JP2019176969A - Golf club head - Google Patents

Abstract

To provide a golf club head capable of suppressing decrease in a back spin amount in a shot from the rough.SOLUTION: A golf club head 1 includes a face 3 for hitting a ball. The face 3 is formed with a plurality of grooves 8 extending along a toe-heel direction, and a plurality of narrow grooves 9 whose groove width is smaller than that of the grooves 8. In a front view of the face 3 in a state in which the golf club head 1 in a reference state in which it is placed on a horizontal plane HP at a prescribed lie angle β and a loft angle, is tilted forward so that the face 3 is made perpendicular, the plurality of narrow grooves 9 are arranged tiled with respect to the toe-heel direction, and the tilt is descending to the right.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a golf club head.

  A plurality of grooves are formed in the face of the golf club head. The grooves typically extend the face along the toe-heel direction and are also referred to as score lines. This groove functions to increase the friction force between the face and the ball and increase the backspin amount of the hit ball when hitting the ball.

  Incidentally, in recent years, various golf club heads have been proposed in which a fine groove different from the groove is formed on the face. Patent Document 1 below describes a golf club head in which a plurality of grooves (score lines) and a plurality of narrow grooves are formed on a face surface. In one embodiment of Patent Document 1, the plurality of narrow grooves are inclined downward to the left, that is, from the top side toward the sole so that the backspin amount of the hit ball can be increased even when the face surface is opened. It inclines so that it may go to the toe side (refer FIG. 7 of patent document 1).

Japanese Patent No. 5592055

  The inventors have made various studies in order to optimize the shot from the rough. In a rough shot, a lot of grass is interposed between the ball and the face, and sufficient friction cannot be obtained between them. For this reason, the backspin amount of the hit ball is greatly reduced. In particular, in approach shots in which the ball is stopped near the drop position on the green using backspin, the reduction of the backspin amount may cause a fatal mistake.

  In approach shots from the rough, attempts have been made to increase the loft angle by opening the face and raise the ball higher, but this alone was not sufficient to compensate for the decrease in the backspin amount.

  In order to suppress the decrease in the backspin amount in shots from the rough, the inventors crushed the turf interposed between the ball and the face with the pressure at the time of the shot, and the ball and the face are further separated from the gap. The knowledge that it is important to make contact in many areas was obtained. Based on this knowledge, we examined in more detail in consideration of the direction of turf fibers. As a result, to effectively crush the turf with the compressive force between the ball and the face, as shown in FIG. 7A, the turf 30 is crushed along a cutting line L1 perpendicular to the longitudinal direction. Rather, as shown in FIG. 7B, it has been found that it is advantageous to tear the turf 30 at a cutting line L2 along the longitudinal direction that coincides with the direction of the fibers. Based on these findings, the inventors have completed the present invention by realizing the function in a narrow groove different from the groove.

  The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a golf club head capable of suppressing a decrease in the amount of backspin in a shot from a rough.

  The present invention is a golf club head having a face for hitting a ball, wherein the face has a plurality of grooves extending along a toe-heel direction and a plurality of grooves having a groove width smaller than the grooves. The golf club head in a reference state placed on a horizontal plane at a specified lie angle and loft angle is formed on the face of the face in a state of being tilted forward so that the face is vertical. In the front view, the plurality of narrow grooves is a golf club head that is disposed to be inclined with respect to the toe-heel direction, and the inclination is downwardly inclined.

  In the golf club head of the present invention, a plurality of grooves extending along the toe-heel direction can give a sufficient backspin amount to the hit ball at the time of teeing up or shot from the fairway.

  The face of the golf club head of the present invention is provided with a plurality of narrow grooves arranged to be inclined with respect to the toe-heel direction, and the inclination is lowered to the right when the face is viewed from the front, that is, the top It extends so that it may go to the heel side toward the sole. In such a golf club head, when the shot is performed with the face opened, the ball easily moves on the face along the longitudinal direction of the narrow groove. Therefore, in the golf club head of the present invention, the turf interposed between the ball and the face is effectively crushed by a cutting line along the longitudinal direction (the direction in which the turf fibers extend) when shot from the rough. The ball and the face can be brought into contact with a larger area. Further, since the longitudinal direction of the narrow groove and the crushed turf are aligned, the crushed turf is pushed into the narrow groove, and the above action is further enhanced.

  As described above, the golf club head of the present invention can suppress a decrease in the backspin amount even in a shot from rough, and can improve the accuracy of approach shots and the like.

  2. The golf club head according to claim 1, wherein the plurality of narrow grooves are inclined at an angle of 30 degrees or more and less than 90 degrees with respect to the toe-heel direction.

  In another aspect of the present invention, the plurality of narrow grooves may have an angle of 30 degrees or more and less than 60 degrees with respect to the toe-heel direction.

  In another aspect of the present invention, the pitch of the plurality of narrow grooves may be 2.5 times or more and 5.0 times or less the groove width of the narrow grooves.

  In another aspect of the present invention, the cross-sectional shape of each of the plurality of narrow grooves is an asymmetric triangular shape having a deepest portion at a position different from the position of the groove width center line.

  In another aspect of the present invention, a cross section of the narrow groove includes a first wall and a second wall having a length longer than the first wall, and the narrow groove includes the first wall, It can be located on the top side of the golf club head.

  In another aspect of the present invention, the narrow groove may include one in which the second wall is located on a top side of the golf club head.

  In another aspect of the present invention, the narrow groove has a groove width of 0.1 to 1.0 mm, and the narrow groove has a depth of 10 to 25 μm.

  The golf club head of the present invention can prevent the backspin amount from decreasing even in a shot from rough, and can improve the accuracy of approach shots and the like.

It is a front view of the golf club head of this embodiment. FIG. 2 is a side view of the golf club head of FIG. 1. It is a partial expanded sectional view of the AA line of FIG. FIG. 2 is a front view of the face in a state where the golf club head of FIG. 1 is tilted forward so that the face is vertical. It is a top view for demonstrating the shot in the state which opened the face. It is a fragmentary sectional view of the BB line of FIG. (A) And (B) is a conceptual diagram explaining crushing of turf, and the left side shows before crushing and the right side shows after crushing, respectively.

  Hereinafter, some embodiments of the present invention will be described with reference to the drawings. The specific configurations shown in the embodiments and drawings described in detail below are for understanding the contents of the present invention, and the present invention is not limited to these specific configurations. Absent.

  FIGS. 1 and 2 respectively show a front view and a side view of a golf club head (hereinafter, simply referred to as “head”) 1 of the present embodiment as viewed from the toe side. As shown in FIGS. 1 and 2, the head 1 of this embodiment is typically configured as an iron type golf club head 2. However, the present invention is not limited to the iron type golf club head 2.

[Definition of standard conditions]
1 and 2 show the reference state of the head 1. In this specification, the “reference state” of the head 1 means that the shaft axis center line CL is disposed in an arbitrary reference vertical plane VP and is held at a specified lie angle β, and the face 3 is at a specified loft angle. It means a state where it is held at α and placed on the horizontal plane HP.

  In this specification, the horizontal direction x along the reference vertical plane VP is the toe-heel direction of the head 1, and the direction y orthogonal to the reference vertical plane VP is the front-rear direction of the head 1, along the reference vertical plane VP. The vertical direction z is the vertical direction of the head 1.

[Basic configuration of the head]
The head 1 has a typical iron shape and includes a face 3, a top 4, a sole 5, a toe 6 and a hosel 7, and each part is made of a metal material.

  The face 3 is a substantially flat surface for hitting a ball. The face 3 is provided with a plurality of grooves 8 and a plurality of narrow grooves 9 in order to increase friction with the ball. The narrow groove 9 has a smaller groove width than the groove 8 (both will be described later).

  The top 4 is an upper surface portion of the head 1 extending rearward from the upper edge of the face 3. The sole 5 is a bottom portion of the head 1 extending rearward from the lower edge of the face 3. The toe 6 is the part farthest from the hosel 7. The hosel 7 is for fixing one end of a club shaft (not shown), and has a cylindrical shape, for example. The center line of the hosel 7 coincides with the shaft axis center line CL.

[Basic structure of groove]
As shown in FIG. 1, all of the plurality of grooves 8 extend along the toe-heel direction. Therefore, they are parallel to each other. FIG. 3 shows a partially enlarged sectional view taken along line AA of FIG. 1 as a transverse sectional view of the groove 8. As shown in FIG. 3, the groove 8 has a groove bottom 8a and a pair of groove walls 8b. For example, the groove bottom 8 a is formed by a plane parallel to the face 3. The pair of groove walls 8 b are inclined so that the groove width increases from the groove bottom 8 a toward the face 3. The groove wall 8b of this embodiment is essentially a flat surface. The pair of groove walls 8 b are symmetrical with respect to the groove width center line GC of the groove 8. The “parallel” and the “symmetrical shape” must be understood in consideration of the processing accuracy when the groove 8 is processed into the face 3, and are substantially “parallel” and substantially It is intended to include such “symmetrical shapes”.

  The corner portion where the groove wall 8b and the face 3 intersect is chamfered with an arc. The radius of curvature r of this arc is, for example, determined to have an effective radius of at least 0.010 inches (0.254 mm) according to the golf rules. In the present specification, the “golf rule” means the “golf rule” defined in R & A.

  Each groove 8 is specified by depth D, width W, groove wall angle θ and pitch P.

  The depth D of the groove 8 is the maximum distance in the direction perpendicular to the face 3 from the face 3 to the groove bottom 8a. The width W of the groove 8 is measured in accordance with “30 degree measurement method for measuring the width of the groove” defined by R & A. The angle θ of the groove wall 8b is an acute angle formed by the normal of the face 3 and the groove wall 8b. The pitch P of the grooves 8 is a distance between the groove width center lines GC of the adjacent grooves 8. In the head 1 of this embodiment, the depth D and width W of the groove 8, the angle θ of the groove wall 8b, the pitch P, the radius of curvature of the arc, and the like are intended to be designed within a range that satisfies the golf rules. Yes.

  In the head 1 of the present embodiment, the plurality of grooves 8 extending along the toe-heel direction can give a sufficient backspin amount to the hit ball at the time of teeing up or shot from the fairway.

[Basic structure of narrow groove]
FIG. 4 is a front view of the face 3 in a state where the head 1 in the reference state is tilted forward so that the face 3 is vertical. As shown in FIG. 4, the plurality of narrow grooves 9 are disposed so as to be inclined with respect to the toe-heel direction, and the inclination is lowered to the right. That is, the narrow groove 9 extends from the top 4 toward the sole 5 toward the heel side (hosel side).

[Operation of narrow groove]
In such a head 1, as shown in FIG. 5, when the face 3 is opened with an angle γ (γ ≠ 0) and shot, the ball B contacts the face 3 and then moves over the face 3 with an arrow. Move in the direction. That is, the ball B moves on the face 3 so as to approach the toe side from the sole 5 toward the top 4. In the head 1 of this embodiment, the narrow groove 9 is inclined so that the longitudinal direction of the narrow groove 9 is closer to the moving direction of the ball B on the face 3. Therefore, in the head 1 of the present embodiment, in a shot in which the face 3 is opened from the rough, the lawn interposed between the ball B and the face 3 is made along the fiber by using the edge of the narrow groove 9. And can be crushed effectively. Thereby, the ball B and the face 3 can be brought into contact with each other with a larger area. Therefore, in the head 1 of this embodiment, a reduction in the backspin amount of the hit ball is suppressed even during a rough shot.

  Moreover, since the longitudinal direction of the narrow groove 9 and the crushed turf are easy to align, the crushed turf is pushed into the fine groove 9 and the above action can be further enhanced.

[Preferred angle of inclination of narrow groove]
In order to further enhance the above action, the narrow groove 9 is preferably inclined at an angle δ of 30 degrees or more and less than 90 degrees with respect to the toe-heel direction. In particular, the narrow groove 9 has an angle δ of 30 degrees or more and less than 60 degrees with respect to the toe-heel direction in order to more effectively crush the turf in correspondence with a typical angle when the face 3 is opened. It is desirable to be inclined at. In the present embodiment, the plurality of narrow grooves 9 are arranged in parallel to each other, but may have different angles within the range of the angles.

[Groove width and depth of narrow grooves]
FIG. 6 shows an enlarged cross-sectional view of the BB part of FIG. The groove width w of the narrow groove 9 can be variously defined without particular limitation as long as it is smaller than the width W of the groove 8, and is, for example, in the range of 0.1 to 1.0 mm, more preferably 0.75. It is desirable to be in the range of ˜1.00 mm. The depth d of the narrow groove 9 can be variously defined without particular limitation as long as it is smaller than the depth D of the groove 8, and is, for example, in the range of 10 to 25 μm, more preferably in the range of 20 to 25 μm. It is desirable to be done. Such a narrow groove 8 can be formed in the face 3 by machining, for example.

[Pitch of narrow grooves]
The pitch p of the fine grooves 9 can be variously determined without any particular limitation as long as it is smaller than the pitch P of the grooves 8. On the other hand, when the pitch p of the narrow grooves 9 is reduced, the turf crushability is improved, but the ball cover tends to be easily damaged. From this point of view, the pitch p of the narrow grooves 9 is desirably 2.5 times or more, more preferably 3.0 times or more, the groove width w of the narrow grooves 9. Conversely, if the pitch p of the narrow grooves 9 is increased, the ball cover can be prevented from being damaged, but the turf crushing effect may be reduced. From such a viewpoint, the pitch p of the narrow grooves 9 is desirably 5.0 times or less, more preferably 4.0 times or less of the groove width w of the narrow grooves 9.

  The width w, depth d, and pitch p of the narrow grooves 9 are specified in the same manner as the width W, depth D, and pitch P of the grooves 8.

[Shape of cross section of narrow groove]
As shown in FIG. 6, in a preferred embodiment, the shape of each cross section of the narrow groove 9 is an asymmetric shape having the deepest portion 10 at a position different from the position of the groove width center line GC. In a preferred embodiment, the cross section of the narrow groove 9 has an asymmetric triangular shape in which the first wall 11 and the second wall 12 having a longer length than the first wall 11 intersect at the deepest portion 10 (groove bottom). . Such a narrow groove 9 is excellent in the turf crushing effect.

  In a preferred embodiment, the cross section of the narrow groove 9 is such that the first corner portion 21 where the first wall 11 intersects the face 3 or the second corner portion 22 where the second wall 12 and the face 3 intersect is chamfered with an arc. . In the present embodiment, the first corner portion 21 and the second corner portion 22 are both chamfered with an arc. In such an aspect, the lawn crushing effect can be enhanced while suppressing damage to the ball cover. In order to exhibit this effect more reliably, it is desirable that the radius of curvature of the arc is 10 μm or less.

  When attention is paid to the land areas on both sides of the narrow groove 9, the first corner portion 21 is relatively sharper than the second corner portion 22. Therefore, in a preferred embodiment, the narrow groove 9 may be arranged such that the first wall 11 (first corner portion 21) is located on the top 4 side of the head 1. In general, in a shot as shown in FIG. 5, the ball B is strongly pressed against the first wall 11 side of the narrow groove 9. Accordingly, by arranging the relatively sharpened first corner portion 21 on the top 4 side of the narrow groove 9, the first corner portion 21 is strongly pressed by the turf, and the above-mentioned turf crushing effect is further increased. Enhanced.

  In another aspect, the narrow groove 9 may be arranged such that the second wall 12 (second corner portion 22) is positioned on the top 4 side of the head 1. As described above, in the shot as shown in FIG. 5, the first wall 11 is preferably located on the heel side of the head. However, for example, when the ball is hit with the face 3 being opened more widely, depending on the angle δ of the narrow groove 9, a shot may occur in a situation where the narrow groove 9 is inclined toward the heel side in the head traveling direction. . When the second wall 12 (second corner portion 22) of the narrow groove 9 is disposed so as to be located on the toe 6 side of the head 1, it is possible to effectively suppress the reduction of back spin in such a shot. it can.

  As mentioned above, although embodiment of this invention was described in detail, it cannot be overemphasized that this invention is not limited to the said embodiment, It can change into a various aspect. In particular, the embodiments should not be strictly interpreted as being independent of each other. For example, an aspect obtained by replacing some elements in one embodiment with elements described in another embodiment should be understood as the scope of the disclosure of the present invention.

  In order to confirm the effect of the present invention, a plurality of types of golf club heads having the basic structures shown in FIGS. 1 to 4 and 6 were manufactured based on the specifications shown in Table 1 (Examples). Then, the same steel shaft of each golf club head was mounted, and an iron type golf club was prototyped.

  Next, using a simple swing robot, a hit test from a rough by each golf club was performed, and the backspin amount of the hit ball was measured. Each golf club was mounted on a swing robot with its face opened 30 degrees.

  As a result of the test, it was confirmed that the golf club head of the example maintained a high backspin amount as compared with the comparative example.

1 Head 3 Face 4 Top 5 Sole 6 Toe 7 Hosel 8 Groove 9 Narrow groove 10 Deepest part 11 First wall 12 Second wall 21 First corner part 22 Second corner part

Claims (8)

A golf club head,
Having a face for hitting the ball,
The face is formed with a plurality of grooves extending along the toe-heel direction and a plurality of narrow grooves having a groove width smaller than the groove,
In the front view of the face with the golf club head in a reference state placed on a horizontal plane at a specified lie angle and loft angle tilted forward so that the face is vertical, the plurality of narrow grooves are , Arranged to be inclined with respect to the toe-heel direction, and the inclination is lower right.
Golf club head.   The golf club head according to claim 1, wherein the plurality of narrow grooves are inclined at an angle of 30 degrees or more and less than 90 degrees with respect to the toe-heel direction.   The golf club head according to claim 1, wherein the plurality of narrow grooves are inclined at an angle of 30 degrees or more and less than 60 degrees with respect to the toe-heel direction.   4. The golf club head according to claim 1, wherein a pitch of the plurality of narrow grooves is 2.5 to 5.0 times a groove width of the narrow grooves. 5.   5. The golf club head according to claim 1, wherein each of the plurality of narrow grooves has an asymmetric triangular shape having a deepest portion at a position different from the position of the groove width center line. . The cross section of the narrow groove has a first wall and a second wall having a length longer than the first wall,
The golf club head according to claim 5, wherein the narrow groove includes one in which the first wall is located on a top side of the golf club head. The cross section of the narrow groove has a first wall and a second wall having a length longer than the first wall,
The golf club head according to claim 5, wherein the narrow groove includes one in which the second wall is located on a top side of the golf club head.   8. The golf club head according to claim 1, wherein a groove width of the narrow groove is 0.1 to 1.0 mm, and a depth of the narrow groove is 10 to 25 μm.

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