JP2008035984A - Iron type golf club head and iron golf club provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To offer an iron type golf club head capable of providing easy strikes and a high explosion effect even with its club face open. <P>SOLUTION: The iron type golf club head 2 comprises a face surface, a back face 6 and a sole face 8 positioned between the face surface and the back face 6. The sole surface 8 has a first sole surface 20 positioned at the side of the leading edge 16 and a second sole surface 22 positioned at the side of the trailing edge 18. The first sole surface 20 has the positive sole angle on the above-mentioned sole surface itself. The second sole surface 22 has the negative sole angle. The sole width wc1 of the first sole surface at the face center position fc is narrower than the sole width wh1 of the first sole surface at the heel side reference point hk and at the same time is narrower than the sole width wt1 of the first sole surface at the toe side reference point tk. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  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.

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

  In an iron type golf club, a shot is made with the face open, especially when it is desired to raise the ball high. This shot is frequently used in a lob shot, for example. Iron-type golf clubs are used in bunker. Bunkers often use so-called explosion shots. Explosion shots are shots that explode sand in a bunker and launch a ball with sand.

  With respect to shots made with the face open, the above prior art has not been sufficiently studied. Further, the golf club head described in JP-A-5-192425 and JP-A-2001-95960 is difficult to obtain an explosion effect (an effect of exploding sand and hitting a ball with sand) in a bunker shot. Met.

  An object of the present invention is to provide an iron-type golf club head that is easy to hit even when the face is open and is easy to perform an explosion shot.

  The iron type golf club head according to the present invention has a face surface, a back face, and a sole surface. When the toe side reference position is a position 25 mm away from the face center position to the toe side, and the heel side reference position is a position 25 mm away from the face center position to the heel side, the sole surface is on the heel side from the toe side reference position. It has a positive sole angle in the toe-heel direction range up to the reference position. The sole width (wc) at the face center position is narrower than the sole width (wh) at the heel side reference position and the sole width (wt) at the toe side reference position.

  Another iron type golf club head according to the present invention has a face surface, a back face, and a sole surface. The sole surface has a first sole surface disposed on the leading edge side and a second sole surface disposed on the trailing edge side. When the position separated by 25 mm from the face center position to the toe side is taken as the toe side reference position, and the position separated by 25 mm from the face center position to the heel side is taken as the heel side reference position, the first sole surface is moved from the toe side reference position. It has a positive sole angle in the toe-heel direction range to the heel side reference position, and the second sole surface has a negative sole angle in the toe-heel direction range from the toe side reference position to the heel side reference position. have. The sole width (wc1) of the first sole surface at the face center position is narrower than the sole width (wh1) of the first sole surface at the heel side reference position and the sole width (wt1) of the first sole surface at the toe side reference position. Has been.

  Preferably, the sole width (wc1) of the first sole surface at the face center position is 0.9 times or less than the sole width (wt1) of the first sole surface at the toe side reference position. Preferably, the sole width (wc1) of the first sole surface at the face center position is 0.9 times or less than the sole width (wh1) of the first sole surface at the heel side reference position.

  Preferably, the sole width (wc1) of the first sole surface at the face center position is 0.7 times or less than the sole width (wt1) of the first sole surface at the toe side reference position. Preferably, the sole width (wc1) of the first sole surface at the face center position is 0.7 times or less than the sole width (wh1) of the first sole surface at the heel side reference position.

  Preferably, in each cross section at the face center position, the toe side reference position, and the heel side reference position, the crossing angle between the inclination line T1 of the first sole surface and the inclination line T2 of the second sole surface is 130 degrees or more and 170 degrees or less. Is done. Each cross section at the toe side reference position and the heel side reference position is a cross section by a reference plane P described later.

  The positive sole angle increases the slipping performance and explosion effect. Further, by defining the sole width as described above, the floating of the leading edge when the face is opened is reduced, and a miss shot such as a top is suppressed.

  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 arranged in an arbitrary 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 vertical. It is inclined with respect to the plane VP1 at the real loft angle and is brought into 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 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.

  The head 2 is a so-called wedge. The real loft angle β of the wedge is usually 40 degrees or more and 68 degrees or less. Examples of the wedge include a pitching wedge (PW), an approach wedge (AW), a sand wedge (SW), and a pitching sand (PS).

  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, 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 cross-sectional view of the present application, the face line 14 is omitted as appropriate.

  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. That is, the head 2 is not provided with a face roll or a face bulge.

  The impact area marking M has the most toe side position et and the most heel side position eh. When the position of the toe side end of the impact area marking M is different, the position et is the most toe side end. When the position of the heel side end of the impact area marking M is different, the position eh is the most heel side end.

  The impact area marking region length E1 (see FIG. 1) 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 or less. is there. 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 face center position fc, a toe side reference position tk, and a heel side reference position hk are defined. The face center position fc, the toe side reference position tk, and the heel side reference position hk are all positions in the toe / heel direction. The face center position fc is a position that bisects the position et and the position eh (see FIGS. 1 and 4). The toe side reference position tk is a position 25 mm away from the face center position fc on the toe side. This “25 mm” is the distance in the toe-heel direction. The heel side reference position hk is a position 25 mm away from the face center 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 perpendicular to the vertical plane VP1 and perpendicular to the horizontal plane h in the head 2 in the reference state. It is. This plane P is also referred to as a reference plane P below. The reference plane P can be set at any position in the toe-heel direction. In FIG. 1 and the like, Pt indicates a reference surface at the toe side reference position tk. In FIG. 1 and the like, Pc indicates a reference plane at the face center position fc. In FIG. 1 and the like, Ph indicates a reference surface at the heel side 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 between the face surface 4 and the back face 6 on the head bottom surface side.

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

  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.

  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 P can be set as the division line 24.

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

  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 sole surface when there are a plurality of sole surfaces.

  The sole angle is determined for the sole surface when there is a single sole surface, and is determined for each sole surface when there are a plurality of sole surfaces. Since the head 2 has a first sole surface and a second sole surface, the sole angle is determined for each of the first sole surface and the second sole surface. As shown in FIG. 5, in the cross section taken along the reference plane P, 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. This tangent line N1 is an inclined straight line T1 of the first sole surface. In the cross section by the reference plane P, the angle formed by the tangent line N2 and the horizontal plane h at the midpoint s2 of the cross section line of the second sole surface 22 is the sole angle θ2 of the second sole surface. This tangent line N2 is the inclined straight line T2 of the second sole surface. Although the case where the head 2 has the first sole surface and the second sole surface has been described here, the definition of the sole angle is the same when the sole surface is single. That is, even when the sole surface is single, the sole angle is an angle formed by the inclined straight line and the horizontal plane h. In the present invention, the second sole surface may be omitted.

  When the cross section of the sole surface by the reference plane P is a convex curve as in the head 2 described above, the sole angle is an angle 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, an angle formed by the inclined straight line T2 passing through both ends of the concave surface and the horizontal plane h is a sole angle. FIG. 6 shows the inclined straight line T2 and the sole angle θ2 of the second sole surface 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. In FIG. 5, the sole angle θ1 of the first sole surface is positive. In FIG. 5, 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 degrees.

In the present invention, the intersection angle θ3 is defined. Similar to the sole angle, the crossing angle θ3 is also determined in the cross section by the reference plane P. The intersection angle θ3 is an angle formed by the inclined straight line T1 of the first sole surface and the inclined straight line T2 of the second sole surface. In the embodiment of FIG. 5, the intersection angle θ3 is an angle formed by the tangent line N1 and the tangent line N2. The unit of the crossing angle θ3 is degrees. When the sole angle θ1 of the first sole surface is positive and the sole angle θ2 of the second sole surface is negative, the crossing angle θ3 can be calculated by the following equation. However, | sole angle θ2 | indicates the absolute value of the sole angle θ2.
Crossing angle θ3 = 180− (sole angle θ1 + | sole angle θ2 |)

  The sole angle θ1 of the first sole surface is positive in the toe / heel direction range from the toe side reference position to the heel side reference position. This positive sole angle increases the explosion effect and the removal performance.

  From the viewpoint of increasing the explosion effect, the sole angle θ1 of the first sole surface is preferably 2 degrees or more, more preferably 4 degrees or more, and particularly preferably 6 degrees or more. From the viewpoint of enhancing the slipping performance, the sole angle θ1 of the first sole surface is preferably 18 degrees or less, more preferably 16 degrees or less, and particularly preferably 14 degrees or less.

  The sole angle θ2 of the second sole surface is smaller than the sole angle θ1 in the toe-heel direction range from the toe side reference position tk to the heel side reference position hk. Further, the sole angle θ2 of the second sole surface has a negative sole angle in the toe-heel direction range from the toe side reference position tk to the heel side reference position hk. When the sole angle θ2 of the second sole surface is negative, the removal performance is enhanced.

  From the viewpoint of enhancing the explosion effect, the sole angle θ2 of the second sole surface is preferably −40 degrees or more, more preferably −30 degrees or more, and particularly preferably −25 degrees or more. From the viewpoint of enhancing the slipping performance, the sole angle θ2 of the second sole surface is preferably −2 degrees or less, more preferably −4 degrees or less, and particularly preferably −6 degrees or less.

  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 plane P. The sole width is determined at each position in the toe-heel direction. The sole width is a distance between both ends of the sole surface on the cross-sectional line by the reference plane P.

  In FIG. 4, wc1 indicates the sole width of the first sole surface at the face center position fc. In FIG. 4, what is indicated by wh1 is the sole width of the first sole surface at the heel side reference position. In FIG. 4, what is indicated by wt1 is the sole width of the first sole surface at the toe side reference position. In FIG. 4, wc2 indicates the sole width of the second sole surface at the face center position fc. In FIG. 4, wh2 indicates the sole width of the second sole surface at the heel side reference position. In FIG. 4, what is indicated by wt2 is the sole width of the second sole surface at the toe side reference position.

  Regarding the first sole surface 20, the sole width wc1 is narrower than the sole width wh1. The sole width wc1 is narrower than the sole width wt1.

  Regarding the second sole surface 22, the sole width wc2 is wider than the sole width wh2. The sole width wc2 is wider than the sole width wt2.

  Regarding the sole width of the first sole surface 20 and the second sole surface 22, the sole width (wc1 + wc2) is wider than the sole width (wh1 + wh2). The sole width (wc1 + wc2) is wider than the sole width wt (wt1 + wt2). With this configuration, the height of the leading edge is suppressed even when the face is opened to a greater extent.

  FIG. 7 is a diagram for explaining a difference between a state where the face is opened and a state where the face is not opened. The head described in FIG. 7 is a conventional head. In FIG. 7, the sole portion and the like of the head in a state where the face is opened are indicated by phantom lines, and the head in a state where the face is not opened are indicated by solid lines.

  When addressing with the face open, the lowest point mp2 of the sole surface moves to the rear of the head as compared to the lowest point mp1 when the face is not open. As the lowermost point moves, the height of the leading edge increases. That is, the leading edge height h2 when the face is opened is higher than the leading edge height h1 when the face is not opened. As the leading edge height increases, top shot miss shots are more likely to occur.

  By making the sole width wc1 narrower than the sole widths wh1 and wt1, the head thickness in the height direction at the position of the lowest point mp2 when the face is opened is suppressed. Therefore, it is possible to suppress the height of the leading edge when the face is opened. Therefore, top shot miss shots are suppressed.

  The ratio (wc1 / wt1) and the ratio (wc1 / wh1) are preferably 0.9 or less and 0.7 or less from the viewpoint of suppressing the leading edge from being increased when the face is opened and suppressing top strike. Is more preferable. From the viewpoint of enhancing the explosion effect, the ratio (wc1 / wt1) and the ratio (wc1 / wh1) are preferably 0.3 or more, and more preferably 0.4 or more.

  The first sole surface of the head 2 has a first sole width minimum portion wm that is a portion where the sole width is the narrowest. In the embodiment of FIG. 4, the first sole width minimum portion wm coincides with the face center position fc. The first sole width minimum portion wm may have a width in the toe-heel direction.

  The head 2 has a specific region T within a range from the toe side reference position tk to the heel side reference position hk. The specific area T will be described with reference to FIG. The specific region T includes a toe side sole width variation portion ts in which the sole width of the first sole surface becomes narrower gradually or stepwise from the toe side toward the face center side and reaches the first sole width minimum portion wm; This is a region having a heel-side sole width variation portion hs in which the sole width of the first sole surface narrows gradually or stepwise from the heel side toward the face center side and reaches the first sole width minimum portion wm. In the present invention, it is preferable to have such a specific region T. In the toe side sole width changing portion ts and the heel side sole width changing portion hs, the “gradually or stepwise” is more preferably “gradually”. In the specific region T, it is preferable that the first sole width minimum portion wm overlaps with the face center position fc, or the distance from the face center position fc is within 5 mm, more preferably within 3 mm. The length of the specific region T in the toe-heel direction is preferably 20 mm or more, more preferably 30 mm or more, still more preferably 40 mm or more, and particularly preferably 50 mm.

  In the section at the face center position fc, the toe side reference position tk, and the heel side reference position hk (cross section by the reference plane P), the intersection angle θ3 is preferably 130 degrees or more, and more preferably 140 degrees or more. By increasing the crossing angle θ3, the second sole surface acts effectively, and in particular, during the explosion shot, the second sole surface acts effectively. That is, by increasing the intersection angle θ3, the second sole surface comes into more reliable contact with the sand surface during a bunker shot, and the explosion effect is enhanced. In the cross section at the face center position fc, the toe side reference position tk, and the heel side reference position hk (cross section by the reference plane P), the intersection angle θ3 is preferably 170 degrees or less, and more preferably 160 degrees or less. By reducing the intersection angle θ3, the grounding resistance of the second sole surface is reduced, and the pull-out performance is improved.

  From the viewpoint of enhancing the explosion effect, the sole width wc1 of the first sole surface at the face center position fc is preferably 5 mm or more, more preferably 6 mm or more, and particularly preferably 8 mm or more. From the viewpoint of suppressing the height of the leading edge when the face is open, the sole width wc1 is preferably 15 mm or less, more preferably 13 mm or less, and particularly preferably 11 mm or less.

  From the viewpoint of enhancing the explosion effect, the sole width wh1 and the sole width wt1 are preferably 10 mm or more, more preferably 12 mm or more, and particularly preferably 15 mm or more. From the viewpoint of suppressing the height of the leading edge when the face is open, the sole width wh1 and the sole width wt1 are preferably 30 mm or less, more preferably 25 mm or less, and particularly preferably 20 mm or less.

  In the present invention, the second sole surface may be omitted. Preferably, the second sole surface 22 is provided. By providing the second sole surface 22, the head behavior at the time of swinging when the ball is hit with the face opened is stabilized. In this respect, the sole width wc2 (see FIG. 4) is preferably 8 mm or more, more preferably 10 mm or more, and particularly preferably 13 mm or more. From the same viewpoint, the sole width wt2 and the sole width wh2 are preferably 3 mm or more, more preferably 4 mm or more, and particularly preferably 6 mm or more.

  If the sole width of the second sole surface 22 is too wide, it is difficult to hit a ball with the face open. In this respect, the sole width wc2 (see FIG. 4) is preferably 23 mm or less, more preferably 20 mm or less, and particularly preferably 18 mm or less. From the same viewpoint, the sole width wt2 and the sole width wh2 are preferably 15 mm or less, more preferably 12 mm or less, and particularly preferably 10 mm or less.

  The iron type golf club head of the present invention is suitable for explosion shots, lob shots and the like in a bunker. Therefore, the iron type golf club head of the present invention is preferably applied to a count frequently used in bunker shots and lob shots. From this viewpoint, the real loft angle of the head is preferably 45 degrees or more, more preferably 50 degrees or more, and particularly preferably 52 degrees or more. The real loft angle of the iron type golf club head is usually 68 degrees or less, and further 66 degrees or less.

  As described above, in the present invention, the second sole surface may be omitted. When there is no second sole surface and there is a single sole surface, all of the above description for the first sole surface applies to this single sole surface. For example, all the descriptions relating to the sole width of the first sole surface can be realized by replacing the sole width wc1 with the sole width (wc) of a single sole at the face center position. Similarly, all the descriptions relating to the sole width of the first sole surface can be realized by replacing the sole width wh1 with the sole width (wh) of the single sole at the heel side reference position. Similarly, all the descriptions relating to the sole width of the first sole surface are valid even if the sole width wt1 is replaced with the sole width (wt) of a single sole at the toe side reference position.

  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.

In order to confirm the effect of the present invention, 10 types of evaluation clubs consisting of Examples 1 to 8 and Comparative Examples 1 and 2 were produced and subjected to an actual hit test.
[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 58 degrees and the head weight was 300 g. The impact area marking area length E1 was 52 mm. 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.

[Examples 2 to 8 and Comparative Examples 1 and 2]
Golf clubs according to Examples 2 to 8 and Comparative Examples 1 and 2 were obtained in the same manner as Example 1 except that the specifications of the sole were as shown in Table 1 below.

  In Table 1, out of the sole angle θ1 of the first sole surface, the sole angle θ1 at the toe side reference position tk is expressed as θ1t, the sole angle θ1 at the heel side reference position hk is expressed as θ1h, and the face center position fc The sole angle θ1 at is indicated as θ1c. In all examples and all comparative examples, θ1t = θ1h = θ1c = 8 degrees. In Table 1, out of the sole angle θ2 of the second sole surface, the sole angle θ2 at the toe side reference position tk is expressed as θ2t, the sole angle θ2 at the heel side reference position hk is expressed as θ2h, and the face center position fc The sole angle θ2 at is indicated as θ2c. Of the crossing angles θ3, the crossing angle θ3 at the toe side reference position tk is expressed as θ3t, the crossing angle θ3 at the heel side reference position hk is expressed as θ3h, and the crossing angle θ3 at the face center position fc is expressed as θ3c. .

[Evaluation methods]
Ten professional golfers made bunker shots and lob shots on the turf, aiming for a pin 10 yards away from each club. Each golfer hit 5 bunker shots and 5 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 grass, three items of “ease of picking up the ball”, “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 10 golfers is shown in Table 1 below. “Ease of picking up a ball” can be rephrased as “difficult to top”. The higher the “Ease of picking up the ball” score, the more difficult it is to make top shots. Further, the higher the evaluation score of “goodness of omission”, the higher the omission performance.

  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 seen from the sole surface side. FIG. 5 is a cross-sectional view of the iron type golf club head of FIG. 1 at the face center position. FIG. 6 is a cross-sectional view of a modification. FIG. 7 is a diagram for explaining a difference between a state where the face is opened and a state where the face is not opened.

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 side reference position Pc ... reference surface at face center position Ph ... reference at heel side reference position Surface tk ... Toe side reference position fc ... Face center position hk ... Heel side reference position wt1 ... Sole width of the first sole surface at the toe side reference position wc1 ... First at the face center position Sole width of the sole surface wh1 ... Sole width of the first sole surface at the heel side reference position wt2 ... Sole of the second sole surface at the toe side reference position wc2 ... Sole width of the second sole surface at the face center position wh2 ... Sole width of the second sole surface at the heel side reference position M ... Impact area marking z ... Shaft axis θ1 ... First Sole angle of the sole surface θ2 ... Sole angle of the second sole surface θ3 ... Crossing angle

Claims (5)

Having a face surface, a back face and a sole surface;
When a position 25 mm away from the face center position to the toe side is a toe side reference position, and a position 25 mm away from the face center position to the heel side is a heel side reference position,
The sole surface has a positive sole angle in a toe-heel direction range from a toe side reference position to a heel side reference position;
An iron type golf club head in which a sole width (wc) at a face center position is narrower than a sole width (wh) at a heel side reference position and a sole width (wt) at a toe side reference position. Having a face surface, a back face and a sole surface;
When a position 25 mm away from the face center position to the toe side is a toe side reference position, and a position 25 mm away from the face center position to the heel side is a heel side reference position,
The sole surface has a first sole surface disposed on the leading edge side and a second sole surface disposed on the trailing edge side;
The first sole surface has a positive sole angle in a toe-heel direction range from a toe side reference position to a heel side reference position;
The second sole surface has a negative sole angle in a toe-heel direction range from a toe side reference position to a heel side reference position;
The sole width (wc1) of the first sole surface at the face center position is narrower than the sole width (wh1) of the first sole surface at the heel side reference position and the sole width (wt1) of the first sole surface at the toe side reference position. Iron type golf club head.   The sole width (wc1) of the first sole surface at the face center position is not more than 0.9 times the sole width (wt1) of the first sole surface at the toe side reference position, and the first sole surface at the heel side reference position The iron-type golf club head according to claim 2, wherein the iron-type golf club head is 0.9 times or less of a sole width (wh1).   The sole width (wc1) of the first sole surface at the face center position is 0.7 times or less of the sole width (wt1) of the first sole surface at the toe side reference position, and the first sole surface at the heel side reference position The iron-type golf club head according to claim 2, wherein the iron-type golf club head is 0.7 times or less of a sole width (wh1). 3. The crossing angle between the inclination line T1 of the first sole surface and the inclination line T2 of the second sole surface in a cross section at the face center position, the toe side reference position, and the heel side reference position is 130 degrees or more and 170 degrees or less. The iron type golf club head described in 1.

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