Golf club head

Abstract

It is possible to obtain a golf club head excellent in stability of spin performance at the time of an off-center hit.SOLUTION: The head 100 includes a face portion 102 having a hitting surface 102a, a sole portion 106, and a hosel portion 108. The hitting face 102a is divided into a central region Rc, a toe region Rt located on the toe side of the central region Rc, and a heel region R h located on the heel side of the central region Rc. The central region Rc has a first processed surface 110 formed by the first concave-convex processing. The toe region Rt and the heel region Rh have a first processed surface 110 formed by the first uneven processing, a second processed surface 112 formed by the second uneven processing, and an overlapped processed surface 114 formed by overlapping the first uneven processing and the second uneven processing. The first machined surface 110 is coated with a coating layer.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] A golf club head has a striking surface. A golf ball collides with this striking surface. The striking surface may be formed with a surface treatment such as grooves. This surface treatment may affect the behavior of the struck golf ball. JP 2017-205359 A discloses a golf club head in which a plurality of first grooves are formed in the toe-side area of ​​the striking surface and a plurality of second grooves are formed in the heel-side area of ​​the striking surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-205359 Summary of the Invention [Problem to be solved by the invention]

[0004] One of the performance features of a head is its spin performance. Spin performance is the performance related to the spin that the head imparts to the ball. A head with excellent spin performance can achieve an appropriate gear effect. Due to the gear effect, a ball that hits the toe region and flies to the right is more likely to reach the target point with a hook spin, and a ball that hits the heel region and flies to the left is more likely to reach the target point with a slice spin. Furthermore, when the ball is hit off-center, hitting the toe or heel region, the ball slides on the hitting surface, making the spin performance less stable. The stability of spin performance contributes to the directional stability of the hit ball. The stability of spin performance contributes to an increase in the average flight distance. A head with excellent stability of spin performance when hit off-center is preferred.

[0005] An object of the present invention is to provide a golf club head that has excellent stability in spin performance when hit off-center. [Means for solving the problem]

[0006] In one aspect, the present invention is a golf club head including a face portion having a striking surface, a sole portion, and a hosel portion. The striking surface is divided into a central region, a toe region located on the toe side of the central region, and a heel region located on the heel side of the central region. The central region has a first processed surface formed by a first uneven processing. The toe region and the heel region have a first processed surface formed by the first uneven processing, a second processed surface formed by a second uneven processing, and an overlapping processed surface formed by overlapping the first uneven processing and the second uneven processing. The first processed surface is covered with a coating layer. [Effects of the Invention]

[0007] As one aspect, a golf club head with excellent stability in spin performance on off-center hits can be obtained. [Brief explanation of the drawings]

[0008] [Figure 1] Fig. 1 is a perspective view of a golf club head according to one embodiment, in which the processed surface formed by the uneven processing is omitted. [Figure 2] Fig. 2 is a front view of the golf club head of Fig. 1. In Fig. 2, the processed surface formed by the uneven processing is also omitted. [Figure 3] Figure 3(a) is a front view of the golf club head of Figure 1, and Figure 3(b) is a cross-sectional view of the outer surface of the head taken along line E1 in Figure 3(a). Figure 3(a) also omits the illustration of the processed surface formed by the uneven processing. [Figure 4] FIG. 4 is a front view showing the first processed surface formed by the first uneven processing (first laser processing). [Figure 5]FIG. 5 is a front view showing the second processed surface formed by the second uneven processing (second laser processing). [Figure 6] Fig. 6 is a front view showing the completed state of the golf club head of Fig. 1. Fig. 6 shows the processed surface formed by carrying out the second uneven processing (second laser processing) after the first uneven processing (first laser processing). [Figure 7] FIG. 7 is an enlarged view of the portion surrounded by the two-dot chain line F7 in FIG. [Figure 8] FIG. 8 is an enlarged view of the portion surrounded by the two-dot chain line F8 in FIG. [Figure 9] FIG. 9 is a conceptual diagram for explaining the reference state. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the present invention will be described in detail based on preferred embodiments, with appropriate reference to the drawings.

[0010] In this specification, a reference state of the head is defined. Based on this reference state, the toe-heel direction, face-back direction, and up-down direction of the head are defined. Furthermore, the face center and front view are defined.

[0011] A state in which the head is placed on the ground plane HP at a predetermined lie angle α is considered to be a reference state. As shown in FIG. 9, in this reference state, the shaft axis line Z is included in a plane VP perpendicular to the ground plane HP. The shaft axis line Z is the center line of the shaft. The plane VP is considered to be a reference vertical plane. The predetermined lie angle α is listed, for example, in a product catalog. Typically, the shaft axis line Z is the center line of the hosel hole. However, in clubs having an adjustment mechanism described below, the shaft axis line Z may not be the center line of the hosel hole. Note that in iron-type heads, the lie angle α can be determined based on the score lines. That is, in the reference state, the score lines can be parallel to the ground plane HP.

[0012] A known club has an adjustment mechanism that allows the loft angle, lie angle, and face angle to be adjusted by, for example, changing the rotational position of a sleeve attached to the tip of the shaft. In this club, the sleeve can be removably fixed to the head with a fastening means such as a screw. This allows the shaft to be attached and detached from the head. In a club with such an adjustment mechanism, in the reference state, the face angle and loft angle can be neutral, and the lie angle can be at its maximum value. Neutral refers to the center of the adjustment range.

[0013] In the above-described reference state, the face angle is set to 0 degrees. That is, in a plan view seen from above, the normal to the face center of the striking surface is parallel to the face-back direction.

[0014] In this specification, the toe-heel direction is the direction of the intersection line NL between the reference vertical plane VP and the ground plane HP (see FIG. 9).

[0015] In this specification, the face-back direction is a direction perpendicular to the toe-heel direction and parallel to the ground plane HP.

[0016] In this specification, the vertical direction is a direction perpendicular to the toe-heel direction and perpendicular to the face-back direction. In other words, in this specification, the vertical direction is a direction perpendicular to the ground plane HP.

[0017] In this specification, the face center is determined as follows: First, an arbitrary point Pr is selected that is approximately near the center of the striking surface in the up-down direction and toe-heel direction. Next, a plane is determined that passes through this point Pr, extends along the normal to the striking surface at point Pr, and is parallel to the toe-heel direction. A line of intersection between this plane and the striking surface is drawn, and its midpoint Px is determined. Next, a plane is determined that passes through this midpoint Px, extends along the normal to the striking surface at point Px, and is parallel to the up-down direction. A line of intersection between this plane and the striking surface is drawn, and its midpoint Py is determined. Next, a plane is determined that passes through this midpoint Py, extends along the normal to the striking surface at point Py, and is parallel to the toe-heel direction. A line of intersection between this plane and the striking surface is drawn, and its midpoint Px is newly determined. Next, a plane is determined that passes through this new midpoint Px, extends along the normal to the striking surface at point Px, and is parallel to the up-down direction. A line of intersection between this plane and the striking surface is drawn, and its midpoint Py is newly determined. This process is repeated to sequentially determine Px and Py. During the repetition of this process, the new position Py (last position Py) when the distance between the new midpoint Py and the immediately preceding midpoint Py becomes 0.5 mm or less for the first time is the face center.

[0018] In this specification, a "front view" refers to a vertical projection of the head obtained by projecting the normal to the face center of the striking surface. Unless otherwise specified, the shape, area, dimensions, etc. of the striking surface are determined from this front view. In this specification, a drawing from a front view is also simply referred to as a front view.

[0019] Fig. 1 is a perspective view of a golf club head 100 according to one embodiment, and Fig. 2 is a front view of the head 100. The head 100 has a face portion 102, a crown portion 104, a sole portion 106, and a hosel portion 108. The hosel portion 108 has a hosel hole 108a.

[0020] The head 100 may be a wood type. Wood type heads include a driver head and a fairway wood type head. The head 100 may be a hybrid type. The head 100 may be an iron type. The head 100 may be a putter type. In this embodiment, the head 100 is a wood type. The head 100 is a driver head. Although not shown, the head 100 has a hollow structure.

[0021] The face portion 102 has a hitting surface 102a. The hitting surface 102a comes into contact with the golf ball when hitting. The hitting surface 102a is the outer surface of the face portion 102. As shown in FIG. 2, the hitting surface 102a has a face center Fc defined as described above. The hitting surface 102a has a bulge and a roll. The hitting surface 102a is a convex curved surface.

[0022] The material of the face portion 102 is not limited. From the viewpoint of strength, metal and CFRP (carbon fiber reinforced plastic) are preferable as the material of the face portion 102. In this embodiment, the material of the face portion 102 is metal. Examples of this metal include titanium alloy, pure titanium, stainless steel, aluminum alloy, maraging steel, and mild steel. In this embodiment, a titanium alloy is used.

[0023] The crown portion 104 forms the upper surface of the head 100. The crown portion 104 has a crown surface 104a. The crown surface 104a is the outer surface of the crown portion 104. The sole portion 106 forms the lower surface of the head 100. The sole portion 106 has a sole surface 106a. The sole surface 106a is the outer surface of the sole portion 106. The hosel portion 108 is provided on the heel side of the head 100. The hosel portion 108 has a hosel hole 108a. A shaft (not shown) can be inserted into the hosel hole 108a. Alternatively, a sleeve (not shown) attached to the tip of a shaft can be inserted into the hosel hole 108a.

[0024] The periphery of the striking surface 102a can be defined as follows. As shown in FIG. 3(a), there are numerous planes E1, E2, E3, etc. that contain the normal to the striking surface 102a at the face center Fc. FIG. 3(b) shows the cross-sectional line of the head's outer surface taken along plane E1. In the cross-sections taken along each of these planes, such as E1, a point Q1 is determined where the radius of curvature r of the cross-sectional line of the head's outer surface reaches 200 mm from the face center Fc toward the outside of the striking surface 102a. The collection of these points Q1 can be considered the periphery (outline) of the striking surface 102a.

[0025] 1, 2, 3(a) and 3(b), the processed surface formed by the uneven processing (laser processing) performed on the striking surface 102a is omitted.

[0026] As shown in FIG. 2, the striking surface 102a is divided into a central region Rc, a toe region Rt, and a heel region Rh. The central region Rc is the region from the toe reference position Pt to the heel reference position Ph. The toe reference position Pt is located a distance D1 away from the face center Fc toward the toe side. The heel reference position Ph is located a distance D1 away from the face center Fc toward the heel side. Thus, the central region Rc is a region having a toe-heel width that is twice the distance D1. The toe region Rt is located on the toe side of the toe reference position Pt. The toe region Rt is located on the toe side of the central region Rc. The toe region Rt is adjacent to the toe side of the central region Rc. The heel region Rh is located on the heel side of the heel reference position Ph. The heel region Rh is located on the heel side of the central region Rc. The heel region Rh is adjacent to the heel side of the central region Rc.

[0027] The striking surface 102a is subjected to texture processing. In this embodiment, the texture processing is laser processing. The laser processing is performed multiple times (at least twice). In this embodiment, the laser processing is performed two times.

[0028] FIG. 4 shows the first processed surface 110 formed by the first laser processing. The first processed surface 110 is indicated by the black line in FIG. 4. The first processed surface 110 is a portion that has been made into a recess by irradiating the laser. The first processed surface 110 is a plurality of microgrooves g1 extending from the toe side to the heel side. These microgrooves g1 are parallel to one another. The width of these microgrooves g1 is constant. The first processed surface 110 is provided across the entire striking surface 102a. The first processed surface 110 is provided in the central region Rc, the toe region Rt, and the heel region Rh.

[0029] The microgrooves g1 are shallow and do not fall under the definition of face grooves as defined by the golf rules. The depth of the microgrooves g1 is 0.001 inches (0.0254 mm) or less. On the other hand, the rules stipulate that the depth of face grooves must be 0.020 inches (0.508 mm) or less, and the lower limit can be 0.005 inches (0.127 mm) or more, or even 0.007 inches (0.178 mm) or more, or even 0.010 inches (0.254 mm) or more.

[0030] The "grooves" defined in the Rules of Golf are defined in the latest equipment rules established by the R&A and the USGA. Grooves defined in the Rules of Golf are also referred to as "face grooves" in this specification. The Rules of Golf also define punch marks in addition to face grooves as markings in the impact area. Punch marks defined in the Rules of Golf are also simply referred to as "punch marks" in this specification. These punch marks have a maximum dimension of 0.075 inches (1.905 mm) in a front view and are typically circular in shape in a front view. The rules stipulate that the depth of these punch marks must be 0.040 inches (1.02 mm) or less, with the lower limit being 0.010 inches (0.254 mm) or more, further 0.015 inches (0.381 mm) or more, and further 0.020 inches (0.508 mm) or more.

[0031] FIG. 5 shows the second processed surface 112 formed by the second laser processing. The second processed surface 112 is shown in black in FIG. 5. The second processed surface 112 is a portion that has been made into a recess by irradiating the laser. The second processed surface 112 is composed of a plurality of microgrooves g2 of varying widths and letters g3. The center lines of the multiple microgrooves g2 are parallel to one another. The second processed surface 112 is provided in the toe region Rt and the heel region Rh. Each of the microgrooves g2 provided in the toe region Rt becomes narrower toward the toe side. Each of the microgrooves g2 provided in the heel region Rh becomes narrower toward the heel side. The second processed surface 112 is not provided in the central region Rc. The second laser processing has not been performed in the central region Rc.

[0032] The microgrooves g2 are shallow and do not qualify as face grooves as defined by the Rules of Golf. The letter g3 is shallow and does not qualify as face grooves as defined by the Rules of Golf. The depth of the microgrooves g2 is 0.001 inches (0.0254 mm) or less. The depth of the letter g3 is 0.001 inches (0.0254 mm) or less.

[0033] The front view of FIG. 5 shows a circle CL1 whose center is the face center Fc and whose radius is r1 (mm). The second processing surface 112 is not provided within the circle CL1. The second processing surface 112 is provided outside the circle CL1. The second laser processing is not performed within the circle CL1. The heel-side end of the microgroove g2 located in the toe region Rt is aligned along the circle CL1. The toe-side end of the microgroove g2 located in the heel region Rh is aligned along the circle CL1.

[0034] The radius r1 of the circle CL1 is not limited. Considering the appropriate range of off-center hits, the radius r1 may be 17 mm or more, further 19 mm or more, or even 21 mm or more, and may be 27 mm or less, further 25 mm or less, or even 23 mm or less. Considering the variation in impact points among beginner golfers, the radius r1 may be set to 27 mm. Considering the variation in impact points among advanced golfers, the radius r1 may be set to 22 mm.

[0035] The front view of Fig. 6 shows the first processed surface 110 and the second processed surface 112. The first and second laser processes are performed on the head 100. Therefore, Fig. 6 shows the appearance of the completed head 100. Note that, for ease of viewing, the first processed surface 110 (fine groove g1) is shown in light gray in Fig. 6, unlike Fig. 4.

[0036] In addition to the first laser processing, the second laser processing is performed on the striking surface 102a of the head 100. The second laser processing is performed after the first laser processing. As a result, an area where the second laser processing overlaps the first processed surface 110 formed by the first laser processing may be formed.

[0037] The striking surface 102a is coated. The coating is applied to the entire area of ​​the striking surface 102a. In this embodiment, the coating is vapor deposition. In this embodiment, the coating is PVD.

[0038] The timing of the coating process is not limited. The coating process may be performed before the first laser processing. The coating process may be performed between the first laser processing and the second laser processing. The coating process may be performed after the second laser processing. In this embodiment, the coating process is performed between the first laser processing and the second laser processing. That is, the coating process is performed after the first laser processing, and the second laser processing is performed after this coating process.

[0039] The coating layer can be peeled off by laser processing. If a coating layer is formed before the first laser processing, the coating layer is peeled off by the first laser processing and then peeled off by the second laser processing. In this case, the coating layer can ultimately remain only on the land surface 116 (described below).

[0040] If a coating process is performed between the first and second laser processes, the coating layer will ultimately not remain on the second processed surface 112 but will remain on the first processed surface 110. If an overlapping processed surface 114 (described later) exists, the coating layer will not remain on the overlapping processed surface 114. The coating layer will remain on the land surface 116.

[0041] If the coating process is performed after the second laser process, the coating layer ultimately remains on the first processed surface 110 and the second processed surface 112. In this case, the coating layer is formed over the entire striking surface 102a.

[0042] FIG. 7 is an enlarged view of the area surrounded by the two-dot chain line F7 in FIG. 6. In FIG. 7, the first processed surface 110 (microgroove g1) formed by the first laser processing is shown in gray. In FIG. 7, the second processed surface 112 (microgroove g2 and character g3) formed by the second laser processing is shown in black. The portion of the first processed surface 110 where the second laser processing was performed (overlap processed surface 114 described below) is also shown in black. Two microgrooves g1 are provided on the first processed surface 110 at a predetermined interval p1, and pairs of these two microgrooves g1 are arranged at a predetermined interval p2. The interval p2 is larger than the interval p1. The second processed surface 112 (microgroove g2 and character g3) has a portion overlapping the first processed surface 110 (microgroove g1). The width of the microgroove g2 is larger than the width of the microgroove g1.

[0043] FIG. 8 is an enlarged view of the area surrounded by the two-dot chain line F8 in FIG. 7. In FIG. 8, the first processed surface 110 is indicated by hatching slanting downward to the right, and the second processed surface 112 is indicated by hatching slanting upward to the right. As described above, the striking surface 102a has the first processed surface 110 and the second processed surface 112. The portion where the first laser processing and the second laser processing have been performed is the overlapping processed surface 114. In this specification, the overlapping processed surface 114 is excluded from the first processed surface 110 and the second processed surface 112. In FIG. 8, the overlapping processed surface 114 is indicated by cross-hatching. This cross-hatching is a combination of the hatching slanting downward to the right representing the first processed surface 110 and the hatching slanting upward to the right representing the second processed surface 112. The striking surface 102a has a land surface 116 that has not been subjected to texture processing (laser processing).

[0044] The coating layer c1 ultimately remains on the first processed surface 110 and the land surface 116. The first processed surface 110 and the land surface 116 are covered with the coating layer c1. The second processed surface 112 and the overlapping processed surface 114 are exposed and not covered with a coating layer.

[0045] As described above, the head 100 has undergone the first laser processing in the center region Rc, toe region Rt, and heel region Rh. In addition to the first laser processing, the toe region Rt and heel region Rh have undergone the second laser processing. The center region Rc has not undergone the second laser processing. In addition, the entire striking surface 102a has been coated. However, part of the coating layer formed by this coating processing is eventually peeled off by the laser processing that follows the coating processing.

[0046] In the head 100, a coating process is performed after the first laser process. Furthermore, a second laser process is performed after this coating process. The coating layer c1 is peeled off by the second laser process. The coating layer c1 remains in the areas where the second laser process has not been performed. The coating layer c1 is a PVD layer. The areas coated with the PVD layer have a different appearance (color) from the areas without the PVD layer.

[0047] In the final completed head 100, the central region Rc has a first machining surface 110, and the toe region Rt and heel region Rh each have a first machining surface 110 and a second machining surface 112. The central region Rc does not have the second machining surface 112. Furthermore, the toe region Rt and heel region Rh each have an overlapping machining surface 114. The central region Rc does not have the overlapping machining surface 114. Furthermore, the central region Rc, toe region Rt, and heel region Rh each have a land surface 116. The first machining surface 110 is coated with the coating layer c1. The second machining surface 112 is exposed and not coated with the coating layer c1. The overlapping machining surface 114 is exposed and not coated with the coating layer c1. The land surface 116 is coated with the coating layer c1.

[0048] The overlapping machining surface 114 has been subjected to the first and second laser machining processes, resulting in a recess that is deeper than the first machining surface 110 and the second machining surface 112. When the depth of the first machining surface 110 is F1 and the depth of the second machining surface 112 is F2, the depth of the overlapping machining surface 114 can be (F1 + F2). These depths are the depths from the land surface 116. The depth of the overlapping machining surface 114 is 0.001 inches (0.0254 mm) or less.

[0049] From the viewpoint of stable spin performance across the entire striking surface 102a, the depth F1 of the first processed surface 110 (fine grooves g1) is preferably 0.01 mm or more, more preferably 0.015 mm or more, and even more preferably 0.02 mm or more. From the viewpoint of stable spin performance on off-center hits, the depth F2 of the second processed surface 112 (fine grooves g2) is preferably 0.01 mm or more, more preferably 0.015 mm or more, and even more preferably 0.02 mm or more.

[0050] The double-headed arrow W1 in Figure 8 indicates the width of the microgrooves g1. From the viewpoint of stable spin performance across the entire striking face 102a, the width W1 of the microgrooves g1 is preferably 0.05 mm or greater, more preferably 0.10 mm or greater, and even more preferably 0.15 mm or greater. If the width W1 is too large, the width of the land surface 116 may be too small. From this viewpoint, the width W1 is preferably 0.3 mm or less, more preferably 0.25 mm or less, and even more preferably 0.20 mm or less.

[0051] The intervals p1 and p2 are the pitch of the microgrooves g1. If the pitch of the microgrooves g1 is too small, the unevenness effect may be reduced. From this viewpoint, the minimum pitch p1 of the microgrooves g1 is preferably 0.5 times or more, more preferably 0.7 times or more, and more preferably 1 time or more, the width W1. From the viewpoint of spin performance, the minimum pitch p1 of the microgrooves g1 is preferably 3 times or less, more preferably 2 times or less, and more preferably 1 time or less, the width W1. If the width of the land surface 116 is too large, the spinness performance may also be reduced. From this viewpoint, the maximum pitch p2 of the microgrooves g1 is preferably 7 times or less, more preferably 6 times or less, and more preferably 5 times or less, the width W1. From the viewpoint of the unevenness effect, the maximum pitch p2 of the microgrooves g1 is preferably 1 time or more, more preferably 2 times or more, and more preferably 3 times or more, the width W1.

[0052] As shown in Figure 4, the first laser processing is performed on the center region Rc, toe region Rt, and heel region Rh. The first laser processing is performed across the entire striking surface 102a. However, this "entire area" does not mean that the entire striking surface 102a is irradiated with the laser for the first laser processing. In other words, this "entire area" does not mean that the entire striking surface 102a is the first processed surface 110. The area formed by the multiple microgrooves g1 and the land surfaces 116 between them occupies the entire striking surface 102a.

[0053] In the case of laser processing, the portions irradiated with the laser become concave, and basically no convex portions are formed by laser irradiation. Therefore, in this case, concaves and convexes are formed by a combination of the concaves (microgrooves g1, first processing surface 110) formed by laser processing and the portions not irradiated with the laser (land surface 116). This type of processing is also included in the concept of concave-convex processing in this specification. Of course, the concept of concave-convex processing also includes processing in which the processing surface itself forms concaves and convexes. Other examples of concave-convex processing will be described later.

[0054] The method for manufacturing the head 100 includes the following steps. (1) A first step of performing a first uneven processing (first laser processing) on ​​the central region Rc, the toe region Rt, and the heel region Rh. (2) A second step of coating the central region Rc, the toe region Rt, and the heel region Rh. (3) A third step of performing a second uneven processing (second laser processing) on ​​the toe region Rt and the heel region Rh, excluding the central region Rc.

[0055] Preferably, the second step is performed after the first step. Preferably, the third step is performed after the second step. In the above embodiment, the second step is performed after the first step, and the third step is performed after the second step. Preferably, in the second step, a coating is applied to the entire striking surface 102a. Preferably, the coating layer formed in the coating process in the second step is peeled off by the second uneven processing (second laser processing) in the third step.

[0056] The head 100 described above can provide the following advantages.

[0057] The first textured surface (laser processing) is applied to the central region Rc, toe region Rt, and heel region Rh. This allows the surface roughness of the striking surface 102a to be controlled by the textured surface, improving the uniformity of spin performance across a wide area of ​​the striking surface 102a. Stable spin performance can be achieved regardless of whether the ball is struck in the central region Rc, toe region Rt, or heel region Rh.

[0058] The first uneven processing (laser processing) is performed over the entire striking surface 102a, so that the surface roughness can be controlled over the entire striking surface 102a by the uneven processing.

[0059] The first unevenness processing (laser processing) is formed uniformly across the entire striking surface 102a. Therefore, even if there are individual differences in the surface roughness of the striking surface 102a before the unevenness processing, these individual differences can be absorbed, and the spin performance can be made uniform between individual golf balls.

[0060] The second unevenness processing (laser processing) is performed on the toe region Rt and the heel region Rh, but not on the center region Rc, which can improve the stability of spin performance on off-center hits.

[0061] The coating layer c1 is removed from the areas where the second unevenness processing (laser processing) was performed, while the coating layer c1 remains in other areas. The contrast between the areas where the coating layer c1 remains and the areas where it has been removed improves the visibility of the striking surface 102a, and particularly improves the alignment effect when addressing the ball.

[0062] In the portion where the coating layer c1 remains, the first processed surface 110 formed by the first uneven processing (laser processing) is protected by the coating layer c1. In addition, the land surface 116 adjacent to this first processed surface 110 is also protected by the coating layer c1. Therefore, the uneven shape of the first processed surface 110 is easily maintained, improving durability.

[0063] In the toe region Rt and heel region Rh, the area where the first asperity processing (laser processing) is performed is different from the area where the second asperity processing (laser processing) is performed. As a result, the area of ​​the land surface 116 where neither asperity processing nor laser processing is performed is reduced in the toe region Rt and heel region Rh. Furthermore, in the toe region Rt and heel region Rh, the area where the first asperity processing (laser processing) is performed and the area where the second asperity processing (laser processing) is performed partially overlap. As a result, an overlapping processed surface 114 is formed. The deeper overlapping processed surface 114 can further improve the stability of spin performance on off-center hits.

[0064] The distance D1 (see FIG. 2) relating to the central region Rc is not limited. Considering the appropriate range of off-center hits, the distance D1 may be 10 mm or more, further 12 mm or more, or even 14 mm or more, and may be 20 mm or less, further 18 mm or less, or even 16 mm or less. Considering the variation in impact points among beginner golfers, the distance D1 may be set to 20 mm. Considering the variation in impact points among advanced golfers, the distance D1 may be set to 15 mm.

[0065] The hitting surface 102a does not have face grooves. Even without face grooves, stable spin performance can be obtained thanks to the first machined surface 110 (fine grooves g1) and the second machined surface 112 (fine grooves g2), etc. The absence of face grooves also helps to increase the strength of the face portion 102. The hitting surface 102a does not have punch marks. The hitting surface 102a may have punch marks.

[0066] In FIG. 6, the broken line indicates a circle CL2 having a diameter of 20 mm, whose center is in the toe region Rt or the heel region Rh and whose entirety is contained within the striking surface 102a. There are an infinite number of circles CL2. The area M2 (mm 2 ) is determined. This area M2 is also referred to as the in-circle area. If an overlapping processed surface 114 exists within the circle CL2, the area of ​​the overlapping processed surface 114 is also included in the in-circle area M2. The in-circle area M2 differs for each circle. The in-circle area M2 is determined for each circle CL2, and the minimum value of these in-circle areas M2 is determined. From the perspective of stability of spin performance on off-center hits, the minimum value of the in-circle area M2 is 3.0 mm 2 More than 3.3mm is preferable. 2 More than 3.6mm is preferable. 2 From the viewpoint of the remaining area of ​​the coating layer c1, the minimum value of the in-circle area M2 is 15.0 mm 2 Less than 12.0mm is preferable 2 Less than 10.0mm is more preferable. 2 The following is more preferable: Circle CL2 is an area that can be a virtual ball contact range when hitting.

[0067] The area of ​​the second processed surface 112 belonging to the striking surface 102a is S2 (mm 2 ) is set. If an overlapping processed surface 114 exists on the hitting surface 102a, the area of ​​the overlapping processed surface 114 is also included in the area S2. The area S2 is the area of ​​the portion where the second uneven processing (second laser processing) is performed. From the viewpoint of the stability of spin performance when hit off-center, the area S2 of the second processed surface 112 is set to 130 (mm 2 ) or more is preferable, and 140 (mm 2) or more is more preferable, and 150 (mm 2 ) or more. From the viewpoint of the remaining area of ​​the coating layer c1, the area S2 of the second processed surface 112 is 200 (mm 2 ) or less is preferable, and 190 (mm 2 ) or less is more preferable, and 180 (mm 2 ) or less is more preferable.

[0068] The area of ​​the toe region Rt is T1 (mm 2 ), and the area of ​​the second processed surface 112 belonging to the toe region Rt is T2 (mm 2 ) In the case where an overlapping processed surface 114 exists in the toe region Rt, the area of ​​the overlapping processed surface 114 is also included in the area T2. The area T2 is the area of ​​the portion in the toe region Rt where the second uneven processing (second laser processing) is performed. From the viewpoint of the stability of spin performance upon off-center hits, the ratio of the area T2 to the area T1 is preferably 3% or more, more preferably 4% or more, and still more preferably 5% or more. From the viewpoint of the remaining area of ​​the coating layer c1, the ratio of the area T2 to the area T1 is preferably 25% or less, more preferably 20% or less, and still more preferably 15% or less.

[0069] The area of ​​the heel region Rh is H1 (mm 2 ), and the area of ​​the second processed surface 112 belonging to the heel region Rh is H2 (mm 2 ) In the case where an overlapping processed surface 114 exists in the heel region Rh, the area of ​​the overlapping processed surface 114 is also included in the area H2. The area H2 is the area of ​​the portion in the heel region Rh where the second uneven processing (second laser processing) has been performed. From the viewpoint of the stability of spin performance upon off-center hits, the ratio of the area H2 to the area H1 is preferably 3% or more, more preferably 4% or more, and still more preferably 5% or more. From the viewpoint of the remaining area of ​​the coating layer c1, the ratio of the area H2 to the area H1 is preferably 25% or less, more preferably 20% or less, and still more preferably 15% or less.

[0070] The total area of ​​the area T1 of the toe region Rt and the area H1 of the heel region Rh is TH1 (mm 2The area of ​​the second processed surface 112 in the toe region Rt and the heel region Rh is the above-mentioned area S2 (mm 2 ) The area S2 is the sum of the area T2 and the area H2. From the viewpoint of the stability of spin performance on off-center hits, the ratio of the area S2 to the area TH1 is preferably 3% or more, more preferably 4% or more, and even more preferably 5% or more. From the viewpoint of the remaining area of ​​the coating layer c1, the ratio of the area S2 to the area TH1 is preferably 25% or less, more preferably 20% or less, and even more preferably 15% or less.

[0071] The area of ​​the first processed surface 110 belonging to the striking surface 102a is S1 (mm 2 ) If an overlapping processed surface 114 exists on the hitting surface 102a, the area of ​​that overlapping processed surface 114 is also included in area S1. Area S1 is the area of ​​the portion subjected to the first uneven processing (first laser processing). From the viewpoint of stable spin performance, the ratio of area S1 to the area of ​​the hitting surface 102a is preferably 20% or more, more preferably 25% or more, and even more preferably 30% or more. The presence of the land surface 116 enhances the effect of the uneven shape. From this viewpoint, the ratio of area S1 to the area of ​​the hitting surface 102a is preferably 50% or less, more preferably 45% or less, and even more preferably 40% or less.

[0072] Examples of texture processing include laser processing, CNC machining, shot blasting, polishing, etching, and electrical discharge machining. Two or more of these may be combined. In laser processing, the area irradiated with the laser melts, forming recesses. The molten metal can evaporate. When the laser is irradiated in a linear fashion, fine grooves are formed. Because the area irradiated with the laser becomes recessed, the area not irradiated with the laser (land surface 116) becomes protruding, resulting in the formation of texture. High-precision irradiation is performed using a computer-controlled laser processing machine. A general-purpose laser processing machine can be used, such as the ML-Z9500 manufactured by Keyence Corporation. The "CNC" in CNC machining stands for Computerized Numerical Control. CNC machining can form recesses by cutting. Shot blasting is a surface processing method that uses granular particles called blasting material to collide with the surface. Examples of blasting material include metal particles and ceramic particles. In electrical discharge machining, the uneven surface is used as an electrode, and the striking surface can be formed with an inverted shape of this uneven surface. From the viewpoint of machining accuracy, laser machining and CNC machining are preferred for uneven machining, with laser machining being more preferred.

[0073] Surface roughness can increase due to uneven processing. The surface roughness can be calculated by the arithmetic mean roughness Ra and The maximum height Rz can be measured. The arithmetic mean roughness Ra can be increased by roughening. The maximum height Rz can be increased by roughening.

[0074] The arithmetic mean roughness Ra and maximum height Rz are defined in JIS B 0601:2013 and are measured in accordance with the JIS standard and JIS B 0633:2001. These values ​​can be measured using a contact or non-contact surface roughness measuring device. For example, these values ​​can be measured using a Keyence VR-5200 3D shape dimension measuring instrument under the following measurement conditions: Measurement conditions Cutoff value (λc): 0.8mm / 2.5mm / 8mm Filter type: Gaussian λs value: None 3D Measurement Settings: High Precision (Roughness)

[0075] The position, length and direction of measurement of the arithmetic mean roughness Ra are set as follows.

[0076] The arithmetic mean roughness Ra of the central region Rc is measured along a 10 mm long line segment Lc with the face center Fc as its center point, with the section length set to 10 mm (see Figure 2). The direction of the line segment Lc (measurement direction) is perpendicular to the direction X1, which is 3.5° upright with respect to the contact plane HP in the reference state. The direction of the line segment Lc is determined in a front view of the reference state.

[0077] The arithmetic mean roughness Ra of the toe region Rt is measured along a 10 mm long line segment Lt with point Ft as its center point, with the section length set to 10 mm (see Figure 2). Point Ft is a point 23.85 mm away from the face center Fc toward the toe side in the toe-heel direction (horizontal direction). The direction of line segment Lt, i.e., the measurement direction, is the same as that of line segment Lc.

[0078] The arithmetic mean roughness Ra of the heel region Rh is measured along a 10 mm long line segment Lh with point Fh as its center point, with the section length set to 10 mm (see Figure 2). Point Fh is a point 23.85 mm away from the face center Fc toward the heel in the toe-heel direction (horizontal). The orientation of line segment Lh, i.e., the measurement direction, is the same as that of line segment Lc.

[0079] The line segments Lc, Lt and Lh are shown in dashed lines in FIG.

[0080] The position, length and direction of the measurement of the maximum height Rz are set as follows:

[0081] The maximum height Rz of the central region Rc is measured along the line segment Lc with a section length of 10 mm. The maximum height Rz of the toe region Rt is measured along the line segment Lt with a section length of 10 mm. The maximum height Rz of the heel region Rh is measured along the line segment Lh with a section length of 10 mm.

[0082] Due to the second asperity processing (laser processing), the arithmetic mean roughness Ra and maximum height Rz are greater in the toe region Rt and heel region Rh than in the center region Rc. That is, one or more selected from the group consisting of the following (a) to (d) may be true. From the viewpoint of stable spin performance on off-center hits, it is preferable that all of the following (a) to (d) be true. (a) The arithmetic mean roughness Ra of the toe region Rt is greater than the arithmetic mean roughness Ra of the central region Rc. (b) The arithmetic mean roughness Ra of the heel region Rh is greater than the arithmetic mean roughness Ra of the central region Rc. (c) The maximum height Rz of the toe region Rt is greater than the maximum height Rz of the central region Rc. (d) The maximum height Rz of the heel region Rh is greater than the maximum height Rz of the central region Rc.

[0083] From the viewpoint of the stability of spin performance on off-center hits, the arithmetic mean roughness Ra of the toe region Rt is preferably 2 μm or more, more preferably 2.5 μm or more, and still more preferably 3 μm or more. From the viewpoint of preventing the area T2 of the second processed surface 112 in the toe region Rt from becoming excessively large, the arithmetic mean roughness Ra of the toe region Rt is preferably 6 μm or less, more preferably 5.5 μm or less, and still more preferably 5 μm or less.

[0084] From the viewpoint of the stability of spin performance upon off-center hits, the maximum height Rz of the toe region Rt is preferably 10 μm or more, more preferably 15 μm or more, and still more preferably 20 μm or more. From the viewpoint of the strength of the face portion 102, the maximum height Rz of the toe region Rt is preferably 35 μm or less, more preferably 30 μm or less, and still more preferably 25 μm or less.

[0085] From the viewpoint of the stability of spin performance on off-center hits, the arithmetic mean roughness Ra of the heel region Rh is preferably 2 μm or more, more preferably 3 μm or more, and more preferably 4 μm or more. From the viewpoint of preventing the area H2 of the second processed surface 112 in the heel region Rh from becoming excessively large, the arithmetic mean roughness Ra of the heel region Rh is preferably 6 μm or less, more preferably 5 μm or less, and more preferably 4 μm or less.

[0086] From the viewpoint of the stability of spin performance on off-center hits, the maximum height Rz of the heel region Rh is preferably 10 μm or more, more preferably 15 μm or more, and still more preferably 20 μm or more. From the viewpoint of the strength of the face portion 102, the maximum height Rz of the heel region Rh is preferably 35 μm or less, more preferably 30 μm or less, and still more preferably 25 μm or less.

[0087] From the viewpoint of a balance with spin performance on off-center hits, the arithmetic mean roughness Ra of the central region Rc is preferably 2 μm or more, more preferably 3 μm or more, and more preferably 4 μm or more. From the viewpoint of stability of spin performance across the entire striking face 102a, the arithmetic mean roughness Ra of the central region Rc is preferably 6 μm or less, more preferably 5 μm or less, and more preferably 4 μm or less.

[0088] From the viewpoint of a balance with spin performance on off-center hits, the maximum height Rz of the central region Rc is preferably 10 μm or more, more preferably 15 μm or more, and more preferably 20 μm or more. From the viewpoint of stability of spin performance across the entire striking face 102a, the maximum height Rz of the central region Rc is preferably 35 μm or less, more preferably 30 μm or less, and more preferably 25 μm or less.

[0089] The coating layer c1 is formed by coating. The coating layer c1 can be formed on the textured surface. After textured, coating can be performed to form the coating layer c1 on the textured surface. The coating layer c1 can form the surface (outermost layer) of the face portion 102. In other words, the coating layer c1 can form the striking surface 102a. The coating layer c1 can protect the textured surface. The coating layer c1 can suppress wear on the textured surface.

[0090] The coating layer c1 can be peeled off by roughening. After the coating layer c1 is formed, roughening can be performed, and the coating layer c1 can be peeled off. In this case, the coating layer c1 disappears in the roughened areas, and remains in the areas where the roughening has not been performed.

[0091] The textured surface can be formed in two stages: a first textured surface and a second textured surface. The order of the first textured surface and the second textured surface is not limited, but the second textured surface is preferably formed after the first textured surface. Preferably, a coating process can be performed between these textured surfaces. Preferably, a coating process can be performed after the first textured surface, and the second textured surface can be formed after the first coating process. In this case, the coating layer c1 can be peeled off by the second textured surface. As a result, the coating layer c1 is absent on the textured surface formed by the second textured surface, while the coating layer c1 can be present in the areas where the first textured surface was formed but not the second textured surface. This coating layer c1 can protect the first textured surface 110 formed by the first textured surface. Protecting the first textured surface 110 helps maintain spin performance.

[0092] The coating layer c1 is peeled off by the second uneven processing, resulting in the formation of areas with and without the coating layer c1. This can create a contrast in appearance, as described above. When the uneven processing is laser processing, the contrast can be formed with high precision. This contributes to improving the alignment effect described above.

[0093] Examples of coating processes include vapor deposition, plating, and painting. Examples of vapor deposition include PVD and CVD. PVD is physical vapor deposition. CVD is chemical vapor deposition. Examples of PVD methods include vacuum deposition, ion plating, and sputtering. Vapor deposition is preferred, and PVD is more preferred, from the viewpoint of forming a thin film with excellent appearance and wear resistance. Examples of types of coating layer c1 (film) formed by PVD include TiN (titanium nitride), TiCN (titanium carbide nitride), TiAlN (titanium aluminum nitride), AlCrN (aluminum chromium nitride), TiC (titanium carbide), CrN (chromium nitride), WC / C (tungsten carbide), and DLC (diamond-like carbon). From the viewpoints of face durability, manufacturability, and appearance quality, TiCN (titanium carbide nitride) is preferred. [Example]

[0094] [Example] A head according to the above embodiment was created. A titanium alloy driver head was created, and its striking surface was laser processed. A coating process was performed after the first laser process, and a second laser process was performed after the coating process. The first and second laser processes were performed using a Keyence ML-Z9500. The coating process was performed using PVD, and the coating layer was TiCN. In this way, the head shown in Figure 6 was obtained. The real loft angle of the head was 10.5 degrees. A shaft and a grip were attached to this head to obtain the golf club of the example.

[0095] [Comparative Example] A head and a golf club of the comparative example were obtained in the same manner as in the example except that the second laser processing was not performed. The front view of the head of the comparative example is the same as that of FIG.

[0096] A golf club was attached to the swing robot so that the normal to the striking surface at the face center Fc was pointing toward the target. Without changing the orientation of the striking surface, golf balls were struck at three impact points: the face center Fc, a point 15 mm to the toe of the face center Fc, and a point 15 mm to the heel of the face center Fc. The head speed was 50 m / s. Five balls were struck at each impact point. The golf balls used were "SRIXON Z-STAR XV" golf balls manufactured by Sumitomo Rubber Industries, Ltd. For each shot, backspin, sidespin, and lateral deviation from the target direction were measured. Lateral deviation was the distance between the line connecting the impact point and the target point and the ball's final destination. A deviation to the right was considered a positive value, and a deviation to the left was considered a negative value. For sidespin, a hook spin was considered a negative value, and a slice spin was considered a positive value. The average values ​​for the five balls are shown in Table 1 below. [Table 1]

[0097] As shown in Table 1, the Examples have higher stability in spin performance when hit off-center, and are superior in directional stability of the hit ball, compared to the Comparative Examples.

[0098] The following notes are part of the invention included in this invention. [Appendix 1] A golf club head including a face portion having a striking surface, a sole portion, and a hosel portion, When the striking surface is divided into a central region, a toe region located on the toe side of the central region, and a heel region located on the heel side of the central region, the central region has a first processed surface formed by a first uneven processing, The toe region and the heel region have a first processed surface formed by the first uneven processing, a second processed surface formed by the second uneven processing, and an overlapping processed surface formed by overlapping the first uneven processing and the second uneven processing, The golf club head has the first working surface covered with a coating layer. [Appendix 2] 2. The golf club head according to claim 1, wherein the second processed surface and the overlapping processed surface are exposed without being covered with the coating layer. [Appendix 3] A golf club head including a face portion having a striking surface, a sole portion, and a hosel portion, When the striking surface is divided into a central region, a toe region located on the toe side of the central region, and a heel region located on the heel side of the central region, a first textured surface is applied to the central region, the toe region, and the heel region; In addition to the first unevenness processing, a second unevenness processing is applied to the toe region and the heel region except for the central region, The golf club head has a coating applied to the entire area of ​​the striking surface. [Appendix 4] the coating process is performed after the first unevenness process, The second unevenness processing is performed after the coating processing, 4. The golf club head according to claim 3, wherein the coating layer formed by the coating process is peeled off by the second unevenness process, and the coating layer remains in the portion where the second unevenness process is not performed. [Appendix 5] When any circle is considered that has its center in the toe region or the heel region, falls entirely within the striking face, and has a diameter of 20 mm: All of the circles have an in-circle area M2 of the second processing surface, The minimum value of the area M2 within the circle is 3.0 mm 2 The golf club head according to Supplementary Note 1 or 2. [Appendix 6] the first uneven processing is a first laser processing, 6. The golf club head according to any one of claims 1 to 5, wherein the second uneven processing is a second laser processing. [Appendix 7] 7. The golf club head according to any one of claims 1 to 6, wherein the central region is within 15 mm on each of the toe side and heel side of the face center. [Appendix 8] The area S2 of the second uneven surface is 130 mm 2 Over 200mm 2 A golf club head according to any one of appendices 1 to 7 below. [Appendix 9] 9. The golf club head according to any one of claims 1 to 8, wherein the area S2 of the portion subjected to the second uneven processing is 3% or more of the total area of ​​the toe region and the heel region. [Appendix 10] 10. The golf club head according to any one of claims 1 to 9, wherein no face grooves are formed on the ball-striking surface. [Explanation of symbols]

[0099] 100 Golf Club Heads 102 Face part 102a Striking surface 104 Crown 106···Sole part 108···Hosel part 110: Machined surface formed by first uneven machining (first machined surface) 112: Machined surface formed by second uneven machining (second machined surface) 114: A machined surface formed by overlapping the first uneven machining and the second uneven machining (overlapping machined surface) 116 Land surface Rc...Central area Rt... Toe region Rh···heel region g1: Micro groove as the first machining surface g2: Micro-groove as the second machining surface g3: Characters as the second machining surface Fc···Face Center

Claims

1. A golf club head including a face portion having a striking surface, a sole portion, and a hosel portion, When the striking surface is divided into a central region, a toe region located on the toe side of the central region, and a heel region located on the heel side of the central region, the central region has a first processed surface formed by a first uneven processing; the toe region and the heel region have a first processed surface formed by the first uneven processing, a second processed surface formed by the second uneven processing, and an overlapping processed surface formed by overlapping the first uneven processing and the second uneven processing, The first working surface is covered with a coating layer.

2. The golf club head according to claim 1 , wherein the second processed surface and the overlapping processed surface are exposed without being covered with the coating layer.

3. A golf club head including a face portion having a striking surface, a sole portion, and a hosel portion, When the striking surface is divided into a central region, a toe region located on the toe side of the central region, and a heel region located on the heel side of the central region, a first textured surface is applied to the central region, the toe region, and the heel region; In addition to the first unevenness processing, a second unevenness processing is applied to the toe region and the heel region except for the central region, The golf club head has a coating applied to the entire area of ​​the striking surface.

4. the coating process is performed after the first unevenness process, the second unevenness processing is performed after the coating processing, 4. The golf club head according to claim 3, wherein the coating layer formed by the coating process is peeled off by the second unevenness process, and the coating layer remains in the portion where the second unevenness process is not performed.

5. When any circle is considered that has its center in the toe region or the heel region, falls entirely within the striking face, and has a diameter of 20 mm, All of the circles have an in-circle area M2 of the second processing surface, The minimum value of the area M2 within the circle is 3.0 mm ２ 3. The golf club head according to claim 1 or 2.

6. the first uneven processing is a first laser processing, 5. The golf club head according to claim 1, wherein the second uneven processing is a second laser processing.

7. 5. The golf club head according to claim 1, wherein the central region is within 15 mm on each of the toe and heel sides of the face center.

8. The area S2 of the second uneven surface is 130 mm ２ More than 200 mm ２ 5. The golf club head according to claim 1, wherein:

9. 5. The golf club head according to claim 1, wherein an area S2 of the portion where the second unevenness is applied is 3% or more of the total area of ​​the toe region and the heel region.

10. 5. The golf club head according to claim 1, wherein no face grooves are formed on the ball-striking surface.

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