JP2017018726A - Golf club head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club head which is excellent in adaptability to rough.SOLUTION: A head 2 comprises a face surface f4, a sole surface f8, and a leading edge Le. In the head 2, a face height HF is 29 mm or more, and a head width HW is 65 mm or less. When FP (mm) represents a face progression, FP/HW is 0.25 or more and 0.40 or less in the head 2. When Wh represents head weight, and Wc represents club weight, preferably, Wh/Wc is 0.75 or more. Preferably, a real loft angle of the head 2 is 25° or more. When MI(g cm) represents a vertical moment of inertia, and Vh(cm) represents a head volume, preferably, MI/Vh is 9.0 or more.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a golf club head.

  Fairway wood and utility type clubs are known. These clubs are often hit from the top of the turf.

  Japanese Patent Application Laid-Open No. 2001-286583 discloses a wood type golf club set including a plurality of fairway woods. FIG. 13 of this publication describes a graph showing the sweet spot height of the wood type golf club set.

JP 2001-286583 A

  On golf courses, the situation of ball lies varies. In particular, with long shots, long grass tends to hinder nice shots. Long grass increases the ground resistance of the golf club. This grounding resistance reduces the flight distance. In addition, this grounding resistance changes the direction of the face surface, which can cause variations in flight distance and trajectory. In the rough, the ball can float on the grass, or the ball can sink into the grass. That is, due to the long grass, the gap between the rough ball and the ground tends to vary. This variation can cause a miss shot. As described above, there are various obstacles in the shot from the rough. A golf club that can improve shots from the rough is preferable.

  An object of the present invention is to provide a golf club head excellent in adaptability to rough.

  The golf club head according to the present invention includes a face surface, a sole surface, and a leading edge. The face height HF is 29 mm or more. The head width HW is 65 mm or less. When the face progression is FP (mm), FP / HW is 0.25 or more and 0.40 or less.

  When the head weight is Wh and the club weight is Wc, Wh / Wc is preferably 0.75 or more.

  Preferably, the real loft angle of the head is 25 ° or more.

When the vertical moment of inertia is MI (g · cm ² ) and the head volume is Vh (cm ³ ), MI / Vh is preferably 9.0 or more.

  Preferably, the sole surface has a smooth continuous surface from the leading edge toward the back side, and a step forming surface located on the back side of the continuous surface. Preferably, in a side view, the step formed by the step forming surface is 4 mm or more.

  When the sweet spot height is SH (mm) and the maximum face height from the ground plane is HX, SH / HX is preferably 0.76 or more.

  Preferably, the head weight Wh is 250 g or more.

  A golf club head having high adaptability to rough can be provided.

FIG. 1 is a perspective view of a head according to the first embodiment of the present invention. FIG. 2 is a plan view of the head of FIG. FIG. 3 is a bottom view of the head of FIG. FIG. 4 is a perspective view of the head of FIG. 1 as viewed from the heel side. FIG. 5 is a perspective view of the head of FIG. 1 as viewed from the toe side. FIG. 6 is a view of the head of FIG. 1 as viewed from the back side. FIG. 7 is an enlarged view of FIG. In FIG. 7, each area | region in a sole surface is shown by hatching. FIG. 8 is an enlarged view of FIG. In FIG. 8, angles θ1 to θ4 are shown. FIG. 9 is a front view of the head of FIG. FIG. 10 is a diagram illustrating the relationship between the swing track and the ground contact portion. FIG. 11 is an exploded perspective view of the head of FIG. FIG. 12 is the same bottom view as FIG. In FIG. 12, the boundary line k1 between members is shown.

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

[Definition of terms]
In the present application, a reference vertical plane, a face-back direction, and a toe-heel direction are defined. A state in which the central axis Z1 of the shaft hole is included in the plane P1 perpendicular to the horizontal plane H and the head 2 is placed on the horizontal plane H at a predetermined lie angle and real loft angle is set as a reference state. The plane P1 is a reference vertical plane. The predetermined lie angle and real loft angle are listed in, for example, a product catalog.

[Grounding plane]
In the present application, the horizontal plane H in the reference state is also referred to as a ground plane.

[Toe-heel direction]
In the present application, the toe-heel direction is a direction of an intersection line between the reference vertical plane and the horizontal plane H.

[Face-back direction]
In the present application, the face-back direction is a direction perpendicular to the toe-heel direction and parallel to the horizontal plane H.

[Toe-heel direction cross section]
A plane parallel to the toe-heel direction and perpendicular to the horizontal plane H is defined as Pth. In the present application, the toe-heel direction cross section is a cross section of the head in the reference state by the plane Pth.

[Face-back direction cross section]
A plane parallel to the face-back direction and perpendicular to the horizontal plane H is defined as Pfb. In the present application, the cross section in the face-back direction is a cross section of the head in the reference state by the plane Pfb.

[Face Center Fc]
In the present application, a face center Fc is defined. On the face surface, a maximum width Wx in the toe-heel direction is determined. Further, the center position Px in the toe-heel direction at the maximum width Wx is determined. At this position Px, the vertical center point Py of the face surface is determined. This point Py is defined as the face center Fc.

[Sole height Hs]
In the head in the reference state, the height from the horizontal plane H is the sole height Hs. The sole height Hs is measured along a direction Vd perpendicular to the horizontal plane H. The sole height Hs can be determined at each point on the sole surface. The point where the sole height Hs is large tends to be difficult to ground. This sole height Hs is shown in FIG.

[Plan view of the bottom of the head]
In the present application, a plan view of the bottom surface of the head is defined. In the head in the reference state, a projection image obtained by projecting the bottom surface of the head onto the horizontal plane H is a plan view. The projection direction in this projection is a direction perpendicular to the horizontal plane H. In the present application, the plan view of the bottom surface of the head is also simply referred to as a plan view. In the head 2 described later, a plan view of the bottom surface of the head is shown in FIG. 3 described later.

[Side view of the bottom of the head]
In the present application, a side view of the bottom surface of the head is defined. In the head in the reference state, a projected image obtained by projecting the bottom surface of the head onto the plane Pfb is a side view. The projection direction in this projection is the toe-heel direction. In the present application, this side view of the bottom surface of the head is also simply referred to as a side view.

[Side view]
In the side view, a step formed by a step forming surface (described later) is also referred to as a side view step.

[Face height HF]
In the head in the reference state, the maximum height of the face in the vertical direction Vd is the face height HF. This face height HF is shown in FIG.

[Face top height HX]
In the head in the reference state, the maximum value of the height of the upper end of the face from the ground plane H is the face maximum height HX. The face maximum height HX is measured along a direction Vd perpendicular to the horizontal plane H. This face maximum height HX is shown in FIG.

[Head width HW]
The maximum width in the face-back direction of the head is the head width HW. This head width HW is shown in FIG.

[Inertia moment MI]
This moment of inertia MI is the moment of inertia of the head around the axis ZH. In the present application, this moment of inertia is also referred to as a vertical moment of inertia. In the reference state, the axis ZH is parallel to the horizontal plane H, passes through the center of gravity of the head, and is parallel to the toe-heel direction (see FIG. 9 described later). In the present application, this axis ZH is also referred to as a horizontal axis passing through the center of gravity of the head. This vertical moment of inertia MI is, for example, INERTIA DYNAMICS INC. It can measure by the brand name "MOMENT OF INTERIA MEASURING INSTRUMENT MODEL NO.005-002" made by a company.

[Head thickness TH]
In the head in the reference state, the maximum thickness of the head in the vertical direction Vd is the head thickness TH. This head thickness TH is shown in FIG.

[Sweet spot height SH]
In the head in the reference state, the height of the sweet spot SS from the horizontal plane H is the sweet spot height SH. The sweet spot height SH is measured along the vertical direction Vd. Note that the sweet spot SS is an intersection of a perpendicular drawn from the center of gravity of the head to the face surface and the face surface. This sweet spot height SH is shown in FIG.

  FIG. 1 is a perspective view of a golf club head 2 according to a first embodiment of the present invention. FIG. 2 is a plan view of the head 2. FIG. 3 is a bottom view of the head 2. FIG. 4 is a perspective view of the head 2 as viewed from the heel side. FIG. 5 is a perspective view of the head 2 as viewed from the toe side. FIG. 6 is a view of the head 2 as viewed from the back side.

  The head 2 has a face 4, a crown 6, a sole 8 and a hosel 10. The face 4 has a face surface f4. The face surface f4 is a hitting surface. The sole 8 has a sole surface f8. The sole surface f8 is an outer surface of the sole. The head 2 is hollow. The head 2 is a so-called wood type golf club head.

  The head 2 is manufactured by joining a plurality of members. This joining is welding. FIG. 1 shows a boundary line k1 of the joint. Details of the boundary line k1 will be described later.

  The hosel 10 has a shaft hole 12 for mounting a shaft (see FIG. 1). A shaft (not shown) is inserted into the shaft hole 12. The shaft hole 12 has a central axis Z1 (not shown). The central axis Z1 coincides with the shaft axis of the golf club provided with the head 2.

  The sole surface f8 has a first sole region R1. In the reference state, the first sole region R1 is in contact with the horizontal plane H. In the reference state, only the first sole region R1 is in contact with the horizontal plane H.

  The first sole region R1 is located approximately at the center of the sole surface f8. The first sole region R1 includes the centroid of the head outline in plan view. The first sole region R1 includes all circles having a radius of 15 mm centered on the centroid.

  Although not shown, the first sole region R1 is provided with a partial recess. These dents indicate characters, marks, and the like. Typically, this letter indicates a product name, brand name, loft angle, count, etc. Except for these partial dents, the entire first sole region R1 is smoothly continuous. In the first sole region R1, the smooth continuous portion is a curved surface. This curved surface has a convex roundness in the toe-heel direction (see FIG. 6). This curved surface has a convex roundness in the face-back direction (see FIGS. 4 and 5). This curved surface is a three-dimensional convex curved surface. From the viewpoint of reducing ground resistance, the width of the partial recess is preferably 8 mm or less. The partial recess is located inside edge lines Eg1, Eg2, Eg3, and Eg4, which will be described later.

  As shown in FIG. 3, the outer edge of the first sole region R1 includes a first edge line Eg1, a second edge line Eg2, a third edge line Eg3, and a fourth edge line Eg4.

  The first edge line Eg1 is inclined so as to approach the face surface f4 toward the toe side. In plan view, the first edge line Eg1 is a curve. This curve is bent so as to be convex toward the back side.

  The second edge line Eg2 is inclined so as to approach the face surface f4 toward the heel side. In plan view, the second edge line Eg2 is a curved line. This curve is bent so as to be convex toward the back side.

  The third edge line Eg3 is inclined so as to approach the face surface f4 toward the heel side. In plan view, the third edge line Eg3 is a curve. This curve is bent so as to be convex toward the toe side.

  The fourth edge line Eg4 is inclined so as to approach the face surface f4 toward the toe side. In plan view, the fourth edge line Eg4 is a curve. This curve is bent so as to be convex toward the heel side.

  The edge lines Eg1, Eg2, Eg3, and Eg4 are ridge lines. These edge lines Eg1, Eg2, Eg3, and Eg4 are connected, and one edge line is formed by this connection. Both end points of this one edge line are point D and point E. These edge lines Eg1, Eg2, Eg3 and Eg4 form the edge of the first sole region R1, but preferably the edge is rounded. The radius of curvature of the roundness is so small that a ridgeline as an edge line can be visually recognized. In this roundness, the points having the smallest curvature radius are edge lines Eg1, Eg2, Eg3, and Eg4. This roundness can reduce ground resistance. This curvature radius is determined in the cross section in the face-back direction. In addition, in the roundness of the edge, when the portion with the smallest curvature radius (the portion with the smallest curvature radius) has a width instead of a point, the cross section in the face-back direction of the portion with the smallest curvature radius is a curve. In this case, the midpoint of this curve is the edge lines Eg1, Eg2, Eg3, and Eg4.

  The midpoint of the first edge line Eg1 is located on the toe side with respect to the face center Fc. The midpoint of the second edge line Eg2 is located on the heel side with respect to the face center Fc. The midpoint of the third edge line Eg3 is located on the toe side with respect to the face center Fc. The entire third edge line Eg3 is located on the toe side with respect to the face center Fc. The midpoint of the fourth edge line Eg4 is located on the heel side with respect to the face center Fc. The entire fourth edge line Eg4 is located on the heel side with respect to the face center Fc.

  The back side end of the first edge line Eg1 and the back side end of the second edge line Eg2 are connected via a connection point A.

  The face side end of the first edge line Eg1 and the back side end of the third edge line Eg3 are connected via a connection point B.

  The face side end of the second edge line Eg2 and the back side end of the fourth edge line Eg4 are connected via a connection point C.

  In FIG. 3, what is indicated by a symbol D is an end point on the face side of the third edge line. Both ends of the third edge line Eg3 are point B and point D.

  The point D is located on the back side with respect to the leading edge Le. The point D may be located on the leading edge Le.

  In FIG. 3, what is indicated by a symbol E is an end point on the face side of the fourth edge line. Both ends of the fourth edge line Eg4 are point C and point E.

  The point E is located on the back side from the leading edge Le. The point E may be located on the leading edge Le.

  The back side end of the first edge line Eg1 and the back side end of the second edge line Eg2 may be connected by another edge line Eg12 (not shown). In this case, the midpoint of the line Eg12 is the connection point A. As the line Eg12, an edge line parallel to the toe-heel direction is exemplified.

  The face side end of the first edge line Eg1 and the back side end of the third edge line Eg3 may be connected by another edge line Eg13 (not shown). In this case, the midpoint of the line Eg13 is a connection point B. An example of the line Eg13 is an edge line parallel to the face-back direction.

  The face side end of the second edge line Eg2 and the back side end of the fourth edge line Eg4 may be connected by another edge line Eg24 (not shown). In this case, the midpoint of the line Eg24 is a connection point C. As the line Eg24, an edge line parallel to the face-back direction is exemplified.

  The connection point A is located in the center range in the toe-heel direction. The center range in the toe-heel direction means from a position 10 mm from the face center Fc to the toe side to a position 10 mm from the face center Fc to the heel side.

  The connection point A is located on the back side from the centroid of the head outline in plan view. The connection point A is located on the back side from the contact point (or contact portion) with the horizontal plane H in the reference state.

  The connection point B is located on the toe side with respect to the face center Fc. The connection point C is located on the heel side with respect to the face center Fc.

  In the cross section passing through the connection point B and the connection point C, the outer surface of the first sole region R1 has a convex curve. This convex curve improves adaptability to lie-up and toe-down lies. With this head 2, it is easy to address both the toe-up lie and the toe-down lie. In the head 2 in the reference state, a cross section passing through the points B and C is perpendicular to the horizontal plane H.

  In the cross section passing through the connection point A and the face center Fc, the outer surface of the first sole region R1 has a convex curve. Due to this convex curve, adaptability is improved with respect to a lie with a left foot up and a left foot down. In the head 2, it is easy to address both the left-footed lie and the left-footed lie. In the head 2 in the reference state, a cross section passing through the point A and the face center Fc is perpendicular to the horizontal plane H.

  A sole rear portion Bc is provided on the back side of the first sole region R1. In this embodiment, the sole rear portion Bc is provided with unevenness such as a step.

  A slope Sp1 is provided on the back side of the edge line Eg1 (see FIG. 5 and the like). The slope Sp1 expands the step between the first sole region R1 and the sole rear portion Bc. A slope Sp2 is provided on the back side of the edge line Eg2 (see FIG. 4 and the like). The slope Sp2 expands the step between the first sole region R1 and the sole rear portion Bc.

  In the present embodiment, the sole rear portion Bc is a portion of the sole surface f8 on the back side of the slope Sp1 and the slope Sp2.

  In order to explain the effect of the step between the first sole region R1 and the sole rear portion Bc, the impact will be described. The impact means a state where the ball and the face surface f4 are in contact. Although the impact time is short, the impact takes a certain amount of time. The impact starts when the contact between the ball and the face surface f4 starts. During the impact, the ball is deformed so as to be crushed, and this deformation is recovered. Thereafter, the ball leaves the face surface f4 and the impact ends.

  In the initial stage of impact, the portion of the sole surface f8 near the face is likely to be grounded. On the other hand, at the final stage of impact, the portion near the back of the sole surface f8 is likely to be grounded. As the swing progresses, the posture of the head 2 changes so that the back side is lowered during the impact. Due to this change in posture, the back side of the head 2 is likely to be strongly grounded at the final stage of impact. The ground resistance in the final stage of impact is suppressed by the step between the first sole region R1 and the sole rear portion Bc. In other words, the ground resistance in the final stage of impact is suppressed by the step in the side view. Therefore, the removal of the sole is good.

  In the cross section in the face-back direction, the maximum value of the sole height Hs in the first sole region R1 is R1x, and the minimum value of the sole height Hs in the sole rear portion Bc is Bcn. From the viewpoint of slipping out of the sole, the difference (Bcn−R1x) is preferably greater than 0 in all toe-heel directions from point B to point C, more preferably 2 mm or more, and more preferably 3 mm or more. From the viewpoint of lowering the center of gravity of the head, in all toe-heel directions from point B to point C, the difference (Bcn-R1x) is preferably 10 mm or less, more preferably 9 mm or less, and more preferably 8 mm or less.

  In the cross section in the face-back direction, a step formed by the slope Sp1 is Ds1 (not shown). From the viewpoint of improving the escape of the sole, the step Ds1 is preferably 3 mm or more, more preferably 4 mm or more, and more preferably 5 mm or more. From the viewpoint of lowering the center of gravity of the head, the step Ds1 is preferably 10 mm or less, more preferably 9 mm or less, and more preferably 8 mm or less.

  When the sole height Hs at the start point of the slope Sp1 is Hf1 and the sole height Hs at the end point of the slope Sp1 is Hb1, the step Ds1 is a difference (Hb1−Hf1). The starting point of the slope Sp1 is a point on the line Eg1. The end point of the slope Sp1 is a point on the valley line tg1. This step Ds1 can be measured at any position in the toe-heel direction.

  Considering the balance between the removal of the sole and the constraint on the sole size, the width of the slope Sp1 in plan view is preferably 2 mm or more, more preferably 5 mm or more, and preferably 10 mm or less, more preferably 7 mm or less. The width of the slope Sp1 is measured along the face-back direction.

  In the cross section in the face-back direction, the step formed by the slope Sp2 is Ds2 (not shown). From the viewpoint of improving the escape of the sole, the step Ds2 is preferably 2 mm or more, more preferably 3 mm or more, and more preferably 4 mm or more. From the viewpoint of lowering the center of gravity of the head, the step Ds2 is preferably 10 mm or less, more preferably 9 mm or less, and more preferably 8 mm or less.

  When the sole height Hs at the start point of the slope Sp2 is Hf2, and the sole height Hs at the end point of the slope Sp2 is Hb2, the step Ds2 is a difference (Hb2-Hf2). The starting point of the slope Sp2 is a point on the line Eg2. The end point of the slope Sp2 is a point on the valley line tg2. This step Ds2 can be measured at any toe-heel direction position.

  The minimum value of the step Ds1 is larger than the maximum value of the step Ds2. In general, it is known that average golfers tend to hit the ball on the outside-in path rather than the inside-out path. In the outside-in path, the ground contact surface easily passes through the step Ds1 (see FIG. 10 described later). By making the level difference Ds1 relatively large, in the outside-in path, the grounding of the portion near the back of the sole surface f8 at the final stage of impact is suppressed. Therefore, the removal of the sole is good. On the other hand, since the step Ds2 is made relatively small, the center of gravity of the head is prevented from becoming excessively high. In addition, since the step Ds2 exists, the effect of improving the slipping out of the sole is ensured even in the inside-out path.

  In consideration of the balance between the omission of the sole and the constraint on the sole dimension, the width of the slope Sp2 in plan view is preferably 2 mm or more, and preferably 10 mm or less. The width of the slope Sp2 is measured along the face-back direction.

  A sole toe portion Bt is provided on the toe side of the third edge line Eg3 (see FIGS. 3 and 5). The sole toe part Bt, together with the sole rear part Bc, forms a part having a relatively large sole height Hs. Since the sole height Hs is large, the sole toe portion Bt is difficult to ground. The sole toe portion Bt extends so as to approach the face surface f4 toward the heel side. The width of the sole toe portion Bt in the face-back direction becomes smaller toward the face side, and is zero at the most face side position. The width in the toe-heel direction of the sole toe portion Bt becomes smaller toward the face side, and is zero at the most face side position. As shown in FIG. 3, the sole toe portion Bt has a pointed shape in plan view.

  A slope Sp3 is provided on the toe side of the edge line Eg3. The slope Sp3 is located between the first sole region R1 and the sole toe portion Bt. Due to the slope Sp3, the sole toe portion Bt is difficult to ground. In the cross section in the toe-heel direction, a step formed by the slope Sp3 is defined as Ds3 (not shown). From the viewpoint of improving the escape of the sole, the step Ds3 is preferably 3 mm or more, more preferably 4 mm or more, and more preferably 5 mm or more. From the viewpoint of lowering the center of gravity of the head, the step Ds3 is preferably 10 mm or less, more preferably 9 mm or less, and more preferably 8 mm or less.

  When the sole height Hs at the start point of the slope Sp3 is Hf3 and the sole height Hs at the end point of the slope Sp3 is Hb3, the step Ds3 is a difference (Hb3-Hf3). The starting point of the slope Sp3 is a point on the line Eg3. The end point of the slope Sp3 is a point on the valley line tg3. This step Ds3 can be measured at any face-back direction position.

  A sole heel portion Bh is provided on the heel side of the fourth edge line Eg4 (see FIGS. 3 and 4). The sole heel portion Bh forms a portion having a relatively large sole height Hs together with the sole rear portion Bc. Since the sole height Hs is large, the sole heel portion Bh is difficult to ground. The sole heel portion Bh extends so as to approach the face surface f4 toward the toe side. The width in the face-back direction of the sole heel portion Bh becomes smaller toward the face side, and is zero at the most face side position. The width in the toe-heel direction of the sole heel portion Bh becomes smaller toward the face side, and is zero at the most face side position. As shown in FIG. 3, the sole heel portion Bh has a pointed shape in plan view.

  A slope Sp4 is provided on the heel side of the edge line Eg4. The slope Sp4 is located between the first sole region R1 and the sole heel portion Bh. Due to the slope Sp4, the sole heel part Bh is difficult to be grounded. In the cross section in the toe-heel direction, a step formed by the inclined surface Sp4 is defined as Ds4 (not shown). From the viewpoint of improving the escape of the sole, the step Ds4 is preferably 3 mm or more, more preferably 4 mm or more, and more preferably 5 mm or more. From the viewpoint of lowering the center of gravity of the head, the step Ds4 is preferably 10 mm or less, more preferably 9 mm or less, and more preferably 8 mm or less.

  When the sole height Hs at the start point of the slope Sp4 is Hf4 and the sole height Hs at the end point of the slope Sp4 is Hb4, the step Ds4 is a difference (Hb4-Hf4). The starting point of the slope Sp4 is a point on the line Eg4. The end point of the slope Sp4 is a point on the valley line tg4. This step Ds4 can be measured at any face-back direction position.

  FIG. 7 is a diagram in which each region on the sole surface f8 is divided by different hatching. A straight line Lf shown in FIG. 7 is a line segment connecting the point D and the point E. The straight line Lf is defined in plan view. The first sole region R1 is a portion surrounded by an edge line and a line segment Lf from the point D to the point E via the points B, A, and C.

  In consideration of the visibility of the drawing, the description of the concavities and convexities provided in the sole rear portion Bc is omitted in FIG.

  The sole surface f8 includes a second sole region R2 and a third sole region R3 in addition to the first sole region R1. Further, the sole surface f8 has a front sole region R4.

  The second sole region R2 is located on the toe side with respect to the end point D. The second sole region R2 is located on the face side with respect to the end point D.

  The third sole region R3 is located on the heel side with respect to the end point E. The third sole region R3 is located on the face side with respect to the end point E.

  The sole surface f8 has a fifth edge line Eg5 extending from the end point D to the toe side. The sole surface f8 has a sixth edge line Eg6 extending from the end point E to the heel side.

  The second sole region R2 is located between the leading edge Le and the fifth edge line Eg5. The third sole region R3 is located between the leading edge Le and the sixth edge line Eg6.

  The second sole region R2 is smoothly continuous from the leading edge Le toward the back side. A continuous surface that smoothly connects the leading edge Le and the fifth edge line Eg5 is formed, and the second sole region R2 is a part of the continuous surface.

  The third sole region R3 is smoothly continuous from the leading edge Le toward the back side. A continuous surface that smoothly connects the leading edge Le and the sixth edge line Eg6 is formed, and the third sole region R3 is a part of the continuous surface.

  The front sole region R4 is smoothly connected to the first sole region R1. The front sole region R4 forms a continuous surface that smoothly connects the leading edge Le and the first sole region R1.

  The front sole region R4 forms a continuous surface that smoothly connects the second sole region R2 and the third sole region R3.

  The front sole region R4 may not be provided. In this case, it is preferable that the first sole region R1 forms a continuous surface extending smoothly from the leading edge Le to the back side.

  FIG. 9 is a front view of the head 2. FIG. 9 shows the reference state described above. As described above, in the present application, the sole height Hs is defined. The sole height Hs can be determined at any point on the sole surface f8.

  In the sole surface f8, the sole height Hs of the first sole region R1 is relatively small. Therefore, the first sole region R1 is easily grounded. Since the first sole region R1 is relatively easily grounded, the effects of the edge lines Eg1 to Eg4 are easily exhibited. From this viewpoint, it is preferable that the sole height Hs of the first sole region R1 is suppressed within a predetermined range. Specifically, it is as follows. In the cross section in the face-back direction, the sole height Hs of the leading edge Le is HLe, and the maximum value of the sole height Hs in the first sole region R1 is Hm1. Preferably, in every toe-heel direction position, the absolute value of the difference (HLe-Hm1) is preferably 8 mm or less, and more preferably 5 mm or less. This absolute value is 0 mm or more.

  In the sole surface f8, the second sole region R2 forms a continuous surface that extends smoothly from the leading edge Le to the back side. Therefore, in the initial stage of impact, the leading edge Le is less likely to pierce the ground, and the ground resistance can be reduced. In addition, the level difference between the second sole region R2 and the leading edge Le is small. Due to the presence of the second sole region R2, the height of the face surface f4 on the toe side can be increased. Therefore, the deflection of the face surface f4 increases and the coefficient of restitution can increase. In addition, the high repulsion area is expanded to the toe side, and a decrease in the flight distance due to the hit point deviation is suppressed. From these viewpoints, it is preferable that the sole height Hs of the second sole region R2 is suppressed within a predetermined range. Specifically, it is as follows. In the cross section in the face-back direction, the sole height Hs of the leading edge Le is HLe, and the maximum value of the sole height Hs in the second sole region R2 is Hm2. Preferably, in any toe-heel direction position, the absolute value of the difference (HLe-Hm2) is preferably 8 mm or less, and more preferably 5 mm or less. This absolute value is 0 mm or more.

  In the sole surface f8, the third sole region R3 forms a continuous surface that extends smoothly from the leading edge Le to the back side. Therefore, in the initial stage of grounding, the leading edge Le is less likely to pierce the ground, and the grounding resistance can be reduced. Further, the step between the third sole region R3 and the leading edge Le is small. The presence of the third sole region R3 can increase the height of the face surface f4 on the heel side. Therefore, the deflection of the face surface f4 increases and the coefficient of restitution can increase. In addition, the high repulsion area is expanded to the heel side, and the decrease in the flight distance due to the hit point deviation is suppressed. From these viewpoints, it is preferable that the sole height Hs of the third sole region R3 is suppressed within a predetermined range. Specifically, it is as follows. In the cross section in the face-back direction, the sole height Hs of the leading edge Le is HLe, and the maximum value of the sole height Hs in the third sole region R3 is Hm3. Preferably, in any toe-heel direction position, the absolute value of the difference (HLe-Hm3) is preferably 8 mm or less, and more preferably 5 mm or less. This absolute value is 0 mm or more.

  In the sole surface f8, the front sole region R4 forms a continuous surface that smoothly extends from the leading edge Le to the back side. Therefore, in the initial stage of grounding, the leading edge Le is less likely to pierce the ground, and the grounding resistance can be reduced. Further, there are few steps between the front sole region R4 and the leading edge Le. The presence of the front sole region R4 can increase the height of the face surface f4 at the center in the toe-heel direction. Therefore, the deflection of the face surface f4 increases and the coefficient of restitution can increase. From these viewpoints, it is preferable that the sole height Hs of the front sole region R4 is suppressed within a predetermined range. Specifically, it is as follows. In the cross section in the face-back direction, the sole height Hs of the leading edge Le is HLe, and the maximum value of the sole height Hs in the front sole region R4 is Hm4. Preferably, in any toe-heel direction position, the absolute value of the difference (HLe-Hm4) is preferably 8 mm or less, and more preferably 5 mm or less. This absolute value is 0 mm or more.

  The second sole region R2, the front sole region R4, and the third sole region R3 extend along the leading edge Le. These three regions R2, R3 and R4 form a smooth continuous surface. This continuous surface makes it difficult for the leading edge Le to pierce the ground in the initial stage of grounding, and the grounding resistance can be reduced.

  The front sole region R4 and the first sole region R1 form a smooth continuous surface. By this continuous surface, the sole surface f8 can easily slide on the ground (lawn), and the grounding resistance can be suppressed. Further, the presence of the front sole region R4 facilitates grounding to the first sole region R1. Therefore, the effect of the first sole region R1 is further enhanced.

[Effect of first sole region R1]

  The first sole region R1 is substantially pentagonal by the lines Eg1 to Eg4 and the straight line Lf. Due to the orientation of these lines Eg1 to Eg4, the distance in the face-back direction from the leading edge Le to the point A is increased. Further, in the cross section passing through the point A and the face center Fc, the outer surface of the first sole region R1 has a convex curve. Therefore, the adaptability to changes in the lie in the face-back direction is high.

  The distance between the point B and the point C is increased by the substantially pentagonal shape. Further, in the cross section passing through the points B and C, the outer surface of the first sole region R1 has a convex curve. Therefore, the adaptability to the change of the lie in the toe-heel direction is high due to the convex curve.

  In addition to straight, inside-out and outside-in are known as swing paths. The swing trajectory differs depending on the golfer. The swing trajectory can also change depending on the lie (the inclination of the ground, etc.). Examples of the lie include a left foot rise, a left foot rise, a toe fall, and a toe rise.

  FIG. 10 is a bottom view showing the relationship between the swing track and the ground contact area. When the swing path is inside-out, the grounding is likely to occur from the toe and face side regions to the heel side and back side regions (see the dashed line arrow in FIG. 10). On the other hand, when the swing path is outside-in, the grounding is likely to occur from the heel side and face side region to the toe side and back side regions (see solid line arrows in FIG. 10).

[Inclination effect a of the first edge line Eg1]
When the swing track is outside-in, the first edge region E1 is inclined as described above, so that the first sole region R1 is not easily grounded at the final stage of impact. Therefore, the omission of the sole is good.

[Inclination effect b of first edge line Eg1]
Further, when the swing track is inside-out, the edge line Eg1 is inclined as described above, so that the width of the first sole region R1 in the track orthogonal direction is narrowed (see FIG. 10). Therefore, the ground resistance can be reduced. The trajectory orthogonal direction means a direction perpendicular to the swing trajectory.

[Inclination effect c of second edge line Eg2]
When the swing track is inside-out, the edge line Eg2 is inclined as described above, so that the second sole region R2 is difficult to be grounded at the final stage of impact. Therefore, the omission of the sole is good.

[Inclination effect d of second edge line Eg2]
Further, when the swing track is outside-in, the edge line Eg2 is inclined as described above, so that the width of the first sole region R1 in the track orthogonal direction is narrowed (see FIG. 10). Therefore, the ground resistance can be reduced.

[Inclination effect e of third edge line Eg3]
When the swing track is outside-in, the edge line Eg3 is inclined as described above, so that the width of the first sole region R1 in the direction orthogonal to the track is narrowed (see FIG. 10). Therefore, the ground resistance can be reduced. This gradient effect e is further enhanced by synergy with the gradient effect d of the edge line Eg2.

  From the viewpoint of preventing duffing, an outside-in swing path is preferable for a lie with a toe-down. Therefore, in this case, the tilt effect d and the tilt effect e are more effectively exhibited.

[Inclination effect f of the fourth edge line Eg4]
When the swing track is inside-out, the edge line Eg4 is inclined as described above, so that the width of the first sole region R1 in the direction orthogonal to the track is narrowed (see FIG. 10). Therefore, the ground resistance can be reduced. The inclination effect f is further enhanced by synergy with the inclination effect b of the edge line Eg1.

  From the viewpoint of preventing duffing, an inside-out swing path is preferable for a toe-up lie. Therefore, in this case, the tilt effect b and the tilt effect f are more effectively exhibited.

  As described above, the shape of the first sole region R1 is highly adaptable to changes in the lie at the time of addressing and highly adaptable to changes in the swing trajectory. Therefore, the swing is easy. This head 2 can be adapted to various situations in a golf course and is effective in improving the score.

  In golf courses, the place where the toe-up lie and the toe-down lie are present is usually rough. The club of this embodiment is particularly effective for shots from rough. Further, the effect of reducing ground resistance is particularly exerted in rough where turf resistance is strong. Also from this point, the club of this embodiment is particularly effective in a shot from a rough.

[Inclination angle of edge lines Eg1 to Eg4]
In FIG. 8, what is indicated by a double arrow θ1 is the inclination angle of a straight line connecting point A and point B. This angle θ1 is an angle with respect to the face-back direction. This angle θ1 is measured in plan view. Considering a swing trajectory that can occur normally, the lower limit of the angle θ1 is preferably 20 ° or more, more preferably 30 ° or more, and more preferably 40 ° or more. The upper limit of the angle θ1 is preferably 80 ° or less, more preferably 70 ° or less, and more preferably 60 ° or less.

  In FIG. 8, what is indicated by a double-headed arrow θ2 is the inclination angle of a straight line connecting point A and point C. This angle θ2 is an angle with respect to the face-back direction. This angle θ2 is measured in plan view. Considering a swing trajectory that can occur normally, the lower limit of the angle θ2 is preferably 20 ° or more, more preferably 30 ° or more, and more preferably 40 ° or more. The upper limit of the angle θ2 is preferably 80 ° or less, more preferably 70 ° or less, and more preferably 60 ° or less.

  In FIG. 8, what is indicated by a double-headed arrow θ3 is the inclination angle of a straight line connecting point B and point D. This angle θ3 is an angle with respect to the face-back direction. This angle θ3 is measured in plan view. Considering a swing trajectory that can occur normally, the lower limit of the angle θ3 is preferably 5 ° or more, more preferably 10 ° or more, and more preferably 20 ° or more. The upper limit of the angle θ3 is preferably 60 ° or less, more preferably 50 ° or less, and more preferably 40 ° or less.

  In FIG. 8, what is indicated by a double-headed arrow θ4 is the inclination angle of a straight line connecting point C and point E. This angle θ4 is an angle with respect to the face-back direction. This angle θ4 is measured in plan view. In consideration of a swing trajectory that can occur normally, the lower limit of the angle θ4 is preferably 2 ° or more, more preferably 5 ° or more, and more preferably 10 ° or more. The upper limit of the angle θ4 is preferably 50 ° or less, more preferably 40 ° or less, and more preferably 30 ° or less.

  In the present application, the inclination angle θg1 of the first edge line Eg1 can be determined. This angle θg1 is an angle with respect to the face-back direction. This angle θg1 is an angle in plan view. This angle θg1 is determined at the midpoint of the line Eg1. When the line Eg1 is a curve, the angle θg1 is an angle of a tangent at the midpoint of the line Eg1 (see FIG. 8). This midpoint is determined based on the length Lg1 (described later) of the first edge line Eg1. Considering a swing trajectory that can occur normally, the lower limit of the angle θg1 is preferably 20 ° or more, more preferably 30 ° or more, and more preferably 40 ° or more. The upper limit of the angle θg1 is preferably 80 ° or less, more preferably 70 ° or less, and more preferably 60 ° or less.

  Although not shown, in the present application, the inclination angle θg2 of the second edge line Eg2 can be determined. This angle θg2 is an angle with respect to the face-back direction. This angle θg2 is an angle in plan view. This angle θg2 is determined at the midpoint of the line Eg2. When the line Eg2 is a curve, the angle θg2 is an angle of a tangent at the midpoint of the line Eg2. This midpoint is determined based on the length Lg2 (described later) of the second edge line Eg2. Considering a swing trajectory that can occur normally, the lower limit of the angle θg2 is preferably 20 ° or more, more preferably 30 ° or more, and more preferably 40 ° or more. The upper limit of the angle θg2 is preferably 80 ° or less, more preferably 70 ° or less, and more preferably 60 ° or less.

  Although not shown, in the present application, the inclination angle θg3 of the third edge line Eg3 can be determined. This angle θg3 is an angle with respect to the face-back direction. This angle θg3 is an angle in plan view. This angle θg3 is determined at the midpoint of the line Eg3. When the line Eg3 is a curve, the angle θg3 is a tangent angle at the midpoint of the line Eg3. This midpoint is determined based on the length Lg3 (described later) of the third edge line Eg3. In consideration of a swing trajectory that can occur normally, the lower limit of the angle θg3 is preferably 5 ° or more, more preferably 10 ° or more, and more preferably 20 ° or more. The upper limit of the angle θg3 is preferably 60 ° or less, more preferably 50 ° or less, and more preferably 40 ° or less.

  Although not shown, in the present application, the inclination angle θg4 of the fourth edge line Eg4 can be determined. This angle θg4 is an angle with respect to the face-back direction. This angle θg4 is an angle in plan view. This angle θg4 is determined at the midpoint of the line Eg4. When the line Eg4 is a curve, the angle θg4 is an angle of a tangent at the midpoint of the line Eg4. This midpoint is determined based on the length Lg4 (described later) of the fourth edge line Eg4. Considering a swing trajectory that can occur normally, the lower limit of the angle θg4 is preferably 2 ° or more, more preferably 5 ° or more, and more preferably 10 ° or more. The upper limit of the angle θg4 is preferably 50 ° or less, more preferably 40 ° or less, and more preferably 30 ° or less.

  2 and 8, the double-headed arrow HW indicates the head width described above. In FIG. 8, a double arrow DA indicates a face-back direction distance between the foremost point of the head and the connection point A. The ratio (DA / HW) is preferably equal to or greater than 0.3, more preferably equal to or greater than 0.4, from the viewpoint of increasing the ground contact area at the time of addressing and enhancing adaptability to changes in the lie in the face-back direction. 5 or more is more preferable. The ratio (DA / HW) is preferably 0.9 or less, more preferably 0.8 or less, and even more preferably 0.7 or less, from the viewpoint of suppressing ground contact at the final stage of impact and improving omission.

[Length of edge lines Eg1 to Eg4]
There is a restriction on the area of the sole surface f8. Therefore, the lengths of the four edge lines Eg1 to Eg4 are also limited. On the other hand, from the viewpoint of enhancing the effects of the edge lines Eg1 to Eg4, the length of the edge lines Eg1 to Eg4 is preferably larger. Note that the lengths of these lines Eg1 to Eg4 are the lengths along the lines. Thus, if the line is a curve, the length is measured along the curve.

  From the above viewpoint, the length Lg1 of the first edge line Eg1 is preferably 30 mm or more, more preferably 35 mm or more, and more preferably 40 mm or more. From the above viewpoint, the length Lg1 of the first edge line Eg1 is preferably 70 mm or less, more preferably 60 mm or less, and more preferably 50 mm or less.

  From the above viewpoint, the length Lg2 of the second edge line Eg2 is preferably 30 mm or more, more preferably 35 mm or more, and more preferably 40 mm or more. From the above viewpoint, the length Lg2 of the second edge line Eg2 is preferably 70 mm or less, more preferably 60 mm or less, and more preferably 50 mm or less.

  From the above viewpoint, the length Lg3 of the third edge line Eg3 is preferably 5 mm or more, more preferably 10 mm or more, and more preferably 15 mm or more. From the above viewpoint, the length Lg3 of the third edge line Eg3 is preferably 50 mm or less, more preferably 40 mm or less, and more preferably 30 mm or less.

  From the above viewpoint, the length Lg4 of the fourth edge line Eg4 is preferably 5 mm or more, more preferably 10 mm or more, and more preferably 15 mm or more. From the above viewpoint, the length Lg4 of the fourth edge line Eg4 is preferably 50 mm or less, more preferably 40 mm or less, and more preferably 30 mm or less.

  In consideration of adaptability to various lies and adaptability to various swing trajectories, the length Lg1 and the length Lg2 are preferably approximately the same. Specifically, the ratio (Lg1 / Lg2) is preferably 0.8 or more, and preferably 1.2 or less.

  In consideration of adaptability to various lies and adaptability to various swing trajectories, the length Lg3 and the length Lg4 are preferably approximately the same. Specifically, the ratio (Lg3 / Lg4) is preferably 0.8 or more, and preferably 1.2 or less.

  In consideration of head loss at the final stage of impact, Lg1 is preferably longer than Lg3, and the ratio (Lg1 / Lg3) is preferably 1.5 or more, and more preferably 2 or more. From the viewpoint of preventing Lg3 from becoming too small, the ratio (Lg1 / Lg3) is preferably 4 or less, and more preferably 3 or less.

  In consideration of head loss at the final stage of impact, Lg2 is preferably longer than Lg4, and the ratio (Lg2 / Lg4) is preferably 1.5 or more, and more preferably 2 or more. From the viewpoint of preventing Lg4 from becoming too small, the ratio (Lg2 / Lg4) is preferably 4 or less, and more preferably 3 or less.

  In the above embodiment, the face height HF is 29 mm or more. As described above, in the rough, the distance between the ball and the ground is likely to vary. For this reason, variations in hit points in the vertical direction are likely to occur. The variation in the hit points causes a variation in the flight distance and the trajectory. By increasing the face height HF, flight distance and ballistic variation are suppressed.

  By increasing the face height HF, the vertical moment of inertia MI can be increased. Therefore, even when the hit points vary in the vertical direction, the rotation of the head is suppressed, and the decrease in the flight distance is suppressed.

  From the above viewpoint, the face height HF (mm) is preferably 29 mm or more, and more preferably 30 mm or more. If the face height HF is excessive, the hit point may be too low in the shot from the fairway. In this respect, the face height HF is preferably 35 mm or less, more preferably 34 mm or less, and more preferably 33 mm or less.

  In the above embodiment, the head width HW is set to 65 mm or less. For this reason, the contact area with the turf is reduced, and the resistance force by the turf can be suppressed. This suppression effect is particularly effective in rough conditions.

  From the viewpoint of suppressing the resistance force by the turf, the head width HW is preferably 65 mm or less, and more preferably 64 mm or less. When the head width HW is excessively small, the sole may be difficult to slide on the grass. From this viewpoint, the head width HW is preferably 50 mm or more, and more preferably 55 mm or more.

  During the swing, centrifugal force acts on the center of gravity of the head. Due to this centrifugal force, the posture of the head 2 changes so that the center of gravity of the head approaches the shaft axis Z1. Since the center of gravity of the head is located on the back side of the shaft axis Z1, the posture of the head 2 changes so that the back side of the sole surface f8 is lowered. Due to this change in posture, the back side of the sole surface f8 can be easily grounded, and the grounding resistance can be increased. Due to this change in posture, the back side of the sole surface f8 can be grounded before impact. This grounding causes so-called duffing and reduces the head speed at the time of impact. Also, this change in posture changes the orientation of the face surface f4. Therefore, the effective loft angle changes and the flight distance may vary. The effective loft angle is the loft angle of the head in impact, and is the loft angle with respect to the vertical direction.

  In the present application, the face progression is FP (mm) (see FIG. 2). The FP / HW is preferably increased. By increasing FP / HW, the face-back direction distance DG (not shown) between the shaft axis Z1 and the center of gravity of the head approaches. By reducing the distance DG, the above-described change in the posture of the head is suppressed. For this reason, the ground resistance can be reduced. In addition, the orientation of the face surface f4 is stable, and variation in flight distance is suppressed.

  For the reasons described above, FP / HW is preferably 0.25 or more, and more preferably 0.26 or more. If the face progression FP is excessive, the golfer may feel uncomfortable at the address. In this respect, FP / HW is preferably equal to or less than 0.40, and more preferably equal to or less than 0.38.

  When the head weight is Wh (g) and the club weight is Wc (g), Wh / Wc is 0.75 or more in the above embodiment. By increasing the weight distribution ratio to the head, the kinetic energy of the head tends to increase. Therefore, even if the resistance of the turf is received, the head speed is not easily lowered, and the head can be easily removed. In this respect, Wh / Wc is preferably equal to or greater than 0.75, more preferably equal to or greater than 0.76, and still more preferably equal to or greater than 0.77. If the head weight Wh is excessive, the head speed may decrease. In consideration of the strength of the shaft, there is a limit to reducing the club weight Wc. From these viewpoints, Wh / Wc is preferably 0.82 or less, more preferably 0.81 or less, and more preferably 0.80 or less.

  Increasing the loft angle decreases the angle formed by the face surface f4 and the sole surface f8. Therefore, the effect that the leading edge Le cuts the turf is increased, and the resistance of the turf is easily reduced. From this viewpoint, the real loft angle of the head 2 is preferably 25 ° or more, more preferably 27 ° or more, and more preferably 30 ° or more. An excessively real loft can reduce flight distance performance. From this viewpoint, the real loft angle of the head 2 is preferably 38 ° or less, more preferably 36 ° or less, and more preferably 34 ° or less.

In the present application, the vertical moment of inertia is MI (g · cm ² ), and the head volume is Vh (cm ³ ). In the said embodiment, MI / Vh is 9.0 or more.

  By suppressing the head volume Vh, the resistance of the turf is reduced and the omission is improved. By increasing the vertical moment of inertia MI, the orientation of the face surface f4 is unlikely to fluctuate. Therefore, for example, even if the resistance of the turf is received before impact, the head rotation is less likely to reduce the effective loft angle. Further, even when the hit points vary up and down, the head 2 is difficult to rotate, and a decrease in flight distance is suppressed. From these viewpoints, MI / Vh is preferably 9.0 or more, and more preferably 9.1 or more. When the head volume Vh is too small, anxiety may occur at the address. In this respect, MI / Vh is preferably 10.0 or less, and more preferably 9.8 or less.

  In the head 2, the sole surface f8 has a smooth continuous surface Cf from the leading edge Le toward the back side (see FIG. 3). In the head 2, the continuous surface Cf is a region obtained by combining the first sole region R1 and the front sole region R4 (see FIG. 7). By this continuous surface Cf, the sole surface f8 can easily slide on the grass, and the grounding resistance can be reduced.

  The sole surface f8 has a step forming surface Df located on the back side of the continuous surface Cf. In the head 2, the step forming surface Df is the slope Sp1 and the slope Sp2.

  As described above, in the present application, a side view step is defined. In the head 2, the step in the side view formed by the step forming surface Df is 4 mm or more.

  As described above, the step formed by the slope Sp1 is Ds1, and the step formed by the slope Sp2 is Ds2. In the head 2, the difference Ds1 or the step Ds2 in the vicinity of the point A is a step in the side view. As described above, the ground contact area is reduced by the level difference Ds1 and the level difference Ds2, and the removal of the sole is improved. These steps Ds1 and Ds2 can be determined at respective positions in the toe-heel direction, but among these, the step in side view is considered to be the most effective representative value. By setting the step in the side view to be 4 mm or more, the ground contact area is reduced and the removal of the sole is improved. From the viewpoint of increasing the sweet spot height SH, it is preferable that the step in the side view is 4 mm or more. From the viewpoint of securing the head weight Wh, the step in the side view is preferably 8 mm or less, and more preferably 7 mm or less.

  As described above, the sweet spot height is SH (mm), and the face maximum height from the ground plane H is HX (mm). As shown in FIG. 9, the sweet spot height SH and the face maximum height HX are both heights from the ground plane H.

  In the said embodiment, SH / HX is 0.76 or more. In the rough, the turf can cause the ball to float from the ground. In this case, an “upper strike” is likely to occur where the hit point is on the upper side of the face surface f4. By increasing the SH / HX, the resilience performance in top hitting is improved and the flight distance performance is enhanced. From this viewpoint, SH / HX is preferably 0.76 or more, more preferably 0.78 or more, more preferably 0.80 or more, and more preferably 0.81 or more. Considering the length of turf in a general rough, SH / HX is preferably 0.90 or less, more preferably 0.89 or less, and more preferably 0.88 or less.

  By increasing the kinetic energy of the head, the influence of turf resistance can be reduced. In this respect, the head weight Wh is preferably 250 g or more. When the head weight Wh is excessive, the head speed can be reduced. In this respect, the head weight Wh is preferably 270 g or less, more preferably 265 g or less, and more preferably 260 g or less.

  As described above, hit points are likely to vary in shots from rough. Also, the longer the club, the more likely it is that the hit points will vary. Therefore, when a long club is used in a shot from the rough, the variation in the hit points tends to increase synergistically. In this respect, the club length is preferably 38.5 inches or less, more preferably 38.25 inches or less, and more preferably 38.0 inches or less. From the viewpoint of flight distance performance, the club length is preferably 37.0 inches or more, and more preferably 37.25 inches or more.

  The club length is based on the description of “1c length” in “1 club” of “Attached Rules II Club Design”, which is a golf rule established by R & A (Royal and Associate Golf Club of Saint Andrews). Measured.

  FIG. 11 is an exploded perspective view of the head 2. The face member fp1 and the other member are welded to form the head 2. In the present embodiment, the other member is the head body mb1. This embodiment has a two-piece structure in which two members are joined. The number of members to be joined is not limited, and a three-piece structure and a four-piece structure are exemplified.

  The face member fp1 constitutes a part f41 of the face surface f4. The face member fp1 does not constitute the entire face surface f4.

  The face member fp1 has a first extending part fp11 and a second extending part fp12. The first extending part fp11 constitutes a part of the crown 6. The second extending part fp12 constitutes a part of the sole 8.

  The head body mb1 constitutes a part of the face surface f4 (heel part f42).

  As a result of such a structure, the weld boundary k1 between the head body mb1 and the face member fp1 includes the boundary kf1 on the face surface (see FIG. 1).

  In FIG. 12, the reference symbol Pk indicates a welding position on the face surface f4 between the face member fp1 and the head main body mb1. In the present embodiment, the welding position Pk is the position of the heel side end of the face member fp1 on the face surface f4. In FIG. 12, what is indicated by a double arrow X1 is the distance between the welding position Pk and the end point E. Of the boundary kf1, the position where the toe-heel direction distance is closest to the point E is the position Pk. This distance X1 is a distance in the toe-heel direction.

  In FIG. 12, a double arrow X2 indicates the distance between the position Pk and the face center Fc. This distance X2 is a distance in the toe-heel direction.

  Since the welding is performed in the vicinity of the boundary k1, the rigidity is high. This is because the thickness of the welded portion is increased. Since the boundary kf1 exists on the face surface f4, the face rigidity is high in the vicinity of the boundary kf1. This high rigidity can reduce the resilience performance.

  In the present embodiment, the distance X1 is small. In the vicinity of the point E, the sole rigidity is reduced. Due to the decrease in the sole rigidity, the sole 8 is easily bent in the vicinity of the point E. This bending of the sole 8 can have an effect of compensating for a decrease in resilience performance caused by the boundary kf1. From the viewpoint of enhancing this resilience improving effect, the distance X1 is preferably 15 mm or less, more preferably 10 mm or less, and more preferably 7 mm or less. As a lower limit, the distance X1 is 0 mm or more.

  In light of the above-described rebound improvement effect, the shortest distance between the boundary kf1 and the point E in the face-back direction is preferably 15 mm or less, more preferably 12 mm or less, and even more preferably 10 mm or less. From the viewpoint of strength at the boundary kf1, the shortest distance between the boundary kf1 and the point E in the face-back direction is preferably 5 mm or more, and more preferably 7 mm or more.

  The head volume is not limited. From the viewpoint of increasing the moment of inertia and expanding the sweet area, the head volume is preferably 100 cc or more, more preferably 110 cc or more, and more preferably 120 cc or more. The head 2 of the above embodiment can effectively suppress the ground contact area even when the area of the sole surface f8 is large. Also from this viewpoint, a head volume equal to or higher than the lower limit is preferable. From this viewpoint, it is preferable that the head volume is large. From the viewpoint of rules, the head volume is preferably 470 cc or less. Further, from the viewpoint of adaptability to various lies, particularly rough, the head 2 is preferably a fairway wood, a utility type head, and a hybrid type head. In this case, the head volume is preferably 200 cc or less, more preferably 180 cc or less, and more preferably 160 cc or less.

  The material of the head is not limited. Examples of the material of the head include metal, CFRP (carbon fiber reinforced plastic) and the like. Examples of the metal used for the head include one or more metals selected from pure titanium, titanium alloy, stainless steel, maraging steel, aluminum alloy, magnesium alloy, and tungsten-nickel alloy. Examples of stainless steel include SUS630 and SUS304. As a specific example of stainless steel, CUSTOM450 (manufactured by Carpenter) is exemplified. Examples of the titanium alloy include 6-4 titanium (Ti-6Al-4V), Ti-15V-3Cr-3Sn-3Al, and the like.

  The method for manufacturing the head is not limited. Usually, a hollow head is manufactured by joining two or more members. The manufacturing method of each member which comprises a head is not limited, Casting, forging, and press forming are illustrated.

  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.

[Example 1]
A head similar to the head 2 described above was produced. The face member fp1 was produced by forging. The head main body mb1 was produced by casting. These were welded, the surface was polished, and the head according to Example 1 was obtained. The real loft angle of this head was 30 °. A shaft fitted with a grip was attached to this head, and a club according to Example 1 was obtained. The length of this club was 37.5 inches. The specifications and evaluation results of Example 1 are shown in Table 1 below.

[Examples 2 to 27 and Comparative Examples 1 to 4]
The clubs of Examples 2 to 27 and Comparative Examples 1 to 4 were obtained in the same manner as Example 1 except that the specifications shown in Tables 1 to 5 below were changed. The specifications related to the head shape were adjusted by surface polishing, overlaying by welding, or die change. Further, the head weight Wh and the sweet spot height SH were adjusted by attaching a thermoplastic adhesive to the inside of the head. This adhesive is fixed to the inner surface of the head at normal temperature and flows at high temperature. This pressure-sensitive adhesive was poured into the head at a high temperature, and then cooled to room temperature and fixed. The club weight Wc was adjusted by the shaft weight and the grip weight. Further, the inertia moment MI was adjusted by combining these adjustment methods. The definition of the inertia moment MI is as described above. In the following table, the value of the moment of inertia MI is rounded off to the first decimal place. The face progression FP was adjusted by changing the casting mold of the head body. The specifications and evaluation results for these examples and comparative examples are shown in Tables 1 to 5 below.

[Evaluation method]

[Good omission]
A ball was placed on the rough golf course and the golfer hit it. Evaluation was made by five testers with handicap of 10-20. Each of the five testers hit 10 balls of each club. Each golfer performed a sensory evaluation on the ease of omission. Evaluation was made in five stages from 1 to 5. The higher the score, the higher the evaluation. The average value of the evaluation points was classified as follows. This classification is shown in the column “Goodness of omission” in Tables 1 to 5 above.
A: The average value is 5.0.
B ⁺ : The average value is 4.5 or more and less than 5.0.
B: The average value is 4.0 or more and less than 4.5.
C: The average value is 3.5 or more and less than 4.0.
D: The average value is 3.0 or more and less than 3.5.
E: The average value is 2.5 or more and less than 3.0.
F: The average value is 2.0 or more and less than 2.5.

[Distance from rough]
In the above-described test for good omission, the flight distance of the hit ball was measured. As a result, 50 flight distance data were obtained for each club. The average value of these 50 flight distance data (rounded off after the decimal point) is shown in the column “Flight distance from rough” in Tables 1 to 5 above. The flight distance is a total flight distance obtained by adding a run to a carry.

[Flight distance variation]
The flight distance variation was analyzed using the 50 flight distance data. In 10 data by each golfer, the difference between the maximum flight distance and the minimum flight distance was calculated. The average value of this difference (rounded off after the decimal point) is shown in the “flying distance variation” column in Tables 1 to 5 above.

  As the evaluation results shown in Tables 1 to 5 show, the examples have higher evaluations than the comparative examples. The advantages of the present invention are clear.

  The present invention can be applied to wood type heads, utility type heads, hybrid type heads, and the like.

2 ... head 4 ... face f4 ... face surface 6 ... crown 8 ... sole f8 ... sole surface 10 ... hosel 12 ... shaft hole Cf ... from leading edge Smooth continuous surface toward the back side Df: Step forming surface R1: First sole region R2: Second sole region R3: Third sole region R4: Front sole region Eg1: 1st edge line Eg2 ... 1st edge line Eg3 ... 1st edge line Eg4 ... 1st edge line Sp1 ... Slope on the back side of 1st edge line Sp2 ... 2nd edge line Back side slope Sp3 ... Toe side slope of the third edge line Sp4 ... Heel side slope of the fourth edge line Le ... Leading edge

Claims (7)

It has a face surface, a sole surface and a leading edge.
The face height HF is 29 mm or more,
Head width HW is 65 mm or less,
A golf club head in which FP / HW is 0.25 or more and 0.40 or less when the face progression is FP (mm). The golf club head according to claim 1, wherein MI / Vh is 9.0 or more when the vertical moment of inertia is MI (g · cm ² ) and the head volume is Vh (cm ³ ). When the sweet spot height is SH (mm) and the maximum face height from the ground plane is HX,
The golf club head according to claim 1, wherein SH / HX is 0.76 or more.   4. The golf club head according to claim 2, wherein Wh / Wc is not less than 0.75 when the head weight is Wh and the club weight is Wc.   The golf club head according to claim 1, wherein a real loft angle is 25 ° or more. The sole surface has a smooth continuous surface from the leading edge toward the back side, and a step forming surface located on the back side of the continuous surface,
6. The golf club head according to claim 1, wherein the step formed by the step forming surface is 4 mm or more in a side view.   The golf club head according to claim 1, wherein the head weight Wh is 250 g or more.

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