JPH0419930B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) This invention relates to a method of forming a hollow rod by using a mandrel and winding prepreg around the mandrel. (Prior art) A method using a mandrel has traditionally been adopted as a method for forming fishing rods, and the fiber base material of the prepreg wound around the mandrel has also changed with the development of high-strength, high-elastic fibers. Fishing rods are becoming thinner and lighter. Recently, unidirectionally aligned sheets have been mainly used as prepreg base materials, which has resulted in problems such as the tendency for vertical cracks to occur. In order to prevent this vertical cracking phenomenon, woven fabric and unidirectionally aligned sheets are replaced with orthogonal ones, but in order to reduce weight, the amount of resin impregnated in the prepreg is small, and the axis of the mandrel is When the orthogonal sides are a woven fabric and a unidirectionally aligned orthogonal sheet, the fibers are not continuous, so there is a problem that delamination tends to occur at the ends when compressive force is applied to the tube. As a means to solve this problem, a method has been proposed in which a tape-shaped prepreg impregnated with resin is wound spirally, but in the case of a tape impregnated with resin, the resin sticks during manufacturing, causing the resin to adhere to rollers, etc. In addition, since the fibers of resin-impregnated tapes and the like are adhered to some extent by the resin, they do not spread even when molded under pressure, resulting in thick molding. In addition, the mandrel used to form tubular objects such as fishing rods has a tapered shape, so when wound at a constant speed,
The necessary thick part creates a large gap, and conversely, if you match it to the thick part, the thin end will overlap. In order to make this uniform, it is very difficult to do things such as having to change the rotation speed to match the taper, and even if it were possible, the fibers would be glued with resin and would not spread, resulting in fiber breakage and the desired strength would not be achieved. There are other problems. One possible way to prevent the phenomenon of delamination is to increase the amount of resin used to bond and integrate the sheets, but if the amount of resin is increased, the wall thickness of the molded tube will become thicker and the weight will also increase. This would go against the weight reduction trend. (Problems to be Solved by the Invention) In view of the above-mentioned circumstances, the present invention has been developed to provide a tubular body with high strength against bending in the longitudinal direction and compression in the radial direction without increasing the amount of resin impregnated in the prepreg. It is an object of the present invention to provide a molding method that can produce a lightweight and inexpensive tubular body extremely efficiently. (Means for Solving the Problems) The method of the present invention for solving the above problems involves winding a prepreg made of high-strength, high-elastic fibers impregnated with a synthetic resin around a mandrel, and then wrapping a cellophane tape around the mandrel. First, a fiber strip that is not impregnated with synthetic resin is wound spirally, and a cellophane tape is wound spirally on the fiber strip. After baking and hardening, only the cellophane tape is removed and the fiber strip is wrapped into a tube as it is. It was designed to remain integrated with the body. (Function) By the method described above, the prepreg wound around the mandrel is tightened by spiral winding using fiber strips that are not impregnated with synthetic resin, and since the fiber strips are not impregnated with resin, they are spread uniformly. Furthermore, the synthetic resin impregnated into the prepreg smoothly penetrates into the fibers and is reliably integrated with the prepreg. (Example) The following will explain based on the drawings. Prepregs 1 and 2, which are carbon fiber aligned sheets impregnated with epoxy resin, are cut into a ladder shape.
The prepregs 1 and 2 are arranged on the mandrel 3 so that the fiber direction of the prepreg 1 in contact with the mandrel 3 is aligned with the axis of the mandrel 3 (Fig. 1 a, b). The fiber direction of the prepreg 2, which is arranged in a perpendicular direction and is arranged outside the prepreg 1, is parallel to the axis of the mandrel 3. In addition, the prepreg 1 is not limited to a simple alignment sheet, but also includes glass fibers 1 for each width as appropriate for the carbon fibers 1a.
You may also use one in which b is woven into a plain weave,
Furthermore, woven fabric may also be used. The prepregs 1 and 2 are attached to a mandrel 3 with one side edge by ironing or the like, and then a rolling device is applied to wrap the prepregs 1 and 2 around the mandrel 3 under pressure to improve the adhesion between the sheets. At the same time, air bubbles in the resin are eliminated. After wrapping the prepregs 1 and 2 around the mandrel 3, a fiber strip 4 not impregnated with synthetic resin is spirally wound around the outer peripheral surface of the prepreg, and a cellophane tape 5 is spirally wound thereon. To wrap the fiber strip 4 and cellophane tape 5 that are not impregnated with synthetic resin, use a wrapping machine or the like, and fix the mandrel 3 around which the prepregs 1 and 2 are wound to a chuck body that rotates to drive the mandrel 3.
Rotate the fiber strip 4 and the cellophane tape 5 on the other hand.
The holding frame is designed to slide parallel to the axis of the mandrel 3, and the ends of the fiber strip 4 and cellophane tape 5 are attached to the side of the mandrel 3 near the chuck body to hold the fiber strip. 4 and cellophane tape 5 at a constant speed and attach the mandrel 3.
It is wound spirally around the outermost periphery of the prepregs 1 and 2 that have been wound. (Fig. 1c) Furthermore, the fiber strip 4 and the cellophane tape 5 are wound so that the fiber strip 4 is wound slightly ahead of the cellophane tape 5, and the fiber strip 4 is wound in a spiral manner.
is covered with cellophane tape 5. The fiber strip 4 that is not impregnated with synthetic resin and is spirally wound on the wound prepreg is a yarn of high-strength, high-modulus fiber such as carbon fiber, glass fiber, or silicon carbide fiber, or carbon fiber yarn with copper, nickel, etc. Select as appropriate, such as metal plating, titanium, stainless steel, etc. thin wire covered with glass fiber, carbon fiber, synthetic fiber, etc. by braiding, or each of the above-mentioned fiber strips colored. An effective pitch for spirally winding these fiber strips 4 is 1 mm to 3 mm. As described above, the surfaces of the prepregs 1 and 2 are not impregnated with synthetic resin and the fiber strips 4 and cellophane tape 5
After wrapping it, it is placed in a firing furnace to be fired and hardened.
After curing, the molded tube 6 is pulled out from the mandrel 3 (Fig. 1 e), then only the cellophane tape 5 is peeled off, and the traces of the cellophane tape 5 are leveled without removing the fiber strips 4. Buffing, such as Scotch blast buffing, Scotch sander buffing, etc., is performed, and finally the surface is painted to complete the work (Fig. 1 f). Next, an experimental example of the method of the present invention will be explained. (A): 2 plies of unidirectionally aligned sheet prepreg with a resin impregnation amount of 35% and a carbon fiber amount of 125 g/m ² are wound, and then 1000 filaments of carbon fiber yarn that is not impregnated with resin is wound at a pitch of 2.5 (B): A tube with the same structure as (A), with the amount of resin impregnated in the prepreg being 40% before and after forming the prepreg and yarn in the above case. The resin content is shown in Table 1.

[Table] As shown above, the amount of resin in the tubular body after molding is
30% or more, there is no decrease in strength due to resin deterioration, and since the same resin is integrally molded, a light and strong tubular body can be manufactured. (Effects of the Invention) The molding method of the present invention involves continuously forming a non-resin-impregnated fiber strip from one end to the other end on a high-strength, high-elastic fiber prepreg wound around a mandrel, slightly prior to winding with cellophane tape. The tape is wound spirally using a conventional mandrel, the cellophane tape is wrapped on top of the tape, and after baking and hardening, only the cellophane tape is peeled off, leaving the fibers behind. It is possible to mold a fishing rod that can prevent the mutual peeling of the laminated sheets with the same number of steps as the molding method that involves winding. Moreover, since the fiber strips are wound slightly ahead of the cellophane tape winding, the spiral winding of the fiber strips is firmly fixed with the cellophane tape, and there is no possibility that the pitch of the fiber strips will be misaligned. Enables wrapping, and also reduces the resin content to 20%.
Comparing the spread of yarn prepreg and yarn that is not impregnated with resin under the same conditions, the width of yarn prepreg is 0.3 to 0.8 mm, while the width of yarn that is not impregnated with resin is 0.3 to 0.8 mm. teeth
Spreads to 1.5-2.0mm. Therefore, it is possible to mold a highly uniform, thin-walled, lightweight, and strong tubular body. In addition, since fibers that are not impregnated with resin are used, the resin transfers smoothly from the prepreg and penetrates easily, and the amount of resin in the tubular body can be kept constant by simply controlling the amount of resin in the prepreg. I can do it.

[Brief explanation of drawings]

Figures 1a to 1f are perspective views showing the manufacturing process, Figure 2 is an enlarged sectional view taken along line 2-2 in Figure 1f, and Figure 3 is an enlarged sectional view taken along line 3-3 in Figure 2. It is an enlarged sectional view that can be followed. In the figure, 1, 2... prepreg, 3... mandrel, 4... fiber strip, 5... cellophane tape.

Claims (1)

[Claims] 1. A prepreg made of high-strength, high-elastic fibers impregnated with a synthetic resin is wound around a mandrel, and then a fiber strip not impregnated with a synthetic resin is wrapped from one end slightly ahead of the cellophane tape winding that tightens the wrapped prepreg. Continuously winding the rod in a spiral toward the other end, and then winding the cellophane tape in a spiral on top of it, peeling off the cellophane tape after baking and hardening, leaving a fiber strip on the surface of the molded rod. Characteristic fishing rod molding method.