JPS59207168A - Production of head for golf club - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This is related to.

Fiber-reinforced plastic golf club heads (hereinafter referred to as FRP heads) that have recently appeared on the market are FRP heads.
Since the specific gravity of RP itself is higher than that of wood, when molding a head with the same volume as a conventional wooden head, the center of the head must be made hollow, or a material with low specific gravity must be placed inside the head. It is known to intervene. However, if the inside of the FRP head is made hollow,
Due to the disadvantages that the vibration damping properties of the head are reduced when hitting the ball, making the ball sting in the hand and making a bad hitting sound, most recent golf balls have become mainstream with a core material interposed between them. However, the center of gravity of the FRP head after molding depends on the core material's size, shape, specific gravity, and placement inside the head.
It plays a major role in the design of FRP heads, as it subtly affects the moment of inertia, repulsion characteristics, and feel when hitting the ball. Therefore, it is necessary to arrange the core material exactly in the desired position, but in conventional FRP heads, the following method has been used.

That is, as shown in FIG. 2, the thickness of the outer shell reinforcing layer 3 of the head soil is determined by the amount of covering by covering with a woven fabric, mat, braid, etc. made of fibers, and the thickness distribution of the core material 4 is determined by the amount of covering. How to determine the position of the head and inside was done. Also the third
As shown in the figure, core material 4. A hole 5 for inserting the shaft foil is drilled in the end of the shaft, and a mandrel is inserted into the hole 5 to form the top of the head. However, in the former case, it is very difficult to mold the head outer shell reinforcing layer 3 in a mold while always maintaining a constant thickness, and it is difficult to mold the head shell reinforcing layer 3 at a constant thickness in the mold. As a result, the position of the core material changes due to variations in the thickness of the head's outer shell reinforcing layer, which causes the center of gravity position of the finished head to change, and the moment of inertia to change slightly accordingly. However, there were drawbacks such as the inability to obtain a head as planned. In particular, if the thickness of the outer shell reinforcing layer in the face portion becomes thinner due to the movement of the core material, there are also drawbacks such as a reduction in the repulsion characteristics of the ball when hit. On the other hand, in the latter method, in which the mandrel is inserted into the shaft insertion hole and held in the mold, there is a high probability that the core material will shift in the front-rear direction of the head due to the pressure generated when the mold is clamped. As a result, the position of the center of gravity of the resulting head was not constant, and the moment of inertia and coefficient of repulsion varied accordingly.

Furthermore, if the pressure is increased to reduce voids in the head shell reinforcing layer, the mandrel may be bent and the hole for inserting the shaft after molding may also be deformed. As described above, the conventional methods have problems such as difficulty in obtaining heads of uniform quality as designed.

In view of these conventional drawbacks, the present invention has been made for the purpose of manufacturing an FRP head as designed.

When the present invention is explained based on the drawings, FIG.
As shown in Figure 2, a head core material 8 into which a core material support bottle 6 of an arbitrary shape is inserted is fitted with a head outer shell made of carbon fiber or other reinforcing fiber impregnated with a synthetic resin as a matrix resin. The reinforcing member 9 is covered with a core supporting pin 6.
A mold l having a head shape with a hole into which a part of the
After placing the core material into the core support bottle 6, the mold]
This is a method for manufacturing a golf club head made of P″BP 2, which is characterized by pressing 0 and heating and curing to integrate.

As described above, in the method for manufacturing an FRP head according to the present invention, the head core material 8 into which the core material support bin 6 of a predetermined shape is inserted is placed at an optimal position within the mold 10. , mold], 0, the core material 8 does not move due to the core material support bin 6, and can be housed in the designed position. In this way, the center of gravity of mass-produced heads becomes uniform, and the moment of inertia!・Can also be made uniform.

In addition, since the core material can be built into a certain position, the thickness of the head outer shell reinforcing layer 9 on the face surface is also constant, which improves the coefficient of restitution when hitting a ball and increases the flight distance of the ball. It is something.

As another embodiment of the present invention, when a core support bottle 6 having a small diameter part and a large diameter part as shown in FIGS. 6 to 8 is used, there is a small diameter part 6a inside the core material. Although it is inserted,
Since insertion into the core material is suppressed by the large diameter portion 6b, the insertion hole 7 for the core material support pin drilled in the core material 8 can be opened appropriately. Further, since the wall thickness of the large diameter portion 6b acts as a spacer as it is as the thickness of the head outer shell reinforcing layer, a more uniform head outer shell reinforcing layer 9 can be formed. The shape of the core material supporting bottle 6 is such that it can sufficiently support the core material in the mold even if the small diameter portion 6C does not have an acute angle as shown in FIG. The core jA support pin 6 used in the present invention is made of tungsten or aluminum.

By molding the pin with any material such as other metals, ABS, nylon, other plastics, or wood, or by changing the shape of the pin itself, it can also function as a weight for adjusting the weight of the head. . As shown in Fig. 8, by providing a slit 6d in the large diameter portion 6b, the FRP forming the head outer shell reinforcing layer is interposed in this slit = ++, so that the core material support pin and Adhesion to the head outer shell reinforcing layer is further improved.

As other embodiments of the core material supporting bottle according to the present invention, straight-shaped ones are shown in FIGS. By equalizing the depth of the holes drilled in the mold and the depth of the holes drilled in the mold, the same effect as that of the bottle described above can be produced, and sufficient pressure is applied to the reinforcing layer of the head outer shell, so that the depth of the holes drilled in the mold is uniform. This has the effect of making the thickness of the shell reinforcing layer uniform. Note that the number of core material support bottles used is arbitrary, but by using at least two or more bottles, it is possible to reliably prevent the core material from shifting back and forth and left and right within the mold, thereby increasing the molding yield of the head. It will also improve further. Note that the core material may be selected from any material such as foamed synthetic resin, wood, or foamed light alloy.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a conventional FRP head. 2 and 3 are cross-sectional views taken along line A-A in FIG. 1. The fourth figure is a perspective view showing the first step of the embodiment according to the present invention. Figure 5 shows
FIG. 3 is a sectional view showing the second step of the embodiment according to the present invention. FIGS. 6 to 11 are perspective views showing several embodiments of core material supporting bins according to the present invention. FIG. 12 is a perspective view showing a golf club head according to the present invention. 1@--head, 2... own shaft, 3... outer shell reinforcing layer, 4... core material, 6... core material support bottle, 8...
Core Io, 9... Head outer shell reinforcing layer, 1'O... Mold, 11... Mandrel, L main... Herad. Figure 1 No. Name River

Claims (1)

[Scope of Claims] 1. A head outer shell member made of carbon fiber or any other reinforcing fiber impregnated with a synthetic resin as a matrix resin is attached to a head core material into which a core support bottle of an arbitrary shape is inserted. The core is placed in a mold having a head shape with a large pin-fitting hole, and then the mold is clamped and heated to harden to integrate the core. 2. A method of manufacturing a golf club head made of fiber-reinforced plastic. 2. The method according to claim 1, wherein the shape of the core support bottle is formed by a small diameter part and a large diameter part. 3. The method of manufacturing a golf club head according to claim 1, wherein the core supporting pins have substantially the same diameter.