JPS62234920A - Preparation of tubular molded product - Google Patents

Abstract

PURPOSE:To remove a core without deforming or destructing a tubular body layer, by a method wherein bundles of reinforcing fibers impregnated with a resin are wound around the core and the resin is cured or solidified to form the tubular body layer comprising the fiber reinforced resin to the entire periphery of the core and tensile force is allowed to act on the substantially greater part of the tubular body layer to remove the core. CONSTITUTION:A strip like projection 7 capable of contacting with the inner peripheral edge of a cap 2 is integrally molded along with a tubular body layer 3 so as to be arranged to the end part of the tubular body layer 3 most separated from the draw-out direction shown by an arrow of a core 1. Subsequently, the cap 2 is inserted up to the strip like projection 7 and fixed to a core remover immovable part 4 in the axial direction through a cap fixing jig 8 so as not to move along with the core 1 and the core 1 is drawn out by the core remover movable part 5 driven by a hydraulic cylinder 6 to obtain a thin wall tubular molded product.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a tubular molded article made of fat.

More specifically, the present invention relates to a method for obtaining a tubular body molded product by removing the core from a fiber-reinforced resin layer tubular body (hereinafter abbreviated as tubular body) formed around the entire circumference of the core metal.

(Prior technology) With the advent of high-strength fibers with excellent specific strength and specific stiffness, molded tubular bodies useful as basic structural members have become lighter in weight, or in other words, thinner in thickness. is desired.

The general molding method for fiber-reinforced plastic tubular products such as fishing rods and golf shafts is to use a reinforcing M fiber impregnated with resin or a resin-impregnated core bar coated with a mold release agent, or winding the desired number of times The reinforcing fiber prepreg sheet is rolled up to form the set j-angle. Next, a heat-shrinkable tape is wrapped around the tape without applying a certain tension. After completing the above steps, the product was placed in a heating furnace to harden the resin, and then cooled and the core metal was removed. There is a demand for thinner tubular molded products, and for this purpose, the number of turns of reinforcing fibers or reinforcing fiber prepreg sheets impregnated with resin must be reduced, or the amount of resin or reinforcing fibers must be reduced. In that case, the strength in the axial direction also decreases, making it extremely difficult to de-center using conventional methods, making it impossible to remove the core.

That is, when de-centering is performed to obtain a tubular molded product such as a fishing rod, a de-centering method as shown in FIG. 1 has conventionally been adopted. In the same figure, a cap having a hole diameter slightly larger than the diameter of the core bar is inserted into the core bar and crimped to either end of the hardened tubular body layer 3, and the cap is inserted into the core bar.
Fix the cap 2 to the fixed part of the de-coring machine so that it does not move along with the core metal in the axial direction of the core metal. At the same time, using a hydraulic cylinder 6 or the like, the core bar was pulled out from the side near the base λ in the direction shown by the arrow, and a core removal operation was performed. Since the core metal is in a similar state to the core metal, there is no need to worry about generating shearing force at the interface between the core metal surface and the inner surface of the tubular body layer when pulling out the core metal, but if the rigidity is high, for example, If the core is thick, the conventional de-coring method will not cause any residual problems, or if the core is thin, the rigidity is low, so the tubular layer is prone to buckling and water rupture, especially if the core is When the peeling length of the tubular body layer peeled off from the gold reaches a certain length, this tendency becomes stronger.
In the end, there was a problem in that it was almost impossible to decenter the tubular body layer without deforming or destroying it.

(Means for solving the illumination point) Therefore, the present inventors conducted intensive studies to solve the problems caused by the conventional forming method, especially the conventional de-centering operation. Since the de-coring operation is performed without applying compressive force to the body layer, it is inconvenient to manufacture thin-walled tubular body molded products with low rigidity without any problems. It has been discovered that the above-mentioned problems can be overcome by applying a tensile force to the body layer instead of a compressive force as in the conventional case, and the present invention has been achieved.

That is, an object of the present invention is to provide a smooth and excellent molding method for tubular molded products, particularly thin-walled tubular molded products.

The purpose is to wind a bundle of reinforcing fibers or a reinforcing fiber prepreg sheet impregnated with resin around a core metal, cure or solidify the resin, and form a tubular body layer made of fibre-reinforced resin around the entire circumference of the core metal. A method for manufacturing a tubular molded product by de-coring gold, the method comprising: applying a tensile force to substantially most of the tubular layer to decore the core metal. This is accomplished by a method.

The present invention will be explained in detail below.

The reinforcing fibers used in the present invention are not particularly limited as long as they are generally used in fiber-reinforced plastic tubular articles such as fishing rods and golf shafts, but specifically carbon fibers, glass fibers, or aramid fibers are used. It is preferable to use high-strength M fibers such as fibers.

As the resin, epoxy resin, phenol resin, thermosetting resin such as unsaturated polyester 1M resin, polyether ether ketone resin, polysulfone resin, etc. are used.

In the present invention, first, the above-mentioned reinforcing fibers are impregnated with resin.
& Fibrous bundles or reinforcing fiber prepreg sheets are laminated on the core bar each time, and the resin is cured or solidified according to a conventional method to form a tubular body layer made of fiber-reinforced 4]I fat around the entire circumference of the core bar, and then the cured or solidified tubular body layer is formed. Decentering is performed by applying a tensile force parallel to the central axis of the body layer.

Here, applying a tensile force parallel to the central axis to the tubular body layer means, for example, pulling out the core metal while fixing the end s of the tubular body layer that is farthest from the direction in which the core metal is being pulled out.) This indicates that only a tensile force acts on the tubular body J-.

To explain more specifically, FIG. 2 shows an example of a specific embodiment of the de-coring operation of the present invention, where / is a core bar, - is a cap, 3 is a tubular body layer, and Z is a de-coring machine operation. Department! indicates the movable part of the core bar 7, B indicates the hydraulic cylinder, 7 indicates the band-shaped protrusion, and r indicates the cap fixture. The end of the tubular body layer 3 furthest from the handling direction indicated by the arrow of the core bar 7 A band-shaped protrusion 7 that can come into contact with the inner peripheral edge of the base i is integrally molded and installed on the tubular body layer 3. Next, insert the cap 2 up to the band-shaped protrusion 2 and secure the cap fixing device so that the cap 2 does not move together with the core metal. The movable part of the de-coring sea bream is fixed in the axial direction to the de-coring machine non-sea bream part through the hydraulic cylinder 6. By pulling out the core metal, a thin-walled tubular molded product is obtained.

In addition, pressure force is applied to the part of the tubular body layer 3 of the bar opposite to the tensile direction of the core metal from the band-like protrusion 7, or the sleeve strength is applied to this part by the band-like protrusion 7 in the circumferential direction. Buckling failure will not occur due to the strip-shaped protrusion 7, and if it is not necessary for the obtained tubular body molded product, it may be removed after the de-centering operation. We have explained how to fix the cap λ and the de-coring machine moving part DA via the cap fixture ♂ so that the cap λ does not move together with the core metal 7. The de-coring operation may be performed by crimping the de-coring machine moving part.
A decentering movable part driven by a hydraulic cylinder! For the attachment 9, a de-centering operation may be performed.

Furthermore, a chuck or the like used in general machine tools may be used instead of the cap.

Similarly, the cross-sectional shape of the tubular molded product of the present invention is not limited to a circular shape, but may have an irregular cross-sectional shape.

(Effects) As explained above in detail, the present invention is a practical method for obtaining thin-walled tubular molded products, and can also be used to produce thin-walled tubular molded products for which de-coring was not possible with conventional methods. This method is industrially very useful as it allows for simple and stable decomposition.

Hereinafter, the present invention will be specifically explained using actual examples, but the present invention is not limited to the following examples unless the gist thereof is exceeded.

Example A carbon fiber prepreg sheet was wound around a non-tapered core metal with a total length of 1600 mm and a diameter of 1 m, and one layer of the carbon fiber prepreg sheet was wound so that the fiber direction coincided with the central axis direction of the core metal, and one end of the sheet was cut into a strip shape. The removed glass fiber woven Gripregs are stacked and stretched in the circumferential direction, the resin is cured using a conventional method, and the tubular body layer with band-like protrusions integrally molded at the end is removed using the method shown in Figure 2. As a result of centering, the length is free of defects on both the inner and outer surfaces/!
A non-tapered tubular molded product with an inner diameter of approximately ρ201 m and a wall thickness/θμ was obtained.

Comparative Example The same carbon fiber prepreg sheet was wrapped around the same core metal as in the example, and a glass fiber prepreg sheet cut into the same band shape as in the example was cut out in the circumferential direction so that the cap was attached to one end of the sheet. I tried to decore a tubular body layer with band-like protrusions at the end, which was made by hardening the resin by a method, using the method shown in Fig. Vertical cracks occurred and took on a lantern-like appearance.

Furthermore, an attempt was made to decore the tubular body obtained by winding and hardening 2 layers and 31 layers of the above-mentioned Charcoal

[Brief explanation of drawings]

FIG. 1 is a schematic diagram illustrating a de-centering operation employed in a conventional molding method, and FIG. 1 is a schematic diagram illustrating an example of the de-centering operation of the present invention. /; Core metal λ; Base 3; Tubular body layer 4t: De-coring machine fixed part! : Decentering machine movable part g; Hydraulic cylinder 7; Band-shaped protrusion? ;
Applicant for cap fixing device Mitsubishi Kasei Korai Co., Ltd. Agent Patent attorney Hase - (7 others)

Claims (1)

[Claims] (1) Wrap a bundle of reinforcing fibers or a reinforcing fiber prepreg sheet impregnated with resin around the core metal, cure or solidify the resin to form a tubular layer made of fiber reinforced resin around the entire circumference of the core metal, and then wrap the core metal around the core metal. 1. A method for manufacturing a tubular molded product by de-coring, the method comprising de-coring a core bar by applying a tensile force to substantially most of the tubular layer.