JPH01244770A - Head for golf club - Google Patents

Abstract

PURPOSE:To lower the position of the center of gravity and to allow a sole surface to be hardly scratched by fixing a metallic sole plate different from a ring in a specific gravity to the sole part of a metallic ring. CONSTITUTION:A main body 8 is composed of a face part 1 and a side sole part 2, they are bond-coupled, and a hollow structure is used. A metallic ring 3 is composed of a neck part 9 having a hole for insert-fitting a shaft and a ring part 10, and it is formed unitedly with the face part 1. The ring part 10 is provided inside the face part 1, and the neck part 9 is projected to the external part of the face part 1. Further, a sole plate 4 is fixed to the sole bottom part of the main body 8 hollow part by a screw 6. The metallic ring is made of an iron, and for the material of the sole plate 4, aluminum of a specific gravity 2, 7 or brass of a specific gravity 8.4 against a specific gravity 7, 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the structure of a golf club head mainly made of thermoplastic resin.

(Prior art) The function of a golf club head is to stably hit the ball long distances, and iron-based head materials have conventionally been made of ferrous metals, while wood head materials have been made with impact noise and appearance. Persimmon wood (supplementary material) is used because of its good properties.

(Problems to be Solved by the Invention) In recent years, as a head material for the above-mentioned medium woods, it has become difficult to obtain Versimmon wood with excellent properties, and with the advent of two-piece balls, head materials that are more durable than Persimmon wood have become available. It's starting to be demanded. Therefore, metal materials, which have greater strength than persimmon materials and can be made into hollow structures, and have a greater degree of freedom in design such as adjustment of the center of gravity, and FRP (
New materials such as fiber-reinforced thermosetting resin (fiber-reinforced thermosetting resin) and FRTP (fiber-reinforced thermoplastic) materials have begun to attract attention. Metal heads have excellent durability, but their high specific gravity makes it difficult to make them as large as Versimon Hendo. On the other hand, FRP heads are suitable for weight reduction because they can increase specific strength and specific modulus of elasticity, and have a feature that allows a greater degree of freedom in design. However, in the -C golf head, a force of 1000 kg is applied to the face surface when hitting a ball, so the face portion and neck portion must be constructed to withstand the above-mentioned impact load.

However, in the case of FRP heads, productivity is poor, and when designed to withstand impact loads, the structure becomes complicated, making it difficult to produce uniform products, and the cost becomes extremely high, which is inconvenient.

On the other hand, FRTP heads can be molded by machines such as injection molding, and have the advantage of being able to produce uniform heads at low cost.
- Since the force specific strength and specific modulus of elasticity are lower than that of FRP, the hollow structure has a thicker wall than FRP, and there is a drawback that the degree of freedom in design is reduced.

Furthermore, a golf head has been proposed in which a metal ring is provided behind the center of the head body, which is mainly made of foam and has a structure in which a hollow ball is provided in the center, and a shaft is attached to the metal ring. However, in this case, although the neck part integrated with the ring-shaped metal frame has the effect of strengthening, it makes the complicated structure of the head body even more complicated, which is undesirable because productivity is low and it is expensive.

Therefore, a golf head has been proposed in which a metal ring having a shaft insertion portion is provided on the outer periphery of a hollow structure mainly made of thermoplastic resin.

This golf head can be molded by injection molding, so productivity is excellent. However, since a metal ring with a high specific gravity is located on the outer periphery, the center of gravity of the golf head is located at the center of the ring. If this continues, the center of gravity will be higher than that of conventional golf heads.

Therefore, when the ball is hit, there is a high possibility that the ball will hit a location lower than the center of gravity of the golf head, resulting in a difficult golf club that tends to have a low trajectory and short flight distance. Further, there is a problem in that the sole portion of the golf head comes into contact with the ground when hitting a ball and is easily damaged. However, the method of widening the shape of the sole part of the ring to lower the center of gravity or to protect the sole part reduces the degree of freedom in design and makes it difficult to manufacture the ring by lowering the center of gravity. Further, it is not preferable because it becomes difficult to integrally mold the ring hollow structure.

The present invention has been made in view of the above problems, and
The aim is to create a golf head that integrates a hollow structure made of highly productive material, mainly injection moldable thermoplastic resin, and a metal ring with a shaft insertion part, with a center of gravity. To provide an excellent golf club head which can be lowered in position and whose sole surface is not easily damaged.

(Means for Solving the Problems) The structure of the present invention for achieving the above object will be explained using FIGS. 1 to 3 corresponding to the embodiments. In a fiber-reinforced plastic golf head that integrates a hollow structure mainly made of plastic resin and a metal ring with a shaft insertion part,
The present invention is characterized in that a metal sole plate having a specific gravity different from that of the ring is fixed to the sole portion of the metal ring.

The thermoplastic resin used in the present invention is, for example, ABS resin, acrylic resin, nylon resin, polycarbonate resin, polyphenylene sulfide resin, polyether ether ketone resin, polyethylene terephthalate resin, etc. As a main body, fillers such as calcium carbonate, silica, etc.
The face part and side sole part or sole part are mechanically formed by injection molding using a material containing powder filler such as glass and short fiber reinforcing materials such as carbon fiber, Gebler fiber, and glass fiber, and these are joined to form a hollow part. A head body having a section is formed. It is okay to fill the hollow part with foam such as urethane foam to improve the impact sound.
The mechanical properties of fiber-reinforced composite materials vary depending on the fiber content and the type of fiber and resin, but they also vary depending on whether the fiber form is short fibers of around 1 cm or long fibers of 2 to 3 cm or more. Fibers have better strength and elastic modulus.

If the structure of the golf head is a hollow structure having a shaft insertion hole, the strength and rigidity of the neck portion must be increased and the neck portion must be increased in thickness, which results in increased weight. Therefore, when the main body is made of thermoplastic resin with low strength and rigidity, making the neck part of metal has a significant weight reduction effect. The shape of the metal ring may be any structure as long as it has a shaft insertion portion, for example, a shaft insertion hole, and has a ring shape and can be integrated with the main body of the hollow structure, for example, a structure that can be fixed to the outer circumference of the main body.

The identification method may be an adhesive method or an integral molding method. That is, although there are no particular restrictions on the width or thickness as long as it is ring-shaped, it is preferable that it be light as long as it can withstand the impact force when hitting a ball. Further, metals or alloys such as iron, aluminum, titanium, etc. are suitable as materials, but iron-based materials are best from the viewpoint of ease of manufacture and cost, and cast iron is particularly preferred.

Next, the metal sole plate may have a structure that can be fixed to the metal ring described above and a shape that can protect the sole portion of the golf head. Adhesive methods may be used for fixing, but it is better to use a fixed type so that it can withstand the impact force when the ball is hit.

By the way, golf heads are not of one type, but have different shapes depending on the intended flight distance of the pole, and it is necessary to make the larger shape lighter and the smaller the shape, the heavier the golf head. Furthermore, when the face plate is made of the same metal as the metal ring, the degree of freedom in design is small and the desired weight adjustment may not be possible. In other words, if you want to make the sole plate larger and lighter, you can use a metal whose specific gravity is lighter than that of the metal ring. For example, aluminum is passed through it. Also, if you want to make it small and heavy, you can use a metal with a higher specific gravity than the metal of the metal ring. For example, brass, copper, etc. are suitable. In this way, by changing the specific gravity of the metals used for the sole plate and ring, the degree of freedom in design can be increased.

(Example) An example of the present invention will be described below based on FIGS. 1 and 2. In FIG. 1, the golf head main body 8 is made of 70% by weight of nylon resin, which is a thermoplastic resin, and 30% by weight of short carbon fibers, and is molded using an injection molding machine. The main body 8 consists of a face part 1 and a side sole part 2, which are adhesively bonded to form a hollow structure. The metal ring 3 has a neck portion 9 having a hole for inserting a shaft and a ring portion 10.
The ring part 10 is provided inside the face part 9, and the neck part 9 projects outside the face part 9.

Further, a sole plate 4 is fixed to the bottom of the hollow portion of the main body 8 with screws 6. Further, the shaft 5 is inserted into the neck portion 9 of the metal ring and fixed by adhesive.

The face part 1 has a face length of 10u+, and in order to increase rigidity, reinforcing ribs each having a height of 7 mm and a width of 1.5 mm are provided on the back surface, 5 in the vertical direction and 5 in the horizontal direction.

The outer periphery of the face portion l has a thickness of 6 mm, and an iron ring is integrally fixed to the inner surface. The end portion is provided with a step so that it can be adhesively bonded to the side sole portion 2. The thickness of the side sole portion 2 is 6fi at the outer periphery, gradually becoming thinner to 411mm, and thickening at the rear end to 7fi.

By the way, since the molding die has a simple shape, it is easy to manufacture.

The metal ring is made of iron and has a width of 10 t and a thickness of 1.2 mm, and the surface in contact with the face part I has a height of 0.0 mm to increase the bonding force.
It has 5mm unevenness. The neck part 9 is designed to allow the shaft 5 to be inserted, and has an outer diameter of 11 mm and a length of 50 mm.
0, and has a hole with an inner diameter of 8.11 mm and a depth of 45 mm. The shape of the ring portion 1o is approximately elliptical, and has a width of 72 mm and a height of 390 mm.

The shape of the sole plate 4 is as shown in FIG. 3 from the bottom direction, and is designed to prevent it from slipping back and forth. The material is aluminum with a specific gravity of 2°7, which is lighter than iron's specific gravity of 7.8, and the thickness is 1 fl. The assembled golf head has a length of 4311 mm, a width of 76 mm, a depth of 70 m from the face surface to the rear end, a volume of 21 oad, and a weight of the face portion of 70 g.
The side sole part weighs 50g, the iron ring weighs 65g, and the sole plate weighs 20g, totaling 205g. Note that by using brass with a specific gravity of 8.4 for the sole plate, it is possible to manufacture a type of golf head that is smaller in volume and heavier in weight.

Comparative example Next, a comparative example will be explained based on FIG. 4.

The golf head body is made of injection molded thermoplastic resin containing 70% by weight of nylon resin and 30% by weight of short carbon fibers, as in the embodiment. It consists of a face part 1, a side sole part 2, and an iron ring 3.

The face portion 11, the side sole portion 2, and the iron ring are connected by adhesive, and the iron ring is provided on the outer periphery of the main body 8.

The dimensions of each part are almost the same as in the embodiment. The shape of the iron ring is almost oval, width litm, thickness 1.3mm, height 43mm.
m, width 76 cranes, which is slightly larger than the example. Also, there is no sole plate.

The assembled golf head has a thickness of 43 m, a width of 76 mm, a depth of 70 mm, and a volume of 210 c+j.

The weight is 70g for the face, 50g for the side sole, and 80g for the iron ring, totaling 200g.

Next, the shaft was inserted into the golf heads produced in the examples and comparative examples, the golf heads were assembled, and test shots were performed. The club of the example had good ball direction, flight distance, and trajectory height, had no problem with the impact sound, and had no change in appearance even after 2,000 strokes, and had no problems with durability.

However, the club of the comparative example had a slightly lower trajectory, and the flight distance was about 10 m less than that of the example.

In addition, as a result of the 2000-stroke test, the sole portion of the golf head was worn out, which was unfavorable in terms of appearance. The rest was almost the same as the example.

(Effects of the Invention) Since the present invention has the above configuration, the following effects can be achieved.

+11 The golf head main body can be machine-formed using a material mainly composed of thermoplastic resin, so it is uniform, and productivity is good, making it possible to reduce manufacturing costs.

(2) The golf head body has a simple shape without a neck portion, so the mold can be made inexpensive.

(3) Since a sole plate having a different specific gravity from the metal ring of the main body is provided on the bottom surface of the golf head, the degree of freedom in moving the center of gravity can be increased.

(4) Since the impact force is received by the metal ring provided with the shaft insertion portion, it is possible to form a golf club with excellent impact resistance and durability even if the head body is a hollow structure.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of a golf club head according to the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG.
The figure is a bottom view of FIG. 1, and FIG. 4 is a perspective view showing a comparative example. Explanation of symbols 1 Face part 2 Side sole part 3 Iron ring 4 Sole plate 5 Shaft 6
Fixing screw 7 Reinforcing rib 8 Golf head main body 9 Neck portion 10 Ring portion Fig. 1 Fig. 2

Claims (1)

[Scope of Claims] 1. A golf head made of fiber-reinforced plastic in which a hollow structure mainly made of thermoplastic resin molded by an injection molding method and a metal ring having a shaft insertion portion are integrated; A golf head characterized in that a metal sole plate having a specific gravity different from that of the ring is fixed to the sole portion of the ring. 2. The golf head according to claim 1, wherein the metal ring is made of iron. 3. The golf head according to claim 1, wherein the metal sole plate is made of aluminum or brass.