Iron golf club head

Abstract

To provide an iron golf club head capable of increasing a spin rate of a ball while conforming to the R&A rule.SOLUTION: An iron golf club head 1 includes: a face part 10 having a face surface 11; a toe part continuing to the face part 10; and a heel part continuing to the face part 10 and facing the toe part across the face part 10. A plurality of score lines 20 are disposed in the face part 10. Each of the plurality of score lines 20 extends in a toe heel direction where the toe part and the heel part face each other. A relation of a width W of the score line 20 measured by a 30° measurement method and a width WR of the score line 20 contacting the face surface 11 is WR / W>1.35.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an iron golf club head. [Background technology]

[0002] The face of an iron golf club has multiple grooves called score lines. The score lines affect the ball's spin rate. Spin performance is determined by many design elements, including the number of score lines, the width and depth of the score lines, and the corner radius of the edge.

[0003] On the other hand, the shape of the score lines needs to be designed to comply with the rules of golf, such as those set by the Royal and Ancient Golf Club of St. Andrews (R&A).

[0004] For example, Japanese Patent Application Laid-Open Publication No. 2010-240262 (Patent Document 1) describes a golf club head with scorelines. In the golf club head described in this publication, the angle between the edge of the scoreline and the side wall of the scoreline is numerically limited. The golf club head described in Patent Document 1 can increase the number of spins while complying with the above-mentioned rules such as R&A. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-240262 A Summary of the Invention [Problem to be solved by the invention]

[0006] The score lines are preferably provided so as to increase the number of spins of the ball. Also, the score lines preferably comply with the rules of the R&A, etc. Further improvement in the number of spins is required in the market, and there is a demand for an iron golf club head that can further improve the spin performance while complying with the rules of the R&A, etc.

[0007] The present invention has been made in consideration of the above problems, and its object is to provide an iron golf club head that can increase the number of spins on the ball while complying with golf rules such as those of the R&A. [Means for solving the problem]

[0008] The iron golf club head of the present invention includes a face portion having a face surface, a toe portion continuous with the face portion, and a heel portion continuous with the face portion and facing the toe portion across the face portion. A plurality of scorelines are provided on the face portion. Each of the plurality of scorelines extends in a toe-heel direction in which the toe portion and the heel portion face each other. The width W of the scoreline measured by the 30° measurement method and the width WR of the scoreline in contact with the face surface are WR / W>1.35. Effect of the Invention

[0009] The iron golf club head of the present invention can improve the spin rate of the ball while complying with the rules of golf such as those of the R&A. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic front view of an iron golf club head according to an embodiment. [Diagram 2] 1 is a schematic cross-sectional view of an iron golf club head according to an embodiment. [Diagram 3] FIG. 3 is an enlarged view of part III in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference characters unless otherwise specified, and the description thereof will not be repeated.

[0012] 1, an iron golf club head 1 according to an embodiment mainly includes a face portion 10, a toe portion 30, and a heel portion 40. The iron golf club head 1 also includes a top edge portion 50, a sole portion 60, and a hosel portion 70.

[0013] The face portion 10 has a face surface 11. The face surface 11 is disposed on the front side of the face portion 10. The face surface 11 constitutes a ball-hitting surface. A plurality of scorelines 20 are provided on the face portion 10. Each of the plurality of scorelines 20 is provided continuously on the face surface 11.

[0014] Each of the multiple scorelines 20 extends in a toe-heel direction in which the toe portion 30 and the heel portion 40 face each other. Each of the multiple scorelines 20 is provided linearly in a direction crossing the face surface 11. The multiple scorelines 20 are provided at intervals in a top-sole direction in which the top edge portion 50 and the sole portion 60 face each other. The multiple scorelines 20 are provided at approximately equal intervals in a direction crossing the face surface 11.

[0015] The toe portion 30 is a portion that connects the top edge portion 50 on the side away from the hosel portion 70 and the sole portion 60. The toe portion 30 is continuous with the face portion 10. The heel portion 40 is a portion that extends from the lower end of the hosel portion 70 to the sole portion 60. The heel portion 40 is continuous with the face portion 10. The heel portion 40 faces the toe portion 30 with the face portion 10 in between.

[0016] The top edge portion 50 constitutes the upper edge portion of the main body of the iron golf club head 1 extending from the hosel portion 70 to the toe portion 30. The sole portion 60 constitutes the bottom portion of the main body of the iron golf club head 1. The hosel portion 70 is a portion to which a shaft (not shown) is connected. The iron golf club head 1 also includes a back portion (not shown) on the rear side of the face portion 10.

[0017] An iron golf club is constructed by combining a shaft and a grip with the iron golf club head 1. The shaft and grip may be any well-known one.

[0018] The configuration of the scoreline 20 of the iron golf club head 1 according to the embodiment will be described in detail with reference to FIGS.

[0019] The shape of the scoreline 20 complies with the rules of the R&A (Royal and Ancient Golf Club of St. Andrews). Specifically, the depth D of the scoreline 20 is 0.508 mm or less. The width W of the scoreline 20 measured by the 30° measurement method is 0.889 mm or less. This 30° measurement method (R&A rule) is a method of measuring the width W of the scoreline 20 between two points where a straight line inclined by 30° to the face surface 11 touches the edge of the scoreline 20. The interval S of the scoreline 20 is 1.905 mm or more. The value (S-3W) obtained by subtracting three times the width W of the scoreline 20 from the interval S of the scoreline 20 exceeds 0. The value (A / (S+W)) obtained by dividing the cross-sectional area A of the scoreline 20 by the sum of the interval S of the scoreline 20 and the width W of the scoreline 20 is 0.0762 mm. 2 / mm or less. The radius of the rounded edge of the scoreline 20 is contained on a concentric circle having a radius of 0.254 mm or more and 0.508 mm or less by the two-circle method. This two-circle method (R&A internal rule) is a method in which, in principle, if the edge of the scoreline 20 protrudes from a circle of radius 0.011 inches that is concentric with a circle of radius 0.010 inches that is in contact with the side wall of the scoreline 20 and the adjacent face surface 11, it is deemed non-compliant.

[0020] The scoreline 20 has a first side wall portion 21, a second side wall portion 22, and a bottom portion 23. The first side wall portion 21 is continuous with the face surface 11. The second side wall portion 22 is continuous with the face surface 11. The bottom portion 23 is continuous with the first side wall portion 21 and the second side wall portion 22. The first side wall portion 21 and the second side wall portion 22 face each other with the bottom portion 23 in between. The bottom portion 23 is provided approximately parallel to the face surface 11.

[0021] The distance between two points where a straight line inclined at 30° with respect to the face surface 11 touches the edge of the scoreline 20 is the width W of the scoreline 20. In other words, the distance between points where a straight line inclined at 30° with respect to the face surface 11 touches each of the first side wall portion 21 and the second side wall portion 22 is the width W of the scoreline 20. The distance between two points where the scoreline 20 touches the face surface 11 is the width WR of the scoreline 20 touching the face surface 11. In other words, the distance between points where the first side wall portion 21 and the second side wall portion 22 touch the face surface 11 is the width WR of the scoreline 20 touching the face surface 11.

[0022] In the iron golf club head 1 according to the present embodiment, the width W of the scoreline 20 measured by the 30° measurement method and the width WR of the scoreline 20 in contact with the face surface 11 satisfy WR / W>1.35.

[0023] The cross-sectional area of ​​the scoreline 20 at the width WR is the cross-sectional area A of the scoreline 20. In other words, the cross-sectional area A of the scoreline 20 is the cross-sectional area of ​​a hollow portion surrounded by the scoreline 20 and an imaginary line along the face surface 11. The cross-sectional area A of the scoreline 20 is the cross-sectional area of ​​a section perpendicular to the toe-heel direction of the scoreline 20. The distance between the centers of adjacent scorelines 20 is the center-to-center distance P of the adjacent scorelines 20. In other words, the center-to-center distance P of the scorelines 20 is the value obtained by adding the width W of the scoreline 20 to the interval S of the scorelines 20. The center-to-center distance P of the scorelines 20 is the pitch of the scorelines 20.

[0024] In the iron golf club head 1 of this embodiment, the width W of the scoreline 20 measured by the 30° measurement method, the width WR of the scoreline 20 that contacts the face surface 11, the cross-sectional area A of the scoreline 20, and the center-to-center distance P of adjacent scorelines 20 satisfy (WR / W) / (A / P)>21.0.

[0025] The edges of the scorelines 20, which are in contact with a straight line inclined at 30° to the face surface 11, are rounded. The edges of the scorelines 20 have a gentle shape in cross-sectional view. The edges of the scorelines 20 are rounded from the edges of the scorelines 20 to the face surface 11. The portions from the edges of the scorelines 20 to the face surface 11 have a gentle shape in cross-sectional view.

[0026] The distance from the face surface 11 to the bottom 23 of the scoreline 20 in a direction perpendicular to the face surface 11 is the depth D of the scoreline 20. The width of the bottom 23 in a cross-sectional view is the bottom width WB.

[0027] Next, the effects of the iron golf club head 1 according to the embodiment will be described.

[0028] In order to increase the spin rate of the ball while complying with the above-mentioned R&A rules, the inventors focused on the width WR of the scoreline 20 that contacts the face surface 11, and designed the shape of the scoreline 20 so that the width WR of the scoreline 20 that contacts the face surface 11 is large. The inventors then found that the spin rate can be improved by making the width W of the scoreline 20 measured by the 30° measurement method and the width WR of the scoreline 20 that contacts the face surface 11 WR / W>1.35.

[0029] The R&A rules prescribe a value (A / (S+W)) obtained by dividing the cross-sectional area A of the scoreline 20 by the sum of the interval S of the scoreline 20 and the width W of the scoreline 20, that is, a value (A / P) obtained by dividing the cross-sectional area A of the scoreline 20 by the center-to-center distance P of the scoreline 20. It is known that increasing this A / P is advantageous in terms of the number of spins. The inventor designed the shape of the scoreline 20 by placing more importance on the value (WR / W) obtained by dividing the width WR of the scoreline 20 in contact with the face surface 11 by the width W of the scoreline 20 measured by the 30° measurement method than on this A / P. The inventor found that the number of spins can be improved by setting the width W of the scoreline 20 measured by the 30° measurement method, the width WR of the scoreline 20 in contact with the face surface 11, the cross-sectional area A of the scoreline 20, and the center-to-center distance P of the scoreline 20 adjacent to each other, to (WR / W) / (A / P)>21.0.

[0030] (Example) An example of an iron golf club according to an embodiment will be described.

[0031] The Examples are examples of the present invention. Comparative Examples 1 to 3 are comparative examples to the Examples.

[0032] With reference to Tables 1 and 2, the relationship between the shape of the score lines and the number of spins for the iron golf clubs according to the example and comparative examples 1 to 3 will be described.

[0033] [Table 1]

[0034] [Table 2]

[0035] The symbols in Tables 1 and 2 correspond to the symbols in the embodiment. The values ​​of the symbols of the iron golf clubs according to the embodiment and comparative examples 1 to 3 are as shown in Tables 1 and 2. The loft angle of each iron golf club head according to the embodiment and comparative examples 1 to 3 is 46°. The spin rate of each iron golf club head according to the embodiment and comparative examples 1 to 3 was measured by a robot test. Specifically, each iron golf club head according to the embodiment and comparative examples 1 to 3 was fixed to a golf robot "Mechanical Golfer" manufactured by Miyamae Co., Ltd., and the carry was set to 120 yards. The backspin rate was measured by hitting five balls with each iron golf club. The backspin rate was measured with a trajectory measuring device "Trackman 4" manufactured by Trackman Co., Ltd. The ball used was "RB TOUR X" manufactured by Mizuno Co., Ltd. The spin rate in Table 2 is the average value of the spin rate of five balls hit with each iron golf club. The iron golf clubs of Example, Comparative Example 1 and Comparative Example 2 have 17 score lines, and the iron golf club of Comparative Example 3 has 14 score lines.

[0036] As shown in Table 2, the Examples had a higher spin rate than Comparative Examples 1 to 3. From the Examples, the inventor found that the spin rate can be improved by having a WR / W of 1.399. As a result of examining the Examples and Comparative Examples 1 to 3, the inventor found that the spin rate can be improved by having a WR / W>1.35. From the Examples, the inventor found that the spin rate can be improved by having a (WR / W) / (A / P) of 21.73. As a result of examining the Examples and Comparative Examples 1 to 3, the inventor found that the spin rate can be improved by having a (WR / W) / (A / P)>21.0.

[0037] The embodiments and examples disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0038] 1 Iron golf club head, 10 Face portion, 11 Face surface, 20 Score line, 30 Toe portion, 40 Heel portion, A Cross-sectional area of ​​score line, P Center distance of score line, S Score line spacing, W Width of score line measured using the 30° measurement method, WR Width of score line in contact with face surface.

Claims

1. a face portion having a face surface; A toe portion continuous with the face portion; a heel portion that is continuous with the face portion and faces the toe portion with the face portion therebetween; A plurality of score lines are provided on the face portion, Each of the plurality of score lines extends in a toe-heel direction in which the toe portion and the heel portion face each other, An iron golf club head, wherein a width W of the score line measured by a 30° measurement method and a width WR of the score line in contact with the face surface satisfy WR / W>1.

35.

2. 2. The iron golf club head according to claim 1, wherein a width W of the scoreline measured by a 30° measurement method, a width WR of the scoreline in contact with the face surface, a cross-sectional area A of the scoreline, and a center-to-center distance P of adjacent scorelines satisfy (WR / W) / (A / P)>21.0.

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