JPH0545271B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a golf club head having a core material made of a synthetic resin material, and the outer periphery of the core material being coated with a resin material mixed with reinforcing fibers.

[Conventional technology]

Recently, with the advent of two-piece balls, the impact force applied to the club head has increased, and there has been a growing demand for improved strength primarily on the hitting surface (face surface). Therefore, a so-called carbon head, which uses carbon fiber reinforced plastic (CFRP) as a lightweight and high-strength material, has been developed. In order to exhibit high strength in this carbon head, the longer the fiber length of the reinforcing fibers, the more effective it is, but if all the fiber lengths used exceed 1 inch (2.54 cm) (This applies to carbon heads), which had the following drawbacks.

Due to the difference in fluidity between resin and resin during molding, molded products with complex shapes such as golf club heads are difficult to form.

Unevenness occurs on the surface.

The fiber content varies locally and the original strength cannot be demonstrated.

When trying to make the CFRP board as thin as possible, the flow of the fibers is much slower than that of the resin, resulting in a layer of only resin, resulting in missing resin layers and shallow but wide areas along the fiber direction during the finishing process. Cracks etc. occur.

In the case of only long fibers, there is anisotropy in strength due to fiber orientation, folding of the fibers near the weld (flow confluence, weld), and insufficient strength near the parting line in upper and lower separate molds. A trend was observed.

The above-mentioned drawback of unevenness on the surface is not only an appearance problem, but also a functional defect. In other words, if the surface is uneven, it will be difficult to match the shape in the finishing process, and in order to match the shape, the shape must be made to match the concave portions (scratching the convex portions), which reduces the size of the head. , the moment of inertia decreases,
The thickness of the CFRP plate decreases, resulting in insufficient strength. Therefore, improving the appearance of molded products leads to improved functionality and strength.

[Problem to be solved]

This invention provides a golf club head with a synthetic resin material as a core material and a resin material mixed with reinforcing fibers coated on the outer periphery of the core material. The purpose is to make the thickness of the resin molded part uniform and to improve the appearance of the molded product.

[Means for solving problems]

In order to solve the above problems, in this invention, the length of the reinforcing fibers to be mixed is set to be 1 inch or more in the striking part and less than 1 inch in the head main body, and a combination of long and short reinforcing fibers is used in combination to reduce the strength. The appearance and functionality have also been improved.

〔Example〕

Preferred embodiments of the invention will be described below.

First, a description will be given of how the golf club head according to the present invention is manufactured. In the manufactured golf club head, reinforcing fibers are mixed into the resin around the core material, and the length of the mixed fibers is, of course, mixed, long and short, and this invention is the manufactured product itself. Needless to say.

First, the core material 1 is molded from a lightweight resin material.
When this core material 1 is molded, the striking part 2 is insert-molded. FIG. 1 shows a molded product of a core material 1 into which a striking portion 2 is inserted. The striking part 2 constitutes a part of the outer shell of the golf club head after completion, and covers the core material 1. In this striking part 2, the reinforcing fibers to be mixed have a fiber length of 1 inch or more,
More preferably, carbon fibers are impregnated with resin and adjusted to wf (fiber content by weight) of 40 to 75% (prepreg). wf＜40
%, only the resin flows during molding, resulting in poor appearance, and when wf<75%, there are areas where the resin is not impregnated, resulting in poor appearance and reduced impact resistance. . The carbon fiber used for the striking part 2 is of a high strength type, for example, polyacrylonitrile (PAN) made into carbon fiber, and the trade name is Torayca T300-3000.

As shown in FIGS. 2 to 4, the core material 1 with the striking part 2 is molded using a first mold that is divided into upper and lower molds, that is, a first upper mold 3 and a first lower mold 4. be done. The first upper mold 3 includes a core material 1 as shown in FIG.
Concave portions 31 and convex portions 32 for forming ribs 13 on
The presence of the convex portion 32 allows the hollow portion 16 to be formed in the core material 1. First lower mold 4
includes a recess 41 into which the member constituting the striking portion 2 is inserted, a convex portion 42 for forming the recess 17 for attaching the sole plate (not shown), and a recess or protrusion 43 for shaft insertion. Recess 4
The cavity of the first lower mold 4 including the first lower die 4 is made up of a replaceable placement piece 41A, and the cavity including the convex portion 42 is also made up of a replaceable placement piece 42A. Therefore, by simply inserting the placement piece 41A corresponding to the shape and size of the striking part 2 into a predetermined position of the first lower mold 4, it is now possible to easily insert mold the striking parts 2 of various shapes and sizes. There is. Similarly, by preparing the mounting pieces 42A in various shapes and sizes, it is possible to correspond to various shapes and sizes of sole plates to be attached after molding. Further, the bottom of the first lower mold 4 includes a convex part (not shown) for molding the weight adjustment boss 14, a convex part (not shown) for molding the sole plate fixing boss 15, and other parts. It is possible to freely provide irregularities and the like to form necessary protrusions and depressions.

A synthetic resin material such as SMC (sort molding compound) is put into the first upper and lower molds 3 and 4, and both molds 3 and 4 are closed and heated (the mold temperature is 120 to 160 degrees Celsius, preferably 130 to 140 degrees Celsius). ℃) and pressurized, and after about 2 to 5 minutes, the upper and lower molds 3 and 4
By separating them again, the core material 1 having the hollow portion 16, the ribs 13, and various irregularities is formed. SMC, which is the material for forming core material 1, is wf=
It is desirable that the carbon fiber content is adjusted to 25-60%.

Once the core material 1 into which the striking part 2 is inserted is molded by the first upper and lower molds 3 and 4 in this way, this is set in a foaming mold (not shown),
A lightweight resin material is foamed in the hollow part 16 to fill the filler 5 into the hollow part 16 (see FIG. 5). At this time, a shaft (not shown) is provided in the foam mold,
A bottle insertion hole 6 is formed in advance. As the filler 5, a so-called masterbatch consisting of polyol...100 parts by weight foam stabilizer...1 part by weight catalyst...0.5 parts by weight water...0.5 parts by weight was mixed with a curing agent (112 parts by weight) for 15 seconds. Pour into a foaming mold that has been preheated to about 50℃, and heat in a 50℃ oven for 15 to 20 minutes.
Let it harden in about a minute. The specific gravity of the filler 5 formed by foaming in this manner was about 0.25 to 0.50.

Next, as shown in FIG. 6, a molding material 10 for the main body part 7 of the head (which covers the outer periphery of the core material 1 together with the striking part 2) is set on the filler material 5 of the core material 1. 2nd of upper and lower molds 100, 200
Set it on the lower mold 200. The molding material 10 has an unsaturated polyester resin (containing a thickener and a peroxide catalyst) at a weight ratio of 50 to 70, and the length of carbon fibers to be mixed is less than 1 inch. The weight ratio of carbon fiber was 43 to 50. Therefore, what covers the outer periphery of the core material 1 is the striking part 2 and the main body part 7 molded from this molding material 10.
(described later), and both are molded from a resin material mixed with reinforcing fibers, and the length of the reinforcing fibers is 1 inch or more in the striking part 2 and less than 1 inch in the main body part 7. As a result, the particles are mixed into the material that covers the outer periphery of the core material 1. In particular, it is desirable that the molding material 10 contains fibers with a length of 15 mm or less, and if the fibers are 15 mm or less, they will flow according to the flow of the resin, and the second upper and lower molds 10
It is easy to be accurately molded into a three-dimensional shape that follows the cavity shape of 0.200 mm. Of course, fibers of 1 inch or more may be mixed in this molding material 10.
The carbon fiber used in the main body 7 is preferably of a high-strength type, and Torayca T300-6000 (trade name), which has 6,000 filaments and a filament diameter of 7 microns, is used.

The second lower mold 200 has a convex portion 22 into which the sole plate attachment recess 17 of the core material 1 is fitted.
0, and a recess 21 into which the striking part 2 fits.
There is also 0. These uneven portions 210, 220 are formed on the placement pieces 210A, 220A. These placement pieces 210A and 220A also have the same function as placement pieces 41A and 42A in the first lower mold 4. The second upper mold 100 includes a shaft pin 101 to be inserted into a pin insertion hole 6 provided in the filler 5, and the tip of the shaft pin 101 penetrates the core material 1 and is inserted into the second
It is designed to be inserted into a hole 230 of the lower mold 200. In this way, the second upper and lower molds 100, 2
00 was heated and pressurized to obtain a golf club head shown in FIG.

Furthermore, the structure of the golf club head is as follows:
The hollow core material 1 without the filler 5 may be covered with the main body part 7 including the striking part 2, and when molding this covering part, the striking part 2 is insert-molded in advance.

〔effect〕

As explained above, the present invention provides a golf club head in which a synthetic resin material is used as a core material and the outer periphery of the core material is coated with a resin material mixed with reinforcing fibers, the resin material covering the outer periphery of the core material. The length of the reinforcing fibers to be mixed in the impact part was 1 inch or more in the striking part, and less than 1 inch in the head body part, so the short fibers flowed according to the flow of the resin and were used in combination. In addition to making it possible to mold the material into a specific mold shape, it is expected that the appearance will be improved since no irregularities will appear on the surface, and improvements can also be expected in terms of functionality and strength. In addition, in terms of strength, the presence of relatively long fibers, that is, fibers of 1 inch or more in length, in the striking portion does not make it inferior to conventional ones.

[Brief explanation of drawings]

Figure 1 is a perspective view of the core material with the striking part inserted, Figure 2 is a perspective view showing the state in which the core material is molded and taken out by the first upper and lower molds, and Figure 3 is a bottom view of the first upper mold. , FIG. 4 is a plan view of the sole portion of the core material, FIG. 5 is a perspective view of the core material filled with filler, FIG. 6 is a perspective view showing the preparation process for molding the main body portion, and FIG.
The figure is a longitudinal sectional view showing a molded product of a golf club head. 1... core material, 2... striking part, 7... main body part.

Claims (1)

[Scope of Claims] 1. A golf club head in which a synthetic resin material is used as a core material and the outer periphery of the core material is coated with a resin material mixed with reinforcing fibers, wherein the reinforcing fibers are mixed in the resin material covering the outer periphery of the core material. The length of the reinforcing fibers should be 1 inch or more in the striking part,
A golf club head characterized in that the head body is less than 1 inch long and short, and is used in combination. 2. The golf club head according to claim 1, wherein the reinforcing fibers mixed in the resin material of the head body include fibers with a length of 15 mm or less.