JPH02111380A - Shaft for golf club - Google Patents

Abstract

PURPOSE:To obtain an FRP-made shaft for golf club with impact strength large in a point end fine diameter side further with light weight as a whole by improving a content of glass fiber in the point end fine diameter side of the shaft by combination of the sheet winding method with the filament winding method. CONSTITUTION:Epoxy resin, impregnated with carbon fiber, is wound over full length of a mandrel by the filament winding method to a predetermined size at a + or -45 deg. and + or -10 deg. orientation angle. Next on top of this, glass fiber is wound by the filament winding method to a predetermined size at a + or -10 deg. orientation angle, performing a thermo-setting process by the normal method, thereafter the mandrel is extracted. Next grinding the surface of a molded product so as to form its point end part in large thickness decreasing the thickness smaller in accordance with a position toward the rear end, a shaft for golf club, having a 8.5phi point end size and a 15.4phi rear end size and comprising an inner layer 2, intermediate layer 3 and an outer layer 4, is obtained. In this way, impact strength is improved despite light weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] 3. The present invention relates to an improvement of a golf club shaft made of fiber-reinforced plastic.

[Conventional technology]

Currently, golf shafts (hereinafter referred to as shafts) are:
It is usually a tapered tubular body made of metal such as stainless steel, or it is made of fiber-reinforced plastic (hereinafter referred to as JR
However, in recent years, FRP shafts have been gaining popularity due to their light weight and high rigidity.

The FRP shaft is usually manufactured using filament winding (FW) method, sheet winding (8W) method, or a combination of these methods, and in order to reduce weight, it is usually manufactured using carbon fiber with high specific strength and specific modulus. This method is used to reduce the cross-sectional area of the shaft, or to reduce this ratio and increase the ratio of carbon fibers when composite materials with high specific gravity such as glass fibers are used.

[Problem to be solved by the invention]

However, in the case of the above-mentioned FFLP shaft, the elongation of carbon fiber is low and the impact strength of this molded product tends to be low. The impact strength on the radial side decreases, which poses a practical problem. As a countermeasure against this problem, there is a method of forming a reinforcing layer using elongated fibers such as glass fibers alone or in combination with other fibers. In this case, if the sheet winding method is adopted, it is possible to partially form the reinforcing layer, but it is not preferable because it increases the number of man-hours such as cutting and winding the material. On the other hand, in the case of the filament winding method, it is difficult to partially form the glass fiber IH reinforcement layer with an effective orientation angle for impact strength, so a reinforcing layer must be formed over the entire length. Because the specific gravity of carbon fiber is higher than that of carbon fiber, the weight of the shaft is heavy and the base is poor.

The present invention was made in view of the above problems, and by increasing the glass fiber content on the small diameter side of the shaft tip by combining the sheet winding method and the filament winding method, the impact strength on the small diameter side of the shaft is increased. The object of the present invention is to provide a golf club shaft made of FRP that is lightweight as a whole.

[Means to solve the problem]

The shaft for a golf club according to the present invention has a tapered tubular shape made of fiber-reinforced plastic, and has an inner layer formed of an alignment sheet and/or woven fabric made of organic fibers such as carbon fibers impregnated with a synthetic resin, except for at least 100M on the tip side. , an intermediate layer formed over the entire length by a filament winding method using organic fibers such as carbon fibers impregnated with a synthetic resin, and a glass fiber alone or together with other fibers formed over the entire length by the filament winding method with an orientation angle of 35° or less, Furthermore, the outer layer is made thicker on the tip side by grinding.

As the organic fibers forming the inner layer and the intermediate layer, carbon fibers and aromatic polyamide fibers (aramid fibers!S) having high specific strength and specific modulus are desirable, and they may be used alone or in combination of two or more. Further, as other fibers to be combined with the glass fibers in the outer layer, carbon fibers, aromatic polyamide fibers, etc. are preferable from the above-mentioned characteristics. Note that epoxy resin, polyester resin, or the like is used as the synthetic resin to be impregnated into the fibers. Note that the small diameter portion at the tip must have an outer diameter within a predetermined range, have various rigidities, and have high impact strength, so the diameter must be at least 10 mm.
The 0 mm range needs to be composed only of an intermediate layer and an outer layer formed by the filament winding method.

In addition, the rear end side is a sheet of carbon fiber etc. impregnated with synthetic resin,
By using woven fabric or the like, the wall thickness can be easily increased, and the outer layer, which is a glass fiber layer, can be removed, and the weight can be reduced at the same time.

〔Example〕

Embodiments will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a golf shaft according to the present invention, and in the figure, 1 is a golf shaft composed of an inner layer 2, an intermediate layer 3, and an outer layer 4. , Torayca P3015 (carbon fiber unidirectional alignment sheet, Toshi Co., Ltd. Product name) is wound in 4 layers using the sheet winding method.

Next, on top of this, yn-128 (epoxy resin, orientation angle ±45 by filament winding method over the entire length)
Wrap it up to the specified dimension at an angle of +/-100°. Next, after performing PGA-1150 hardening treatment on this, the mandrel was pulled out, and then the surface of the molded body was ground so that the tip part was thicker and the thickness became thinner toward the rear end, and the tip diameter was 8.5φ.
A shaft for a golf club according to the present invention is obtained, which comprises an inner layer 2, an intermediate layer 3, and an outer layer 4, each having a rear end diameter of 15.4φ.

〔Effect of the invention〕

The comparison results between the shaft according to the present invention and a conventional shaft that does not use glass fiber are as shown in Table 751.
The golf shaft according to the present invention has improved impact strength regardless of the presence of menstrual blood.

Fossa 1 table The Izotsu # impact test piece is made from the tip of the shaft.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a golf shaft according to the present invention. 1...Golf club shaft, 1t...tip, 1b
... rear end, 2 ... inner layer, 3 ... middle layer, 4 ...
outer layer.

Claims (1)

[Claims] 1. In a tapered tubular golf club shaft made of fiber-reinforced plastic, an inner layer (excluding at least 100 mm on the tip (1a) side) is formed using a stretched sheet and/or woven fabric made of organic fibers such as carbon fibers impregnated with synthetic resin. 2), an intermediate layer (3) formed over the entire length by a filament winding method using organic fibers such as carbon fibers impregnated with a synthetic resin, and a filament winding method in which glass fibers are used alone or together with other fibers at an orientation angle of 35° or less. A shaft for a golf club characterized by comprising an outer layer (4) formed over the entire length by grinding and made thicker on the tip (1a) side by grinding.