JP2008142321A - Golf club - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a golf club which can easily improve repeatability of batted balls even by beginners in particular, or by mid-level players. <P>SOLUTION: A golf club head 3 is formed in a way that the size of an inertia moment I around a shaft which goes through a gravity point G of the head and is perpendicular to a face surface 3a is 2,800 g-cm<SP>2</SP>or more, or that a value I/M provided by dividing the inertia moment I by the weight M of the golf club head 3 is 14.1 g-cm<SP>2</SP>/g or more, and that the gravity point depth D in a direction perpendicular to the face surface 3a is between 10 mm and 25 mm so that a head height H and a head width L of the golf club head 3 are relatively larger than the size in the depth direction and that the area of the face surface 3a can be made larger than general golf clubs. By this a ball can be hit by a wide range of the face surface 3a and missing shots can be reduced by the secure feeling caused by the fact that the face surface 3a is wide. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a golf club having a golf club head at a tip portion.

Conventionally, wood-based golf clubs such as drivers have been desired to have excellent directivity as well as the flight distance of the hit ball. From this point, various studies have been made on the center of gravity characteristics of golf club heads. In particular, in order to improve the ease of hitting and the flight distance, the center of gravity position is set at the rear part of the golf club head or set at a low position (for example, see Patent Document 1 or 2). . Also known is a technique in which the depth of the center of gravity from the face surface is reduced in order to suppress the backspin amount and improve the flight distance (see, for example, Patent Document 3).
JP 2004-673 A Japanese Patent Laid-Open No. 10-15120 Utility Model Registration No. 2588485

  However, if the depth of the center of gravity is excessively increased, the direction of the golf club head is likely to change due to the bending of the shaft. Therefore, variations in the height and direction of the hit ball occur, and a stable flight distance is not always obtained. If the depth of the center of gravity is too shallow, the face surface and the center of gravity are close to each other, and therefore the direction of the hit ball is likely to be distorted even by a slight positional deviation between the hit point and the center of gravity. In any case, such a center of gravity characteristic is considered to be one of the causes for increasing the difficulty of shots with golf clubs, and it has been difficult for beginners and intermediate players to improve the reproducibility of the hit ball.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a golf club that can easily improve the reproducibility of a hit ball even for beginners or intermediate players.

In order to achieve the above object, the present invention provides a golf club having a golf club head at a tip portion, wherein the moment of inertia about an axis passing through the center of gravity of the golf club head and perpendicular to the face surface is 2800 g · cm. ^The depth of the center of gravity in the direction perpendicular to the face surface is 2 mm or more and 10 mm or more and 25 mm or less.

In order to achieve the above object, according to the present invention, in a golf club having a golf club head at a tip portion, the golf club head is subjected to a golf ball having a moment of inertia about an axis passing through the center of gravity and perpendicular to the face surface. The value divided by the mass of the club head is 14.1 g · cm ² / g or more, and the center of gravity depth in the direction perpendicular to the face surface is 10 mm or more and 25 mm or less.

  According to the present invention, since the head height and the head width of the golf club head are relatively large with respect to the dimension in the depth direction, the face surface area can be made larger than that of a general golf club. Become.

  According to the golf club of the present invention, since the area of the face surface can be made larger than that of a general golf club, the ball can be hit in a wide range of the face surface, and the sense of security due to the wide face surface can be achieved. Thus, the number of miss shots can be reduced. In particular, even a beginner or intermediate player can easily improve the reproducibility of the hit ball in the flight distance and direction.

  1 to 14 show an embodiment of the present invention. FIG. 1 is a front view of a main part of a golf club, FIG. 2 is a side view thereof, FIG. 3 is a plan view thereof, and FIG. FIG. 5 is a front view of the main part showing the measurement state, FIG. 6 is a front view of the center of gravity measuring device, FIG. 7 is a front view of the balance, FIG. 8 is a front view showing the measurement by the balance, and FIG. Is a plan view, FIG. 10 is a perspective view of a loft angle measuring device, FIG. 11 is a diagram showing a loft angle measuring protractor, and FIGS. 12 to 14 are diagrams showing experimental results.

  A golf club 1 shown in FIG. 1 includes a golf club shaft 2 made of steel or carbon, a golf club head 3 attached to the distal end portion of the golf club shaft 2, and a grip attached to the proximal end portion of the golf club shaft 2. (Not shown).

In the golf club head 3, the magnitude of the moment of inertia I about the axis perpendicular to the face surface 3 a through the center of gravity G is 2800 g · cm ² or more, or the value I obtained by dividing the moment of inertia I by the mass M of the golf club head 3. / M is 14.1 g · cm ² / g or more, and the center-of-gravity depth D in the direction perpendicular to the face surface 3 a is 10 mm or more and 25 mm or less. Accordingly, the golf club head 3 has a shape in which the head height H and the head width L are relatively large with respect to the dimension in the depth direction, and the area of the face surface 3a is larger than that of a general golf club.

  The golf club head 3 is formed so that the loft angle θ is 5 ° or more and 22 ° or less, and the value obtained by dividing the head height by the head width, that is, the ratio H / L of the head height H to the head width L is 0. It is formed to be 55 or more and 1.0 or less. In this case, as shown in FIG. 1, the golf club head 3 is installed at a normal address position, and the height from the reference plane X to the uppermost end portion of the top of the crown portion of the golf club head 3 is the head height. The head width L is defined as a length parallel to the reference plane X from the position on the heel side positioned 22.23 mm above the reference plane X to the end portion positioned closest to the toe side.

  Further, the golf club head 3 has a hosel portion 3b to which the golf club shaft 2 is fixed, and is formed such that a value obtained by dividing the hosel height H1 by the head height H is 1.02 or more and 1.23 or less. Is formed. In this case, as shown in FIG. 1, the vertical height from the reference plane X to the upper end of the hosel portion 3b is defined as a hosel height H1.

  As shown in FIG. 3, the golf club head 3 is formed such that the bulge radius R of the face surface 3a is 225 mm or more. The bulge is a lateral roundness on the face surface 3a.

  The value of the moment of inertia I about the axis that passes through the center of gravity G of the golf club head 3 and is perpendicular to the face surface 3a is measured using the moment of inertia measuring instrument 10 shown in FIG. This moment of inertia measuring instrument 10 includes a measurement unit 11, a calculation unit 12, a start lever 13, a display unit 14, and an operation button 15. A measurement object is placed on the measurement unit 11, and the start lever 13 is manually moved. It is a device that, after picking and displacing, releases the hand and torsionally vibrates, measures the moment of torsional vibration at this time, measures the moment of inertia through the arithmetic unit 12, and displays the numerical value of the moment of inertia on the display unit 14. . As the inertia moment measuring device 10, for example, an inertia moment measuring device “Model MOI-005-014” manufactured by Inertia Dynamics may be used.

  As shown in FIG. 5 (a), the inertia moment measuring instrument 10 measures the inertia moment Ia by fixing only the jig 16 to the measuring section 11, and then continues to FIG. 5 (b). As shown, the face surface 3a of the golf club head 3 is fixed to the upper surface of the jig 16, the inertia moment Ib is measured, and the inertia moment I of the golf club head 3 is obtained from (Ib-Ia). In this case, the golf club head 3 is fixed to the inertia moment measuring device 50 so that the normal line N of the face surface 3 a passing through the center of gravity G and the rotational axis A of the torsional vibration of the inertia moment measuring device 10 coincide or substantially coincide. It is preferred that The term “substantially coincides” means that the horizontal distance between a point g where the normal N passes through the face surface 3a and a point where the rotation axis A passes through the face surface 3a is within 3 mm, preferably within 2 mm, more preferably within 1 mm. is there. By fixing the face surface 3a of the golf club head 3 within this range, the moment of inertia can be accurately measured.

  A point g on the face surface 3a of the golf club head 3 is obtained by a centroid measuring device 20 shown in FIG. The center-of-gravity measuring instrument 20 includes a support portion 21 that supports a measurement object on the upper portion, and a position at which the support portion 21 supports the measurement object in equilibrium can be obtained on the measurement object. That is, the point g on the face surface 3a is obtained by placing the golf club head 3 on the support portion 21 as shown in FIG. 6 and searching for a position where the golf club head 3 is kept in balance even when released. Is possible.

  In addition, the jig 16 of the moment of inertia measuring device 10 is preferably mounted on the moment of inertia measuring device 10 so that the position of the center of gravity of the jig itself coincides with or substantially coincides with the rotation axis A. In order to fix the golf club head 3 and the jig 16, fixing with an adhesive such as double-sided tape or clay, fixing with an adhesive, fixing using a magnetic force, or the like can be considered. In this case, in the wood-based golf club head 3, since the face surface 3a is formed so as to form a convex curved surface, the upper surface of the jig 16 is also a concave curved surface that matches the face surface 3a. However, when the upper surface of the jig 16 is a flat surface, the adhesive body 17 is formed and fixed so as to match the face surface 3a and the upper surface of the jig 16 as shown in FIG. In this case, an adhesive body 17 having a mass is included in a part of the jig 16 and is pulled as a tare in the same manner as the jig 16.

  Using the above measuring apparatus and measuring method, the value of the moment of inertia I about the axis passing through the center of gravity G of the golf club head 3 and perpendicular to the face surface 3 a was measured before assembling the golf club 1. Here, Moment of inertial Model MOI-005-014 made by Inertia Dynamics was used as the moment of inertia measuring instrument 10, and Calibration Weight (Part No. CW005-001) made by the same company was used for the jig 16. . The golf club head 3 was fixed so that the normal line N and the rotation axis A coincided with each other as shown in FIG. The fixing means was fixed with a double-sided tape (product number: GW-350) manufactured by Lion Corporation. A point g on the face surface 3a is a G.A. Determined by MAKERMODEL FG-102RM. The inertia moment I was measured in accordance with the operating manual created by the company. The measurement was performed three times, and the average value of the three times was taken as the measured value.

  The center-of-gravity depth D of the golf club head 3 is measured by a balance 30 shown in FIG. This balance 30 includes a seesaw-like arm 32 supported swingably at a fulcrum 31, and a weight body 33 placed on one end side of the arm 32 and a center of gravity G are located on the other end side of the arm 32. The center of gravity depth D is measured by balancing with the golf club head 3. A vertical plate 34 located on the fulcrum 31 is provided at the longitudinal center of the arm 32, and the golf club head 3 is mounted on one surface of the vertical plate 34 (the surface on the other end side of the arm 32). It has become. When the golf club head 3 and the weight body 33 are not attached, the arms 32 are balanced so as to be horizontal.

  Using the balance 30 having the above configuration, the gravity center depth D in the direction perpendicular to the face surface 3a was measured. That is, as shown in FIGS. 8 and 9, the golf club head 3 having a mass M is mounted on one surface of the vertical plate 34 and fixed so that the face surface 3 a is orthogonal to the longitudinal direction of the arm 32. Then, the arm 32 is balanced so as to be horizontal by the weight body 33 of mass M ′, and the horizontal length D ′ from the center of gravity G ′ of the weight body 33 to the fulcrum 31 is obtained.

  From the above, the center-of-gravity depth D in the direction perpendicular to the face surface 3a can be obtained by (D + d) = (M ′ × D ′) / M from the balance equation M × (D + d) = M ′ × D ′. In this case, d is the thickness from the fulcrum 31 to one surface of the vertical plate 34. As the balance 30, for example, a balance manufactured by Sanko Seisakusho Co., Ltd. can be used.

  The loft angle θ of the golf club head 3 is measured by a loft angle measuring device 40 shown in FIG. 10 and a protractor 50 shown in FIG. Here, the loft angle θ is an angle formed by the shaft axis S and the face surface 3a. The loft angle measuring device 40 includes a shaft holding portion 41 that holds the golf club shaft 2, a lie angle adjustment portion 42 to which the shaft holding portion 41 is attached, a measurement table 43 that is provided integrally with the angle adjustment portion 42, And a face angle adjuster 44 mounted on the measurement table 43 so as to be movable in the front-rear direction. In this loft angle measuring device 40, the golf club 1 is held by the shaft holding portion 41, and the angle of the shaft holding portion 41 is adjusted by the lie angle adjusting portion 42, so that the golf club 1 becomes the reference plane of the measuring table 43. The angle of the golf club shaft 2 is adjusted so that the golf club shaft 2 is installed at an address position corresponding to the lie angle with respect to 43a. Next, the sole portion 3b of the golf club head 3 is brought into contact with the reference surface 43a, and the face surface 3a is brought into close contact with the tip portion 44a of the face angle adjuster 44, whereby the face angle with respect to the tip portion 44a becomes 0 °. Thus, the golf club shaft 2 is fixed by the chuck portion 41 a of the shaft holding portion 41. Thereafter, as shown in FIG. 11, a protractor 50 standing upright with respect to the reference surface 43a is used to measure the loft angle θ of the face surface 3a of the golf club 1 held by the loft angle measuring device 40. The loft angle measuring device 40 may be a known one that is commercially available. For example, Takahio ball head measuring table manufactured by Shoho Company, Golf Club angle measuring device manufactured by Golf Garage, Golf Golf manufactured by Golf Smith A measuring instrument such as a club gauge can be used. Such a measuring device may be a known one and is not particularly limited in the present invention.

  In the measurement of the loft angle, setting the golf club 1 at the address position according to the lie angle means that the golf club head 3 is set at the lie angle and the shaft axis S of the golf club 1 and the leading edge 3c are This means that they are installed parallel to each other when viewed from above. Also, installation according to the lie angle means that the lie angle is set to 60 °. The golf club length refers to a length measured in accordance with “c. Length” of “1. Club” in Supplementary Rules II of the Golf Rules issued by the Japan Golf Association. At the address position, the direction of the leading edge 3c is set to a direction perpendicular to the direction indicated by the face surface 3a. As described above, the direction of the face surface 3a is specified, and the dimension measurement of the golf club head 3 performed in a state in which a normal address position is set is, for example, Takahio ball head measurement table manufactured by Shoho Enterprise Co., Ltd., Golf Garage Co., Ltd. This is possible with a measuring instrument such as a golf club angle measuring instrument or a golf club gauge manufactured by Golf Smith. Such a measuring device may be a known one and is not particularly limited in the present invention.

  Here, about the experimental examples 1-21 of this invention and the prior art examples 1-3, the flight distance and directionality experiment were done. In this experiment, a golfer as a subject hits a pin provided at a predetermined position in the hitting field, records the flight distance (yard) from the hit position to the position where the ball stops, and from the hitting stop position to the pin. Is recorded as the direction blur width (yard). These were performed ten balls at a time for one golf club, and the standard deviation of the flight distance and the direction blur width was obtained. Here, 20 subjects were tested using the golf clubs of Experimental Examples 1 to 21 and Conventional Examples 1 to 3, and the average value of standard deviations was obtained. Then, the standard deviation of Conventional Examples 1 to 3 was set to 100, and Experimental Examples 1 to 21 were evaluated by an index ((Standard Deviation of Conventional Example / Standard Deviation of Experimental Examples 1 to 21) × 100). In this case, the flight distance was evaluated as 1, the directional blur width was evaluated as 2, the shot feeling was evaluated as 3, and the sum of the evaluations 1, 2, and 3 was defined as the overall evaluation. That is, it was determined that the higher the sum of the evaluations 1, 2, and 3, the better the balance of flight distance, directionality, and feel at impact. In Examples 1 to 19 and Conventional Example 1, a golf club having a loft angle of 11 °, in Experimental Example 20 and Conventional Example 2, a loft angle of 17 °, and in Experimental Example 21 and Conventional Example 3, a golf club having a loft angle of 24 ° is used. It was. All golf clubs were 45 inches long.

  Experimental Examples 1 to 19 are experiments according to the scope of the present invention, and are all superior to Conventional Example 1 as shown in FIG.

  In the comparison of the moment of inertia, the range of the moment of inertia in Experimental Example 1 is outside the range of the present invention. In contrast, in Experimental Examples 4, 5, 6, 7, and 10, the range of the moment of inertia is within the range of the present invention, and only the value of the moment of inertia is changed. It can be seen that all of these experimental examples have preferable results compared to Experimental Example 1. In Experimental Example 10, the range of the moment of inertia is outside the preferable range of the present invention. On the other hand, it can be seen that all of Experimental Examples 4, 5, 6, and 7 have the range of the moment of inertia within the range of the present invention, and all of them are preferable results compared to Experimental Example 10.

  In the comparison of the center of gravity depth, Experimental Examples 2 and 3 have a center of gravity depth range outside the scope of the present invention. On the other hand, in Experimental Examples 4, 8, and 9, the range of the centroid depth is within the range of the present invention, and only the numerical value of the centroid depth is changed. It can be seen that all of these experimental examples have preferable results compared to Experimental Examples 2 and 3.

  In the H / L comparison, Experimental Example 11 has an H / L range outside the preferred range of the present invention. In contrast, in Experimental Examples 4, 15, and 16, the H / L range is within the scope of the present invention, and only the H / L value is changed. It can be seen that all of these experimental examples have preferable results compared to Experimental Example 11.

  In the comparison of H1 / H, Experimental Examples 13 and 14 have a H1 / H range outside the preferred range of the present invention. In contrast, in Experimental Examples 4, 18, and 19, the range of H1 / H is within the range of the present invention, and only the value of H1 / H is changed. It can be seen that all of these experimental examples have preferable results compared to Experimental Examples 13 and 14.

  In comparison of bulge radii, Experimental Example 12 has a bulge radius range outside the preferred range of the present invention. On the other hand, in the experimental examples 4 and 17, the range of the bulge radius is within the range of the present invention, and only the numerical value of the bulge radius is changed. It can be seen that all of these experimental examples have preferable results compared to Experimental Example 12.

  In Experimental Example 20, the loft angle was set to 17 °, and the range of the loft angle was within the scope of the present invention. In this case, as shown in FIG. 13, it can be seen that a preferable result is obtained as compared with the conventional example 2 having the same loft angle. In Experimental Example 21, the loft angle was 24 °, and the range of the loft angle was outside the scope of the present invention. In this case, as shown in FIG. 14, it is superior to Conventional Example 3 having the same loft angle. However, since the range of the loft angle is outside the scope of the present invention, it is more effective than Experimental Example 20 that is within the scope of the present invention. Is small.

As described above, according to the present embodiment, the golf club head 3 is subjected to a golf ball having an inertia moment I of 2800 g · cm ² or more around the axis passing through the center of gravity G and perpendicular to the face surface 3a. The value I / M divided by the mass M of the club head 3 is 14.1 g · cm ² / g or more, and the center-of-gravity depth D in the direction perpendicular to the face surface 3 a is 10 mm or more and 25 mm or less. Therefore, by selecting such numerical values, the head height H and the head width L of the golf club head 3 can be made relatively large with respect to the dimension in the depth direction. The area of the surface 3a can be increased. As a result, the ball can be hit over a wide area of the face surface 3a, and the number of miss shots can be reduced due to the sense of security due to the wide face surface 3a, especially for beginners or intermediate players. In addition, the reproducibility of the hit ball in the direction can be easily improved. The magnitude of the moment of inertia I is preferably 3000 g · cm ² or more.

  Further, the golf club 1 in which the loft angle θ of the golf club head 3 is not less than 5 ° and not more than 22 ° as in the present embodiment is a golf club that mainly flies the ball far away with a full swing. By applying the present invention to the golf club 3 having θ, it is possible to obtain a relatively stable hitting ball reproducibility result even after a full swing. The loft angle θ is preferably 8 ° or more and 20 ° or less.

  Further, since the golf club head 3 is formed such that the value obtained by dividing the head height H by the head width L is 0.55 or more and 1.0 or less, the face surface 3a closer to a circle can be formed. As a result, a more equivalent result can be obtained with respect to the variation in the hit points in the toe and heel directions and the variation in the hit points in the sole and crown directions, and the reproducibility of the hit ball in the flight distance and direction can be further improved. . In this case, the shape is different from that of a general golf club head having a horizontally long face surface. However, especially for golfers who have little prejudice against the shape of the golf club head, such as beginners, it is not very comfortable. It can be used without being generated, and rather it can absorb blurring of hitting points in the vertical direction, which is extremely advantageous for improving the reproducibility of the hit ball.

  Further, the golf club head 3 is formed so that the value obtained by dividing the hosel height H1 of the golf club head 3 by the head height H is 1.02 or more and 1.23 or less, thereby further improving the reproducibility of the hit ball in the flight distance and directionality. In addition, it is possible to improve the feel at impact. The value obtained by dividing the hosel height H1 by the head height H is preferably 1.15 or less.

  Furthermore, since the golf club head 3 is formed so that the bulge radius R of the face surface 3a is 225 mm or more, the reproducibility of the hit ball against a so-called off-center hit in which the hit position on the face surface 3a is shifted in the width direction. Can be increased.

The principal part front view of the golf club which shows one Embodiment of this invention Golf club side view Top view of golf club Perspective view of moment of inertia measuring instrument Front view of the main part showing the measurement state of the moment of inertia measuring instrument Front view of center of gravity measuring instrument Front view of balance Front view showing the state of measurement with a balance Top view of the balance Perspective view of loft angle measuring instrument Diagram showing protractor for loft angle measurement Figure showing experimental results Figure showing experimental results Figure showing experimental results

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Golf club, 2 ... Golf club shaft, 3 ... Golf club head, 3a ... Face surface.

Claims (6)

In a golf club having a golf club head at the tip,
The golf club head has a moment of inertia of 2800 g · cm ² or more passing through its center of gravity and perpendicular to the face surface, and a center of gravity depth of 10 mm or more and 25 mm or less in a direction perpendicular to the face surface. A golf club characterized by being formed as described above. In a golf club having a golf club head at the tip,
The value obtained by dividing the magnitude of the moment of inertia about the axis perpendicular to the face surface through the center of gravity of the golf club head by the mass of the golf club head is 14.1 g · cm ² / g or more. A golf club, characterized in that the depth of the center of gravity in the vertical direction is 10 mm or more and 25 mm or less. The golf club according to claim 1, wherein the golf club head has a loft angle of 5 ° to 22 °. 4. The golf club according to claim 1, wherein the golf club head is formed such that a value obtained by dividing a head height by a head width is 0.55 or more and 1.0 or less. 5. The golf club according to claim 1, wherein the golf club head is formed such that a value obtained by dividing a hosel height by a head height is 1.02 or more and 1.23 or less. . 6. The golf club according to claim 1, wherein the golf club head is formed so that a bulge radius of a face surface is 225 mm or more.

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