JP4855967B2 - Iron type golf club head - Google Patents

Description

  The present invention relates to an iron type golf club head and the like.

  Iron-type golf clubs often hit a ball placed on the ground. It is the sole surface that touches the ground during a shot. The shape of the sole surface affects the result of the shot. Typically, the shape of the sole surface affects the goodness of omission (high omission performance). A head with high pull-out performance has low ground resistance during shots, and has excellent flight distance and directionality. A head with low dropout performance tends to have a reduced head speed due to duffing. Heads with low dropout performance tend to change head speed. Changes in head speed can vary flight distance. A head with low removal performance tends to change the face orientation due to duffing. The change in the orientation of the face causes the hitting direction to vary.

An iron type golf club head characterized by the shape of the sole surface has been proposed. Japanese Patent Application Laid-Open No. 5-192425 discloses an iron type golf club head in which a runner is provided on a sole to reduce a ground contact area. Japanese Patent Laid-Open No. 2001-95960 discloses a golf club head in which the entire sole has a positive sole angle, and the sole angle on either the toe side or the heel side of the sole is larger than the other sole angle. Disclose. Japanese Patent Laying-Open No. 2005-287749 has a groove-like portion extending inclinedly from the toe side toward the heel side from the trailing edge side toward the leading edge side on the sole surface on the heel side with respect to the face center position. An iron type golf club head is disclosed.
JP-A-5-192425 JP 2001-95960 A Japanese Patent Laying-Open No. 2005-287749

  Of iron type golf clubs, a club having a particularly large loft angle is generally called a wedge club. The real loft angle of the wedge club is set to about 55 degrees. This wedge club is suitable for obtaining a high trajectory. The wedge club is suitable for bunker shots and approach shots.

  In order to escape from a deep bunker, it is necessary to launch the ball high. In approach shots, there are situations where it is desired to suppress the ball run. A high trajectory is often required for approach shots and bunker shots. A particularly high trajectory approach shot is generally referred to as a lob shot.

  In bunker shots and lob shots, hitting with an open face is often used. By opening the face, the effective loft angle becomes larger than the real loft angle. High trajectory can be obtained by increasing the effective loft angle. The effective loft angle is a loft angle in impact and is a loft angle with respect to the vertical direction.

  However, by opening the face and hitting, various miss shots are likely to be born. Opening the face reduces the distance between the ball and the neck in impact. For this reason, when the face is opened and hit, a shank is likely to occur. A shank is a miss shot caused by the ball hitting the neck. With the shank, the ball is launched in a direction greatly deviating from the target direction.

  The degree of opening of the face is determined by the player's feeling. The degree of opening of the face varies greatly from shot to shot. The direction of the hit ball changes depending on the degree of opening of the face. For a right-handed golfer, the ball flies to the right as the face opens. The effective loft angle changes depending on the degree of opening of the face. The more you open the face, the higher the ball will fly. When hitting with the face open, flight distance and directionality tend to vary. Due to this variation, the probability of the ball approaching the pin decreases.

  As a means for eliminating the drawbacks of hitting with the face open, it is conceivable to increase the real loft angle of the head. However, it has been found that simply increasing the real loft angle tends to cause so-called duffing and makes it difficult to obtain a nice shot. “Duff” is a miss shot that occurs when the head contacts the ground before the impact. Due to duffing, the head speed at impact can be greatly reduced. The orientation of the face surface can change due to duffing.

  An object of the present invention is to provide an iron type golf club head that can raise a ball highly without opening a face and can reduce miss shots.

  The golf club head of the present invention has a face surface, a back face, and a sole surface. The sole surface has a first sole surface disposed at the front and a second sole surface disposed at the rear. The first sole surface has a positive sole angle at the center reference position. The second sole surface has a negative sole angle at the center reference position. The sole angle θ1c (degrees) at the center reference position of the first sole surface is not less than 20 degrees and not more than 40 degrees. The real loft angle is not less than 60 degrees and not more than 80 degrees.

  Preferably, the sole angle θ2c (degrees) at the center reference position of the second sole surface is set to be −40 degrees or more and −2 degrees or less.

  Preferably, when the sole width at the center reference position of the first sole surface is wc1, and the sole width at the center reference position of the second sole surface is wc2, the ratio (wc2 / wc1) is 1.0 or more. 4.0 or less.

Preferably, the angle θ3c calculated by the following equation (1) is 120 degrees or more and 160 degrees or less.
θ3c = 180− (θ1c + | θ2c |) (1)
However, in formula (1), | θ2c | is the absolute value of the sole angle θ2c.

  A large real loft angle can provide a high trajectory without opening the face. The first sole surface and the second sole surface can reduce miss shots in a head having a large real loft angle.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 is a front view of an iron type golf club head 2 according to an embodiment of the present invention. FIG. 1 is a diagram in a reference state placed on a horizontal plane h. FIG. 2 is a view of the head 2 in the reference state as viewed from above. FIG. 3 is a perspective view of the head 2 as viewed from the back face side. FIG. 4 is a view of the head 2 as seen from the sole surface side.

  The reference state of the head 2 means that the shaft axis line z of the head 2 is disposed in the vertical plane VP1, the shaft axis line z is inclined with respect to the horizontal plane h by the lie angle α, and the face surface 4 is aligned with the vertical plane VP1. Is inclined at the real loft angle to be in contact with the horizontal plane h (see FIGS. 1 and 2).

  Unless otherwise specified herein, the head 2 is described as being in a reference state. The vertical direction or height direction with respect to the head 2 means the vertical direction or height direction with respect to the head 2 in the reference state. The toe-heel direction of the head 2 is a direction parallel to the vertical plane VP1 and parallel to the horizontal plane h in the head 2 in the reference state. The front-rear direction with respect to the head 2 is a direction perpendicular to the vertical plane VP1 and parallel to the horizontal plane h in the head 2 in the reference state, the face surface 4 side is the front side, and the back face 6 side is the rear side. It is.

  The real loft angle β of the head 2 is 60 degrees or more and 80 degrees or less. With this real loft angle β, a large effective loft angle can be obtained without opening the face. This real loft angle β eliminates the need to open the face, so that miss shots can be reduced. From the viewpoint of obtaining a large effective loft angle without opening the face, the real loft angle β is preferably 60 degrees or more, and more preferably 65 degrees or more. From the viewpoint of suppressing the occurrence of duff, the real loft angle β is preferably 80 degrees or less, and more preferably 75 degrees or less.

  In FIG. 1, what is indicated by a double arrow FH is the vertical face height (effective face height) in the reference state. When the real loft angle is large, the effective face height FH is small. Therefore, in this case, a miss shot is likely to occur when the vertical position of the head is slightly shifted in impact. When the head position is shifted upward with respect to the ball, the top is obtained. When the head position is shifted downward with respect to the ball, the head is duffled. When the effective face height FH is small, duff and top are likely to occur. In approach shots, it is easy to work especially to prevent the top. This is because the top often has a greater degree of error compared to duff. The top is likely to cause a result that the flying distance is remarkably excessive as compared with the intended flight distance, and the score is greatly deteriorated. When the real loft angle is large, the consciousness to prevent the top is excessive. When the consciousness to prevent the top works, the head tends to shift downward with respect to the ball, and duffing easily occurs. The present invention can effectively suppress miss shots caused by duff in a head having a large real loft angle.

  The head 2 is entirely made of a metal material. The metal material is not particularly limited, and is preferably one or more of soft iron (soft steel), stainless steel, maraging steel, pure titanium, titanium alloy, aluminum alloy, and the like. A fiber reinforced resin and / or an ionomer resin may be used for a part of the head.

  The head 2 has a face surface 4, a back face 6, and a sole surface 8. The head 2 has a hosel 10. The hosel 10 has a shaft hole 12. A face line 14 is provided on the face surface 4. A plurality of face lines 14 are provided at regular intervals. Each of the face lines 14 extends in the toe-heel direction. The face line 14 has a groove shape. In the sectional view of the present application, the description of the face line 14 is omitted.

  The head 2 has an impact area marking M. The impact area marking M is provided to increase friction with the ball. In the head 2 of the present embodiment, the impact area marking M is the face line 14. As the impact area marking M, for example, as described in the section “5. Club face” in Appendix II of the Golf Rules established by the Japan Golf Association, it is a face line (groove) and / or a small dot-like depression. There are certain punch marks. The face surface 4 is formed of a substantially single plane except for the impact area marking M. The head 2 is not provided with a face roll or a face bulge.

  As shown in FIG. 1, the impact area marking M has its most toe side position et and most heel side position eh. When there are a plurality of positions on the toe side of the impact area marking M, the position et is the end on the most toe side among the plurality of positions. When there are a plurality of positions on the heel side of the impact area marking M, the position eh is the end on the most heel side among the plurality of positions.

  The area length E1 (see FIG. 1) of the impact area marking M is preferably 40 mm or more, more preferably 50 mm or more, and the length E1 is preferably 90 mm or less, more preferably 80 mm or less, and even more preferably 70 mm. It is as follows. If the impact area marking area length E1 is too small, the backspin amount of the ball may be reduced during a miss shot. This length E1 is the length in the toe-heel direction from the position et to the position eh.

  In the present invention, a center reference position fc, a toe reference position tk, and a heel reference position hk are defined. The center reference position fc, the toe reference position tk, and the heel reference position hk are all positions in the toe-heel direction. The center reference position fc is a position that bisects the position et and the position eh (see FIGS. 1 and 4). The toe reference position tk is a position 25 mm away from the center reference position fc on the toe side. This “25 mm” is the distance in the toe-heel direction. The heel reference position hk is a position 25 mm away from the center reference position fc toward the heel side. This “25 mm” is the distance in the toe-heel direction.

  In this specification, when the shape of the sole surface 8 is described by a cross-sectional shape, the cross-section is a plane P that is perpendicular to the vertical plane VP1 and perpendicular to the horizontal plane h in the head 2 in the reference state. is there. This plane P is also referred to as a reference plane below. The reference plane can be set at any position in the toe-heel direction. In FIG. 1 and the like, Pt indicates a reference plane at the toe reference position tk. In FIG. 1 and the like, Pc indicates a reference surface at the center reference position fc. In FIG. 1 and the like, Ph indicates a reference surface at the heel reference position hk.

  An edge portion of the sole surface 8 on the face surface 4 side constitutes a leading edge 16. The leading edge 16 forms a boundary between the face surface 4 and the sole surface 8. An edge of the sole surface 8 on the back face 6 side constitutes a trailing edge 18. The trailing edge 18 forms a boundary between the back face 6 and the sole surface 8. The leading edge 16 and the trailing edge 18 constitute a visible ridgeline. The sole surface 8 connects the face surface 4 and the back face 6 on the bottom surface side of the head.

  When the contour shape before and after the sole surface 8 is an arc having a large radius of curvature, when a clear edge cannot be specified, the leading edge 16 is defined as the leading edge 16 in the cross-sectional line by the reference surface. The trailing edge 18 can be a position that is the farthest away from the face surface 4 in the cross-sectional line in the direction perpendicular to the face surface (the point having the longest distance from the face surface 4).

  As shown in FIGS. 3 and 4, the sole surface 8 has a first sole surface 20 and a second sole surface 22. The first sole surface 20 is located in front of the second sole surface 22. The first sole surface 20 is located on the leading edge 16 side of the second sole surface 22. The second sole surface 22 is located behind the first sole surface 20. The second sole surface 22 is located on the trailing edge 18 side of the first sole surface 20.

  Although not shown, the sole surface 8 is usually provided with a groove that indicates a number, letters, and the like. Except for this groove, the first sole surface 20 is a smoothly curved convex surface. Except for this groove, the second sole surface 22 is a smoothly curved convex surface.

  The sole surface 8 has a partition line 24. The first sole surface 20 and the second sole surface 22 are partitioned by a partition line 24. The first sole surface 20 and the second sole surface 22 are adjacent to each other via a partition line 24. A typical lane marking 24 constitutes a corner. A typical lane marking 24 constitutes an edge. The division line 24 is a ridge line. The dividing line 24 can be visually observed as a line. When the division line 24 is unclear, the midpoint of the portion where the radius of curvature is 3.0 mm or less in the cross-sectional line by the reference plane can be the division line 24.

  FIG. 5 is a cross-sectional view of the head 2 taken along the reference plane Pc. In the present invention, the sole angle is defined. In the present invention, the sole angle is determined in the cross section by the reference plane. The sole angle is determined at every position in the toe-heel direction. That is, a reference surface exists at each position in the toe-heel direction, and the sole angle is determined in each of the cross sections by the reference surfaces. The sole angle is determined in a cross section by the reference plane.

  In general, a so-called bounce angle or scoop angle may also be referred to as a sole angle. The “sole angle” which may be generally referred to may mean a tangential angle of a cross section of the sole surface at the center in the toe-heel direction of the sole and the center in the front-rear direction of the sole. This is different from the meaning of “sole angle” in the present application. The “sole angle” in the present application is determined at each position in the toe-heel direction. Furthermore, the “sole angle” in the present application is determined for each of the first sole surface 20 and the second sole surface 22.

  As shown in FIG. 5, in the cross section by the reference plane, the angle formed by the tangent line N1 and the horizontal plane h at the midpoint s1 of the cross section line of the first sole surface 20 is the sole angle θ1 of the first sole surface. The sole angle θ1 on the reference plane Pc is the sole angle θ1c. In the cross section by the reference plane, the midpoint s2 of the cross section line of the second sole surface 22 is determined. The angle formed by the tangent N2 at the midpoint s2 and the horizontal plane h is the sole angle θ2 of the second sole surface. The sole angle θ2 on the reference plane Pc is the sole angle θ2c.

  Although not shown, the sole angle θ1 on the reference plane Pt is the sole angle θ1t, the sole angle θ2 on the reference plane Pt is the sole angle θ2t, the sole angle θ1 on the reference plane Ph is the sole angle θ1h, and the reference plane Ph The sole angle θ2 is the sole angle θ2h.

  When the cross section of the sole surface by the reference surface is a convex curve as in the head 2 described above, the sole angles θ1 and θ2 are angles formed by a tangent at the midpoint of the cross section line of the sole surface and the horizontal plane h. When the midpoint is located at a portion where the cross section line of the sole surface is a straight line, the angle formed by this straight line and the horizontal plane h is the sole angle. When the sole surface is a concave surface and the midpoint is included in the cross-sectional line of the convex surface, the angle formed by the inclined straight line T1 passing through both ends of the cross-sectional line of the concave surface and the horizontal plane h is the sole angle. FIG. 6 shows the sole angle θ2 when the second sole surface 23 is a concave surface.

  As the sole angle, a positive sole angle and a negative sole angle are defined. The sole angle θ1 of the first sole surface is positive. The sole angle θ2 of the second sole surface is negative. When the tangent line (inclined straight line) of the sole surface is inclined so as to be higher toward the front of the head, the sole angle is positive. When the tangent line (inclined straight line) of the sole surface is inclined so as to become downward as it goes to the front of the head, the sole angle is negative. When the tangent line (inclined straight line) of the sole surface is parallel to the horizontal plane h, the sole angle is 0 degree. The unit of the sole angle is degree.

In the present invention, the angle θ3 is defined. Similar to the sole angle, the angle θ3 is also determined in the cross section by the reference plane. The angle θ3 is determined at every position in the toe-heel direction. The angle θ3 (degrees) can be calculated from the sole angles θ1 and θ2 by the following equation.
θ3 = 180− (θ1 + | θ2 |)
However, | θ2 | is the absolute value of θ2.

The angle θ3 on the reference plane Pc is the angle θ3c. This angle θ3c is calculated by the following equation (1).
θ3c = 180− (θ1c + | θ2c |) (1)
However, | θ2c | is the absolute value of θ2c. For example, when the sole angle θ1c is 20 degrees and the sole angle θ2c is −10 degrees, θ3c is 150 degrees.

The angle θ3 on the reference plane Pt is the angle θ3t. This angle θ3t is calculated by the following equation (2).
θ3t = 180− (θ1t + | θ2t |) (2)
However, | θ2t | is the absolute value of θ2t.

The angle θ3 on the reference plane Ph is the angle θ3h. This angle θ3h is calculated by the following equation (3).
θ3h = 180− (θ1h + | θ2h |) (3)
However, | θ2h | is the absolute value of θ2h.

  The angle θ3c is set to be 120 degrees or more and 160 degrees or less. The angle θ3t is 120 degrees or more and 160 degrees or less. The angle θ3h is not less than 120 degrees and not more than 160 degrees. In every toe-heel direction position from the toe reference position tk to the heel reference position hk, the angle θ3 is 120 degrees or more and 160 degrees or less. At every position in the toe-heel direction, the angle θ3 is set to 120 degrees or more and 160 degrees or less.

  The value of the sole angle θ1c is positive (plus). Further, the value of the sole angle θ1 of the first sole surface is positive at any toe-heel direction position from the toe reference position to the heel reference position. Furthermore, the value of the sole angle θ1 of the first sole surface is positive at all toe-heel direction positions. This positive sole angle makes the sole surface slippery with respect to the ground contact surface. This positive sole angle increases the explosion effect and the sliding effect. The value of the sole angle θ1 can particularly reduce the ground resistance from immediately before impact to impact.

  The explosion effect is an effect of exploding sand in a bunker shot and flying a ball together with sand. A normal bunker shot is an explosion shot. A club with a high explosion effect facilitates bunker shots.

  The value of the sole angle θ2c is negative (minus). Further, the sole angle θ2 of the second sole surface is negative in any toe-heel direction range from the toe reference position tk to the heel reference position hk. Further, the sole angle θ2 of the second sole surface is negative in all toe-heel direction ranges. This negative sole angle increases the removal performance. The value of the sole angle θ2 can particularly reduce the ground resistance from impact to immediately after impact.

  When the bounce angle is large on the entire sole surface, the explosion effect can be enhanced, but the slipping performance is deteriorated. Due to the poor dropout performance, the flight distance performance and the hitting ball directivity deteriorate. The present invention improves the pull-out performance by the second sole surface while reducing the ground resistance by the first sole surface. By setting the sole angle θ1c to be positive and the sole angle θ2c to be negative, it is possible to achieve both the removal performance and the explosion effect. By making the sole angle θ1c positive and the sole angle θ2c negative, mistakes due to duffing are easily mitigated.

  The sole angle θ1c of the first sole surface is set to 20 degrees or more, which is larger than the bounce angle of the conventional head. By setting the sole angle θ1c to 20 degrees or more, the sliding effect and the explosion effect are sufficiently ensured even though the first sole surface is only a part of the sole surface. The slip effect is an effect that makes the sole surface slip easily with respect to the ground contact surface. In the conventional head, when the bounce angle of the entire sole is set to 20 degrees or more, the head tends to be caught on the ground surface, and the ground resistance tends to increase. On the other hand, in the present invention, due to the presence of the second sole surface having a negative sole angle, the removal performance is enhanced even if the sole angle θ1c is 20 degrees or more. The presence of the second sole surface having a negative sole angle can reduce the ground resistance at the rear portion of the sole surface.

  In the present invention, the sole width is defined. The sole width is the width of the sole surface at the cross-sectional line by the reference surface. The sole width is determined at every position in the toe-heel direction. The sole width is a distance between both ends of the sole surface at the cross-sectional line by the reference surface. The sole width of the first sole surface 20 is the sole width w1. The sole width w1 is determined at every position in the toe-heel direction. The sole width of the second sole surface 22 is the sole width w2. The sole width w2 is determined at every position in the toe-heel direction.

  In FIG. 4, what is indicated by a double-headed arrow wc1 is the sole width of the first sole surface at the center reference position fc. In FIG. 4, a double arrow wh1 indicates the sole width of the first sole surface at the heel reference position. In FIG. 4, what is indicated by a double arrow wt1 is the sole width of the first sole surface at the toe reference position. In FIG. 4, what is indicated by a double arrow wc2 is the sole width of the second sole surface at the center reference position fc. In FIG. 4, what is indicated by a double-headed arrow wh2 is the sole width of the second sole surface at the heel reference position. In FIG. 4, what is indicated by a double arrow wt2 is the sole width of the second sole surface at the toe reference position. The sole widths wc1 and wc2 are measured in a cross section by the reference plane Pc. The sole widths wh1 and wh2 are measured in a cross section by the reference plane Ph. The sole widths wt1 and wt2 are measured in a cross section by the reference plane Pt.

  In the head 2, the ratio (wc2 / wc1) is 1.0 or more and 4.0 or less. In the head 2, the ratio (wt2 / wt1) is set to 1.0 or more and 4.0 or less. In the head 2, the ratio (wh2 / wh1) is 1.0 or more and 4.0 or less. In every toe-heel direction position from the toe reference position tk to the heel reference position hk, the ratio (w2 / w1) is 1.0 or more and 4.0 or less. In all toe-heel direction positions, the ratio (w2 / w1) is 1.0 or more and 4.0 or less.

  In the head 2, the sole width wc1 is narrower than the sole width wc2. In the head 2, the sole width wt1 is narrower than the sole width wt2. In the head 2, the sole width wh1 is narrower than the sole width wh2. The sole width w1 of the first sole surface 20 is narrower than the sole width w2 of the second sole surface 22 at every position in the toe-heel direction from the heel reference position hk to the toe reference position tk. The sole width w1 of the first sole surface 20 is narrower than the sole width w2 of the second sole surface 22 at every position in the toe-heel direction.

  The shape of the face surface according to the present invention (any provision in the present invention) is preferably achieved at the center reference position fc, more preferably at the center reference position fc, the toe reference position tk, and the heel reference position hk. More preferably, it is achieved at any toe-heel direction position from the toe reference position tk to the heel reference position hk, and even more preferably at any toe-heel direction position. It is because the effect is so high that it is achieved in a wide range.

  If the sole angle θ1 is too small, the sole surface becomes difficult to slide smoothly with respect to the grounding surface, and the grounding resistance can be increased. If the sole angle θ1 is too small, the sole surface is less likely to collide with the sand of the bunker, and the explosion effect tends to decrease. If the sole angle θ1 is too large, the sole surface 8 tends to be caught on the ground contact surface, and the ground resistance of the first sole surface 20 tends to be high.

  From the viewpoint of enhancing the slipping performance and the explosion effect, the sole angle θ1c is preferably 20 degrees or more, and more preferably 25 degrees or more. From the viewpoint of preventing the occurrence of duffing, the sole angle θ1c is preferably 40 degrees or less, and more preferably 35 degrees or less.

  From the viewpoint of enhancing the slipping performance and the explosion effect, the sole angle θ1t is preferably 20 degrees or more, and more preferably 25 degrees or more. From the viewpoint of preventing the occurrence of duffing, the sole angle θ1t is preferably 40 degrees or less, and more preferably 35 degrees or less.

  From the viewpoint of enhancing the slipping performance and the explosion effect, the sole angle θ1h is preferably 20 degrees or more, and more preferably 25 degrees or more. From the viewpoint of preventing the occurrence of duff, the sole angle θ1h is preferably 40 degrees or less, and more preferably 35 degrees or less.

  From the viewpoint of enhancing the slipping performance and the explosion effect, the sole angle θ1 is preferably 20 degrees or more, and more preferably 25 degrees or more, in any toe-heel direction position from the heel reference position hk to the toe reference position tk. From the viewpoint of making it difficult to cause duffing, the sole angle θ1 is preferably 40 degrees or less and more preferably 35 degrees or less at any position in the toe-heel direction from the heel reference position hk to the toe reference position tk.

  From the viewpoint of enhancing the slipping performance and the explosion effect, the sole angle θ1 is preferably 20 degrees or more, and more preferably 25 degrees or more at any position in the toe-heel direction. From the viewpoint of making it difficult to cause duffing, the sole angle θ1 is preferably 40 degrees or less and more preferably 35 degrees or less at any position in the toe-heel direction.

  If the sole angle θ2 is too small, the second sole surface 22 will not easily collide with the sand of the bunker, and the explosion effect tends to be reduced. If the sole angle θ2 is too large, the second sole surface 22 is likely to be grounded, and the slipping performance is likely to deteriorate.

  In light of enhancing the explosion effect, the sole angle θ2c is preferably −40 degrees or greater, more preferably −30 degrees or greater, and even more preferably −20 degrees or greater. From the viewpoint of improving the slipping performance, the sole angle θ2c is preferably −2 degrees or less, more preferably −5 degrees or less, and still more preferably −10 degrees or less.

  From the viewpoint of enhancing the explosion effect, the sole angle θ2t is preferably −40 degrees or more, more preferably −30 degrees or more, and more preferably −20 degrees or more. From the viewpoint of improving the removal performance, the sole angle θ2t is preferably −2 degrees or less, more preferably −5 degrees or less, and still more preferably −10 degrees or less.

  From the viewpoint of enhancing the explosion effect, the sole angle θ2h is preferably −40 degrees or more, more preferably −30 degrees or more, and more preferably −20 degrees or more. From the viewpoint of improving the removal performance, the sole angle θ2h is preferably −2 degrees or less, more preferably −5 degrees or less, and still more preferably −10 degrees or less.

  From the viewpoint of enhancing the explosion effect, the sole angle θ2 is preferably −40 degrees or more, more preferably −30 degrees or more, and −20 degrees at any toe-heel direction position from the heel reference position hk to the toe reference position tk. The above is more preferable. From the viewpoint of improving the slipping performance, the sole angle θ2 is preferably −2 degrees or less, more preferably −5 degrees or less, and −10 degrees at any toe-heel direction position from the heel reference position hk to the toe reference position tk. The following is more preferable.

  From the viewpoint of enhancing the explosion effect, the sole angle θ2 is preferably −40 degrees or more, more preferably −30 degrees or more, and more preferably −20 degrees or more at any toe-heel direction position. From the viewpoint of improving the slipping performance, the sole angle θ2 is preferably −2 degrees or less, more preferably −5 degrees or less, and further preferably −10 degrees or less at any position in the toe-heel direction.

  From the viewpoint of enhancing the removal performance and the explosion effect, the sole width wc1 of the first sole surface is preferably 5 mm or more, more preferably 6 mm or more, and still more preferably 8 mm or more. When the sole width wc1 is large, the height HL (see FIG. 1) of the leading edge from the ground contact surface becomes large, and a miss shot called a top tends to occur. In this respect, the sole width wc1 is preferably equal to or less than 15 mm, more preferably equal to or less than 13 mm, and still more preferably equal to or less than 12 mm. Note that the top is a miss shot resulting from the ball hitting the leading edge.

  From the viewpoint of enhancing the slipping performance and the explosion effect, the sole width wt1 of the first sole surface is preferably 5 mm or more, more preferably 6 mm or more, and still more preferably 8 mm or more. From the viewpoint of suppressing a miss shot called a top, the sole width wt1 is preferably 15 mm or less, more preferably 13 mm or less, and even more preferably 12 mm or less.

  From the viewpoint of enhancing the removal performance and the explosion effect, the sole width wh1 of the first sole surface is preferably 5 mm or more, more preferably 6 mm or more, and further preferably 8 mm or more. From the viewpoint of suppressing a miss shot called a top, the sole width wh1 is preferably 15 mm or less, more preferably 13 mm or less, and further preferably 12 mm or less.

  From the viewpoint of enhancing the slipping performance and the explosion effect, the sole width w1 of the first sole surface is preferably 5 mm or more and more preferably 6 mm or more at any toe-heel direction position from the toe reference position tk to the heel reference position hk. 8 mm or more is more preferable. From the viewpoint of suppressing a miss shot called a top, the sole width w1 is preferably 15 mm or less, more preferably 13 mm or less, and more preferably 12 mm or less at any toe-heel direction position from the toe reference position tk to the heel reference position hk. Further preferred.

  From the standpoint of enhancing the slipping performance and the explosion effect, the sole width w1 of the first sole surface is preferably 5 mm or more, more preferably 6 mm or more, and even more preferably 8 mm or more at any position in the toe-heel direction. From the viewpoint of suppressing a miss shot referred to as a top, the sole width w1 is preferably 15 mm or less, more preferably 13 mm or less, and even more preferably 12 mm or less at any position in the toe-heel direction.

  As described above, the shape of the second sole surface is related to the head behavior from the impact to immediately after the impact. From the viewpoint of stabilizing the head behavior immediately after impact from the impact and improving the flight distance and hitting directionality, the sole width wc2 of the second sole surface is preferably 10 mm or more, more preferably 12 mm or more, and still more preferably 14 mm or more. From the viewpoint of suppressing an excessive weight increase of the head, the sole width wc2 is preferably 25 mm or less, more preferably 23 mm or less, and further preferably 20 mm or less.

  From the viewpoint of stabilizing the head behavior immediately after impact from the impact and improving the flight distance and hitting directionality, the sole width wt2 of the second sole surface is preferably 10 mm or more, more preferably 12 mm or more, and still more preferably 14 mm or more. From the viewpoint of suppressing an excessive increase in the weight of the head, the sole width wt2 is preferably 25 mm or less, more preferably 23 mm or less, and even more preferably 20 mm or less.

  From the viewpoint of stabilizing the head behavior immediately after impact from the impact and improving the flight distance and hitting directionality, the sole width wh2 of the second sole surface is preferably 10 mm or more, more preferably 12 mm or more, and still more preferably 14 mm or more. In light of suppressing excessive weight increase of the head, the sole width wh2 is preferably equal to or less than 25 mm, more preferably equal to or less than 23 mm, and still more preferably equal to or less than 20 mm.

  From the viewpoint of stabilizing the head behavior immediately after the impact and improving the flight distance and hitting direction, the sole width w2 of the second sole surface at any toe-heel direction position from the toe reference position tk to the heel reference position hk. Is preferably 10 mm or more, more preferably 12 mm or more, and still more preferably 14 mm or more. From the viewpoint of suppressing an excessive increase in the weight of the head, in any toe-heel direction position from the toe reference position tk to the heel reference position hk, the sole width w2 is preferably 25 mm or less, more preferably 23 mm or less, and further 20 mm or less. preferable.

  From the viewpoint of stabilizing the head behavior immediately after the impact and improving the flight distance and hitting direction, the sole width w2 of the second sole surface is preferably 10 mm or more, more preferably 12 mm or more at any toe-heel direction position. Preferably, 14 mm or more is more preferable. From the viewpoint of suppressing an excessive increase in the weight of the head, the sole width w2 is preferably 25 mm or less, more preferably 23 mm or less, and even more preferably 20 mm or less at any position in the toe-heel direction.

  From the viewpoint of suppressing the sole width wc2 from becoming excessively small and suppressing the sole width wc1 from excessively increasing, the ratio (wc2 / wc1) is preferably 1.0 or more, and more preferably 1.1 or more. 1.4 or more is more preferable. From the viewpoint of suppressing the sole width wc1 from becoming excessively small and suppressing the sole width wc2 from excessively increasing, the ratio (wc2 / wc1) is preferably 4.0 or less, and more preferably 3.0 or less. 2.5 or less is more preferable.

  From the viewpoint of suppressing the sole width wt2 from becoming excessively small and suppressing the sole width wt1 from excessively increasing, the ratio (wt2 / wt1) is preferably 1.0 or more, and more preferably 1.1 or more. 1.4 or more is more preferable. From the viewpoint of suppressing the sole width wt1 from becoming excessively small and suppressing the sole width wt2 from excessively increasing, the ratio (wt2 / wt1) is preferably 4.0 or less, and more preferably 3.0 or less. 2.5 or less is more preferable.

  From the viewpoint of suppressing the sole width wc2 from becoming excessively small and suppressing the sole width wc1 from excessively increasing, the ratio (wc2 / wc1) is preferably 1.0 or more, and more preferably 1.1 or more. 1.4 or more is more preferable. From the viewpoint of suppressing the sole width wc1 from becoming excessively small and suppressing the sole width wc2 from excessively increasing, the ratio (wc2 / wc1) is preferably 4.0 or less, and more preferably 3.0 or less. 2.5 or less is more preferable.

  From the standpoint of suppressing the sole width w2 from becoming excessively small and suppressing the sole width w1 from excessively increasing, the ratio (w2) at any toe-heel direction position from the toe reference position tk to the heel reference position hk. / W1) is preferably 1.0 or more, more preferably 1.1 or more, and still more preferably 1.4 or more. From the viewpoint of suppressing the sole width w1 from becoming excessively small and suppressing the sole width w2 from becoming excessively large, the ratio (w2) at any toe-heel direction position from the toe reference position tk to the heel reference position hk. / W1) is preferably 4.0 or less, more preferably 3.0 or less, and even more preferably 2.5 or less.

  From the viewpoint of suppressing the sole width w2 from becoming excessively small and suppressing the sole width w1 from excessively increasing, the ratio (w2 / w1) is preferably 1.0 or more at any position in the toe-heel direction. 1.1 or more is more preferable, and 1.4 or more is more preferable. From the viewpoint of suppressing the sole width w1 from becoming excessively small and suppressing the sole width w2 from excessively increasing, the ratio (w2 / w1) is preferably 4.0 or less at any position in the toe-heel direction. 3.0 or less is more preferable, and 2.5 or less is more preferable.

  If the angle θ3 is too small, the second sole surface is less likely to be grounded, and the effects resulting from the second sole surface are likely to be reduced. When the angle θ3 is too small, the second sole surface is difficult to be grounded, and therefore the explosion effect is likely to be reduced. In addition, when the face is opened, the head is inclined so that the effective loft angle is increased, so that the second sole surface is easily grounded. When the angle θ3 is too large, the ground resistance of the second sole surface when hitting with the face opened tends to be excessive. Therefore, when the angle θ3 is too large, the pull-out performance tends to deteriorate due to the ground resistance of the second sole surface.

  From the viewpoint of enhancing the effect of providing the second sole surface and enhancing the explosion effect, the angle θ3c is preferably 120 degrees or more, and more preferably 130 degrees or more. From the viewpoint of improving the slipping performance when hitting with the face open, the angle θ3c is preferably 160 degrees or less, and more preferably 150 degrees or less.

  From the viewpoint of enhancing the effect of providing the second sole surface and enhancing the explosion effect, the angle θ3t is preferably 120 degrees or more, and more preferably 130 degrees or more. From the viewpoint of improving the pull-out performance when hitting with the face open, the angle θ3t is preferably 160 degrees or less, and more preferably 150 degrees or less.

  From the viewpoint of enhancing the effect of providing the second sole surface and enhancing the explosion effect, the angle θ3h is preferably 120 degrees or more, and more preferably 130 degrees or more. From the viewpoint of improving the dropout performance when hitting with the face open, the angle θ3h is preferably 160 degrees or less, and more preferably 150 degrees or less.

  From the viewpoint of enhancing the effect of providing the second sole surface and enhancing the explosion effect, at any position in the toe-heel direction from the toe reference position tk to the heel reference position hk, the angle θ3 is preferably 120 degrees or more, and 130 degrees The above is more preferable. From the viewpoint of improving the slipping performance when hitting with the face open, the angle θ3 is preferably 160 degrees or less, and more preferably 150 degrees or less at any toe-heel direction position from the toe reference position tk to the heel reference position hk. .

  From the viewpoint of enhancing the effect of providing the second sole surface and enhancing the explosion effect, the angle θ3 is preferably 120 degrees or more and more preferably 130 degrees or more at any position in the toe-heel direction. From the viewpoint of improving the pull-out performance when hitting with the face open, the angle θ3 is preferably 160 degrees or less, and more preferably 150 degrees or less at any position in the toe-heel direction.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

Evaluation clubs consisting of Examples 1 to 9 and Comparative Examples 1 and 2 were produced and tested.
[Example 1]
The iron type golf club head according to Example 1 was obtained by forging soft iron (S25C), marking a face line, and performing surface polishing and plating. The real loft angle was 70 degrees and the head weight was 300 g. An iron-type golf club according to Example 1 was obtained by attaching a steel shaft to this head and further attaching a grip. S400 made by Dynamic Gold Co. was used for the shaft. For the grip, Eaton's tour velvet (no cord, no backline) was used. The club length was 35 inches. The specifications and evaluation results of Example 1 are shown in Table 1 below.

  In Table 1 below, “sole angle θ1” means the sole angle θ1 at any toe-heel direction position from the toe reference position tk to the heel reference position hk. For example, in Example 1, the sole angle θ1 is 20 degrees at any toe-heel direction position from the toe reference position tk to the heel reference position hk. Similarly, in Table 1 below, “sole width w1” means the sole width w1 at any toe-heel direction position from the toe reference position tk to the heel reference position hk. Similarly, in Table 1 below, “sole angle θ2” means the sole angle θ2 at any toe-heel direction position from the toe reference position tk to the heel reference position hk. Similarly, in Table 1 below, “sole width w2” means the sole width w2 at any toe-heel direction position from the toe reference position tk to the heel reference position hk. Similarly, in Table 1 below, “angle θ3” means an angle θ3 at any toe-heel direction position from the toe reference position tk to the heel reference position hk. In all examples, the sole angle θ1, the sole width w1, the sole angle θ2, the sole width w2, and the angle θ3 are constant at all toe-heel direction positions from the toe reference position tk to the heel reference position hk.

[Examples 2 to 9 and Comparative Examples 1 and 2]
Golf clubs according to Examples 2 to 9 and Comparative Examples 1 and 2 were obtained in the same manner as Example 1 except that the specification of the sole surface was as shown in Table 1 below. The specifications and evaluation results of each example are shown in Table 1 below.

[Evaluation by golfer]
Six golfers made a bunker shot and a lob shot on the grass, aiming for a pin 10 yards away. The handicap of the six golfers is 10-20. Each golfer took 10 bunker shots and 10 lob shots at each club. As the ball, “SRIXON Z-UR” manufactured by SRI Sports Co., Ltd. was used.

  In the evaluation by the lob shot on the turf, three items of “difficulty in duffing”, “goodness of omission”, and “feeling of distance” were evaluated. In the evaluation by bunker shot, “goodness of omission” and “feeling of distance” were evaluated. For each evaluation item, 10-step sensory evaluation was performed by the 10-point method. 10 points were given to the highest evaluation, and the higher the evaluation, the higher evaluation point was assigned among 1 to 10 points. The average score (rounded to the nearest decimal point) of the six golfers is shown in Table 1 below. “Diffle difficulty” is the degree to which a dull miss shot is unlikely to occur. The higher the score of “good omission”, the higher the omission performance. The higher the “distance” evaluation score, the easier it is to match the flight distance to the target distance and the higher the flight distance performance. Easy distance to target. These evaluation results are shown in Table 1 below.

  As shown in the table, the example has a higher evaluation than the comparative example. From this evaluation result, the superiority of the present invention is clear.

  The present invention can be applied to any iron type golf club head.

FIG. 1 is a front view of an iron type golf club head according to an embodiment of the present invention. FIG. 2 is a view of the iron type golf club head of FIG. 1 as viewed from above. FIG. 3 is a perspective view of the iron type golf club head of FIG. 1 viewed from the back face side. FIG. 4 is a view of the iron type golf club head of FIG. 1 as viewed from the sole surface side. FIG. 5 is a cross-sectional view of the iron type golf club head of FIG. 1 at the center reference position. FIG. 6 is a cross-sectional view of a modification.

Explanation of symbols

2 ... head 4 ... face surface 6 ... back face 8 ... sole surface 10 ... hosel 12 ... shaft hole 14 ... face line 16 ... leading edge 18 ... Trailing edge 20 ... first sole surface 22 ... second sole surface Pt ... reference surface at toe reference position Pc ... reference surface at center reference position Ph ... reference surface at heel reference position tk ... toe reference position fc ... center reference position hk ... heel reference position wt1 ... sole width of the first sole surface at the toe reference position wc1 ... sole width of the first sole surface at the center reference position wh1 ... sole width of the first sole surface at the heel reference position wt2 ... sole width of the second sole surface at the toe reference position wc2 ... center reference position Sole width of the second sole surface wh2 ... Sole width of the second sole surface at the heel reference position M ... Impact area marking z ... Shaft axis θ1 ... Sole angle of the first sole surface θ2, ...・ Sole angle of the second sole surface

Claims (6)

Having a face surface, a back face and a sole surface;
The sole surface has a first sole surface disposed at the front and a second sole surface disposed at the rear,
The first sole surface and the second sole surface are adjacent to each other via a lane marking,
The first sole surface has a positive sole angle at a central reference position;
The second sole surface has a negative sole angle at a central reference position;
The sole angle θ1c (degrees) at the center reference position of the first sole surface is 20 degrees or more and 40 degrees or less,
Real loft angle der 80 degrees or less than 60 degrees is,
When the sole width of the first sole surface at any position in the toe-heel direction is w1, and the sole width of the second sole surface at any position in the toe-heel direction is w2, the heel reference from the toe reference position An iron type golf club head having a ratio (w2 / w1) of 1.4 or more and 4.0 or less at any toe-heel direction position up to the position .   2. The golf club head according to claim 1, wherein a sole angle θ <b> 2 c (degrees) at a central reference position of the second sole surface is −40 degrees to −2 degrees. The golf club head according to claim 1 or 2 , wherein an angle θ3c calculated by the following formula (1) is 120 degrees or more and 160 degrees or less.
θ3c = 180− (θ1c + | θ2c |) (1)
However, in formula (1), | θ2c | is the absolute value of the sole angle θ2c. The section line of the first sole surface in the central reference position, the golf club head according to any one of claims 1 to 3, a convex curve. The golf club head according to claim 1 of the second sole surface is concave surface. In every toe-heel direction position from the toe reference position to the heel reference position, the sole width w1 of the first sole surface is 5 mm or more and 15 mm or less, and the sole width w2 of the second sole surface is 10 mm or more and 25 mm or less. The golf club head according to claim 1, wherein:

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