JPH01190374A - Golf club head - Google Patents

Abstract

PURPOSE:To obtain a lightwt. and impact-resistant golf club head which is moldable by injection molding by using fiber reinforced plastics having a thermoplastic resin matrix, by integrally arranging, at a face part, a reinforced layer composed of fiber reinforced plastics contg. continuous fibers. CONSTITUTION:In a golf club head which is an outer shell, formed by injection molding, composed of fiber reinforced plastics having thermoplastic resin as a matrix, and which has a head body 1 with a face part 5 and a back part 6, the face part 5 consists of an integrally reinforced layer composed of fiber reinforced plastics contg. continuous fibers. Glass fibers, carbon fibers, or Kevlar fibers are preferable for continuous fibers, and cloth or unidirectional material in combination with suitable angles is preferable. Although thermoplastic resin used in the head body is the most preferable material for the matrix of the above described continuous fibers, a different material may also be employed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a golf club head having a head body made of fiber-reinforced thermoplastic.

(Prior Technology) The function of the head of a golf club is to stably hit the ball long distances. Conventionally, the head of a golf club, commonly known as a wood club, is made of persimmon wood (seed material) because of its impact sound and good appearance. ) have been used. However, in recent years, it has become difficult to obtain persimmon materials with excellent properties, and with the advent of two-piece poles, there has been a demand for a head material with excellent durability to replace the persimmon phase.

Therefore, metal materials, which are stronger than persimmon materials and allow for hollow structures, and have a greater degree of freedom in design such as adjusting the center of gravity, fiber-reinforced thermosetting resins (FRP), and fiber-reinforced thermoplastic resins (FRTP), etc. New materials are attracting attention, and golf clubs are being manufactured using these materials as head materials.

(Problems to be Solved by the Invention) However, although metal heads are excellent in durability, they have a large specific gravity, so there is a problem that it is difficult to make them as large as a persimmon head. In addition, FRP and FRTP heads have the characteristics of being able to have higher specific strength and specific modulus of elasticity than metal heads, being lighter in weight, and having a greater degree of freedom in design.

By the way, when a golf club head hits a ball, a force of about 100 (lFf) is applied to the face, so the face and neck parts need to be designed to withstand the above impact load. However, if the reinforcing fibers are oriented to withstand impact loads, the head will have a complicated structure, making it difficult to produce a uniform head (and making it expensive). There were drawbacks.

On the other hand, when FRTP material is used, it has the advantage of being able to be mechanically formed, so the forming time is short and a homogeneous head can be manufactured at low cost. However, the specific strength and specific modulus of FRTP material are Since the thickness of the hollow structure is lower than that of FRP material, it is necessary to make the wall thickness of the hollow structure thicker than that of FRP material, which poses the problem of hindering the weight reduction of the head and the degree of freedom in design.

Further, a golf head has been proposed in which a metal ring is provided at a rear portion of the head body from 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 ring. This has the advantage that the neck portion is strengthened because the shaft is inserted into metal, but the head body has a complicated structure, resulting in low productivity and high cost.

The present invention has been made in view of the above-mentioned problems, and provides a golf club head that is lightweight and able to withstand impact loads, which can be molded by injection molding using fiber-reinforced plastic having a thermoplastic resin as a matrix. It is intended for this purpose.

(Means for Solving the Problems) The present invention will be explained below using FIGS. 1 and 2 corresponding to embodiments.

The present invention relates to a golf club head body (1) which is made of fiber-reinforced plastic with a thermoplastic resin matrix and is formed by injection molding, and which has a face part (5) and a back part (6). This is a golf club head in which the face portion (5) is integrally provided with a reinforcing layer (7) made of fiber-reinforced plastic using continuous fibers.

The thermoplastic resin in the fiber-reinforced plastic having a thermoplastic resin matrix that forms the outer shell by injection molding in the present invention is not particularly limited, but examples include nylon, ABS, acrylic resin, polyphenylene sulfide resin (PPS), polyether Ether resin (P E
EK) etc. Further, as the reinforcing fibers, short fibers such as short glass fibers, short carbon fibers, and short Kevlar fibers are used.

The above-mentioned fiber-reinforced plastic material made of thermoplastic resin and reinforcing fiber has the characteristic that it can be formed into a uniform product in a short time using an injection molding machine.

Furthermore, the outer shell constituting the face part and the back part by injection molding in the present invention may have a shape in which only the sole side that contacts the ground is open, or the two may be joined to form a hollow body.

The face part and the back part may have two shapes.

Next, the reinforcing layer according to the present invention will be explained. When a golf head collides with a ball, it receives a large impact force, and generally generates an impact force of about 1 ton, particularly on the face portion. Therefore, the face portion needs to have increased strength and rigidity. Normally, if the head body is made using thermosetting resin as a matrix and continuous fibers, the strength of the face part will also be large and there will be no problem. When making the main body, the face part had to have sufficient strength and rigidity, so the wall thickness of the face part had to be at least 20cm thick, making it difficult to mold a hollow body due to the weight, but using continuous fibers. This problem could be solved by forming a reinforcing layer made of fiber-reinforced plastic. For example, the mechanical properties of an injection molded product made of 30% Wt short glass fiber material with a matrix of nylon, which is a thermoplastic resin, are that the bending strength is 25%.
Niri V-1 has a bending modulus of elasticity of 800 K9f/rmA, whereas a continuous fiber reinforced material, such as a unidirectional carbon fiber material with a thermosetting epoxy resin as a matrix, has a bending strength of 160 K9f/rmA. , the bending modulus is 12
000 Kj'f/m [lt, and the bending strength is 85 Kpf/rni, and the bending modulus is 6 for the black cloth material with the same composition.
00 (ljlf/-.The above shows the case of continuous reinforcing fibers using a thermosetting resin as a matrix, but the continuous reinforcing fibers using a thermoplastic resin as a matrix also have a higher resistance than the case of using short fibers. This is because you can also change to something with greater strength.

The types of continuous fibers mentioned above are preferably glass fibers, carbon fibers, and Keplerian fibers, and the preferred form is cloth or unidirectional materials combined at different angles for convenience.

Next, as the matrix of the continuous fibers, it is most preferable to use the same material as the thermoplastic resin of the head body, but it may be different. However, in terms of form, the fibers and the resin are already short, making it suitable. As a matrix for the prepreg, thermoplastic resins such as nylon, PPS resin, and PEEK are suitable because they have excellent workability and can be matched to the shape of the face. However, if the shape is simple and there is no problem, a molded product prepared by preforming a prepreg using a thermosetting resin to match the shape of the face may be used. The strength and elastic modulus of the reinforcing fiber layer are greater in a prepreg using a thermosetting resin than in the case of a thermoplastic resin, and epoxy resin is most commonly used as the thermosetting resin in this case.

Furthermore, regarding the position of the reinforcing layer on the face part, placing it on the surface that collides with the ball has the greatest reinforcing effect on strength, but considering that the strength will decrease due to delamination at the interface between the reinforcing layer and the injection-molded face part. Fatigue resistance is improved by using it as an intermediate layer in the face part.

In addition, in order to change the hitting sound when hitting the ball, the specific gravity is 0.
．． There is no problem in filling the head body with polyurethane foam having a low specific gravity of 2 or less. However, if the specific gravity is 0.2 or more, the weight increases and the degree of freedom in design decreases, which is not preferable.

(Example) Hereinafter, the present invention will be described in detail based on the drawings. .

FIG. 1 is a perspective view showing an embodiment of a golf club head according to the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG.

Embodiment 1 1 is a head main body formed by joining a face part 5 and a back part 6, which are outer shells, and providing a hollow part 4. The face part 5 and the back part 6 are each molded by injection molding of a nylon material mixed with 3 Qwt% of short glass fibers, and the molding in this case is performed in a cycle of about 2 minutes. The thickness of the face part 5 on the face surface 5a side is 12 cm, and a reinforcing layer 7 formed by integrally molding a prepreg made of carbon fiber cloth impregnated with nylon at the same time as the face part 5 is provided in the middle. The thickness of the reinforcing layer 7 is 6 m, and the end portion is bent backward by about 5 m along the face surface 5a. The thickness of the portion of the face portion 5 other than the face surface 5a side is approximately 8 digits,
The total weight of the face portion is 63g. The thickness of the back portion 6 is approximately 8 mm and the weight is 45 g.

A side sole 9 made of aluminum and weighing 20 g is attached to the rear end of the back portion 6.

The metal frame 2 is made of cast iron, and the thickness of the ring-shaped frame portion is approximately 1.
2 van, width 10cm. Also, the width of the ring part is 80+
It has a substantially elliptical shape with a height of 44 cm, and fits into a notch 5b provided at the rear of the face portion 5.

The shaft insertion part 2a provided in the metal frame 2 has an outer diameter of 11+
A hole with an internal diameter of 8.1 rtm s and a depth of 50 mm is provided. Note that the weight of the metal frame 2 is 67 g.

The head configured as described above has a thickness of 44 mm, a width of the face surface 5a of 80 mm, a length of 15 mm from the face surface 5a to the metal frame 2, a length of 35 rIm from the metal frame 2 to the side sole 9, and a side sole. 9 has a width of 10 mm, a length from the face surface 5a to the rear end of 7 ONn, a weight of 195 g, and a volume of 210 afl.

Example-2 The hollow part 4 of the head body prepared in Example-1 was given a specific gravity of 0.
10g of hard polyurethane liquid mixed so that it becomes 15
A foam was formed by injecting the mixture into a head weighing 205 g.

Example 3 As the reinforcing layer 7 in Example 1, a laminate was used in which carbon fiber unidirectional prepregs impregnated with an epoxy resin, which is a thermosetting resin, were laminated to have a thickness of 6 m and formed into the shape of the face surface 5a. The rest of the head is exactly the same as in Example-1.

Comparative Example 1 This head was completely the same as Example 1 except that the reinforcing layer 7 was not provided on the face portion 5.

Next, the moment of inertia of each of the above golf heads was measured. This moment of inertia affects the directionality of the ball when the golf head and the ball collide, and the larger the moment of inertia, the less the golf head will shake during the collision, and the ball will have better directionality. The center of gravity of the head was suspended by a piano wire, the sole surface was rotated so that it was horizontal, the natural frequency was measured, and the moment of inertia was calculated from this measured value.Also, for comparison, a golf ball made of conventional persimmon material was used. A head with approximately the same weight and volume was selected and measured in the same manner.As a result, Example 1.
The moment of inertia of the injection molded golf head of 2.3 and comparative example is 2.1 x 10-"K!f 1118'
In the case of a golf head made of persimmon material, it is 1.3.
x10""K9fmS", which is 1.6 times that of the conventional persimmon material in the golf head according to the present invention, and it was confirmed that the directionality is improved.

In addition, shafts with the same specifications were inserted into each head, assembled into a wood golf club, and tested.

Head speed when colliding with the ball: 40m/s
As a result of continuously hitting the ball, the club of the comparative example had a slight dent in the face after about 500 hits, and a hair crack appeared after about 1,000 hits.

On the other hand, in the golf head of Example 1.2.3, 300
I tried hitting up to 0 strokes, but there was no abnormality.

Furthermore, although the impact sound of the golf club of Example 2 was slightly lower than that of Examples 1 and 3, there was no difference in the four-directionality of the ball or flight distance between the golf clubs of the Examples. It was better than any other golf club. Note that the golf club in the comparative example has a soft face surface, which causes energy loss and loss due to deformation, and the ball flight distance is lower than that of Persimmon material.
It was lower than that of No. 1 golf club.

(Effects of the Invention) As described above, the golf club head according to the present invention has
The head body is composed of an outer shell made of fiber-reinforced plastic with a matrix of thermoplastic resin molded by injection molding, and a reinforcing layer made of resin using continuous fibers is provided on the face of the outer shell. Despite being lightweight, there are no problems with strength, rigidity, or durability, and productivity is also good, and ball direction and flight distance when hitting the ball are also superior to conventional golf heads made of persimmon material. There are effects such as:

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a golf club head according to the present invention, and FIG. 2 is a sectional view taken along line A--A in FIG. Explanation of symbols

Claims (1)

[Scope of Claims] 1. A golf club head comprising a head body made of fiber-reinforced plastic with a thermoplastic resin as a matrix and having an outer shell formed by injection molding and having a face portion and a back portion; A golf club head characterized in that a reinforcing layer made of fiber-reinforced plastic using continuous fibers is integrally provided in the face portion. 2. The golf club head according to claim 1, wherein the reinforcing layer is made of fiber-reinforced plastic with a thermoplastic resin matrix. 3. The golf club head according to claim 1, wherein the reinforcing layer is a fiber-reinforced plastic having a thermosetting resin as a matrix. 4. Claim 1, wherein the head body is filled with urethane foam having a specific gravity of 0.2 or less.
Or the head of the golf club according to 2.