JPH0659335B2 - Golf club head - Google Patents

Description

The present invention relates to a golf club head, which is a so-called carbon head.

[Conventional technology]

Recently, the appearance of two-piece balls has increased the impact force applied to the club head, and there has been an increasing demand for improving the strength of the striking surface (face surface). Therefore, a head using a carbon fiber reinforced plastic (CFRP) material, a so-called carbon head, has been developed as a lightweight and high-strength material.

The function of the head is to stably fly the ball further, but this requires that the center of gravity of the head be lower and deeper (far from the face surface).

The head may be provided with a reinforcing body parallel to the striking direction, especially a plate-like rib connected to the ceiling, and the role thereof is considered to be the following three points.

It suppresses the deformation of the face surface when hit, and transmits impact energy to the ball to extend the flight distance.

Improves the hitting sound and feel when hitting (gives a feeling similar to that of the conventional Persimmon head).

It catches the impact on the crown when the caddy bag falls (iron club head collision, etc.).

As such a reinforcing body (rib) is formed,
The one described in Japanese Utility Model Publication No. 59-93565 is known. This is a so-called metal head,
A rib made of a metal material is fixed to a main body of a head having a sole surface portion and a side peripheral surface portion having a thickness of 1.2 mm by means such as welding. Since this conventional example is not a carbon head in the first place, the size of the head cannot be increased without increasing the weight, and therefore the sweet spot cannot be enlarged. As a carbon head having ribs formed therein, there is a carbon head as disclosed in Japanese Utility Model Laid-Open No. 59-64167.
Those described in Japanese Patent Publication No. 59-24069 and Japanese Utility Model Publication No. 59-24069 are known. The former rib is integrally formed with the face portion inside the face portion, and the face portion is integrally formed with the side wall portion and the sole portion to form the main body of the head.
Therefore, the rib is formed on the main body of the head, and is connected to the sole portion, the side wall portion and the upper surface portion. The latter rib is an outer shell (head body) molded from a synthetic resin material.
Is integrally formed in the cavity portion from the ball striking face side to the rear side. The rib is connected to the face portion but not to the bottom surface.

In addition, the conventional carbon head is molded by inserting a male mold from the upper surface to mold the face portion, the sole portion, and the side wall portion, and closing the opening of the upper surface portion with the upper surface plate, or by using a lightweight foam as a core. It is common to wrap the periphery of the head with FRP and press-mold the main body of the head, and all the ribs integrally molded with the face portion are formed on the main body of the head.

Further, as a double-structured head, Japanese Patent Laid-Open No. 59-91 is available.
The one described in Japanese Patent No. 976 is known. This is a golf club head in which the outer circumference of a synthetic resin hollow core material is coated with FRP. The hollow core material is a synthetic resin plate formed into a hollow shape, ABS resin, polyethylene resin, or the like. The core material is obtained by melting an appropriate resin and providing a hollow synthetic resin plate by a molding method such as blow molding, and no rib is formed inside and no filler is filled.

[Problems to be solved]

In the golf club head in the above-mentioned conventional example, the face surface deformation at the time of hitting is suppressed while maintaining the light weight, and the low center of gravity
It is difficult to obtain a head with a deep center of gravity, and even in the case where a plate-shaped rib that is parallel to the striking direction and is connected to the ceiling is provided inside the head, this rib serves as a partition wall and the inside of the head is completely separated. One partition, filler (foam polyurethane, etc.)
Two injection ports were required, and the man-hours such as weight management were complicated. In the case of a single structure having only a main body without a hollow core material, as described in JP-A-59-91976, chip-like short carbon fibers have been mixed with a synthetic resin and molded by injection molding. Since the fibers have the same direction and are strong against impact from one direction, they have the drawback that they are weak against impact from other directions, and it is difficult to increase the amount of carbon fiber used in molding. It was not possible to take advantage of the various advantages that it has. In addition, a prepreg such as chopped fiber of long carbon fiber prepreged with thermosetting resin or woven or knitted and prepreged with thermosetting resin is attached to the outer periphery of the urethane foam core material. In the case where a golf club head is formed by applying the prepreg to the outer periphery of the core material with a certain thickness, the prepreg cannot be sufficiently pressed even when molded with a molding die, and the prepreg material with a certain thickness adheres. This creates a small gap between them. The presence of these voids has been a cause of receiving a shock when the golf ball is hit and causing cracks or depressions in the head body.

However, even with the double structure described in JP-A-59-91976, since there is no rib inside the hollow core material and no filler is filled, the prepreg product is subjected to heating and pressure molding. In order to have the strength to withstand the pressure, the hollow core material must be thickened, which makes it difficult to obtain a lightweight and large head. In order to obtain a lightweight and large-sized head, it is necessary that the core material that serves as a hollow core at the time of molding the main body has sufficient compressive strength and is lightweight even when it is increased in size.

Therefore, the present invention provides a golf club head that is lightweight and large-sized, secures sufficient strength of the face portion, improves striking sound and feel, and easily has a low center of gravity and a deep center of gravity. With the goal.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a hollow core material having an upper surface opening integrally formed with a face portion by introducing SMC into a mold in which a face portion made of a synthetic resin material of a prepreg is preset. , The core material and the hollow portion are integrally molded from the same material as the core material, are connected to the back surface of the face portion, extend from the back surface to the back surface of the face portion in the direction of the side portion, and extend on the bottom surface of the core material. A rib that connects to
A filler having a specific gravity of about 0.25 to 0.50 made of a lightweight foam filled in the hollow portion of the core material, and a reinforcing fiber mixed so as to cover at least the side circumference and the upper surface opening of the core material excluding the face portion. A main body formed by heating and pressurizing a molding material made of a resin material, the rib is not connected to the inside of the crown formed by the main body, and there is a gap between the rib and the inside of the crown. The gap is filled with a filler.

〔Example〕

Preferred embodiments of the present invention will be described below with reference to the drawings.

A core material 1 to be a hollow core shown in FIG. 1 has a face portion 2 insert-molded at the time of molding. Hollow part 1
In the inside of 1, the ribs 3 extending from the back surface of the face portion 2 toward the side portion 14 are integrally formed when the core material 1 is formed. The rib 3 is, as shown in FIGS. 1 and 2,
It is formed in a triangular shape, and is connected to the back surface of the face portion 2 and to the bottom surface 13 of the core material 1. Also,
The rear end of the rib 3 is connected to the side portion 14 of the core 1.
That is, the rib 3 is only connected to the back surface of the face portion 2 and extends longer than the length connected to the back surface of the face portion 2 in the direction of the side portion 14 from the back surface, and is connected to the bottom surface 13 of the core material 1. is there. A weight adjusting boss 15 is formed on the bottom surface 13 of the core material 1. Reference numeral 12 is a toe portion.

In order to mold the core material 1 with the face portion 2 shown in FIG. 1, the face portion 2 is set in a predetermined position in an upper and lower split mold (not shown), and the SMC (sheet molding compound) is set. It suffices to put in, close the mold, and apply heat and pressure. As the thing to be set in the mold for forming the face portion 2, an arbitrary carbon fiber woven fabric is impregnated with a resin and wf (fiber content by weight) is adjusted to 40 to 75% (prepreg ) Is suitable. When wf <40%, only the resin flows during molding, resulting in poor appearance. When wf> 40%, some parts are not impregnated with resin, resulting in poor appearance and reduced impact resistance. Was seen. It is also possible to form various patterns by changing the fiber fabric. The SMC forming the core material 1 is wf2
Those containing carbon fibers adjusted to 5 to 60% are preferable. SMC is a sheet-shaped molding material composed of a thermosetting resin, a filler, and carbon fiber, and is charged to 60 to 90% of the mold surface by compression molding, and 120 to 160 ° C.
It is formed with a mold clamping pressure of 0 to 300 kg / mm ² and a curing time of about 2 to 5 minutes. The fiber length and the number of fiber bundles of carbon fibers can be arbitrarily selected. The positions of use of these prepregs and SMC are arbitrary, and the appearance (pattern) of the head main body can be freely designed by selecting these positions of use.

In the embodiment shown in FIGS. 1 and 2, the length of the rib 3 connected to the bottom surface 13 of the core 1 is longer than the length of the rib 3 connected to the face portion 2, and the top surface of the rib 3 is formed. The shape of 31 is linear. Further, the top surface 31 of the rib 3 is not connected to both sides of the crown portion formed by the main body portion 7 described later,
There is a gap between the top surface 31 and the inside of the crown portion.

The rib 3 shown in FIG. 3 has a top surface 31 of the rib 3 shown in FIG.
Is formed in an arc shape which is recessed in the direction of the bottom surface 13.

After forming a core material 1 having an upper surface opening as shown in FIGS. 1 to 3, the core material 1 is set in a foaming mold (not shown), and a lightweight resin material is foamed in the hollow portion 11 to fill the filler. 4 is filled in the hollow portion 11 (see FIG. 4). At this time, a shaft (not shown) is provided in the foam mold so that the pin insertion hole 5 is formed in the filler 4. As a material of the filler 4, for example, a so-called masterbatch composed of polyol: 100 parts by weight, foam stabilizer: 1 part by weight, catalyst: 0.5 parts by weight, water: 0.5 parts by weight is used as a curing agent ( 112 parts by weight)
And mix for about 15 seconds, put in a foaming mold that has been heated to about 50 ° C. in advance, and cure in an open at 50 ° C. for about 15 to 20 minutes. The specific gravity of the filler 4 foam-molded in this manner was about 0.25 to 0.50.

In this way, the core material 1 having the ribs 3 integrally formed with the face portion 2 and the core material 1 with the upper surface opened is filled with the filler material 4. In order to reduce the weight, the thickness of the core material 1 is reduced. Also, due to the presence of the ribs 3 and the filling material 4, the ribs 3 and the filling material 4 have sufficient strength to withstand the pressure applied during the molding of the main body 7. That is, the core material 1 serves as a hollow core when molding the main body portion 7, and it is necessary to have sufficient compressive strength at the time of heat and pressure molding, and in order to manufacture a large head, The core material 1 is also required to be lightweight (the thinner the thickness is, the better). However, the core material 1 used in the present invention has both the strength and the lightness because of the lip 3 and the filler 4. Will be satisfied.

Next, as shown in FIG. 5, the main body 7 of the head (the core member 1 together with the face member 2 covers the filler member 4 exposed on the upper surface of the core member 1 and surrounds the side surface of the core member 1 excluding the face member 2). The part coated with the molding material 6 of the outer periphery of (1) is set in the lower mold of the upper and lower separation molds (not shown), and heated and pressed by both molds. As the molding material 6, an unsaturated polyester resin (including a thickener and a peroxide catalyst) is mixed in a weight ratio of 50 to 70, and the length of the carbon fiber to be mixed is less than 1 inch. A carbon fiber having a blending ratio of 35 to 50 in weight ratio was used. Therefore, as shown in FIG. 6, the one that covers the side circumference and the upper surface opening (the upper surface of the filler 4) of the core material 1 is
The face portion 2 and the main body portion 7 molded from the molding material 6 are both molded from a resin material mixed with reinforcing fibers, and the reinforcing fibers having a length of 1 inch or more are less than 1 inch. As a result, the core material is mixed with the material that covers the outer periphery of the core material 1 in combination. Further, the carbon fiber used for the main body portion 7 is preferably of high strength type, and trade name Trayca T300-6000 having 6,000 filaments and a filament diameter of 7 microns was used. When the main body portion 7 is molded and the ceiling (crown portion) is formed, a gap is created between the top surface 31 of the rib 3 and the inside of the crown portion, and the gap is filled with the filler 4.

Finally, a metal piece having a high specific gravity was inserted into the hole of the weight adjusting boss 15 in accordance with the weight of the head, and the side sole and the sole plate were attached by a usual method to finish the club. The main body portion 7 may extend to the attachment surface boundary line of the sole plate and may be molded to a part of the bottom portion of the core material.

A club having the golf club head configured in this manner is fixed with a grip, and the
0 m / sec. An experiment was carried out in which a two-piece ball was hit at a speed of, and collided with the central portion of the face portion 2. In this experiment, one club tried to hit 3000 two-piece balls, and the hitting point was changed. As a result, in each club having the head having the configuration shown in FIGS. 2 to 3, no abnormality was found in the head,
There was no problem in strength.

Next, head speed 40 to 45 m / sec. An actual test was conducted by a tester having the power of. At this time, the actual hitting test was also conducted with a club having a head having a rib that connects to the ceiling (referred to as a comparative example). As a result, the feel on impact was good together with the comparative example and the example of the present invention, and the flight distance of the example of the present invention was improved by 2 to 3% as compared with the comparative example.

From these experiments, if the ribs 3 are integrally formed (connected) with the back surface of the face portion 2 and the bottom surface 13 of the core material 1, even if they are not connected with the crown portion, they can sufficiently withstand the impact upon impact. found. The weight of the head is reduced by the amount that the rib 3 is not connected to the crown portion, the degree of freedom in design is increased due to the reduction in weight, and a head having a high function, that is, a low center of gravity and a deep center of gravity can be provided. By selecting the rib shape, it has become clear that a lower center of gravity and a deeper center of gravity are possible, the sweet area is expanded, and a golf club with more stable flight than before can be obtained.

It was also found that if the specific gravity of the filler 4 is about 0.25 to 0.50, the weight can be reduced without being deformed during the heat and pressure molding of the main body 7. By selecting the filling material 4, it is possible to improve the hitting and hitting feeling.

〔effect〕

As described above, according to the present invention, the SMC is put into a mold in which the face portion made of the synthetic resin material of the prepreg is preset and the hollow core material having the upper surface opening integrally formed with the face portion, and the core. It is integrally molded from the same material as the core material in the hollow part of the material, and it is connected to the back surface of the face part, extends from the back surface to the back surface of the face part in the side direction, and extends to the bottom surface of the core material. Specific gravity of 0.25 consisting of ribs and lightweight foam filled in the hollow part of the core material
~ 0.50 main body part covered with a molding material made of a resin material mixed with reinforcing fibers so as to cover at least the side circumference and the upper surface opening of the core material excluding the face part, and heated and pressed. The rib is not connected to the inside of the crown portion formed by the main body portion, and there is a gap between the rib and the inside of the crown portion, and the gap is filled with a filler. Play. That is, since the core material has sufficient strength when the main body is heated and pressed, the main body can be molded well, and even when the thickness of the core material is reduced, the presence of the ribs and the filler prevents the core material from being added during molding. Withstanding pressure, the molded head is lightweight and can be upsized, resulting in a wider sweet area. Further, the rib is not connected to the inside of the crown portion formed by the main body portion, and there is a gap between the rib and the inside of the crown portion, and since this gap is filled with the filler, the core material with the rib connected to the inside of the crown portion In addition, the hollow core material with ribs having the upper opening can be easily formed in the forming process. Since this core material has an upper surface opening, the filler can be easily filled through this opening. Furthermore, by filling with a filler having a specific gravity of about 0.25 to 0.50, not only can the core material be provided with strength that can withstand the pressing force at the time of molding the main body portion, but also the hit feeling is improved. Furthermore, since sufficient pressure can be applied to the core material, small voids do not occur between the molding materials, so that the main body is molded to the designed thickness. A low center of gravity and a deep center of gravity can be easily achieved by controlling the thickness of the main body and designing the thickness and shape of the rib. Further, the molded head has a double structure, and the strength is also improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a molded product of a core material of a golf club head in which a face portion is insert-molded, FIG. 2 is an end view taken along the rib of FIG. 1, and FIG. 3 is a modification of the rib. FIG. 4 is a cut end view similar to FIG. 2, FIG. 4 is a perspective view of a hollow part of a core material filled with a filler, FIG. 5 is a perspective view of a preparation state for molding a main body part, and FIG. It is a head cross-sectional view of the finished product. 1 ... Core material, 2 ... Face portion, 3 ... Rib, 4 ... Filling material, 6 ... Molding material, 7 ... Main body portion, 11 ... Hollow portion, 13 ... Bottom surface, 14 ... Side Department.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-91976 (JP, A) Actually open 59-177463 (JP, U) Actually open 59-93565 (JP, U) Actually open 59- 64167 (JP, U) Actual development Sho 59-24069 (JP, U)

Claims (2)

[Claims] 1. A hollow core material having an upper surface opening integrally formed with a face portion by introducing SMC into a mold in which a face portion made of a synthetic resin material of a prepreg is set in advance, and inside the hollow portion of the core material. , Molded integrally from the same material as the core material,
A rib that connects to the back surface of the face part and extends from the back surface to the back surface of the face part in the direction of the side part and that connects to the bottom surface of the core material, and a lightweight foam filled in the hollow part of the core material. A filler having a specific gravity of about 0.25 to 0.50 and a molding material made of a resin material mixed with reinforcing fibers so as to cover at least the side circumference and the upper surface opening of the core material excluding the face portion, and the mixture is heated. A pressure-formed main body, wherein the rib is not connected to the inside of the crown formed by the main body and there is a gap between the rib and the inside of the crown, and the gap is filled with a filler. Golf club head to do. 2. The ribs are formed so that the top surface shape thereof is linear and gradually lowers toward the side portion, or the top surface shape of the ribs is formed in an arc shape which is depressed toward the bottom surface side. The golf club head according to claim 1, wherein: