JP2006110009A - Putter type golf club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a putter type golf club head enhancing ball hitting feeling and durability. <P>SOLUTION: The putter type golf club head 1 has a face portion 4 and a vibration absorbing material 3 comprising a fiber-reinforced material arranged on at least a part of an upper face part 5 of a head body 2 formed of a metal material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a putter-type golf club head that can improve the feel at impact and durability.

  A putter-type golf club is required to have a stable stroke until impact, a feeling of hitting a ball at the time of impact, difficulty in blurring of the head when the hitting point position is shifted, and good rolling of the ball. In particular, in putting that controls the rolling of the ball, the influence of the feeling element is very large, and therefore the quality of the hitting feeling is particularly important.

  Conventional putter type golf club heads can be broadly classified into those made only of a metal material, those made by combining a metal material with a non-metal material such as resin or rubber, and those made entirely of resin. Since a head made of a metal material has a low ability to absorb vibration or shock at the time of impact, the vibration is likely to last for a long time and feel bad at impact. Such a head is difficult to control the rolling distance of the ball except for some limited golfers such as professionals.

  Further, a head in which a resin or the like is combined with a metal often uses an ionomer resin or solid rubber as an insert material on the face surface. Since this material absorbs most of the impact at the time of impact with the insert material, a very soft material is used for the insert material. For this reason, the feel at impact is good, but there is a drawback that the insert material is easily damaged, and the insert material is easily damaged and inferior in durability. Also, a head made entirely of resin has a drawback that the entire head is easily damaged when hitting or transporting. The prior art includes the following.

JP-A-3-170175 JP 2003-339926 A

  The inventors have conducted various studies to achieve both a shot feeling and durability. As a result, a vibration made of a fiber reinforced resin is formed on at least a part of an upper surface portion of a head body having a face portion and made of a metal material. It has been found that by arranging the absorbent material, the vibration of the head main body at the time of impact is absorbed by the matrix resin of the fiber reinforced resin, and an excellent feeling can be obtained.

  Moreover, as a result of various tests, it was found that the fiber reinforced resin can significantly improve the durability as compared with the ionomer resin and the solid rubber. Furthermore, the vibration absorbing material is arranged on the upper surface of the head body, so that even if an insert material is arranged on the face surface, even if a hard insert material that is harder to be scratched than before is used, the insert material and vibration The inventors have found that a good feeling can be obtained by synergistic action with the absorbent material, and have completed the present invention.

  As described above, an object of the present invention is to provide a putter-type golf club head that can achieve both hit feeling and durability.

  The invention according to claim 1 of the present invention is characterized in that a vibration absorbing material made of a fiber reinforced resin is arranged on at least a part of an upper surface portion of a head body having a face portion and made of a metal material. It is a putter type golf club head.

  The invention according to claim 2 is the putter type golf club head according to claim 1, wherein the vibration absorbing material is disposed only on an upper surface portion of the head main body.

  The invention according to claim 3 is the putter type golf club head according to claim 1 or 2, wherein the vibration absorber is in close contact with the head main body without having a gap.

  According to a fourth aspect of the present invention, there is provided the putter type golf club head according to any one of the first to third aspects, wherein the head main body comprises a solid body having no space between the upper surface portion and the bottom surface portion thereof. is there.

  According to a fifth aspect of the present invention, the vibration absorbing material has a plate shape with a thickness of 1 to 5 mm, a resin content of 25 to 50%, and a surface area of 10 to 80% of the total surface area of the head. A putter-type golf club head according to any one of claims 1 to 4.

  In the putter type golf club head of the present invention, a vibration absorbing material made of a fiber reinforced resin is disposed on at least a part of the upper surface portion of the head body having a face portion and made of a metal material. The vibration of the head body at the time of impact is transmitted to the vibration absorbing material and is sufficiently absorbed by the matrix resin. For this reason, a good shot feeling can be obtained. Further, since the fiber reinforced resin is reinforced with fibers, it is difficult to be damaged even in long-term use, and durability can be improved. Thus, the putter type golf club head of the present invention can achieve both a shot feeling and durability.

  The putter type golf club head of the present invention may include an aspect in which an insert material is disposed on the face surface. In this case, since the vibration absorbing material is disposed on the upper surface portion of the head body, even if a material that is harder and less scratched than the conventional insert material is used for the face surface, the insert material and the vibration absorbing material The synergistic impact absorbing action can further improve the shot feeling and durability.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a putter-type golf club head (hereinafter simply referred to as “head”) 1 of the present embodiment, and FIG. 2 is an exploded perspective view thereof. 3 is a plan view of the head 1 in a reference state, FIG. 4 is a side view thereof, FIG. 5 is a front view thereof, and FIG. 6 is a cross-sectional view taken along line AA in FIG.

  Here, the reference state of the head 1 uniquely defines the position of the head 1 with respect to the horizontal plane HP. In this specification, the shaft axis SL of the head 1 is arranged in an arbitrary reference vertical plane VP1, and As shown in FIG. 5, the vertical distance A1 between the toe side end of the bottom surface portion 6 of the head 1 and the horizontal plane HP is adjusted to be equal to the vertical distance A2 between the heel side end of the bottom surface portion 6 and the horizontal plane HP. Thus, the ground plane is brought into contact with the horizontal plane HP. Hereinafter, unless otherwise specified, dimensions and the like of each part of the head are specified in this reference state.

The shaft axis line SL is the axis center line of the shaft S when the shaft S is mounted on the target head. When the shaft S is bent, its axis centerline SL is 1 within 5 inches (127 mm) above the sole surface from the upper end of the grip as defined in the Golf Rules “Attachment Rules II, 2.a Linearity”. Only the “straight part to the point” is defined as the target. When the shaft is not attached to the head 1, the center line of the shaft insertion hole 10 for attaching the shaft provided to the head 1 is used as a reference.

  The head 1 according to this embodiment includes a head main body 2 made of a metal material and a vibration absorbing material 3 made of a fiber reinforced resin disposed on the upper surface of the head main body 2. In this embodiment, the head 1 is exemplified as having a substantially T-shaped plan view in the reference state.

  The head main body 2 constitutes a main part of the head 1. In this embodiment, the head main body 2 is connected to the face portion 4 defining the face surface F for hitting a ball and the upper edge Fa of the face surface F. An upper surface portion 5 that forms a bottom surface portion of the head 1 that is connected to the lower edge Fb of the face surface F, a toe side surface portion 7 that is connected to a toe side edge Fc of the face surface F and forms the toe side of the head, The heel side surface portion 8 is connected to the heel side edge Fd of the face surface F and forms the heel side of the head, and the back face portion 9 is connected to the heel side surface portion 8 and the toe side surface portion 7.

  The face portion 4 has a substantially smooth face surface F. The face surface F is given a loft angle of, for example, about 0 to 4 degrees in the reference state in order to smoothly roll the impacted ball on the green. Further, as shown in FIG. 5, the face surface F of the present embodiment has, for example, chamfered corner portions 11 and 12 on the side of the bottom surface portion 6 on the toe and heel sides. This helps to prevent the corner portion from interfering with the green during the stroke and to obtain a stable stroke.

  Further, the face surface F of the present embodiment is exemplified in that the entire region is formed of a metal material constituting the head body 2. Use of a metal material for the face surface F is preferable in that a relatively loud and comfortable hitting sound can be obtained at the time of impact. On the other hand, by inserting a plate-like elastic material such as resin or rubber into the face portion 4, the face surface F can be made of a metal material and an elastic material (non-metal material). However, when such a face insert material such as a resin is used, the ball hitting sound at the time of impact tends to be low and low, so that preferably all of the face surface F is made of a metal material as in this embodiment. It is desirable to do.

  As shown in FIG. 2, the upper surface 5 of the head body 2 includes a recess 5 a that is recessed toward the bottom surface 6, a wall-like edge 5 b that rises around the recess 5 a at a small height, and a shaft S ( A shaft insertion hole 10 to which is attached) is provided. The recess 5a is shown to be substantially T-shaped along the contour shape of the head body 2. Thereby, the edge 5b has a substantially constant width and continuously extends around the recess 5a. Further, the shaft insertion hole 10 is provided on the heel side of the upper surface portion 5 and is formed in a substantially cylindrical shape.

  The bottom surface portion 6 is formed to be substantially flat except for marks such as trademarks. In this example, as shown in FIGS. The thing provided with the slope part 13 which inclines in the upper surface part 5 toward the back face side 9 is illustrated. Such a slope part 13 prevents the back face part 9 side of the bottom face part 6 from interfering with the lawn during a stroke, and is useful for obtaining a stable stroke. From such a viewpoint, the inclination angle θ of the slope portion 13 with respect to the horizontal plane HP is preferably 10 degrees or more, more preferably 20 degrees or more. However, if the inclination angle θ is too large, the back face surface 9 side becomes thin and a large amount of weight cannot be distributed to the back of the head. Therefore, it is preferably 70 degrees or less, more preferably 60 degrees or less.

  Although the metal material which comprises the head main body 2 is not specifically limited, For example, it can form with aluminum alloy, stainless steel, maraging steel, titanium alloy, carbon steel etc., and aluminum alloy is used in this embodiment. Particularly preferred is a metal material having a specific gravity of 3.2 or less, more preferably 3.0 or less, and even more preferably 2.8 or less. Thereby, the head main body 2 can have a sufficiently large volume without excessively increasing the weight. On the other hand, even if the specific gravity of the material of the head body 2 is too small, the strength and the moment of inertia are likely to be reduced. From such a viewpoint, the specific gravity is preferably 1.0 or more, more preferably 1.3 or more, and still more preferably 1.5 or more. Needless to say, the head body 2 may use two or more kinds of metal materials having different specific gravities. The head body 2 can be formed by various molding methods such as casting, forging, and machining.

  Further, the head body 2 of the present embodiment is provided with indentations K on the rear end surfaces of the toe side surface 7, the heel side surface 8 and the back face portion 9, respectively. The indented portion K makes the respective surfaces non-flat and the golf rule that the club head should have only one hitting surface (“c. Hitting surface” in “4. Club head” of the attached rules). Helps to satisfy. In other words, in the head 1 of this embodiment, only the face surface F constitutes a hitting surface for hitting a ball. As for the depth of the hollow part K, the thing of about 1-2 mm is illustrated, for example.

  The vibration absorbing material 3 is formed of a fiber reinforced resin in which a fiber as a reinforcing material and a matrix resin are combined. The vibration absorbing material 3 of the present embodiment is formed in a plate shape having a substantially T shape in plan view, is fitted into the concave portion 5a of the upper surface portion, and is firmly fixed to the head body 2. The vibration absorbing material 3 has a thickness t substantially equal to the depth of the recess 5 a and is fixed to the head main body 2 to flatten the upper surface of the head 1.

  The vibration of the head main body 2 generated when the ball is impacted is also transmitted to the vibration absorbing material 3. The vibration absorbing material 3 absorbs the vibration by converting the vibration into heat by the energy loss of the matrix resin. As a result, unpleasant vibrations at the time of impact are removed in a short time, and the feel at impact is improved. In addition, since the fiber reinforced resin is reinforced with fibers, the fiber reinforced resin has high rigidity and excellent trauma resistance. As a result, sufficient durability can be exhibited.

  The vibration absorbing material 3 needs to be provided on at least a part of the upper surface portion 5 of the head body 2. Since the upper surface portion 5 of the head main body 2 is close to the face portion 4, it can absorb vibrations effectively, and there is virtually no opportunity to contact the ground and the ball, thereby protecting the vibration absorbing material 3 over a long period of time. Yes. In addition, it is arbitrary to provide the vibration absorbing material 3 other than the upper surface portion 5. However, when the vibration absorbing material 3 is provided on the bottom surface portion 6 or the face surface F, damage or damage is liable to occur due to contact with the ground or a ball, stone engagement, or the like, and durability is reduced. If the vibration absorbing material 3 is disposed on the toe side surface 7 or the heel side surface 8, the weight is reduced on the toe and heel sides, and the inertia moment of the head 1 is reduced. This is not preferable because when the impact position is deviated, head blurring increases and the directionality of the hit ball deteriorates. From such a viewpoint, it is most preferable that the vibration absorbing material 3 is disposed only on the upper surface portion 5 of the head body 2 as in the present embodiment.

  Further, in order to absorb vibration from the face surface 2 of the head body 2 more efficiently, as shown in FIG. 6, the maximum separation distance K between the face surface F and the shock absorbing material 3 in the head front-rear direction is minimized. It is desirable to do. Specifically, the separation distance K is preferably 15 mm or less, more preferably 10 mm or less. If the separation distance K is too small, the shock absorbing material 3 is exposed on the face surface 2 and peeling is likely to occur therefrom. Therefore, the lower limit value of the separation distance K is preferably 1 mm or more, more preferably 2 mm. The above is desirable.

  Further, since vibration at impact is transmitted from the head 1 to the player's hand through the shaft, it is effective to prevent transmission of vibration to the shaft as much as possible. In this embodiment, as shown in FIGS. 1 to 3, the shaft insertion hole 10 serving as a coupling portion between the head main body 2 and the shaft S is surrounded by at least 180 degrees of the surrounding angle θ. The absorbent material 3 is arranged. Such a vibration absorber 3 can more efficiently prevent vibration transmission to the shaft S, and further helps to improve the feel at impact.

  In order to more effectively absorb the vibration of the head main body 2 at the time of impact, as shown in FIG. 6, the vibration absorbing material 3 of the present embodiment is in close contact with the head main body 2 without having a gap. Illustrated. In the present embodiment, the vibration absorbing material 3 has an outer shape that substantially matches the shape of the concave portion 5a of the upper surface portion 5, and is fitted into the concave portion 5a and is firmly fixed to the head body 2 using an adhesive. Has been. For this reason, air does not intervene between the head main body 2 and the vibration absorbing material 3. Therefore, the vibration absorbing material 3 can absorb the vibration of the head body 2 more efficiently.

  In another embodiment shown in FIG. 7, there is a portion where a cavity C is interposed between the vibration absorbing material 3 and the head body 2. In such an aspect, the vibration absorbing material 3 itself easily vibrates, and the vibration of the head 1 is promoted by resonance between the vibration absorbing material 3 and the head main body 2, and variations in the distance and directionality of the hit ball are likely to occur. This is not preferable because of its tendency.

  In relation to the above point, the head body 2 is preferably configured as a solid body having no space between the upper surface portion 5 and the bottom surface portion 6. Thereby, in the head 1, the part which is easy to vibrate can be eliminated, and a shot feeling can be further improved. In the case where the head main body 2 is formed of a hollow body having a space 15 between the upper surface portion 5 and the bottom surface portion 6 as in another embodiment shown in FIG. 8, the vibration absorbing material 3 and the head main body 2 The composite portion composed of the wall portion of the recess 5a tends to vibrate, and the vibration of the head 1 tends to be promoted as a whole, and the distance and directionality of the hit ball tend to vary.

  Further, if the thickness t of the vibration absorbing material 3 is too small, the vibration absorbing ability is lowered and the molding tends to be difficult. On the other hand, if the thickness t is too large, the shot feeling becomes excessively soft and the ball becomes too soft. It becomes difficult to grasp the sense of distance to roll. From such a viewpoint, although not particularly limited, the thickness t of the vibration absorbing material 3 is preferably 1 mm or more, more preferably 2 mm or more, and the upper limit is preferably 5 mm or less, more preferably 4 mm or less. desirable. The thickness t may be substantially constant in each part or may be different.

  Particularly preferably, as shown in FIG. 9, in the shock absorber 3, the end thickness tf on the face surface F side is relatively larger than the end thickness tb on the back face portion 9 side, and It is desirable to change the thickness smoothly between these. In such an embodiment, the vibration transmitted from the face surface F to the rear of the head can be more effectively absorbed by the portion where the thickness of the shock absorption 3 is large, and the vibration of the head main body 2 can be quickly absorbed. desirable.

  As shown in FIG. 10, the vibration absorbing material 3 includes a substantially cylindrical portion 3 b having a large thickness ta at a portion surrounding the shaft insertion hole 10 of the head body 2 and a substantially constant thickness tc. And the equal thickness portion 3a. Further, the concave portion 5a of the head body 2 is formed in an arc shape around the first concave portion 5a1 facing the equal thickness portion 3a and the shaft insertion hole 10, and the substantially cylindrical portion 3a is densely formed. A first recess 5a2 to be inserted can be included. In such an embodiment, more vibration absorption effect is achieved around the shaft insertion hole 10 and it is useful for obtaining a better shot feeling. The thickness ta is not particularly limited, but is preferably 10% or more, more preferably 20% or more of the depth D of the shaft insertion hole 10, and the upper limit is preferably 90% or less, more preferably 80%. The following is desirable.

  The resin used for the vibration absorbing material 3 is not particularly limited, and for example, an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a phenol resin, a nylon resin, or a polycarbonate resin is preferable. Similarly, the fibers used for the fiber reinforced resin are preferably organic fibers such as carbon fibers, glass fibers, aramid fibers, or polyphenylene benzoxazole resin fibers (PBO fibers), and metal fibers such as amorphous fibers or titanium fibers. In particular, carbon fibers having a low specific gravity and a high tensile strength are particularly preferable. The fibers can include either long fibers or short fibers or both.

  The tensile elastic modulus of the fiber is not particularly limited, but if it is too small, the rigidity required for the vibration absorbing material 3 cannot be secured and the durability tends to decrease. There is a tendency to lead to a decline. From such a viewpoint, the elastic modulus of the fiber is 50 GPa or more, more preferably 100 GPa or more, more preferably 150 GPa or more, particularly preferably 200 GPa or more, and the upper limit is preferably 450 GPa or less, more preferably 350 GPa or less, and further Preferably it is 300 GPa or less. The tensile elastic modulus is a value measured according to “Carbon Fiber Test Method” of JIS R7601. The vibration absorbing material 3 of the present embodiment is made of a fiber reinforced resin in which an epoxy resin and carbon fiber are combined, and a material having a specific gravity of approximately 1.3 to 1.4 is employed.

  Further, the fiber reinforced resin of the vibration absorbing material 3 absorbs vibration mainly by the matrix resin. For this reason, if the resin content of the fiber reinforced resin is too small, the vibration absorption effect tends to be reduced. On the other hand, if the resin content is too large, the fiber content is reduced, the rigidity of the vibration absorbing material 3 is lowered, and the durability tends to deteriorate. From such a viewpoint, the resin content of the vibration absorbing material 3 is preferably 20% or more, more preferably 30% or more, and the upper limit is preferably 50% or less, more preferably 40% or less.

  The “resin content” is the weight ratio of the resin to the total weight of the fiber reinforced resin. The weight of the resin can be obtained by chemically decomposing and removing only the resin from the fiber reinforced resin to be measured, taking out only the fiber, and subtracting the total weight of the fiber from the previously measured weight of the fiber reinforced resin. it can. In order to chemically remove the resin from the fiber reinforced resin, for example, a heated nitric acid solution is used. For example, methyl ethyl ketone is used to chemically remove the resin from the prepreg.

  Further, as a result of various experiments conducted by the inventors, it has been found that when the surface area of the vibration absorbing material 3 is reduced, there is a tendency for the shock absorbing ability to decrease. Therefore, although not particularly limited, the surface area of the vibration absorbing material 3 is preferably 10% or more, more preferably 15% or more, further preferably 20% or more, particularly preferably 30% or more of the total surface area of the head. Is desirable. On the other hand, even if the surface area of the vibration absorbing material 3 is too large, vibrations are excessively absorbed and the feel at impact is excessively soft, making it difficult to grasp the sense of distance. For this reason, the surface area of the vibration absorbing material 3 is preferably 80% or less, more preferably 75% or less, and particularly preferably 60% or less of the total head surface area. The total surface area of the head is specified by filling the shaft insertion hole 10. The surface area 3 of the vibration absorbing material 3 is the area of the portion where the vibration absorbing material 3 is exposed to the outside.

  Further, the head 1 of the present embodiment can distribute more weight in each of the above directions by forming a substantially T-shape projecting from the toe, heel, and back face in plan view as described above. . This effectively increases the moment of inertia around the vertical axis passing through the center of gravity of the head 1 (hereinafter, such moment of inertia may be referred to as “left and right moment of inertia”) in the reference state of the head 1. it can. When the right and left moments of inertia are increased, the stroke is stabilized, the blurring of the head 1 at the time of a miss hit is minimized, and the directionality of the hit ball can be stabilized.

  In particular, as in the present embodiment, the head main body 2 is provided with the concave portion 5a in which the vibration absorbing material 3 is disposed, and the wall-shaped edge portion 5b is provided around the concave portion 5a. It is possible to distribute. This serves to effectively increase the left and right moments of inertia in a head of limited head weight. From such a viewpoint, the width We of the edge portion 5a is preferably 5 mm or more, more preferably 8 mm or more. Note that the height of the edge portion 5 a is formed to be substantially equal to the thickness t of the vibration absorbing material 3.

  Also, as shown in FIG. 3, in the plan view of the head 1, the face width FW, which is the length of the face surface F in the toe heel direction, is preferably 80 mm or more, more preferably 90 mm or more. When the face width FW is less than 80 mm, the weight distribution in the toe and heel directions is not sufficiently performed, and the effect of increasing the right and left moments of inertia is reduced. Conversely, even if the face width FW is too large, the head weight increases excessively, so that it is preferably 170 mm or less, more preferably 160 mm or less.

  Further, as shown in FIG. 3, in the plan view of the head 1, the length HL in the head front-rear direction from the face surface F to the back face portion 9 is preferably 60 mm or more, more preferably 70 mm or more. desirable. When the face width FW is less than 60 mm, the weight distribution to the back face portion 9 side is not sufficiently performed, and the effect of increasing the left and right moments of inertia is reduced. Conversely, even if the head length in the front-rear direction HL is too large, the head weight increases excessively, so that it is preferably 150 mm or less, more preferably 140 mm or less.

  Further, for the rear portion 20 (the portion constituting the T-shaped vertical bar) of the head 1 with the reduced width in the toe and heel directions, the width TW in the toe and heel directions is set to the face width FW from the same viewpoint as described above. The upper limit is preferably not more than 10%, more preferably not less than 20%, still more preferably not less than 25%, and the upper limit is preferably not more than 60%, more preferably not more than 50%, still more preferably not more than 45%. Further, the length TL in the front-rear direction of the rear portion 20 is 30% or more of the length HL in the head front-rear direction, more preferably 40% or more, still more preferably 50% or more, and the upper limit is preferably 90% or less. Preferably it is 80% or less, more preferably 75% or less.

Head 1, for example, by adopting such a shape as described above, the left and right moment of inertia of the head 1, preferably 4000 g · cm ² or more, more preferably 5000 g · cm ² or more, more preferably 6000 g · cm ² The above is desirable. On the other hand, in order to increase the left and right moments of inertia, a weight corresponding to the moment is required, so that the head weight increases excessively and the operability tends to decrease. From this point of view, the upper limit of the left and right moment of inertia, preferably 9000 g · cm ² or less, more preferably 8500 g · cm ² or less, more preferably is desirably at 8000 g · cm ² or less.

  The head weight is not particularly limited, but if it is too small, the stroke is difficult to stabilize and the impact during impact tends to be relatively large. On the contrary, if the head weight is too large, the operability is lowered as described above, and the stroke tends to be difficult. From such a viewpoint, the head weight is preferably 250 g or more, more preferably 300 g or more, and the upper limit is 450 g or less, more preferably 370 g or less.

  Although the embodiment of the present invention has been described above, it goes without saying that the shape of the head body can be variously modified. For example, as shown in FIG. 11, a so-called mallet type having a D-shape in plan view may be used, and a toe, heel type, pin type, or the like well known in the art may be used. In the present embodiment, the concave portion 5a is provided in the upper surface portion 5 of the head main body 2, and the shock absorber 3 is disposed there. However, the upper surface portion of the head main body 2 is provided without providing the concave portion 5a. It is also possible to affix the shock absorbing property directly to 5.

  In order to confirm the effect of the present invention, a plurality of types of putter-type golf club heads were prototyped based on the specifications shown in Table 1, and an actual hit test was performed on each. In any of the heads, an aluminum alloy (specific gravity 2.7) was used for the head body, and a carbon fiber reinforced resin (specific gravity 1.3) was used for the vibration absorber.

  The actual hit test was conducted by 10 golfers (handicap 5-15, age 30-52), with 10 golf balls (made by SRI Sports Co., Ltd.) aiming for a cup 5 yards ahead in each test club. It was performed by putting "HI-BRID Everio"). Specific test contents and evaluation criteria are as follows.

<Head weight>
The head weight excluding the shaft was measured.

<Left and right moment of inertia>
The moment of inertia of the head in the reference state was measured using MOMENT OF INERTIA MEASURING INSTRUMENT MODEL NO.005-002 manufactured by INERTIA DYNAMICS Inc.

<Shock absorbency at impact>
Based on the result of putting 10 balls, the impact (mainly vibration persistence) felt on the hand was scored. Evaluation was made into the average score (rounded off after the decimal point) of each golfer's scoring value. The larger the value, the better.
5: Impact is hardly felt 4: Impact is present but very small 3: Normal 2: Impact is large 1: Impact is extremely large

<Hit feel>
Based on the result of putting 10 balls, the hit feeling (mainly softness) felt on the hand was scored. Evaluation was made into the average score (rounded off after the decimal point) of each golfer's scoring value. The larger the value, the better.
5: Too soft 4: Slightly soft 3: Good 4: Slightly hard 1: Too hard

<Dispersion of hitting distance>
The rolling distances of 10 balls put toward the target cup were measured, respectively, and the maximum variation in distance obtained by subtracting the minimum rolling distance from the maximum rolling distance was measured. Evaluation was made into the average score of each golfer's scoring value. The smaller the value, the better.

<Directional variation in hitting ball>
With respect to 10 hit balls, the maximum shake amount in the left direction and the right direction was measured at right angles to the target line, and the maximum shake amount, which is the sum of both, was obtained. Evaluation was made into the average score of each golfer's scoring value. The smaller the value, the better. Table 1 shows the test results.

  As a result of the test, it was confirmed that the heads of the examples had good impact absorbability and feel at impact and a stable rolling distance was obtained.

It is a perspective view of a head showing an embodiment of the present invention. FIG. It is a top view of the head which shows embodiment of this invention. FIG. 4 is a side view of FIG. 3. FIG. 4 is a front view of FIG. 3. It is AA sectional drawing of FIG. It is sectional drawing which shows other embodiment of this invention. It is sectional drawing which shows other embodiment of this invention. It is a top view which shows other embodiment of this invention. It is a disassembled perspective view which shows other embodiment of this invention. It is a top view which shows other embodiment of this invention. (A), (B) is the top view which shows the head of Example 6, and its AA sectional drawing. (A), (B) is the top view which shows the head of the comparative example 1, and its AA sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Putter type golf club head 2 Head main body 3 Vibration absorber 4 Face part of head main body 5 Upper surface part of head main body 6 Upper surface part of head main body F Face surface

Claims (5)

  A putter-type golf club head, wherein a vibration absorbing material made of a fiber reinforced resin is disposed on at least a part of an upper surface portion of a head body having a face portion and made of a metal material.   The putter type golf club head according to claim 1, wherein the vibration absorbing material is disposed only on an upper surface portion of the head main body.   The putter-type golf club head according to claim 1, wherein the vibration absorber is in close contact with the head main body without having a gap.   The putter-type golf club head according to any one of claims 1 to 3, wherein the head body is formed of a solid body having no space between an upper surface portion and a bottom surface portion thereof.   5. The vibration absorbing material has a plate shape with a thickness of 1 to 5 mm, a resin content of 25 to 50%, and a surface area of 10 to 80% of the total head surface area. The putter type golf club head according to any one of the above.

Images