 is a partially broken 1 new front view showing another embodiment of the core mold. 1-FRPiiQ bent pipe, 2.2'... core type, 2a...
・Gold hf4? ! : Hollow tube or hollow pipe, 3. Woven fabric,
4. Mold groove, 5. Outer mold patent applicant: Sumitomo Electric Industries, Ltd. Agent: Kama 1) Text 2

Claims (10)

[Claims] (1) A bent metal or thermoplastic resin solid rod or hollow pipe is used as a core, and a resin-impregnated woven fabric or tape-shaped fibers continuous in one direction is wrapped around the core, and then a core is formed. A fiber-reinforced plastic product characterized in that the wrapped material is hardened and molded after being covered with an outer mold with a protruding end, and then a core mold is pulled out once the outer mold is covered, and then the outer mold is removed from the mold. Method for manufacturing face-mounted pipes. (2) A method for manufacturing a m-thin reinforced plastics face-walled tube according to claim (1), wherein the core mold is made of aluminum or an alloy thereof. (3) The method for producing a fiber-reinforced plastic facing pipe according to claim (1), wherein the thermoplastic resin is polyethylene, nylon, or Teflon. (4) Claim No.
A method for manufacturing a fiber-reinforced plastic facing pipe according to item 1) or item (3). (5) A method for producing a fiber-reinforced plastic facing pipe according to any one of claims (1) to (4), wherein the woven fabric is a bias-cut woven fabric. . (6) A core is made by covering a bent metal solid rod or hollow pipe with a thermoplastic (1 mm fat tube), and on top of that a woven fabric impregnated with resin or a tape-shaped fiber continuous in one direction. (1) Curing and molding the product, then pulling out the core mold with the outer mold attached, and then removing the outer mold. A method for manufacturing a fiber-reinforced plastic facing pipe characterized by: (7) The method for manufacturing a fiber-reinforced plastic split tube according to claim (6), wherein the core-shaped solid rod or hollow pipe is made of aluminum or an alloy thereof. (8) A fiber-reinforced plastic tube according to claim 6 or 7, characterized in that the thermoplastic resin tube is made of polyethylene, nylon, or Teflon. Method for manufacturing bent pipes. (9) Claims (6) to (8) characterized in that a reinforcing material is inserted into the thermoplastic resin tube.
The method for producing a fiber-reinforced plastic facing pipe according to item 1.tljJ). (10) The method for manufacturing a fiber-reinforced plastic facing pipe according to any one of claims (6) to (9), wherein the woven fabric is a bias-cut woven fabric. .