JPH0793950B2 - Method for manufacturing shaft and grip of racket frame for badminton - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a badminton racket frame (hereinafter referred to as a racket frame) made of fiber reinforced synthetic resin (hereinafter referred to as FRP), and more specifically, a shaft portion and a grip portion are integrally formed. The present invention relates to a method of manufacturing a shaft and a grip of a molded racket frame.

[0002]

2. Description of the Related Art Badminton games require extremely agile and fast swing compared to tennis. And to enable these demands,
As an element required for the racket frame, it is lightweight and has good operability brought by moderate flexibility,
The mechanical strength that enables speedy swing is mentioned.

In order to satisfy the above factors, the racket frame has come to have an outer shape and a molding method different from those of the racket frame of tennis and the like. Most grip parts of racket frames are currently formed by bonding a grip member made of a material different from that of the shaft part and the frame part to the end part of the shaft part. Also, the actual development 6
As disclosed in No. 2-174555, a tubular shaft of a racket frame for the purpose of effectively utilizing the impact force when the shuttlecock collides with a gut stretched on the racket frame as a repulsive force to the shuttlecock. There is also seen a shape in which the outer diameter is tapered from the rear part to the front part of the shaft so that the outer diameter of the rear part is larger than the outer diameter of the front part.

In addition, as disclosed in Japanese Unexamined Patent Publication No. 2-274270, the end portion side of the shaft-corresponding portion of the frame molding material in which the FRP molding raw material forming the frame outer shell is wound around the tube. The core material of the grip, which constitutes the core of the grip, is inserted into the outer periphery of the pipe, and the FRP molding raw material forming the outer shell of the grip is wound around the outer periphery of the pipe core material. After the mold is clamped, the tube is expanded. There is also a method of manufacturing a racket frame by using the internal pressure of letting it out and hot pressing.

[0005]

However, these conventional racket frames have the following problems. That is, in a preformed shaft end portion, in which the grip member made of a material different from the shaft portion molding material is adhered, the weight of the grip portion becomes large,
It is easy to get a good balance, and there is not much freedom in design. Further, in the manufacturing process, the number of parts is increased and the number of processes is increased, so that there is a problem that the cost is increased. Also, in the case where the frame, shaft, and grip are integrally molded by applying internal pressure to the tube, the pressure may not be evenly distributed over the entire frame part because air or the like is pressed in from the grip end side. There was a drawback that the quality was difficult to maintain.

[0006]

In view of the above-mentioned conventional drawbacks, the present invention has a simple manufacturing process, good productivity, lightweight, high strength and rigidity, and a high degree of freedom in designing balance and the like. It is a method of manufacturing a racket frame shaft and a grip. The manufacturing method of the present invention is a method of continuously and integrally molding a shaft portion and a grip portion when molding a racket frame including a hitting portion, a shaft portion, and a grip portion.

First, a mandrel having a shape in which a shaft portion and a grip portion are continuously integrated is used, and a prepreg cut into a length and shape capable of integrally forming the grip portion and the shaft portion is wound on the mandrel until a desired thickness is obtained. Laminate and stack. After that, the outer periphery of the laminated prepreg is tightened with a tightening tape, heat-cured, and after curing, the mandrel is removed and molded, and the shaft and grip of the racket frame are manufactured. The taper of the transition from the shaft to the grip is 200/100
It is preferably 0 to 400/1000.

If the taper is smaller than 200/1000, the rigidity of the shaft becomes large and the grip length becomes too short. On the other hand, if it is 400/1000 or more, stress concentrates on the boundary portion between the shaft portion and the grip portion, and is easily broken.

[0009]

According to the manufacturing method of the present invention, the FRP material for molding the shaft portion and the grip portion is wound and laminated on the mandrel, and the outer periphery thereof is tightened to perform heat-curing molding. Since pressure can be applied uniformly, variations in quality such as strength and rigidity are reduced. Moreover, since the shaft portion and the grip portion can be molded at the same time, the number of molding steps can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a racket frame 1 formed by the method of the present invention. The racket frame 1 includes a hitting portion 2, a shaft portion 3 and a grip portion 4, and as shown in FIG. 2, the shaft portion 3 and the grip portion 4 are integrally molded continuously.

In order to integrally manufacture the above-mentioned grip portion and shaft portion, as shown in FIGS. 3 to 4, a mandrel 5 having a shape in which the shaft portion and the grip portion are continuously integrated is used. The prepreg 6 cut into the shape for forming the shaft portion 3 and the grip portion 4 is wound and laminated to have a desired thickness. Then, wrap a wrapping tape around the outer periphery where the prepreg 6 is wound and laminated, and tighten it.
Curing and molding are carried out by a conventional method. After curing and molding, a grip tape is wound around the grip surface for use. As the reinforcing fiber constituting the prepreg 6, carbon fiber, glass fiber or the like is used as necessary in the form of cloth, bias cloth, unidirectional aligning or the like. A prepreg having a reinforcing fiber is suitable for improving strength and rigidity.

Then, the mold of the present invention in which the shaft portion 3 and the grip portion 4 are previously hardened and molded by the method of the present invention and the FRP molding material for internal pressure molding of the frame portion 2 are molded. It is possible to integrally form the frame portion 2, the shaft portion 3 and the grip portion 4 by arranging the frame portion 2 and pressing air or the like from the grip end portion.

[0013]

As is apparent from the above description, according to the method of the present invention, the shaft portion and the grip portion are continuously integrated with each other, and the shaft portion and the prepreg for molding the grip portion are wound and laminated on the mandrel. After that, since it is a manufacturing method of tightening the outer periphery with a wrapping tape etc. and hardening and molding,
The shaft portion and the grip portion can be formed to have a desired thickness, and variations in quality can be prevented. Further, since a separately molded grip forming member and a grip member made of a different material are not bonded, the weight can be reduced, the degree of freedom in balance adjustment can be increased, and the process can be simplified. .

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a badminton racket frame manufactured by a manufacturing method of the present invention.

FIG. 2 is a cross-sectional view of a shaft portion and a grip portion of the badminton racket frame manufactured by the manufacturing method of the present invention.

FIG. 3 is an explanatory view of a manufacturing method of the present invention.

FIG. 4 is an explanatory cross-sectional view of the manufacturing method of the present invention.

[Explanation of symbols]

 1 Racket frame for badminton 2 Frame part 3 Shaft part 4 Grip part 5 Mandrel 6 Prepreg

Claims (2)

[Claims] 1. When molding an FRP badminton racket frame including a hitting ball portion, a shaft portion, and a grip portion, a mandrel having a shape in which the shaft portion and the grip portion are continuously integrated is used, and the mandrel has a substantially outer periphery. A prepreg cut into the shape of the shaft and grip is continuously wound around the grip from the shaft and laminated, then the outer circumference is tightened and heat-cured to integrally form the shaft and grip. A method of manufacturing a shaft and a grip of a racket frame for badminton, which is characterized in that. 2. The taper of the portion that transitions from the shaft portion to the grip portion is 200/1000 to 400/1000.
The method of manufacturing a shaft and a grip of a racket frame for badminton according to claim 1, wherein