JPS5914867A - Production of wood club head for golf - 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 The present invention relates to a method for manufacturing a wood club head for golf with an outer shell made of fiber reinforced plastic (hereinafter abbreviated as FRP), and involves devising a means for molding the FRP outer shell that constitutes the head body. This is intended to improve moldability and quality.

Conventionally, this type of wood club head has a structure in which the outer shell of the head body is made of FRP and the core is filled with foamed synthetic resin, as disclosed in Japanese Patent Publication No. 51-21436. There are things that I have.

However, as is well known, in such conventional devices, there are various difficulties in the specific molding method due to the complexity of the unique shape of the outer periphery of the head.

In addition, because the cavity shape of the mold used in general-purpose FRP molding has a fixed size, the volume of the component material for head molding introduced into the cavity may vary depending on the size, the amount of material used, or a combination thereof. If excess or deficiency occurs due to uneven work9, etc., excess or deficiency will occur in the clamping force applied to the FRP molding material filled in the υ mold due to mold clamping, resulting in pressure instability during hot pressing. When the FRP molding material is composed of a plurality of laminates, it tends to cause insufficient interlayer adhesion and voids (bubbles) between the layers or on the surface of the molded product, resulting in an unavoidable deterioration in quality.

This invention aims to eliminate the drawbacks of the above-mentioned conventional methods, and its gist is that the FRP molding material constituting the head shell is wound around the core material and coated. When placed in the cavity of a mold having the shape of the outer periphery of the head and subjected to heat pressure, the core material is formed of a synthetic resin part that has already been foamed and an unfoamed material part that can be foamed or vaporized by heating in a post-process, and is made of FRP. It is characterized in that the core material is foamed during heating of the molding material for molding and curing.

The present invention will be explained below based on illustrated embodiments.

As shown in FIGS. 1 and 2, numeral 1 in the figures is a head main body obtained by a manufacturing process described later.

The bed body 1 is formed from an outer shell 2 made of FRP and a core material 3 made of foamed synthetic resin, and the FRP outer shell 2 has a laminated structure. Further, the face part 1a of the head body 1 has a face plate 4 made of hardened FRP (carbon fiber is used as reinforcing fiber), and the sole part 1b and back part 1C have a sole weight member made of a metal material such as brass. 5 and a back weight member 6 are embedded and fixed as necessary, and furthermore, in the figure, 7 is a club shaft inserted and fixed into the neck portion 1d of the head body 1, and 8 is the club shaft 7 and the head body neck. It is a cap-shaped protector that protects the periphery of the attachment base to the portion 1d, and each of these members is integrated at the same time as the head body is molded.

That is, in order to manufacture the above-mentioned head according to the present invention, as shown in FIGS. 3 to 5, a core material 11 formed in a desired head core shape is made of, for example, a small piece of foamed synthetic resin 1. 1 a and unfoamed foamable synthetic resin composition It b
The FRP molding material 12 and 13, which is a shell molding material, is wrapped around the molded mixture. At this time, the FRP molding material is used in a state in which reinforcing fibers are impregnated with prepreg or uncured liquid synthetic resin. In particular, surface mat or satin cloth is used alone or as reinforcing fibers in the outer shell molding material 13. By using it in conjunction with a hollow weave body, the surface smoothness and shape followability are improved, while the elastic modulus is improved by using mat or hollow weave carbon fiber as reinforcing fibers for the inner shell forming material. is preferable. Next, such head molding material is placed in the cavity 15 of the mold 14 having the outer peripheral shape of the head, and the unfoamed foamable synthetic resin is mixed into the core material 11 by the heating action of increasing temperature during hot pressing. By further foaming composition 1] and b, the compositions shown in FIGS.
A wood club head as shown in the figure is obtained.

By the way, in the above examples, the core material was composed of a mixture of foamed synthetic resin pieces that have already been foamed and an unfoamed foamable synthetic resin composition that can be foamed by heating in a post-process. Other examples include, but are not necessarily limited to, foamed beads that have been partially foamed and contain residual foamable material that can be further foamed by heating, and further foamed beads. The functions and effects of the present invention can be fully exhibited by using a core material made of a foamed synthetic resin and forming an unfoamed foamable synthetic resin composition layer on the peripheral surface and foaming it during hot pressing. can.

As explained above, the present invention is characterized in that when the FRP molding material constituting the head outer shell is wrapped around a core material and heat-pressed into a mold, the core material is combined with a foamed synthetic resin and an unfoamed Since the core material is formed with a substance and foamed by the temperature increase during hot pressurization during mold clamping, the volume of the core material in the mold expands, and the surrounding FRP molding material is pressed against the inner peripheral surface of the mold. This eliminates the lack of pressure applied to the molding material as in conventional molding methods, and reliably prevents insufficient adhesion between layers and the occurrence of defects, thereby improving the quality and surface smoothness of FRP. It also has excellent practical effects, such as being able to reduce the overall weight.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of a golf wood club head according to the present invention, FIG. 2 is an enlarged cross-sectional view of the main part, and FIGS. 3 to 5 are explanations showing the manufacturing process according to the invention. It is a diagram. 1...Head body, 2.21.22...
...FRP outer shell, 3...core material, 1J...core material, 11a...foamed synthetic resin, ]], b...
...Unfoamed substance,]2.13...FRP molding material, J4...molding mold, 15...cavity. Patent applicant Nippon Musical Instruments Manufacturing Co., Ltd.

Claims (1)

[Claims] (],) FR constituting the head outer shell around the core material
When the P molding material is wound and coated and placed in the cavity of a mold having the shape of the outer periphery of the head and hot-pressed, the core material is formed of a foamed synthetic resin and a foamable substance, and the FR
A method for manufacturing a wood club head for golf, which comprises foaming the core material during heating of the P-molding material. (2. The method for manufacturing a wood club head for golf according to claim 1, characterized in that the core material is bonded with foam beads that can be further foamed by heating. (3) ) The method for manufacturing a wood club head for golf according to claim 1, wherein the core material is made of a mixture of foamed synthetic resin pieces and a foamable synthetic resin composition. 4) In the method for manufacturing a wood club head for golf according to claim 1, the core portion is formed by forming a layer of a foamable synthetic resin composition on the circumferential surface of a core material made of a foamed synthetic resin. A manufacturing method characterized by