JP2005253606A - Golf club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise the degree of freedom in the weight distribution designing without spoiling the durability by using a fiber-reinforced resin at least at parts of the crown and sole parts. <P>SOLUTION: The golf club head 1 of a hollow structure is formed by arranging a head shell part M made of a metal material and a resin member FR composed of the fiber-reinforced resin. The resin member FR contains the resin member FR1 on the side of the crown making at least a part of the crown part 4 corresponding to the top surface of the head and the resin member FR2 on the side of the sole making at least a part of the sole part 5 corresponding to the bottom surface of the head. The content Js of the resin in the resin member FR2 on the side of the sole is larger than the content Jc of the resin in the resin member FR1 on the side of the crown. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a golf club head that can increase the degree of freedom of weight distribution design without impairing durability by using a fiber reinforced resin in at least a part of a crown portion and a sole portion.

  In recent years, various golf club heads have been proposed in which a metal material is mainly used and a part thereof is combined with a fiber reinforced resin. For example, Patent Document 1 below describes a wood-type golf club head in which a fiber reinforced resin is used for a crown portion that forms the upper surface of the head and a sole portion that forms the bottom surface of the head.

  Such a composite head can reduce the weight by using a fiber reinforced resin for a part thereof, so that the head volume can be increased. Further, the reduced weight can be distributed to a side portion of the head such as a toe or a heel or a back face. In the former configuration, the moment of inertia around the center of gravity of the head can be increased, and in the latter configuration, the depth of the center of gravity of the head can be increased. In addition, when fiber reinforced resin is used for the crown portion, the weight of the upper portion of the head can be reduced, which helps to lower the center of gravity. Thus, the composite head increases the degree of freedom in weight distribution design.

  However, the composite head tends to have insufficient strength at the joint between the fiber reinforced resin and the head shell made of a metal material. In particular, the sole part has many opportunities to come into contact with the ground at the time of hitting the ball, and when a so-called duff (a miss shot in which the head strikes the ground strongly before impact) occurs, a very large impact force is applied to the sole part. Works. As a result, there is a possibility that the joint part may come off or the fiber reinforced resin disposed on the sole part may be damaged.

JP 2003-199848 A

  The present invention has been devised in view of the above circumstances, and a crown-side resin member and a sole-side resin member made of fiber-reinforced resin are provided on at least a part of each of the crown portion and the sole portion. At the same time, based on the fact that the resin content Js of the resin member on the sole side is made larger than the resin content Jc of the resin member on the crown side, the impact absorbing ability of the resin member on the sole side is increased to impair durability. An object of the present invention is to provide a golf club head that can increase the degree of freedom of weight distribution design without any problems.

  The invention according to claim 1 of the present invention is a golf club head having a hollow structure formed using a head shell portion made of a metal material and a resin member made of a fiber reinforced resin, wherein the resin member is A resin member on the crown side that forms at least a part of the crown portion that forms the upper surface of the head, and a resin member on the sole side that forms at least a part of the sole portion that forms the bottom surface of the head, The resin content Js is characterized by being larger than the resin content Jc of the resin member on the crown side.

  In the invention according to claim 2, the ratio (Js / Jc) of the resin content Js of the resin member on the sole side and the resin content Jc of the resin member on the crown side is 1.2 to 5.0. The golf club head according to claim 1, wherein:

  The invention according to claim 3 is characterized in that the average elastic modulus Es of the fibers contained in the sole side resin member is larger than the average elastic modulus Ec of the fibers contained in the crown side resin member. Item 3. A golf club head according to item 1 or 2.

  According to a fourth aspect of the present invention, the ratio (Es / Ec) between the average elastic modulus Es of the fiber of the resin member on the sole side and the average elastic modulus Ec of the fiber of the resin member on the crown side is 1.2-3. 5. The golf club head according to claim 3, wherein the golf club head is.

  According to a fifth aspect of the present invention, the head shell portion includes a face portion for hitting a ball, a crown that is connected to the face portion and forms an upper surface of the head, and an opening portion to which the resin member on the crown side is joined. An edge, a sole edge that is continuous with the face and forms a bottom surface of the head, and an opening to which the resin member on the sole side is joined; and a heel of the face by extending the back face from the toe of the face 5. The golf club head according to claim 1, further comprising a side portion connected to the golf club.

  The golf club head of the present invention is formed using a head shell portion made of a metal material and a resin member made of a fiber reinforced resin, and the resin member is a crown side forming at least a part of a crown portion forming the upper surface of the head. And a resin member on the sole side that constitutes at least a part of the sole portion that forms the bottom surface of the head. Therefore, since the head weight can be reduced, the degree of freedom in weight distribution design can be increased by increasing the head volume and distributing the reduced weight freely in place. The resin content Js of the sole side resin member is larger than the resin content Jc of the crown side resin member. In the fiber reinforced resin, when the resin content is increased, the impact resistance is increased, and conversely, when the fiber ratio is increased, the specific gravity is increased. Therefore, the golf club head of the present invention can improve the impact absorbing ability of the resin member on the sole side, and can exhibit durability capable of withstanding the impact force generated during impact or duff. Also, the resin member on the crown side can be reduced in weight as compared with the resin member on the sole side, and as a result, an increase in the center of gravity of the head can be effectively prevented.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a reference state in which a golf club head (hereinafter, simply referred to as “head”) 1 according to the present embodiment is placed on a horizontal plane with a specified lie angle and loft angle, and FIG. 2 is a plan view thereof. 3 is a bottom view thereof, FIG. 4 is an enlarged cross-sectional view of FIG. 2 along AA, and FIG. 5 is an exploded perspective view of the head.

  The head 1 of the present embodiment includes a face portion 3 having a face surface 2 that is a surface for hitting a ball, a crown portion 4 that is continuous with the face portion 3 and forms the top surface of the head, and a bottom surface of the head that is continuous with the face portion 3 and forms the head bottom surface. A sole part 5, a side part 6 that extends between the crown part 4 and the sole part 5, extends from the toe 3 a of the face part 3 to the heel 3 b through the back face, and is provided on the heel side of the crown part 4; A wood type thing such as a driver (# 1) or a fairway wood having a hollow structure including a neck portion 7 to which one end of a shaft (not shown) is attached and having a hollow portion i provided therein is illustrated.

  The head 1 is formed using a head shell portion M made of a metal material and a resin member FR made of a fiber reinforced resin.

  The resin member FR includes at least a crown-side resin member FR1 constituting at least a part of the crown part 4 and a sole-side resin member FR2 constituting at least a part of the sole part 5. In this embodiment, An example in which the resin member FR is composed of these two members independent of each other is illustrated. The resin member FR is a composite material in which a matrix resin and a fiber that serves as a reinforcing material are combined, and has a lower specific gravity than a metal material. Therefore, the head 1 of the present invention can obtain a relatively large weight reduction effect by using the resin member FR. The reduced weight can be adjusted, for example, at a proper position of the head shell M, so that the position of the center of gravity and the moment of inertia can be adjusted, which helps to increase the degree of freedom of weight distribution design.

  Although it does not specifically limit as a matrix resin, For example, thermoplasticity, such as an epoxy resin, a phenol resin, a nylon resin, a polycarbonate resin, is desirable. These matrix resins are preferred because they are inexpensive, have good adhesion to fibers, and have a relatively short molding time. However, it is of course possible to use a thermosetting resin. The fiber is not particularly limited, and for example, organic fiber such as carbon fiber, glass fiber, aramid fiber or PBO fiber, metal fiber such as amorphous fiber or titanium fiber, etc. can be used. Carbon fibers having a high tensile strength are preferred. In the present embodiment, carbon fiber is employed.

  As shown in FIG. 5, the head shell M of the present embodiment is provided with a face 3 and an opening O1 where the crown-side resin member FR1 is joined, and the crown edge connected to the face 3 10 and an opening O2 to which a resin member FR2 on the sole side is joined, and a sole edge portion 11 connected to the face portion 3, the side portion 6, and the neck portion 7 are included. ing. The head shell M can be integrally formed from the beginning by casting or the like, and after molding two or more parts by a processing method such as forging, casting, pressing or rolling, these are welded or the like. It can also be formed by joining together.

  The metal material forming the head shell M is not particularly limited. For example, stainless steel, maraging steel, titanium, titanium alloy, aluminum alloy, magnesium alloy, or amorphous alloy can be used. A titanium alloy, aluminum alloy or magnesium alloy having a large thickness is desirable. The head shell M can be formed using two or more kinds of metal materials.

  As shown in FIGS. 4 to 5, the crown edge portion 10 of the head shell portion M includes an annular crown surface portion 10a that forms the outer surface portion of the crown portion 4 and a crown surface portion 10a. And a receiving portion 10b that has a step and is recessed toward the hollow portion i. The receiving portion 10b can hold the inner surface side and the peripheral portion of the crown-side resin member FR1. The receiving portion 10b is useful for finishing the crown-side resin member FR1 and the crown surface portion 10a flush with each other by the step.

  The receiving portion 10b is bonded to the crown side resin member FR1. The receiving portion 10b of the present embodiment is provided on the entire circumference around the opening O1. As a result, the entire circumference of the peripheral edge portion of the crown-side resin member FR1 can be adhered and held. This helps to obtain a strong bond strength. The width Wa of the receiving portion 10b (measured in the direction perpendicular to the edge of the opening O1) is not particularly limited, but if it is too small, the bonding area between the head shell portion M and the resin member FR1 on the crown side becomes small. For this reason, the bonding strength tends to be reduced, and conversely, if it is too large, the area of the opening O1 tends to be small and the weight reduction effect tends not to be sufficiently obtained. From such a viewpoint, the width Wa of the receiving portion 10b is, for example, 3 mm or more, more preferably 5 mm or more, and the upper limit is 30 mm or less, more preferably 20 mm or less. The width Wa may be constant or can be changed.

  Further, as shown in FIGS. 4 to 5, the sole edge portion 10 of the head shell portion M includes an annular sole surface portion 11 a that forms an outer surface portion of the crown portion 5 and a surface that is a sole surface portion. And a receiving portion 11b having a step from 11a and recessed toward the hollow portion i. That is, it has the same configuration as the crown edge portion 10. The receiving portion 11b can hold the inner surface side of the sole side resin member FR2 and the peripheral portion thereof. The receiving portion 11b is also useful for finishing the sole-side resin member FR2 and the sole surface portion 11a to be flush with each other by the step.

  The receiving portion 11b is bonded to the sole side resin member FR2. The receiving portion 11b of the present embodiment is provided on the entire circumference around the opening O2. As a result, the entire periphery of the peripheral portion of the sole-side resin member FR2 can be adhered and held. The width Wb of the receiving portion 11b (measured in a direction perpendicular to the edge of the opening O2) is not particularly limited, but if it is too small, the bonding area between the head shell portion M and the sole side resin member FR2 becomes small. For this reason, the bonding strength is liable to decrease, and conversely, if it is too large, the area of the opening O2 tends to be small and the weight reduction effect tends not to be sufficiently obtained. From such a viewpoint, the width Wb of the receiving portion 11b is, for example, 3 mm or more, more preferably 5 mm or more, and the upper limit is 30 mm or less, more preferably 20 mm or less. The width Wb may be constant or can be changed.

  Each of the resin members FR1 and FR2 does not need to form the entire crown portion 4 and sole portion 5, and may constitute at least a part thereof. However, if each area is small, the weight can be reduced sufficiently. There is a tendency not to be effective. From such a viewpoint, in the plan view of the reference state shown in FIG. 2, the ratio (S1 / S) between the area S1 on the opening O1 side provided in the crown 4 and the area S surrounded by the head contour Is 0.5 or more, more preferably 0.6 or more, and the upper limit is, for example, 0.9 or less, preferably 0.8 or less. Also in the sole side resin member FR2, in the bottom view of the reference state shown in FIG. 3, the ratio of the area S2 of the opening O2 provided in the sole portion 5 to the area S surrounded by the head outline (S2). / S) is 0.5 or more, more preferably 0.6 or more, and the upper limit is, for example, 0.9 or less, preferably 0.8 or less. Although not particularly limited, in order to set the head center of gravity lower, the ratio (S1) of the area S1 of the opening O1 of the crown portion obtained by the above method and the area S2 of the opening O2 of the sole portion is obtained. / S2) is preferably larger than 1.0, more preferably 1.2 or more.

  The resin member FR1 on the crown side and the resin member FR2 on the sole side can be molded by various methods. For example, as shown in FIG. 6, a predetermined temperature and pressure are applied to a laminate P in which a plurality of prepreg sheets P1 to P4, for example, 2 to 7, more preferably about 3 to 5, are desired. The resin members FR1 and FR2 can be molded into a desired shape by baking into a shape of When a plurality of prepreg sheets P1 to P4 are used, it is desirable that the orientation angle θ of the fibers f of the prepreg sheet is different from the arbitrary reference line C. Specifically, prepreg sheets P1 and P2 having fibers f inclined by about ± 45 ° with respect to the reference line C, and prepreg sheets P3 and P4 having fibers f inclined by 0 ° and 90 ° are included. desirable. In this case, a variation of ± 10 ° can be allowed for each angle. In particular, it is particularly preferable that the reference line C is used so as to be in the normal direction of the face surface. The normal direction of the face surface is the longitudinal direction in which the normal line from the center of gravity of the head to the face surface is projected onto the horizontal plane in the reference state. In addition, the resin members FR1 and FR2 formed in this way are bonded to the receiving portions 10b or 11b of the head shell M using an adhesive at the edges.

  Also, the resin members FR1 and FR2 can be molded using a so-called internal pressure molding method as shown in FIG. 7, for example. For example, as shown in FIG. 7A, the internal pressure forming method is performed by first forming one or a plurality of prepreg sheets in a semi-cured state so as to cover the openings in the openings O1 and O2 of the head shell M. The head substrate to which the laminates P and P are respectively attached is put into a mold 20 including a pair of separable upper mold 20a and lower mold 20b. The head shell M is provided with a through hole 22 communicating with the hollow portion i in the side portion 6 or the like in advance, and a bladder B that can expand or contract is inserted therethrough. At this time, a thermosetting adhesive or primer may be applied between the prepreg sheet laminate P and the receiving portion 10b or between the prepreg sheet laminate P and the receiving portion 11b in advance. it can.

  Thereafter, as shown in FIG. 7B, the mold 20 is heated and the bladder B is expanded and deformed in the hollow portion i. As a result, the prepreg sheet laminate P that has received heat and pressure from the bladder B is molded into a desired crown-side resin member FR1 along the cavity of the upper mold 20a and is integrally bonded to the receiving portion 10b. Is done. Similarly, the laminate P of prepreg sheets is molded into a desired sole-side resin member FR2 along the cavity of the lower mold 20b and is integrally bonded to the receiving portion 11b. After forming the prepreg sheet, the bladder B is contracted and taken out from the through hole 22. Further, the through hole 22 can be closed later by a badge, a cover or the like with a product name or a decorative pattern of the head.

  When the internal pressure molding method is used, for example, as shown in FIG. 8A, an auxiliary prepreg sheet 24 is preliminarily pasted on the inner surface 10bi facing the hollow portion of the receiving portion 10b in the opening O1 of the head shell M, for example. It is desirable to attach it. The auxiliary prepreg sheet 24 is attached to the inner surface 10bi of the receiving portion 10b with a protruding portion 24a protruding from the edge of the opening O1 to the opening O1 side. The auxiliary prepreg sheet 24 is provided, for example, in at least a part of the periphery of the opening O1, and it is preferable that the auxiliary prepreg sheet 24 is continuously attached in an annular shape around the opening O1.

  Next, as shown in FIG. 8B, the prepreg sheet 13 is pasted on the receiving portion 10b so as to cover the opening O1 as described above. At this time, for example, at least one auxiliary prepreg sheet 24 is attached. The protruding portion 24a can be temporarily bonded to the inner surface of the laminate P of prepreg sheets. Then, as shown in FIG. 8C, by performing internal pressure molding with the mold 20, the peripheral portion of the resin member FR has an outer piece portion 26a extending from the outer surface side of the receiving portion 10b, and the receiving portion 10b. It can be formed as a bifurcated portion 26 having an inner piece portion 26b extending on the inner surface side. As described above, when the composite head is manufactured, the resin member FR and the head shell portion can be formed in a simple procedure by including the step of arranging the auxiliary prepreg sheet 24 having the protruding portion 24a on the inner surface side of the receiving portion in advance. This is useful for manufacturing the head 1 having a strong bonding strength by increasing the bonding area with M. Needless to say, the sole-side resin member FR2 can also be formed by similarly providing the auxiliary prepreg sheet 24 for the opening O2 on the sole side.

  One feature of the head 1 of the present invention is that the resin content Js of the resin member FR2 on the sole side is larger than the resin content Jc of the resin member FR1 on the crown side. Generally, in a fiber reinforced resin, impact resistance can be improved by increasing the resin content. Further, since the resin content in the resin member FR2 is improved, the adhesiveness with the receiving portion 11b is improved, and the strength of the joint portion can be improved. Therefore, in the head 1 of the present invention, the resin member FR2 on the sole side effectively relieves strain against a large impact force generated in the sole portion 5 at the time of impact or duff of the ball, thereby improving durability over a long period of time. Can be maintained. Further, since the adhesive strength between the sole side resin member FR2 and the head shell portion M is improved, it is possible to prevent damage such as detachment of both members against a large impact force. On the other hand, the resin component FR1 on the crown side can have a smaller resin content than the resin member FR2 on the sole side. Thereby, the resin member FR1 on the crown side can be reduced in weight because the specific gravity is reduced, and the center of gravity of the head can be prevented from increasing.

  In the present specification, the resin content of the resin member FR made of fiber reinforced resin is determined as a ratio of the weight of the resin to the total weight of the resin member. The resin weight is determined by adding nitric acid and hydrofluoric acid to the resin member and heating it to chemically decompose and remove only the resin component, take out only the fiber, and subtract the total fiber weight from the weight of the resin member measured in advance. Can be obtained at

  Further, the absolute value of the resin content Js in the sole side resin member FR2 is not particularly limited, but if the value is too small, there is a tendency that the impact absorbing ability cannot be obtained sufficiently. The reinforcement effect due to the lowering of the strength is likely to occur, resulting in insufficient strength. From such a viewpoint, the resin content Js in the resin member FR2 on the sole side is preferably 15% or more, more preferably 20% or more, further preferably 25% or more, and the upper limit is preferably 45% or less. More preferably, it is 40% or less, and further preferably 35% or less.

  Also, the absolute value of the resin content Jc in the crown-side resin member FR1 is not particularly limited, but if the value is too small, there is a tendency that the impact absorbing ability cannot be obtained sufficiently, and conversely if it is too large. Insufficient strength is likely to occur. From such a viewpoint, the resin content Jc in the resin member FR1 on the crown side is preferably 10% or more, more preferably 15% or more, further preferably 20% or more, and the upper limit is preferably 40% or less. More preferably, it is 35% or less, and further preferably 30% or less.

  The ratio (Js / Jc) between the resin content Jc of the resin member FR1 on the crown side and the resin content Js of the resin member FR2 on the sole side is not particularly limited, but if the value is too large Further, the rigidity of the resin member FR2 on the sole side is excessively decreased, or the bonding strength with the head shell portion M, which is a metal material, is easily decreased on the resin member FR1 on the crown side. On the other hand, if the ratio (Js / Jc) is too small, the impact absorption capacity of the sole-side resin member FR2 tends to decrease, or the weight tends to increase in the crown-side resin member FR1. From such a viewpoint, the ratio (Jc / Js) is preferably 1.2 or more, more preferably 1.4 or more, still more preferably 1.6 or more, and the upper limit is preferably 5.0 or less. More preferably 4.0 or less, and still more preferably 3.0 or less.

  As a particularly preferred embodiment, it is desirable that the average elastic modulus Es of the fibers included in the sole-side resin member FR2 is larger than the average elastic modulus Ec of the fibers included in the crown-side resin member FR1. For example, when the resin member FR1 on the crown side and the resin member FR2 on the sole side are formed of the same fiber and the same matrix resin, the resin member FR2 on the sole side has a relatively large resin content, so Although a decrease in rigidity occurs as compared with the resin member FR1, in the above embodiment, the decrease in rigidity accompanying a decrease in the amount of fibers in the sole-side resin member FR2 can be compensated by improving the elastic modulus of the fibers. Therefore, the strength of the resin member FR2 on the sole side can be given more effectively.

The elastic modulus is a tensile elastic modulus and is a value measured according to “Carbon Fiber Test Method” of JIS R7601. When two or more kinds of fibers are included, the average value of the elastic modulus of each fiber is calculated by weighting the weight ratio as represented by the following formula (1). .
Average elastic modulus = Σ (Ei · Vi) / ΣVi (i = 1, 2,...)
(Here, Ei is the elastic modulus of the fiber i, and Vi is the total weight of the fiber i.)

Here, the absolute value of the average elastic modulus Es of the fibers in the resin member FR2 on the sole side is not particularly limited, but if the value is too small, there is a tendency that the rigidity cannot be sufficiently compensated. If it is too large, the strength tends to decrease. From such a viewpoint, the average elastic modulus Es of the fiber of the resin member FR2 on the sole side is preferably 15 ton / mm ² or more, more preferably 20 ton / mm ² or more, and further preferably 25 ton / mm ² or more. Is preferably 45 ton / mm ² or less, more preferably 40 ton / mm ² or less, and still more preferably 35 ton / mm ² or less.

Further, the absolute value of the average elastic modulus Ec of the fiber in the resin member FR1 on the crown side is not particularly limited, but if the value is too small, there is a tendency that the rigidity cannot be sufficiently compensated, and conversely large. If too much, the strength tends to decrease. From this point of view, the average elastic modulus Ec of the fibers of the crown side resin member FR1 is preferably 10ton / mm ² or more, more preferably 15 ton / mm ² or more, more preferably 20ton / mm ² or more is preferable, an upper limit Is preferably 40 ton / mm ² or less, more preferably 35 ton / mm ² or less, and still more preferably 30 ton / mm ² or less.

  Further, the ratio (Es / Ec) between the average elastic modulus Es of the fiber of the resin member FR2 on the sole side and the average elastic modulus Ec of the fiber of the resin member FR1 on the crown side is not particularly limited, but is too small. In some cases, the resin member FR2 on the sole side cannot sufficiently increase the rigidity. On the other hand, if it is too large, the strength tends to decrease. From such a viewpoint, the ratio (Es / Ec) is preferably 1.2 or more, more preferably 1.3 or more, and the upper limit is preferably 3.5 or less, more preferably 3.0 or less. More preferably, 2.5 or less is desirable.

The head 1 configured as described above can increase the moment of inertia of the head as a result of increasing the degree of freedom in designing the weight distribution. For example, in the reference state, the moment of inertia around the vertical axis passing through the center of gravity of the head can be adjusted to 3000 (g · cm ² ) or more, more preferably 3500 (g · cm ² ) or more. The moment of inertia can be measured using a moment of inertia measuring instrument (for example, MOMENT OF INERTIA MEASURING INSTRUMENT MODEL NO.005-002 manufactured by INERTIA DYNAMICS Inc.).

The head 1 of the present invention is more effective when applied to a head having a head volume of 250 cm ³ or more, more preferably 280 cm ³ or more. When the head volume is less than 250 cm ³ , the moment of inertia is reduced and the sweet area is also reduced. On the other hand, since the weight increases even if the head volume is too large, it is preferably 600 cm ³ or less, more preferably 500 cm ³ or less. Particularly preferably, the moment of inertia per unit volume obtained by dividing the moment of inertia by the head volume is 7 (g · cm ² / cm ³ ) or more, more preferably 10 (g · cm ² / cm ³ ) or more, and still more preferably. Is preferably 15 (g · cm ² / cm ³ ) or more.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be applied to, for example, iron-type, utility-type, and putter-type golf club heads having a hollow structure. Moreover, in the said embodiment, although the resin member which consists of fiber reinforced resin has shown what consists of resin member FR1 by the side of a crown, and resin member FR2 by the side of a sole, for example, it arranges the resin member in the side part It goes without saying that it is also good. Further, the thickness of each part of the resin member FR and the head shell M can be appropriately determined according to the custom.

In order to confirm the effect of the present invention, a wood-type driver head having a head volume of 350 cm ³ was made on the basis of the specifications shown in Table 1. The head shell and the resin member were shaped as shown in FIGS. 1 to 5, and the head shell was molded by integral casting of Ti-6Al-4V. The width of the receiving part was 10 mm on the back face side, and 15 mm for the other parts. Then, the moment of inertia around the vertical axis passing through the center of gravity of each head and the durability were measured. For durability, each test head was mounted on a carbon shaft MP-200 made by SRI Sports, and a 45-inch wood-type club was prototyped. This was attached to a swing robot made by Miyamae, with a head speed of 50 m / s and a face. A golf ball was hit at the center position, and the number of hit balls until the head was damaged was measured. Table 1 shows the test results.

  As a result of the test, it can be confirmed that the head of the example exerts sufficient durability while increasing the right and left moments of inertia.

It is a perspective view of the standard state of the head which shows the embodiment of the present invention. FIG. It is the bottom view. It is AA sectional drawing of FIG. It is a disassembled perspective view of a head. It is an expanded view which illustrates the laminated body of a prepreg sheet. (A), (B) is sectional drawing explaining the internal pressure forming method. It is a fragmentary sectional view showing other embodiments of an internal pressure molding method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Golf club head 2 Face surface 3 Face part 4 Crown part 5 Sole part 6 Side part 7 Neck part 10 Crown edge part 11 Sole edge part FR1 Crown side resin member FR2 Resin member on the sole side

Claims (5)

A hollow golf club head formed using a head shell made of a metal material and a resin member made of fiber reinforced resin,
The resin member is a crown-side resin member that constitutes at least a part of the crown portion forming the upper surface of the head;
A sole-side resin member constituting at least a part of the sole portion forming the bottom surface of the head, and the resin content Js of the sole-side resin member is greater than the resin content Jc of the crown-side resin member A golf club head characterized by.   The ratio (Js / Jc) of the resin content Js of the resin member on the sole side and the resin content Jc of the resin member on the crown side is 1.2 to 5.0. Golf club head.   3. The golf club head according to claim 1, wherein an average elastic modulus Es of fibers contained in the sole side resin member is larger than an average elastic modulus Ec of fibers contained in the crown side resin member. .   The ratio (Es / Ec) between the average elastic modulus Es of the fiber of the resin member on the sole side and the average elastic modulus Ec of the fiber of the resin member on the crown side is 1.2 to 3.5. The golf club head according to claim 3.   The head shell portion is connected to the face portion for hitting a ball, a crown edge portion which is continuous with the face portion and forms an upper surface of the head and is provided with an opening to which the resin member on the crown side is joined. A sole edge portion that forms a bottom surface of the head and is provided with an opening to which the resin member on the sole side is joined, and a side portion that extends from the toe of the face portion and extends to the heel of the face portion. The golf club head according to any one of 1 to 4.

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