JP2005253562A - Iron golf club head and iron golf club using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an iron golf club head capable of suppressing the floating of a leading edge and exiting excellently in a sand shot. <P>SOLUTION: For the iron golf club head 1, a loft angle is ≥50 degrees and ≤62 degrees and a groove-like part 4 extended in a prescribed direction is provided on the sole surface. In a projection image to a horizontal plane in a reference state of mounting the head 1 on the horizontal plane at a prescribed loft angle and a prescribed lie angle, the installation direction of the groove-like part 4 forms an angle less than 30 degrees to a track orthogonal direction d3 which is a direction vertical to the direction d2 of 30-degree outside-in. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an iron golf club head used for bunker shots and the like.

  Iron golf club heads such as sand wedges, which are frequently used in bunker, are required to have good omission in bunker shots that often perform so-called explosion shots (shots in which balls are shot with sand in the bunker). If you take a bunker shot with a good head, the speed of the head will not slow down due to the resistance of the sand, it will be easier for the ball to escape from the bunker, and the ball will spin more easily and stop on the green. It becomes easier to lean on the pin. Therefore, in order to improve the omission in the bunker shot, the sand wedge generally has a larger bounce angle than other clubs.

On the other hand, since the above-mentioned sand wedge has a loft angle suitable for a so-called approach or the like, it is also important as a club used in a place other than a bunker (for example, fairway). When the bounce angle is increased as described above, the sole shape swells in a substantially convex shape. Therefore, when used in a fairway or the like, the leading edge floats from the ground (the height from the ground to the leading edge at the time of addressing). There is a problem that the distance) becomes large, and it becomes difficult to address by a fairway or the like, and it is easy to invite a miss shot such as a top.
In view of this, an iron golf club head has been proposed in which a recess provided along the direction parallel to the face surface on the entire sole makes it easy to hit with a fairway without increasing the bounce angle and is suitable for bunker shots. (See Patent Document 1).
JP-A-7-299164 (FIG. 5)

However, the conventional technique described in Patent Document 1 described above does not necessarily have a satisfactory omission in a bunker shot.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an iron golf club head that can suppress the floating (height) of the leading edge at the time of addressing and that has good omission on a bunker shot. .

  In the present invention, an iron golf club head having a loft angle of not less than 50 degrees and not more than 62 degrees and having a groove-like portion extending in a predetermined direction on a sole surface thereof, the head is defined by the predetermined loft angle and In the projected image on the horizontal plane in a reference state placed on the horizontal plane at a predetermined lie angle, the groove-shaped portion is installed in a direction perpendicular to the trajectory orthogonal direction that is perpendicular to the direction of 30 degrees outside in The iron golf club head is characterized by having an angle of less than 30 degrees.

In this case, since the groove portion is provided on the sole surface, during bunker shot, the sand entering the groove portion collides with the inner surface on the back side of the groove portion, so that an upward force acts on the head. As a result, the head can be prevented from entering the sand, and the effect of improving the omission (hereinafter also referred to as the Vance effect) can be obtained. In addition, since the groove-shaped portion is installed in a state that is relatively close to a right angle with respect to the 30-degree outside-in direction, which is a standard head track direction in a bunker shot, the inner surface on the back side of the groove-shaped portion The force received from the sand is maximized, and the Vance effect is increased. And, the Vance effect is not caused by providing a convex part on the sole and giving a bounce angle like a conventional sand wedge, but conversely, a concave groove part is provided on the sole, Since the back side inner surface of the part is caused by the same role as the bounce, the leading edge can be prevented from floating from the ground.
In this case, further, when the installation direction of the groove-like part is an angle of 20 degrees or less with respect to the trajectory orthogonal direction, the installation direction of the groove-like part is closer to a right angle with respect to the direction of 30 degrees outside-in. Therefore, the Vance effect is further increased.

  In the above golf club head, it is preferable that the total sum of the lengths of the groove-shaped portions in the projected image is equal to or greater than 40 mm and equal to or less than 200 mm. The longer the groove length is, the wider the back-side inner surface becomes, so the bounce effect increases. However, the groove length that substantially contributes to the vance effect is the standard track direction of 30 degrees outside-in. Is a length component in a direction orthogonal to the above, that is, the trajectory orthogonal direction component described above. Therefore, if the sum of the components in the direction perpendicular to the trajectory of the groove-shaped portion is too short, a sufficient Vance effect tends not to be obtained. In addition, when trying to increase the sum of the components in the direction orthogonal to the orbit of the length of the groove portion in the sole having a limited area, the width of the groove portion has to be reduced, and sand entering the groove portion is reduced. Vance effect tends to decrease. Therefore, a sufficient bounce effect can be obtained by setting the sum of the components in the direction perpendicular to the orbit in the length of the groove-like portion within the above numerical range.

  According to the present invention, since the groove portion is provided in the sole and the vance effect is generated by the back side inner surface of the groove portion, the floating (height) of the leading edge at the time of addressing is suppressed and the bunker shot is performed. It is possible to provide an iron golf club head that can be easily removed and a golf club including the same.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1A is a view of an iron golf club head (hereinafter also simply referred to as a head) 1 according to an embodiment of the present invention as viewed from the sole surface 2 side, and FIG. 1B is a view of FIG. It is sectional drawing in the AA line. The iron golf club head 1 is an iron type golf club head having a loft angle (real loft angle) of 50 degrees or more and 62 degrees or less, and includes a face surface 3 that is a plane for hitting a ball and a lower end of the face surface 3. A sole surface 2 that extends from the leading edge 10 that is an edge toward the back side of the head 1, and a trailing edge 12 that is located on the back side of the face surface 3 and that is the back side edge of the sole surface 2. And a hosel 13 having a shaft hole (not shown) for inserting a shaft provided on the heel side of the head 1. One end side of a shaft (not shown) is inserted and bonded to a shaft hole (not shown) of the hosel 13, and a grip (not shown) is attached to the other end of the shaft, whereby an iron golf club having the head 1 is obtained. Provided for practical use.

  The sole surface 2 is provided with a single groove portion 4 extending in a predetermined direction. FIG. 8 is an enlarged cross-sectional view of the groove-like portion 4. As shown in FIG. 8, the peripheral edge 4a of the groove-like portion 4 has a smooth curved surface. Is not clearly visible. In FIG. 1 (a), for the sake of clarity, the outline 4b is slightly emphasized and described as a solid line (a partly intermittent annular solid line). In FIG. 4b is indicated by an annular broken line. In FIG. 1 and FIG. 2 and the subsequent drawings, a groove direction line m indicating the installation direction of the groove-like portion 4 which is a line connecting the deepest point f (see FIG. 8) of the groove-like portion 4 is indicated by a one-dot chain line.

In addition, from the viewpoint that a smoother shot is possible on any ground (such as a bunker or lawn), the peripheral edge 4a of the groove-like portion 4 is preferably configured with a smooth curved surface, and foreign matters such as dirt are groove-like. From the viewpoint of preventing fitting into the portion 4, the groove bottom and / or the groove side wall of the groove-like portion 4 may be configured with a smooth curved surface. The entire sole surface 2 including the groove-shaped portion 4 is preferably configured with a smooth curved surface. For example, a cross section of the sole surface 2 cut by a plane perpendicular to the groove direction line m is configured with a smooth curve. It is preferable to have a corrugated cross section.
Thus, when the cross-sectional line in the cross section perpendicular to the groove direction line m is a smooth curve, the curve having a radius of curvature (R) of 2 mm or more, or a combination of curves having a radius of curvature (R) of 2 mm or more. In other words, it is preferable not to have an edge-like portion with a small curvature radius such that the curvature radius (R) is less than 2 mm. It should be noted that the numerical value “2 mm” in this rule is preferably defined in the same manner as described above as “2.5 mm”, particularly “3 mm”.
All the embodiments in the present application are constituted by continuous curves composed of a combination of curves having a curvature radius (R) of 2.5 mm or more in a cross section perpendicular to the groove direction line m.

  FIG. 1 (a) (and all the drawings of a head to be described later seen from the sole surface 2 side) is a view seen from the sole surface 2 side, and is also a projected image of the head 1 in the reference state on the horizontal plane. . The reference state is a state in which the head is placed on a horizontal plane at a predetermined loft angle (real loft angle) and a predetermined lie angle. Hereinafter, directions and angles related to the installation direction of the groove direction line m will be described. These directions and angles are all directions and angles on the projection image.

  In the projected image of FIG. 1A, an angle of 30 degrees is formed with respect to the normal direction d1 of the face surface 3 (matching the AA line in FIG. 1A) and the front side of the head 1 on the heel side The direction from the rear to the toe side is the 30-degree outside-in direction d2. The orbit orthogonal direction d3 which is a direction perpendicular to the 30-degree outside-in direction d2 and the direction d4 of the groove direction line m indicating the installation direction of the groove-like portion 4 form an angle θ. The angle θ is the smaller of the angles formed by the trajectory orthogonal direction d3 and the direction d4 of the groove direction line m.

  FIG. 11 is an enlarged view showing the directions d1 to d4 and the angle θ in the head 1. In the head 1, the angle θ is less than 30 degrees. In other words, the angle formed by the 30-degree outside-in direction d2 and the direction d4 of the groove direction line m (plus (+) in the clockwise direction from the direction d2 to the direction d4 in FIG. The angle α in which the rotation direction is minus (−) is greater than +60 degrees and smaller than +120 degrees. Accordingly, in the present invention, the angular range σ in the installation direction of the groove 4 is positive when clockwise (clockwise) and negative when counterclockwise (counterclockwise) in FIG. The range is less than ± 30 degrees from the direction d3, and the range α is greater than 60 degrees and less than 120 degrees (see FIG. 11). In FIG. 1A, the angle α is an angle in the clockwise direction from the direction d2 to the direction d4. This is a case of a right-handed golfer iron club head, and a left-handed golfer iron golf club. In the case of the head, conversely, the angle α is “an angle in which the counterclockwise direction from the direction d2 to the direction d4 is positive and the clockwise direction is negative”.

  As shown in FIGS. 1 and 8, the groove-shaped portion 4 has a face-side inner surface 41 and a back-side inner surface 42 that are divided with the groove direction line m as a boundary. During the bunker shot, the sand that has entered the groove-like portion 4 collides with the back-side inner surface 42, whereby an upward force (vertically upward) is applied to the head 1, thereby suppressing the head 1 from entering the sand. In other words, an effect of improving so-called omission (Vance effect) is achieved.

  The 30-degree outside-in direction d2 is a general head trajectory during a bunker shot impact. FIG. 10 is a schematic diagram showing a head trajectory at the time of a bunker shot, and is a view (right-handed) of an impact state that is a moment when a golf ball gb is hit by an iron golf club 21 in which a shaft 20 is mounted on the head 1. FIG. In bunker shots, it is usual to use a so-called outside-in trajectory k1 hitting method (a method called cut hitting), but this time, the trajectory in such a bunker shot was investigated in detail. That is, the trajectory at the time of impact on a bunker shot was investigated for a total of 100 golfers, 50 golfers with handicap of 0-15 and 50 golfers with handicap of 16-30. As a result, it was found that the average value of the impact trajectory directions of these 100 golfers was a 30-degree outside-in direction d2 that is 30 degrees with respect to the normal direction d1 of the face surface 3. 1A and the like are views seen from the sole surface 2 side (lower side), while FIG. 10 is a view seen from the face surface 3 side (upper side) of the head 1. The direction of the outside-in direction d2 is the same between both drawings.

  Thus, since the 30-degree outside-in direction d2 is a general head trajectory at the time of impact of a bunker shot, the groove-shaped portion can be obtained by making the installation direction of the groove-shaped portion 4 perpendicular to this direction d2. The force which the back side inner surface 42 of 4 receives from sand becomes larger, and a Vance effect increases. That is, the Vance effect is increased by bringing the groove direction line m indicating the installation direction of the groove-like portion 4 closer to the trajectory orthogonal direction d3. Therefore, the Vance effect is enhanced by setting the angle θ between the direction d4 of the groove direction line m indicating the installation direction of the groove-like portion 4 and the orbit orthogonal direction d3 to be less than 30 degrees. In addition, the Vance effect is further increased by setting the angle α to 20 degrees or less. When the groove direction line m indicating the installation direction of the groove-like portion 4 is a curve, the angle formed between the tangential direction at each point on the groove direction line m and the trajectory orthogonal direction d3 is the angle θ. Just think about it.

FIG. 9 is a side view of a conventional sand wedge as seen from the toe side. As shown in FIG. 9, in the conventional sand wedge, the convex portion 30 of the sole surface is protruded relatively large in order to increase the bounce angle bs to enhance the bounce effect. Therefore, the floating of the leading edge from the ground was relatively large. That is, as shown in FIG. 9, the minimum value h (vertical height h from the horizontal plane y of the leading edge 10 of the head in the reference state in which the head is placed on the horizontal plane y at a predetermined loft angle and a predetermined lie angle. Hereinafter, the floating height h of the leading edge) was relatively large.
However, in the present embodiment, instead of providing a convex portion on the sole surface 2 and providing a bounce angle as in the conventional sand wedge, a vance effect is achieved by a method of providing a concave groove-like portion 4 on the sole. Thus, the floating height h of the leading edge can be made relatively low.

  In the present invention, when the floating height h of the leading edge is 8 mm or less, more preferably 6 mm or less, and particularly 5 mm or less, so-called top shot misses are suppressed, and addressing even on fairways and the like is preferable. . In addition, if the floating height h of the leading edge is too small, the leading edge is likely to pierce the ground especially in shots on fairways and the like, and misshots such as so-called duff are likely to occur. Is preferably 2 mm or more, more preferably 4 mm or more.

  As shown in FIG. 1, in the present embodiment, the length L of the length d of the groove-like portion 4 and the d3 component in the trajectory orthogonal direction is 40 mm or more and 200 mm or less. As the length of the groove-shaped portion 4 increases, the area of the back side inner surface 42 increases and the bounce effect increases. However, the length of the groove-shaped portion 4 that substantially contributes to the bounce effect is the standard track direction. This is the total sum L of the length components in the direction orthogonal to the direction of a certain 30-degree outside-in direction, that is, the length components in the trajectory orthogonal direction d3 described above. Therefore, a sufficient Vance effect can be obtained by setting the total length L of the length components in the trajectory orthogonal direction d3 described above to 40 mm or more. Here, the “sum” refers to the case where a plurality of groove-like portions 4 are provided, and each of the length components of the plurality of groove-like portions 4 in the direction orthogonal to the trajectory d3. Means the total length plus all For example, when five groove portions 4 are provided as shown in FIG. 2, if the length components in the orbit orthogonal direction d3 of each groove portion 4 are L1, L2, L3, L4, and L5, respectively, L = L1 + L2 + L3 + L4 + L5.

  As described above, since the Vance effect increases as the total sum L increases, the total sum L of the lengths of the groove portions 4 in the orbit orthogonal direction d3 component is more preferably 50 mm or more, and more preferably 60 mm or more. The thickness is preferably 100 mm or more. However, if the total sum L of the lengths of the grooves 4 in the trajectory orthogonal direction is too long in the sole surface 2 having a limited area, the width of the grooves 4 becomes excessively narrow and enters the grooves 4. Sand may be reduced and the Vance effect may be reduced. Therefore, the total sum L is preferably 175 mm or less, and more preferably 150 mm or less.

  The number of the groove-like portions 4 in the present invention is not particularly limited as long as one or more groove-like portions 4 are provided. However, since the total sum L tends to increase as the number of grooves increases, the number of the groove-like portions 4 is more preferably 2 or more, more preferably 3 or more, and particularly preferably 4 or more. However, if the number of grooves is excessively large, the width of the groove-shaped portion 4 becomes excessively narrow, and sand entering the groove-shaped portion 4 may be reduced to reduce the Vance effect. It is preferable to make it below this.

In the case where a plurality of groove-like portions 4 are provided, the interval between the groove-like portions 4 in the projection view on the horizontal plane of the head in the above-mentioned reference state, that is, the groove pitch p (see FIG. 2) is preferably 7 mm or more, and 8 mm or more. More preferably, it is more preferably 10 mm or more. This is because if the groove pitch p is too narrow, the width of the groove-like portion 4 becomes excessively small, and sand entering the groove-like portion 4 is reduced, which may reduce the Vance effect. In addition, if the groove pitch p is too wide, the sum L of the components in the direction perpendicular to the orbit of the length of the groove-shaped portion 4 may not be sufficiently long. Therefore, the groove pitch p is preferably 20 mm or less, more preferably 18 mm or less, More preferably, it is 15 mm or less.
The groove pitch p is a groove interval in a direction perpendicular to the groove direction line m. However, when the groove direction lines m of the two groove-like portions 4 where the groove pitch p is measured are not parallel to each other, The measurement direction of the pitch p is bisected at the intersection of the two groove direction lines m and bisects the angle formed by the two groove direction lines m and passes between the two groove direction lines m. The direction can be perpendicular to the line.

The groove width W that is the width of the groove-like portion 4 is preferably 7 mm or more, more preferably 8 mm or more, and further preferably 9 mm or more. This is because if the groove width W is too narrow, the sand entering the groove-like portion 4 is reduced and the Vance effect may be reduced. The groove width W is preferably substantially equal to the groove pitch p. In this case, the groove-like portion 4 can be provided in the sole surface 2 without a substantial gap, and the sum L of the length of the groove-like portion 4 in the orbital direction and the groove width within the sole surface 2 of a limited area. This is because W can be maximized. In addition, if the groove width W is too wide, the sum L of the lengths of the groove-like portions 4 may be too short. Therefore, the groove width W is preferably 20 mm or less, more preferably 18 mm or less, and 15 mm. The following is more preferable.
The groove width W is a groove width in a direction perpendicular to the groove direction line m (or a tangent line at each point on the curve when the groove direction line m is a curve) (that is, an interval between the contour lines d4). Yes (see FIG. 1).

If the groove depth dm (see FIG. 8) of the groove-shaped portion 4 is too shallow, the amount of sand entering the groove-shaped portion 4 is reduced, and the Vance effect by the groove-shaped portion 4 is reduced, and the effect of improving the removal performance may not be sufficient. Therefore, the groove depth dm is preferably 0.5 mm or more, more preferably 0.7 mm or more, and particularly preferably 0.8 mm or more. Further, if the groove depth dm is too deep, the workability of the polishing process of the head surface (sole surface) may be reduced or the cost of the head molding may be increased. Therefore, the groove depth dm is 1.5 mm or less. Is preferable, 1.3 mm or less is more preferable, and 1.2 mm or less is particularly preferable.
The groove depth dm of the groove-like portion 4 is a straight line r connecting two contour lines 4b of the groove-like portion 4 in a cross section perpendicular to the groove direction line m of the groove-like portion 4 as shown in FIG. It is the distance from the cross-section deepest point f of the groove-like portion 4.

The groove angle g of the groove-like portion 4 shown in FIG. 8 is preferably 10 degrees or more, more preferably 15 degrees or more, and particularly preferably 20 degrees or more. This is because if the groove angle g is too small, the back side inner surface 42 becomes nearly parallel to the sole surface 2 and becomes close to a state where the groove-like portion 4 is not provided, and the Vance effect tends to be reduced. On the other hand, if the groove angle g of the groove-like portion 4 is too large, the angle formed by the back side inner surface 42 and the sole surface 2 becomes close to 90 degrees, and the vertical upward component of the force that the back side inner surface 42 receives from the sand. Since the force decreases and the horizontal component increases, the Vance effect decreases and the head speed tends to decrease. Therefore, the groove angle g is preferably 45 degrees or less, more preferably 30 degrees or less, and particularly preferably 25 degrees or less.
The groove angle g of the groove-like portion 4 is an angle formed by the tangent line sm at the midpoint mp of the cross-sectional line of the back side inner surface 42 and the straight line r in the cross section perpendicular to the groove direction line m shown in FIG. It is.
If the cross-sectional shape of the groove-like portion 4 is substantially symmetrical with respect to a line that passes through the deepest cross-section point f of the groove-like portion 4 and is perpendicular to the straight line r, the groove-like portion 4 can be easily processed and the aesthetic appearance of the head. The above is also advantageous because it is advantageous.

  Next, the result of having produced the Example and comparative example of this invention, and performing the comparative test is shown. Table 1 summarizes the results of comparative tests on a total of nine types of iron golf clubs including six types of Examples 1 to 6 and three types of Comparative Examples 1 to 3. These nine types of iron golf clubs all share the same shaft, grip, club length, club balance, total club weight, and head weight. For all nine clubs, the lie angle was 63.5 degrees and the real loft was 58 degrees.

In Table 1, the total sum L is the total sum L of the lengths of the groove-shaped portions 4 described above, and the floating height h is the above-described floating height h of the leading edge. There are other head specifications as described above.
In addition, “disengagement performance” in Table 1 refers to the ease of disengagement when 20 golfers with handicap from 0 to 15 are used as testers and each tester takes a bunker shot from 15 yards to the pin. The sensory evaluation was performed with a score of 100, and the score was averaged by 20 golfers. The higher the score, the better the evaluation.
The “distance to the pin” is the ball obtained as a result of each of the 20 testers aiming for 10 balls from the bunker on the green side (the distance to the pin is 15 yards) and aiming at the bunker shot. It is the value which measured the distance of a stop position and a pin, Comprising: It is the value which further averaged the average value of 10 balls in each tester with 20 golfers. The smaller the value, the closer the ball hits the pin.

The form of the groove part 4 of each Example and a comparative example is demonstrated.
5A is a view of the head of Comparative Example 1 as viewed from the sole surface 2 side, and FIG. 5B is a cross-sectional view taken along the line AA. As described above, the groove portion 4 is not provided in the comparative example 1.
FIG. 6 is a view of the head of Comparative Example 2 as viewed from the sole surface 2 side, in which one groove-like portion 4 is provided. The angle α formed by the 30-degree outside-in direction d2 and the direction d4 of the groove direction line m is 40 degrees, and is formed by the trajectory orthogonal direction d3 and the direction d4 of the groove direction line m indicating the installation direction of the groove-shaped portion 4. The angle θ is 50 degrees.
FIG. 7A is a view of the head of Comparative Example 3 viewed from the sole surface 2 side, and FIG. 7B is a cross-sectional view taken along the line BB. In Comparative Example 3, three groove-like portions 4 are provided, and the angle α is 130 degrees, that is, the angle θ is 40 degrees for any groove-like portion 4.

FIG. 1 (a) and FIG. 1 (b), which is a cross section taken along the line AA, are diagrams showing the first embodiment and the second embodiment. In each of Example 1 and Example 2, there is only one groove-like portion 4 and the angle θ is 20 degrees (angle α is 70 degrees), but the length of the groove-like portion 4 in the longitudinal direction is the same. As a result, the total sum L is 60 mm in the second embodiment and 40 mm in the first embodiment.
2A is a view of the head of Example 3 as viewed from the sole surface 2 side, and FIG. 2B is a cross-sectional view taken along the line BB. In the third embodiment, five groove-like portions 4 are provided with substantially no gap, and any groove-like portion 4 has an angle θ of 0 degree, that is, the groove-like portion 4 is provided in a direction parallel to the trajectory orthogonal direction d3. It has been.

FIG. 3A is a view of the head of Example 4 as viewed from the sole surface 2 side, and FIG. 3B is a cross-sectional view taken along the line BB. In Example 3, ten groove-like portions 4 are provided with substantially no gap, and any groove-like portion 4 has an angle θ of 0 degree, that is, the groove-like portion 4 is provided in a direction parallel to the trajectory orthogonal direction d3. It has been.
4A is a view of the head of Example 5 as viewed from the sole surface 2 side, and FIG. 4B is a cross-sectional view taken along the line BB. In Example 4, four groove-like portions 4 are provided with a predetermined gap therebetween, and each groove-like portion 4 has an angle α of 110 degrees and an angle θ of 20 degrees. Although not shown in the drawings, in Example 6, seven groove-like portions 4 are provided substantially without any gap, and each groove-like portion 4 has an angle α of 90 degrees, that is, an angle θ of 0 degrees. All the groove-like portions 4 are oriented parallel to the trajectory orthogonal direction d3. Note that the cross-sectional shapes of the groove-like portions 4 in all the examples and the comparative examples are each configured with a smooth curve as shown in FIG. 8, and the groove direction line m and the contour line 4b are clearly shown on the head appearance. Not visible.
As shown in Table 1, Examples 1 to 6 are better than Comparative Examples 1 to 3 in terms of both evaluation items of the removal performance and the distance to the pin.

It is a figure of the head of one embodiment of the present invention and Examples 1 and 2, (a) is a view seen from the sole surface side, (b) is a cross-sectional view taken along line AA of (a). (A) is the figure which looked at the head of Example 3 from the sole surface side, (b) is sectional drawing in the BB line of (a). (A) is the figure which looked at the head of Example 4 from the sole surface side, (b) is sectional drawing in the BB line of (a). (A) is the figure which looked at the head of Example 5 from the sole surface side, (b) is sectional drawing in the BB line of (a). (A) is the figure which looked at the head of the comparative example 1 from the sole surface side, (b) is sectional drawing in the AA of (a). It is the figure which looked at the head of comparative example 2 from the sole surface side. (A) is the figure which looked at the head of the comparative example 3 from the sole surface side, (b) is sectional drawing in the BB line of (a). It is sectional drawing of a groove-shaped part. It is the side view which looked at the iron golf club head from the toe side for showing the floating height of a leading edge. It is a figure for demonstrating the head track | orbit when performing a bunker shot. It is a figure for demonstrating the installation direction of a groove-shaped part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Iron golf club head 2 Sole surface 4 Groove part 42 Back side inner surface d2 30 degree outside in direction d3 Orbit orthogonal direction d4 Groove direction line direction (installation direction of groove part)
θ Angle formed between the direction perpendicular to the track and the direction in which the groove is installed L The sum of the components in the direction perpendicular to the track in the length of the groove

Claims (4)

An iron golf club head having a loft angle of not less than 50 degrees and not more than 62 degrees and having a groove-like portion extending in a predetermined direction on a sole surface thereof,
In the projected image onto the horizontal plane in a reference state where the head is placed on the horizontal plane at the predetermined loft angle and the predetermined lie angle, the groove-shaped portion is installed in a direction perpendicular to the direction of 30 degrees outside in. An iron golf club head having an angle of less than 30 degrees with respect to the direction perpendicular to the trajectory.   2. The iron golf club head according to claim 1, wherein, in the projected image, an installation direction of the groove-shaped portion forms an angle of 20 degrees or less with respect to the trajectory orthogonal direction.   3. The iron golf club head according to claim 1, wherein, in the projected image, a sum total of the orbital orthogonal direction components of the length of the groove-shaped portion is not less than 40 mm and not more than 200 mm.   The iron golf club provided with the iron golf club head in any one of Claims 1-3.

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